book of short abstracts poster presentations · book of short abstracts - poster presentations ......

BOOK OF SHORT ABSTRACTS

-

POSTER PRESENTATIONS

19TH NATIONAL SYMPOSIUM ON APPLIED

BIOLOGICAL SCIENCES

GEMBLOUX AGRO-BIO TECH

GEMBLOUX

FEBRUARY 7TH, 2014

Website

http://www.nsabs2014.be/

2

MODELLING AND DATA MANAGEMENT

P1 - Impact of tillage and crop residues restitution on phosphorus distribution within topsoil in loamy

soils of Wallonia .................................................................................................................................8

P2 - Drivers of estimated above-ground biomass in Central African forests: what really matters ..........9

P3 - Hyperspectral reflectance measurements for the detection of tree diseases.................................. 10

P4 - Assessing the influence of cover crop management on the spatio-temporal dynamic of soil water

content by electrical resistivity tomography....................................................................................... 11

P5 - Simulations of a beta amphiphilic peptide as potential surfactant of membrane proteins ............. 12

P6 - The uses of mid-infrared spectral information from milk recording organization to certify milk

geographic origin .............................................................................................................................. 13

P7 - archiDART: a R package allowing root system architecture analysis using Data Analysis of Root

Tracings (DART) output files ........................................................................................................... 14

P8 - Estimation of dominance effect for growth traits with sire-dam subclass effects in a crossbred

population of pigs ............................................................................................................................. 15

P9 - Modelling the wall elasticity of plant cells in VirtualLeaf........................................................... 16

P10 - An algorithm for efficient computation of genomically-enhanced inbreeding coefficients......... 17

P11 - Anthropogenic effect on African landscapes: Typologies, spatial structure, impact ................... 18

P12 - Consequences of Selection for Environmental Impact Traits in Dairy Cows ............................. 19

P13 - How to preserve microbial biodiversity: functional and structural cryopreservation of mixed

microbial cultures ............................................................................................................................. 20

P14 - Bacterial lipopeptides as elicitors of plant defence.................................................................... 21

P15 - Integrated farming systems in Kinshasa. Diversity of agricultural practices .............................. 22

P16 - Sugar-based bolaforms as new potential drug delivery system. Importance of the sugar residues

in the modulation of the membrane activity ....................................................................................... 23

P17 - Do lipid interaction properties of novel rhamnolipids govern their plant-elicitor activities? ...... 24

P18 - Finding Interesting Elicitor LipiDs- FIELD Project in Gembloux Agro-Bio Tech. An original

multidisciplinary bottom-up approach for the future of agriculture. ................................................... 25

P19 - Performance variations of the noxious invader Ambrosia artemisiifolia L. along a latitudinal

gradient: Is there an impediment to invasion? .................................................................................... 26

P20 - Habitat suitability modelling in auto-ecology analysis of Azolla filiculoides (Lam.) Azollaceae

in Selkeh Wildlife Refuge (Iran) ....................................................................................................... 27

P21 - Analysis of environmental factors determining the distribution pattern of Azolla filiculoides

(Lam.) Azollaceae in Anzali wetland, northern Iran .......................................................................... 28

P22 - Synthesis and study of biophysical and biological properties of new aromatic ester derivatives.

......................................................................................................................................................... 29

P23 - Modeling using the SWAT model of water flow and transport in suspension in the watershed of

the valley of Wadi El-Hachem .......................................................................................................... 30

P24 - The influence of plant functional diversity on ecosystem services: methods to calculate and

create a functional diversity gradient ................................................................................................. 31

3

P25 - Modelling and simulation of a chemical air scrubber for ammonia removal from pig housing

facilities ............................................................................................................................................ 32

P26 - Phenotypic and genetic variability of methane emissions and milk fatty acid contents of Walloon

Holstein dairy cows .......................................................................................................................... 33

P27 - Profiling natural low HCT poplar mutants using catalytic micropyrolysis ................................. 34

P28 - Prerequisites for a black locust genomic selection program ...................................................... 35

P29 - Aquatic vegetation growth and its effect on river resistance in hydraulic modelling .................. 36

P30 - Effect of dog breed "varieties" on population genetic structure ................................................. 37

BIOTECHNOLOGIES

P1 - Elevated CO2 reduces the impact of drought stress in Arabidopsis thaliana ................................ 39

P2 - Biofilms from entomopathogenic fungi in mosquito control ....................................................... 40

P3 - Using micro-injection technique to assess fungal toxicity in mosquito control ............................ 41

P4 - Realized niche of 8 endemic plant species of katangan Copperbelt (D.R.C.): implications for

copper species conservation .............................................................................................................. 42

P5 - Use of on-line flow cytometry for the characterization of microbial stress dynamics during the

bioprocess ......................................................................................................................................... 43

P6 - Bacteriotherapy to obtain a better body odour ............................................................................ 44

P7 - Optimization of heterologous protein production in Pichia pastoris using a methanol/sorbitol co-

feeding strategy ................................................................................................................................ 45

P8 - Identification of bacterial symbionts in the banana aphid (Pentalonia nigronervosa) coupling

genomics and proteomics .................................................................................................................. 46

P9 - Biofilter in aquaponics ............................................................................................................... 47

P10 - Using Salix spp. in phytostabilization of metal pollution in soils: an example of

phytoremediation appropriate to the brownfields of Wallonia ............................................................ 48

P11 - Promotor screening with reporter proteins for the yeast Starmerella bombicola ........................ 49

P12 - The effect of the electron beam treatment on polymer surface characteristics ........................... 50

P13 - Evaluation of the antifungal chitinase activity of two strains of Bacillus subtilis ....................... 51

P14 - Influence of steam explosion on crystallinity properties of pure cellulose fiber ......................... 52

P15 - Enzymes of Oenological interest from Wine Lactic Acid Bacteria ............................................ 53

P16 - Effect of Two Volatiles Organic Compounds on wheat seeds attacked by Fusarium ................. 55

P17 - Development of an anaerobic, thermophilic and cellulolytic consortium to improve anaerobic

digestion of lignocellulosic biomass. ................................................................................................. 56

P18 - Developing a formulation of elicitors to control bioagressors of wheat: which interests? .......... 57

P19 - Screening of essential oils on rice pathogens isolated in Madagascar ........................................ 58

P20 - Filamentous fungi (Trichoderma harzianum) behaviour in biofilm culture for 6-pentyl-α-pyrone

production us secondary metabolite with coconut like aroma ............................................................. 59

4

P21 - Impacts of organic matter type and biostimulant products on the growth of wheat and the

microbial communities of its rhizosphere under contrasted production systems ................................. 60

P22 - Susceptibility of avian pathogenic Escherichia coli from laying hens in Belgium to antibiotics

and disinfectants and integron prevalence.......................................................................................... 61

P23 - Optimization of the methane production from Mangifera Indica and Manihot Utilissima leaves

in co-digestion .................................................................................................................................. 62

P24 - Interactions of a potential plant elicitor mannolipid with plant model membranes..................... 63

P25 - Kinetic resolution of lactid acid esters in heptane or in a solvent free system ............................ 64

P26 - Screening of two agricultural genomic DNA libraries to seek new glycoside hydrolases........... 65

P27 - Role of exopolysaccharide excretion on Bifidobacterium bifidum survival after heat stress ...... 66

P28 - Molecular understanding of factors important for probiotic lactobacilli outside the gut ............. 67

P29 - Diatom silica-titania materials for photocatalytic air purification .............................................. 68

P30 - Effects of dietary α-lipoic-acid on feed intake and hypothalamic AMPK activity of young broiler

chicks ............................................................................................................................................... 69

SUSTAINABLE PRODUCTION

P1 - Impact of tillage systems and working depth on the agronomic behavior of a biological potato

crop .................................................................................................................................................. 71

P2 - Effect of encapsulated nanoparticles on thermophillic anaerobic digestion ................................. 72

P3 - A diachronic analysis of the dynamic of two cities: Kisangani and Lubumbashi (Democratic

Republic of Congo). How do the extension and/or of the densification of these cities impact the urban

internal and peripheral ecosystems? .................................................................................................. 73

P4 - Analyzing relationships between cattle grazing behavior and pasture attributes using the inertial

measurement unit of a mobile phone. ................................................................................................ 74

P5 - Estimating daily yield of major fatty acids from single milking .................................................. 75

P6 - How much light is a tree allowed to take from a crop? ............................................................... 76

P7 - Rhizobacterial volatile organic compounds implication in Brachypodium distachyon response to

phosphorus deficiency ...................................................................................................................... 77

P8 - Pivot ramps irrigation constraints in southern Algeria ................................................................ 78

P9 - Contribution of splashing drops in spray retention by barley leaves ............................................ 79

P10 - Coupling shadowgraphy and spectrofluorometry to measure spray retention ............................ 80

P11 - Impact of agricultural practices on bacterial and fungal communities in soil ............................. 81

P12 - Quantitative gas chromatography - mass spectrometry profiling of volatile organic compounds

produced by barley (Hordeum distichon L.) roots according to plant age ........................................... 82

P13 - Old inks: pigments extracted from plants ................................................................................. 83

P14 - Impact of abiotic stresses on volatile organic compound production of field crops .................... 84

P15 - Soil seed bank: a poorly know component of forest regeneration. ............................................. 85

5

P16 - Use of GC-MS in SIM-Scan mode for a selective quantitation of pollutant volatile organic

compounds (VOC) in food industries ................................................................................................ 86

P17 - Use of Near Infrared Hyperspectral Imaging (NIR-HSI) to discriminate wheat roots and straws

in soil................................................................................................................................................ 87

P18 - Agroecology: a framework to rethink academic research in agriculture .................................... 88

P19 - Impact of cover crop management on crop production: a field experiment in Wallonia context. 89

P20 - Plasmon activated photocatalysts for soot degradation ............................................................. 90

P21 - Introduction of new species of fodder shrubs in Manombo (Southern part of Madagascar): The

importance of endomycorrhizae symbiosis ........................................................................................ 91

P22 - The role of bacterial endotoxins in airborne particulate matter .................................................. 92

P23 - Impact of GLOBALG.A.P. and Organic Certifications on farmers health : case of Tunisia ....... 93

P24 - Paints based on renewable materials ........................................................................................ 94

P25 - An attempt to optimize spray retention on black grass leaves using a shielded rotary atomizer . 95

P26 - Soil infrastructure evolution and its effect on water transfer processes under contrasted tillage

systems ............................................................................................................................................. 96

P27 - Lignin as a raw material for industrial materials applications .................................................... 97

P28 - Development of an ex-vitro system allowing plant-bacteria interactions through VOCs in the

context of water stress ....................................................................................................................... 98

P29 - Airborne microorganisms for the biodegradation of air pollutants ............................................ 99

P30 - Plasma catalysis: the integration of a photocatalytic coating in a corona discharge unit........... 100

P31 - Is the behavior of grazing cattle influenced by the presence of a hedge in the pasture? ........... 101

P32 - Testing the stability of a ZSM-5 catalyst under biomass fast pyrolysis conditions ................... 102

FEED, FOOD AND HUMAN HEALTH

P1 - Angiotensin-Converting Enzyme Inhibitory Effects by Plant Phenolic Compounds .................. 104

P2 - Effect of sun-drying on flavonoid composition and antioxidant activity of three dark fig varieties

....................................................................................................................................................... 105

P3 - Effect of wheat bran fiber components on intestinal mucosal barrier function in the weaned piglet

....................................................................................................................................................... 106

P4 - Can phytoestrogen-rich plants restore the image of livestock products in terms of human health?

....................................................................................................................................................... 107

P5 - A stochastic spatial individual-based model for three competitively interacting microbial

populations ..................................................................................................................................... 108

P6 - Weaning induces oxidative stress in pigs ................................................................................. 109

P7 - Intrauterine growth retardation does not affect the intestinal barrier function in weaning piglets

....................................................................................................................................................... 110

P8 - Contribution to the study of alliinase, the active principle of garlic ........................................... 111

6

P9 - Profiles of the volatile organic compounds emitted by the masses of Abies nordmanniana somatic

embryos at maintenance and maturation stages. ............................................................................... 112

P10 - Rapid method for the structural characterization of flavonoid-O-glycosides from plant extract

using UPLC-ESI-IMS-HDMS/MSE ................................................................................................ 113

P11 - Functional differences of storage proteins are reflected in their mobilization patterns from

protein bodies in cotyledon cells during olive (Olea europaea L.) seed germination ......................... 114

P12 - Design of a low-cost, vision-based robot for automated weed destruction ............................... 115

P13 - Hesperidin conversion in the Simulator of the Human Intestinal Microbial Ecosystem (SHIME)

....................................................................................................................................................... 116

P14 - From wood charcoal to trees: pitfalls and successes of the taxonomic identification in tropical

contexts .......................................................................................................................................... 117

P15 - Reduction of furan formation by high pressure-high temperature treatment of singular vegetable

purées ............................................................................................................................................. 118

P16 - Field Bordering Flower Strips as Source of Lipids ................................................................. 119

P17 - Spoilage potential of psychrotrophic lactic acid bacteria (LAB) Leuconostoc gasicomitatum and

Lactococcus piscium under different packaging conditions.............................................................. 120

P18 - Life Cycle Evaluation of using insect-derived proteins as animal feed .................................... 121

P19 - Isolation and in vitro characterization of skeletal muscle myoblasts from chronic heart failure

patients ........................................................................................................................................... 124

P20 - Microbial ecology of Vietnamese Tra fish (Pangasius hypophthalmus) fillets during processing

....................................................................................................................................................... 125

P21 - Microbiological safety of Vietnamese Tra fish (Pangasius hypophthalmus) fillets during

processing ....................................................................................................................................... 126

P22 - Functional traits and speciation of tropical African species: the case of genus Guibourtia Benn

....................................................................................................................................................... 127

P23 - Prebiotic Effects of Novel Nondigestible Carbohydrates on Bacterial Community with

Challenge of S. Typhimurium in Pigs .............................................................................................. 128

P24 - The intestinal matrix modulates polyphenol transport and metabolism by Caco-2 cells ........... 129

P25 - Scaling-up adoption of improved technologies: The impact of the promotion of row planting on

farmers’ teff yields in Ethiopia ........................................................................................................ 130

P26 - Perceptions of traditional food and European food in Chinese consumers' minds .................... 131

P27 - Effects of intrauterine growth retardation on intestinal barrier function in neonatal piglets...... 132

P28 - Assessment of lipoxygenase activity in seeds and leaves of Nigella sativa L. and Cassia absus L

....................................................................................................................................................... 133

7

MODELLING AND DATA MANAGEMENT

8

P1 - Impact of tillage and crop residues restitution on phosphorus

distribution within topsoil in loamy soils of Wallonia

Sophie Barbieux, Gilles Colinet, Bernard Bodson, Malorie Renneson and Florian Cobert

Université of Liège, Gembloux Agro-Bio Tech, Belgium Corresponding author: [email protected]

A recent study [1] showed the reserves of total phosphorus (P) in Walloon soils were high.

However, only a small part of this total P is available for plant nutrition. Hence P already

present in soil needs to be re-mobilized without further increasing P inputs. In this context, we

studied the influence of tillage and crop residues restitution on P distribution within topsoil.

Since 2008 a field experiment (Gembloux; Luvisol) is carried through four modalities: Till

without residues restitution (T OUT); Till with residues incorporation (T IN); No-till without

residues (NT OUT); and No-till with residues (NT IN). Soil samples were taken from all

modalities at three depths between 0 and 30cm. Phosphorus, calcium and magnesium contents

were measured using water extraction (Pw, Caw and Mgw) and ammonium acetate-EDTA

extraction (PNH4, CaNH4, MgNH4).

Results showed that till treatments mainly influence the spatial distribution of Pw within

topsoil. Under NT practices, a higher Pw content occurred at the soil surface and decrease

with depth while it was quite homogenous under till soil. Pw content was significantly higher

under NT IN than NT OUT from 2013 proving an effect of crop residues restitution. However

no significant increase under T IN could be observed compared to T OUT. Results also

revealed a negative correlation between PNH4 and CaNH4 as well as between Pw and Mgw.

This observation coincides with another study [2]. Indeed it also showed the Mg content in

Walloon soils was increasing and suspected risks of P immobilization. Further researches are

planned about the effect of Mg fertilization on soil P dynamics.

[1] Renneson et al. Soil Use Manag 2013; 29:103–13

[2] Genot et al. Base de données sols de REQUASUD 2012

9

P2 - Drivers of estimated above-ground biomass in Central

African forests: what really matters

Jean-François Bastin1,2

, Jan Bogaert2 and Charles De Cannière

1

1 Université Libre de Bruxelles, Belgium 2 Université de Liège, Belgium

Corresponding author: [email protected]

National estimations and monitoring of tropical forest carbon stocks, required by international

policies aiming to reduce emissions from deforestation in developing countries (the REDD+

program), are currently based on scarce but intensive field measurement campaigns. The

methodology generally consists in a systematic sampling of ground plots, stratified between

different land cover types. In dense forests, above ground biomass (AGB) holds a large share

of the C stock. AGB is conventionally estimated by measuring simple tree dimensions (trunk

diameter, tree height and wood density) on every tree with a diameter superior-or-equal to 10

cm (~400 stem per hectare). However, the induced cost, time and botanical-knowledge

required result in less than 0.0001% of total area sampled in African forests by conventional

plots, which strongly limits the accuracy of national estimates. Although the preponderance of

large trees in dense forest AGB prediction is known for some time, it remains poorly

investigated such as large resource shares continue to be dedicated to measuring and

identifying nearly every single stem in forest plots. Here we show, in line with the metabolic

theory, that a few trees are sufficient to explain most of forest AGB variance. We measured

76 plots (1ha) spanning distant geographic locations in the Congo Basin (Cameroon, Gabon,

RDC), we developed local and global prediction models reaching up to 90% of explained

AGB variance when considering only the 20 heaviest trees per plot (5% of all sampled trees).

Our results provide the opportunity to significantly simplify existing methodologies, thus

offering the possibility to rapidly increase the sampling coverage in Africa, required for

national implementation of the REDD+.

10

P3 - Hyperspectral reflectance measurements for the detection of

tree diseases

Melanka Brackx

Universiteit Antwerpen, Belgium


This study examines how different tree infections influence the hyperspectral reflectance

(VIS-NIR) of the leaves. The objective is to gain insight in the potential of reflectance

measurements, as a fast and non-destructive technique for mapping the occurrence of tree

diseases and isect plagues.

The following cases are studied:

- Mildew on pedunculate oak and field maple;

- Tar spot disease on sycamore maple;

- Horse chestnut leaf miner on horse chestnut.

For each case about 16 trees were sampled. For each tree 15 leaf spectra were obtained using

a Agrispec spectroradiometer (ASD inc.). The spectra of healthy and infected trees are

compared visually and statistically by means of spectral indices found in literature (NDVI,

RVSI, WI, NDWI, NPCI and SIPI). These have been proposed as indicators of

photosynthesis, chlorophyll, water, senescence and pigment content. Moreover, we examine

the correlations between measurements on the same trees. For the analyses, linear mixed

effects models are used.

The results show that each disease has a particular effect on the reflectance and that indices

are able to discriminate the healthy and the infected group. However, high within-tree

correlations were found which indicates that other factors than infection also have influence

on the spectra. Better indices could be developed by selecting wavelengths that are invariant

of these other factors. We conclude that spectral reflectance is a promising technique for

disease detection in trees.

11

P4 - Assessing the influence of cover crop management on the

spatio-temporal dynamic of soil water content by electrical

resistivity tomography

Marie Chélin and Sarah Garré

Université de Liège, Gembloux Agro-Bio Tech, Belgium


Amongst other functions, cover crops are known to increase the stability of the soil structure.

Commonly, their suppression is realized by using conventional tillage, but that it has been

demonstrated to damage the soil structure, which directly impacts the soil water content. The

proposed alternatives vary in terms of date, depth and type of tillage. As the soil water content

is a major factor in agriculture, it is essential to better understand the influence of the cover

crop management on its spatio-temporal distribution. Recent studies demonstrated the

relevancy of the electrical resistivity tomography (ERT) to estimate the three-dimensional soil

water content distribution. However, only a few of them were performed under field

conditions. This study aims at (i) validating the use of the ERT method to estimate the soil

water content distribution under field conditions (ii) quantifying the influence of cover crop

management on the dynamic of soil water content along the growing season of a maize crop

and on Belgian soil types. Three types of cover crop management content will be daily

monitored: strip tillage, spring tillage and winter tillage. In order to assess the impact of plants

on the soil water distribution, an additional plot will be burned after winter tillage. ERT will

be used on a surface of 2 m² for each cover crop management. The validation of the average

soil water content will be attended by using Time Domain Reflectrometers (TDR) and suction

cups. The water stock obtained by ERT will be validated by using data from a weather station

for the estimation of the evapotranspiration and rainfall and minirhizotrons for the assessment

of the root water uptake.

12

P5 - Simulations of a beta amphiphilic peptide as potential

surfactant of membrane proteins

Jean-Marc Crowet1, Nicolas Dony

1, Antoine Deschamps

2, Patrice Soumillion

2 and Laurence

Lins1

1 University of Liège, Belgium 2 Université Catholique de Louvain-la-Neuve, Belgium


The peptide studied here was designed to form beta amphiphilic films with the aim to stabilize

purified membrane proteins. This interaction has notably been followed by FRET.

Hydrophobic and hydrophilic residues are alternate and positively and negatively charged

residues place respectively at the start end the end of the peptide. The peptide has been

studied by atomistic and coarse grained molecular dynamics in water, chloroform and mixed

solutions. The peptide was observed to spontaniously form beta films at the chloroform water

interface. Moreover, when we simulate the interaction of this peptide with a membrane

protein and with a membrane protein in a micelle of dodecylphosphocholine. The peptide was

observed to form beta films at the membrane protein surface and even remove surfactants

from the membrane protein surface. The simulations confirms the behaviour of this peptide

observed in vitro and shows that it could be used instead of detergents.

13

P6 - The uses of mid-infrared spectral information from milk

recording organization to certify milk geographic origin

Laura Monica Dale1, Aurelie Laine

1, Catherine Bastin

1, Amaury Goubau

1, Hana Belmabrouk

1,

Hedi Hammami1,2

and Nicolas Gengler1

1 University of Liège, Gembloux Agro-Bio Tech, Belgium 2 National Fund for Scientific Research, Bruxelles, Belgium


This study investigated the opportunity to detect the geographic origin of milk from the mid-

infrared (MIR) analysis of milk. Milk MIR spectral data related to milk recording data were

available in the Belgium Walloon Region via European project OptiMIR (INTERREG IVB

North West Europe Program). In Wallonia, the Ardenne region is associated to a traditional

product of the area, a appellation d'origine “Beurre d’Ardennes”. Therefore, discrimination

studies were conducted to distinguish Ardennes region from the rest of Wallonia. A total of

542,733 Walloon spectral records linked to their geographic origin were used (97,369 of MIR

spectra for Ardennes region and 450,326 for the rest of Wallonia). The spectral data selected

and pre-treated were adjusted for the effects of breeds, months, years and days in milk using

ab appropriate mixed model. To test the MIR ability for milk authentication, chemometric

tools, such as quadratic discriminant analysis were applied to the adjusted spectrafor three

MIR spectral regions (e.g. 930-1600 cm-1, 1710-1810 per cm and 2560-2990 per cm). Results

of classification showed that 94% of the records from the Ardernnes region were properly

classified. Based on this results, MIR spectroscopy techniques may provide useful fingerprints

to detect geographic origin and could be potentially used in routine management decision and

quality assurance tools.

14

P7 - archiDART: a R package allowing root system architecture

analysis using Data Analysis of Root Tracings (DART) output files

Benjamin M. Delory1,4

, Caroline Baudson1, Yves Brostaux

2, Loïc Pagès

3, Patrick du Jardin

1 and

Pierre Delaplace1

1 University of Liège, Gembloux Agro-Bio Tech, Plant Biology Unit, Belgium 2 University of Liège, Gembloux Agro-Bio Tech, Applied Statistics, Computer Science and Mathematics Unit,

Belgium 3 INRA, Centre d’Avignon, UR 1115 Plantes et Systèmes de culture Horticoles, France

4 National Fund for Scientific Research (F.R.S.-FNRS), Bruxelles, Belgium Corresponding author: [email protected]

In 2010, Le Bot et al presented a free and open-access software (Data Analysis of Root

Tracings - DART) allowing the analysis of complex root system architectures from captured

images, particularly across time series. Using this software, a user has to manually identify

roots as a set of links. After vectorization of a root system, three final data sets (RAC, TPS

and LIE) can be exported as table files containing several attributes for each individual root

(e.g. the root length), each observation day or each point used to construct the vectorized root

system for RAC, TPS and LIE files respectively. These data sets can be finally used either to

calculate derived root system architecture (RSA) parameters or to draw the root system

architecture at selected observation dates. However when an experiment involves the analysis

and comparison of many root systems, the calculation of RSA parameters for each data set

and the drawing of the corresponding vectorized root systems become time-consuming. In this

context, we developed a R package, called archiDART, allowing both the automatic

calculation of common root architecture parameters and the X-Y plotting of vectorized root

systems for selected observation dates.

15

P8 - Estimation of dominance effect for growth traits with sire-

dam subclass effects in a crossbred population of pigs

Marie Dufrasne1, Pierre Faux

1, Maureen Piedboeuf

2, José Wavreille

3 and Nicolas Gengler

1

1 University of Liège, Gembloux Agro-Bio Tech, Animal Science unit, Belgium 2 Association Wallonne des Eleveurs de Porcs (AWEP), Belgium

3 Walloon Agricultural Research Centre, Belgium


Nonadditive genetic effects may be not negligible but are often ignored in genetic evaluations.

The most important nonadditive effect is probably dominance. Prediction of dominance

effects should allow a more precise estimation of the total genetic merit, particularly in

populations that use specialized sire and dam lines, and with large number of full-sibs, like

pigs. Computation of the inverted dominance relationship matrix, D-1, is difficult with large

datasets. But, D-1 can be replaced by the inverted sire-dam subclass relationship matrix F-1,

which represents the average dominance effect of full-sibs. The aim of this study was to

estimate dominance variance for longitudinal measurements of body weight (BW) in a

crossbred population of pigs The dataset consisted of 20,120 BW measurements recorded

between 50 and 210 d of age on 2,341 crossbred pigs (Piétrain X Landrace). A random

regression model was used to estimate variance components. Fixed effects were sex and date

of recording. Random effects were additive genetic, permanent environment, parental

dominance and residual. Dominance variance represented 7 to 9% of the total variance and 11

to 30% of additive variance. Those results showed that dominance variance exists for growth

traits in pigs and may be relatively large. The estimation of dominance effects may be useful

for mate selection program to maximize genetic merit of progeny.

16

P9 - Modelling the wall elasticity of plant cells in VirtualLeaf

Abdiravuf Dzhurakhalov, Gerrit Beemster and Jan Broeckhove

University of Antwerp, Belgium Corresponding author: [email protected]

A recently developed modelling and simulation tool VirtualLeaf is the cell-based framework

for studying plant tissue morphogenesis. In VirtualLeaf a tissue is represented by a mesh of

cells where a cell is a polygon surrounded by walls. Two neighboring cells share one cell wall

which avoids a sliding of neighboring cells relatively each other. The wall represents also

membrane and transporter proteins on either side of the cell wall. The correct describing of

the mechanical properties of the cell wall is important for the studying the role of cell wall

mechanics in the cell and tissue growth processes. We defined the mecanical properties of

tissue in the cellular level expressing these properties to the cell wall. In this model the wall

has both an elastic properties counteracting to the turgor pressure of the cell and plastic

properties allowing the cell growth. The elastic properties of the cell wall has been expressed

by the Hook's law. In contrast to the existing length constraint term in Hamiltonian which

represents the property of the part of wall we use this new model for the entire length of wall.

We introduced the rest length of wall wich corresponds to the state of the wall in the absence

of the turgor pressure. The plasticity of the cell wall, i.e. its irreversible deformation is

described by updating the rest length of the wall if the length of the wall exceeds some

predefined theshold value. Results obtained by this new model is presented.

17

P10 - An algorithm for efficient computation of genomically-

enhanced inbreeding coefficients

Pierre Faux and Nicolas Gengler

University of Liège, Gembloux Agro-Bio Tech, Belgium


In common livestock species, increase of inbreeding generates two types of troubles. First, it

has been shown that such an increase could impact reproductive traits. Secondly, an increase

in inbreeding leads to a loss of genetic diversity in the population. The population becomes

genetically less resilient. Therefore, a frequent estimation of the evolution of the pedigree-

based inbreeding coefficients (PBI) for a given population is important, as well as it is

important to manage the breeding schemes in order to keep a low or negative gain in

inbreeding from a generation to the next one. However, pedigrees are sometimes incompletes,

what leads to under-estimations of PBI. Besides, the recent boom in genomic prediction

methods led to genotype animals increasingly. The availability of such an amount of genomic

information allows a better estimation of PBI. Our objective is to propose and test an

algorithm that efficiently incorporates the genomic information in the usual computing of

inbreeding coefficients. This algorithm mixes a method of combination of pedigree-based and

genomic relationships and an algorithm for quick computation of PBI. It is efficient in terms

of time and memory and it returns “genomically-enhanced” inbreeding coefficients (GEI).

The algorithm was applied to the dairy cattle population from Luxembourg (~400,000

animals), using genotypes from 440 bulls. We have found that the GEI is greater than the PBI

for animals poorly related, on a pedigree base, to the genotyped sub-population. This result

may be explained by the fact that animals poorly related to the genotyped sub-population are

such because their pedigrees are incomplete. The PBI was therefore low for those animals.

18

P11 - Anthropogenic effect on African landscapes: Typologies,

spatial structure, impact

Isabelle Vranken

Université de Liège, Gembloux Agro-Bio Tech, Belgium

Université Libre de Bruxelles, Belgium

Fonds National de la Recherche Scientifique (FNRS), Bruxelles, Belgium


The aim of this landscape ecology research is to address different types of anthropogenic

activities, the type of changes they induce in their spatial structure, particularly heterogeneity,

and their ecological impacts. The spatial heterogeneity (compositional and configurational) of

20 zones under growing anthropogenic pressure in tropical Africa was analysed using spatial

structure metrics and classified LANDSAT TM/ETM+ scenes.

The scatter plot shows bell curves with maximal entropy at intermediate anthropogenic

effects. Distinction of natural and anthropogenic heterogeneities shows opposed tendencies

according to class and compositional/configurational type. These results have been interpreted

as spatial transformation processes and linked to the habitat heterogeneity and intermediate

disturbance hypotheses in order to infer the potential impact of anthropogenic effect on

biodiversity in the area.

19

P12 - Consequences of Selection for Environmental Impact Traits

in Dairy Cows

Purna Bhadra Kandel1, Sylvie Vanderick

1, Marie-Laure Vanrobays

1, Amélie Vanlierde

2,

Frederic Dehareng2, Eric Froidmont

2, Hélène Soyeurt


1

1 University of Liège, Gembloux Agro Bio-Tech, Belgium 2 Walloon Agriculture Research Center, Gembloux


Environmental sustainability is gaining importance in dairy industry due to enteric methane

(CH4) emission from dairy cows. We predicted CH4 indicator trait (CH4 intensity: CH4 g/kg

of milk) from Mid-infrared spectra of milk samples and recorded milk yield. Genetic

correlations between CH4 intensity and milk production traits were estimated on Holstein

cows from correlations of estimated breeding values. Genetic correlations between CH4

intensity and milk yield (MY) was -0.67, fat yield (FY) -0.13, protein yield (PY) -0.46,

somatic cell score (SCS) 0.02, longevity -0.07, fertility 0.31, body condition score (BCS) 0.27

and average of confirmation traits -0.23. Currently, there is no CH4 emission trait in genetic

evaluation selection index. Putting an hypothetical 25% weight on CH4 intensity on current

Walloon genetic evaluation selection index and proportional reduction on other selection

traits, the response to selection will be reduction of CH4 emission intensity by 24%, increase

in MY by 30%, FY by 17%, PY by 29%, SCS by -15%, longevity by 24%, fertility by -11%,

BCS by -13% and conformation traits by 24%. In conclusion, introduction of environmental

traits in current selection index will affect selection responses. As there is no economic value

of these traits presently alternative methods like putting correlated traits with clear economic

value (e.g. feed efficiency) in the selection objective could generate appropriate index

weights.

20

P13 - How to preserve microbial biodiversity: functional and

structural cryopreservation of mixed microbial cultures

Frederiek - Maarten Kerckhof1, Emilie Courtens

1, Annelies Geirnaert

1, Sven Hoefman

2, Adrian

Ho3, Ramiro Vilchez-Vargas

1, Dietmar Pieper

4, Ruy Sandoval

4, Siegfried E. Vlaeminck

1, Tom

Vandewiele1, Kim Heylen

2, Peter Vandamme

2 and Nico Boon

1

1 Ghent University, LabMET, Belgium 2 Ghent University, Laboratory of microbiology, Belgium

3 Netherlands institute of ecology (NIOO-KNAW), Netherlands 4 Microbial Interactions and Processes Research Group, Department of Medical Microbiology, Helmholtz

Centre for Infection Research, Braunschweig, Germany


The use of mixed microbial cultures in biotechnology is steadily increasing over the last

decades. They overcome many issues of sustainability of pure culture biotechnology and

provide many new perspectives as well. However, these mixed cultures are not readily

available from public culture collections, hampering the advancement of science and

technology. The main reason for this lack of availibility is the lack of a cryopreservation

protocol.

Therefore we evaluated two different cryoprotective agents (CPA) on three different types of

mixed microbial cultures. The cultures were selected based upon their relevance towards

applications: (1) a methanotrophic co-culture (MOB), which can be applied to mitigate

greenhouse gas emissions, remove environmental pollutants or produce bioplastics (2) oxygen

limited autotrophic nitrification/denitrification biofilm, which provides economical and

ecological benefits compared to the conventional process of nitrification and heterotrophic

denitrification in wastewater treatment and (3) fecal material from a human donor which can

provide applications for fecal transplants and pre/probiotics research.

After three monts of cryopreservation at -80°C we found that addition of our selected CPA

(dimethyl sulfoxide, DMSO and DMSO with added trehalose and TSB, DMSO+TT)

enhanced fast specific activity recovery of MOB and the aerobic ammonium oxidizing

bacteria (AerAOB) and anaerobic AOB (AnAOB, anammox) in the OLAND mixed culture.

However, the fecal community was not influenced by CPA addition for activity recovery.

This is due to the difference between heterotrophic ecosystem drivers of the fecal community

and the autotrophic, fastidious nature of the key ecosystem drivers in the MOB and OLAND

community. Preservation of community structure (as determined by 16S high throughput

Illumina sequencing) was enhanced by addition of a CPA, despite some minute differences.

In summary, whether or not addition of DMSO+TT is required for activity recovery depends

upon the autotrophic or heterotrophic nature of the key ecosystem drivers of the mixed

culture. In any case, DMSO+TT allowed for a better retention of community structure.

Overall we have established a cryopreservation protocol that succeeds in preserving both

community structure and functionality of mixed mirobial cultures. This will allow individual

laboratories and culture collections to boost the use of mixed communities in biotechnological

applications.

21

P14 - Bacterial lipopeptides as elicitors of plant defence

W. Patricio Luzuriaga Loaiza, Mehmet Nail Nasir, Laurent Franzil, Marie-Laure Fauconnier,

Laurence Lins and Marc Ongena

University of Liège, Belgium

Corresponding author : [email protected]

Until 2012, the EU retired from the market 74% of the synthetic pesticides used in agriculture

because of their negative effects on human health and environment. In this context, the EU

Law stipulates as a preference the use of eco-friendly alternatives such as beneficial plant

microorganisms (Biological Control Agents, BCA).

Attention on BCAs has increased because of the multiplicity of their modes of action involved

in plant protection, including induction of host defence, a phenomenon termed Induced

Systemic Resistance (ISR). ISR is a particularly interesting mechanism because of its long-

term “vaccination effect” along the whole plant but with low negative effects on host

development.

Previous works showed that the most efficient ISR elicitor produced by Bacillus sp. is

surfactin (SF), a surface-active lipopeptide. The target of the biological activity of SF is the

plant plasma membrane (PPM), more precisely its lipidic phase. However, the mechanisms of

the SF-PPM interactions are still poorly understood.

This work is therefore focused on the mechanism of the SF-PPM interactions at the molecular

level. Because of the complexity of PPM, our strategy consists to analyze the effect of SF on

biomimetic membranes of plants by biophysical tools and in silico modelling. These results

will provide us valuable information to continue research on natural membranes from

Arabidopsis thaliana.

22

P15 - Integrated farming systems in Kinshasa. Diversity of

agricultural practices

Patrick Mafwila Kinkela1,2

, Emilie Willems1, Bienvenu Kambashi

1,2, Pascale Picron

1, Roger

Ntoto2, Xavier Rollin

3, Denis Dochain

3, Jacques Mafwila

2 and Jérôme Bindelle

1

1 University of Liège, Belgium 2 University of Kinshasa, The Democratic Republic of the Congo

3 Catholic University of Leuven, Belgium


In Kinshasa in the Democratic Republic of the Congo, integrated systems of livestock and fish

farming are little documented while they represent an interesting option for ecological

intensification. After identifying the density of fish ponds in the territory of the city using

satellite images, approx. 200 farms with at least one pond and located in 2 in periurban and in

1 rural area were surveyed to characterize the degree of integration in the agricultural system.

The preliminary results in one of the valleys indicate that the practice of agriculture in

synergy with pig and fish farming is a common practice although flow of components are still

insufficiently integrated and some of them are not optimized . The fish - pig farming

associations with or without vegetable production represent 44 % of the sample. The

identification of flows on farms showed that the manure of pigs is mainly used for crops

(51%) or sold (28%), while a small part is used to fertilize the ponds. This may be explained

by the predominant share of income (67%) devoted to vegetable production while sludge of

ponds is rarely used to fertilize vegetable crops. Vegetable residues are rarely used to feed

pigs and fish because of their limited availability. Feeding pigs and fish is primarily based on

agro-industrial by-products, such as wheat bran (81%) and brewers grains (62%), and forages

(62%). The presentation will analyze the results obtained in the three sites visited and outline

opportunities for improvement.

23

P16 - Sugar-based bolaforms as new potential drug delivery

system. Importance of the sugar residues in the modulation of the

membrane activity

Mehmet Nail Nasir1, Jean-Marc Crowet

1, Laurence Lins

1, Marc Ongena

1, Marie-Laure

Fauconnier1, Sylvain Gatard

2, Sandrine Bouquillon

2 and Magali Deleu

1

1 University of Liège, Gembloux Agro-Bio Tech, Belgium 2 Université de Reims, France


Among glycolipid surfactants, bolaforms constitute an important class. Their interest lies

mainly in the development of the efficient and low cost lipid-based drug delivery systems.

In this context, our work was focused on two sugar-based bolaforms. They are composed by

two identical hydrophilic head constituted by xylose (BolaX) or rhamnose (BolaR), connected

by an ether link to a hydrocarbon segment with one unsaturation.

The interactions of BolaX and BolaR with model phopsholipid and phospholipid/sterol model

membranes (Langmuir monolayers at the air-water interface and multilamellar vesicles) were

investigated with biophysical and in silico approaches.

Our results indicate that both bolaforms interact with model membranes at the level of

hydrocarbon chain and, at the phosphate and the carbonyl group of phospholipids. The

presence of sterol in the system has an influence on the bolaform insertion of and changes

slightly the nature of the interactions. The insertion of BolaR within a phospholipid bilayer

was deeper than that of BolaX and its interaction with phospholipids is energetically more

favorable, suggesting an important role of the nature of sugar residues.

24

P17 - Do lipid interaction properties of novel rhamnolipids govern

their plant-elicitor activities?

Mehmet Nail Nasir, Jean-Marc Crowet, Laurence Lins, Marc Ongena, Katherine Nott, Marie-

Laure Fauconnier and Magali Deleu



Among glycolipids, natural rhamnolipids (RLs) produced mainly by strains of Pseudomonas

aeruginosa, have drawn particular attention because of their interesting biological properties

including antimicrobial, antiphytoviral, zoosporicidal and plant-elicitor activities. It is

generally recognized that these activities must be linked to the interactions of the natural RLs

with constituents of biological membranes. However, the molecular mechanisms of these

interactions are far from being fully understood.

In this context, highlighting these mechanisms in order to understand their plant- elicitor

activities becomes important. New RLs with various chain lengths and with or without a

terminal carboxylic acid function were obtained via the development of a synthesis procedure

consisting of two biocatalyzed steps involving naringinase and lipase.

Because of the complexity of the plant plasma membrane (PPM), our strategy is based on the

use of biomimetic membranes of PPM. Our objective was to investigate the interactions

between PPM and novel RLs in relation with their structure in order to give insight about the

mechanism of their biological action. A range of complementary experimental and modelling

methods was used. Results reveal differential interaction with PPM lipids according to the

structure of the RLs. In this way, we showed that little structural differences could give drastic

changes on the biological activity. The nature of the lipid constituting the PPM is also a key

parameter for the interactions.

25

P18 - Finding Interesting Elicitor LipiDs- FIELD Project in

Gembloux Agro-Bio Tech. An original multidisciplinary bottom-

up approach for the future of agriculture.

Mehmet Nail Nasir, W. Patricio Luzuriaga Loaiza, Damien Polo Lozano, Magali Deleu,

Laurence Lins, Marc Ongena, Mohamed Haïssam Jijakli and Marie-Laure Fauconnier


Corresponding authors: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]

Nowadays, many health and environmental problems are caused by the use of chemical

pesticides. In this context, an increasing demand for alternative products such as biopesticides

has been observed. Among biopesticides, elicitor molecules which are able to trigger immune

defense responses in plants are one of the most promising options. Although numerous

elicitors have been discovered, the mechanisms involved in the perception, by plants, of only

a few molecules have been identified. These elicitors usually interact with proteic receptors

but we have recently shown that they may also act on the lipid phase of the plasma

membrane. This project first aims to improve our understanding of the molecular mechanisms

involved in the recognition of specific lipid based elicitors (LBE). On that basis, the FIELD

project will contribute to the design and the development of innovative compounds derived

natural LBE. A multi-disciplinary approach, based on chemistry, bio-physics, bio-chemistry,

and phytopathology will be followed by a consortium of different research groups from

Gembloux Agro-Bio Tech in close collaboration with teams from foreign institutions.

26

P19 - Performance variations of the noxious invader Ambrosia

artemisiifolia L. along a latitudinal gradient: Is there an

impediment to invasion?

William Ortmans1, Arnaud Monty

1 and Bruno Chauvel

2

1 University of Liège, Gembloux Agro-Bio Tech, Belgium 2 INRA, France


Ambrosia artemisiifolia L. is an invasive species from North America, causing a health crisis

in Europe due to its highly allergenic pollen. In Southern France, the invasion is highly

virulent. Populations can be found further north, but hardly survive thanks to a steady income

of seeds from human activities.

To understand how the invasion will evolve, we need to understand the role of both climate

and competition on the development of A. artemisiifolia. A way to decrypt that role, is to

assess the performances of the species along a latitudinal gradient. To do so, we chose 14

populations from Netherlands to Southern France. Populations and its habitats were recorded.

Furthermore, we measured phenological, reproductive, and functional traits on randomly

selected plants, together with the surrounding completion by native vegetation. Two

campaigns were necessary to measure both the maximum biomass occurring in August and

the seed production in October. We used multiple regression analysis, to show the variation

traits along the climatic gradient and determined if there is a drag against the invasion

expansion.

This study was performed in collaboration with the National Institute of Agricultural

Research (INRA), which provided useful tools and a laboratory to analyze samples. The

campaigns were subsided by an action of the European framework COST: SMARTER

(Sustainable management of Ambrosia artemisiifolia in Europe), which involves over 120

experts from 33 countries.

27

P20 - Habitat suitability modelling in auto-ecology analysis of

Azolla filiculoides (Lam.) Azollaceae in Selkeh Wildlife Refuge

(Iran)

Roghayeh Sadeghi1, Rahmat Zarkami

2, Karim Sabetraftar

2 and Patrick Van Damme

1

1 Ghent University, Belgium 2 Guilan University, Islamic Republic of Iran


Invasive aquatic species are more and more becoming a worldwide problem. Especially exotic

species are affecting biodiversity. They may substantially change communities and

ecosystems. Azolla filiculoides (Lam.) is such an exotic species in Selkeh Wildlife Refuge

(northern Iran). It is rapidly spreading and has a serious impact on the area’s aquatic

communities. The purpose of the present study was to make use of field data and modelling

techniques to analyse the ecology of A. filiculoides in Selkeh wetland. Classification tree

(CT) methods were used for habitat suitability modelling of A. filiculoides. Various structural

habitat and physico-chemical variables were used as inputs whereas and 3 classes (low,

medium and high) of A. filiculoides cover served as output for the models. Of the 33 variables

presented to the model, validity of 9 variables was confirmed for the prediction of habitat

requirements of A. filiculoides. A logical link was found between A. filiculoides distribution

and structural habitat variables such as depth, air temperature, humidity and light intensity of

wetland. Besides, nitrate and orthophosphate concentrations were found to be two main

nutrients for prediction. CTs allow the selection of the most important variables and thus

provide critical information to support definition and implementation of an A. filiculoides

management programme in Anzali wetland.

28

P21 - Analysis of environmental factors determining the

distribution pattern of Azolla filiculoides (Lam.) Azollaceae in

Anzali wetland, northern Iran

Roghayeh Sadeghi1, Rahmat Zarkami

2, Karim Sabetraftar

2 and Patrick Van Damme

1

1 Ghent University, Belgium 2 Guilan University, Islamic Republic of Iran


The first consideration in predictive ecological modelling is the selection of appropriate input

variables. Numerous variables can, however, be involved whereas most of them cannot be

omitted from the analysis without a significant loss of information. Therefore, rigorous

methods are needed to distinguish which variables are essential from those which are not. In

this paper, the use of greedy stepwise (GS) and genetic algorithm (GA) is explored to

automatically select the relevant input variables to be used in classification trees (CTs) for

predicting the cover percentage of Azolla filiculoides (Lam.). The database applied consisted

of measurements from 7 sites in Selkeh wetland (northern Iran). Biotic and abiotic variables

were collected over the 2007-2008 study period. The results showed that after variable

selection, the predictive performances of the CTs had improved. GS was shown to be less

efficient than GA. Optimization of GA and GS resulted in an easy interpretation of the

selected variables. Both structural habitat and physico-chemical variables can affect habitat

requirements of A. filiculoides in the wetland, but the dependence of this aquatic fern on

structural habitat parameters was well-confirmed by the CTs after variable selection.

Application of the given algorithms in combination with CTs thus proved to have a good

capability in selecting the most important variables explaining the cover of A. filiculoides in

Selkeh wetland.

29

P22 - Synthesis and study of biophysical and biological properties

of new aromatic ester derivatives.

P. Sainvitu, M.N. Nasir, L. Lins, J.-M. Crowet, L. Willems, J.-P. Cosse, C. Jérôme and M. Deleu



Aromatic glycolipids are of both medical and pharmaceutical interest. Antimicrobial, antiviral

and antiinflammatory activities have been reported (Otto, 2000, Journal of Molecular

Catalysis B: Enzymatic). Moreover, they are expected to have interesting antioxidant

properties when they contain phenolic groups. The alkyl chain should enhance their ability to

penetrate into the cellular membrane (Nicolosi, 2002, Journal of Molecular Catalysis B:

Enzymatic). The presence of a sugar unit could also be useful to target specific cells.

In this study, novel aromatic glycolipids were synthesized as useful models for studying the

structure–activity relationships, in particular as regards to the sugar moiety presence. Their

effect on cell viability when an oxidative stress is induced was tested. In parallel, their

interaction with cell membrane phospholipids was studied by Langmuir monolayer technique,

Infrared spectroscopy, molecular modeling and permeability measurements.

30

P23 - Modeling using the SWAT model of water flow and

transport in suspension in the watershed of the valley of Wadi El-

Hachem

Nassima Tadrist and Olivier Debauche



In the Maghreb, dams regularly suffer from excessive siltation due to erosion problems

present in the catchment areas. The origins of this erosion are multiple: land use,

deforestation, land affectation, ...

Hydrology coupled with geographic information systems allows using distributed and

physically based models to predict the evolution of siltation of dams.

The application of these models in Algeria will finally predict the impact of anti-erosion

measures, land use patterns on the siltation of dams accurately estimating the amount of

sediment produced by erosion runoff and the degree of filling.

A methodology based on the map data (digital terrain model, map soil science, geology map

and mapping of land use ) and daily meteorological data (temperature, relative humidity, wind

speed, solar radiation) is being development and testing of the dam Bourkourdane.

This methodology uses the SWAT model.

The SWAT model is used to predict the amount of sediment accumulating in the dam, the

water flow rate inbound, outbound, and the volumes of water and sediment stored in the dam.

Adequate management of releases, coupled with better management of erosion upstream of

the dam will extend the life of dams Algerians. Especially for Boukourdane , improved

management of releases is paramount to improve groundwater recharge , fight against the

intrusion of marine waters and prevent the accumulation of fine particles that reduce soil

permeability.

31

P24 - The influence of plant functional diversity on ecosystem

services: methods to calculate and create a functional diversity

gradient

Roel Uyttenbroeck1, Séverin Hatt

1, Aman Paul

1, Fanny Boeraeve

1, Frédéric Francis

1, Sabine

Danthine1, Michel Frederich

2, Marc Dufrêne

1, Bernard Bodson

1 and Arnaud Monty

1

1 University of Liège, Gembloux Agro-Bio Tech, Belgium 2 University of Liège, Département de Pharmacie, Belgium


During the last years, several studies and reviews have considered the relation between

biodiversity and ecosystem functioning or the provision of ecosystem services. Many studies

found that plant functional traits and plant functional diversity (FD) are key drivers in this

relation in terrestrial ecosystems. Researchers used different methods to obtain a gradient in

plant FD to examine the effect on ecosystem services, going from observational studies of

natural communities to synthetic assemblages. Furthermore, different methods exist to

quantify plant FD going from simple functional trait richness to indices, distance-based

frameworks and the division into FD components. In the AgricultureIsLife project, we set up

a field experiment aiming to examine the biodiversity – ecosystem service relation in

agricultural context. The experiment consists of perennial wildflower strips with different

plant functional diversities in an arable field with conventional crop production. The

wildflower strips were sown as synthetic assemblages but are subject to natural succession

during the following years. We monitor the evolution of FD from the sowing to the

establishment of a typical wildflower strip using Rhao’s quadratic entropy index to quantify

FD. In addition, the flower strips will be monitored for four ecosystem services they are

expected to provide: pollination, pest control, biodiversity support and provision of valuable

compounds.

32

P25 - Modelling and simulation of a chemical air scrubber for

ammonia removal from pig housing facilities

Caroline Van der Heyden1, Peter Demeyer

2 and Eveline Volcke

1

1 Ghent University, Belgium 2 Institute for Agricultural and Fisheries Research, Belgium


Since 2004, newly built pig housing facilities in Flanders are legally required to be emission-

low with respect to ammonia. This can be achieved by applying air scrubbers that remove

ammonia from the outgoing ventilation air through absorption in water, followed by chemical

and/or biological conversions. Despite the widespread use, measurements show that the

promised removal efficiency is not always reached. To fully exploit the potential of air

scrubbers, further process optimisation in terms of design and control is required.

In this study, a mechanistic (physical-based) model for a chemical air scrubber was set up,

including mass (ammonia and water) and heat balances, which are coupled. The transfer of

ammonia from the exhaust air to the water exhibits a relative constant profile throughout the

scrubber and a steady removal efficiency in time. Upon start-up, the temperature of the

washing water increases while flowing over the packing until sensible and latent heat

exchange are in equilibrium.

The influence of some design parameters, disturbance variables and control handles on the

removal efficiency and evaporation rate were investigated through a simulation study. An

increased load, temperature or higher ventilation rate resulted in a decreasing ammonium

removal efficiency. The influence of packing dimensions, pH and discharge rate was assessed

as well, leading to a better insight in the operation of air scrubbers.

33

P26 - Phenotypic and genetic variability of methane emissions and

milk fatty acid contents of Walloon Holstein dairy cows

Marie-Laure Vanrobays1, Purna Bhadra Kandel

1, Hélène Soyeurt

1, Amélie Vanlierde

2, Frédéric

Dehareng2, Eric Froidmont


1

1 University of Liège, Gembloux Agro-Bio Tech, Department of Agricultural Science, Belgium 2 Walloon Agricultural Research Centre, Belgium


There is a growing interest in reducing methane (CH4) emissions from enteric fermentation of

dairy cows because these emissions contribute to climate change and represent losses of gross

energy intake for cows. Milk fatty acid (FA) profile is influenced by rumen fermentations.

The aim of this study was to estimate phenotypic and genetic variability of enteric CH4

emissions of dairy cows and FA contents of milk. CH4 emissions (g/d) and milk FA contents

are predicted from milk mid-infrared (MIR) spectra based on calibration equations developed

by Vanlierde et al. (2013) and Soyeurt et al. (2011), respectively. Data included 161,681

records from 22,642 cows in 489 herds. Genetic parameters of MIR CH4 emissions and 7

groups of FA contents in milk were estimated for Walloon Holstein cows in first parity using

bivariate (CH4 emission with a FA trait) random regression test-day models. Saturated FA

presented higher genetic correlations with MIR CH4 production than unsaturated FA (0.25 vs.

0.10). Genetic correlations with MIR CH4 emissions were higher for short- (SC) and

medium-chain (MC) FA (0.24 and 0.23, respectively) than for long-chain (LC) FA (0.13).

Phenotypic correlations between MIR CH4 emissions and SC and MC FA were also higher

than those between MIR CH4 emissions and LC FA (0.20 vs. -0.08). Finally, results showed

that MIR milk FA profile and MIR CH4 emissions are correlated emphasizing indirect link

between milk FA and CH4 emissions through rumen metabolism.

34

P27 - Profiling natural low HCT poplar mutants using catalytic

micropyrolysis

Jop Vercruysse1, Ruben Vanholme

2, Bartel Vanholme

2, Wout Boerjan

2, Wolter Prins

1 and

Frederik Ronsse1

1 Ghent University, Belgium 2 VIB, Belgium


The thermochemical non-catalytic and catalytic pyrolysis of low HCT mutant poplar (Populus

nigra) with an altered lignin composition, was investigated to assess the potential of these

mutant poplars as a biomass feedstock for fast pyrolysis leading to an improved yield of

valuable chemicals. Micropyrolysis coupled with GC-MS generated a wide range of

degradation products, which were lumped into major compound classes (alifatics, aldehydes,

phenols, sugars etc.) for a correlation analysis between the pyrolysis conversion products and

feedstock composition. Non-catalytic results showed an increase in non-methoxylated

phenolic compounds at the expense of mono-methoxylated phenols for the homozygote low

HCT poplar mutants compared to wild type samples, clearly derived from a higher H-unit

content in the lignin of the homozygote plant cell wall. Zeolite based catalytic experiments

also generated differences in the phenolic spectrum of the fast pyrolysis vapours indicating a

different thermochemical decomposition behavior of different poplar mutants.

35

P28 - Prerequisites for a black locust genomic selection program

Cindy Verdu and Ludivine Lassois

University of Liège, Gembloux Agro-Bio tech, Belgium Corresponding author: [email protected]

The use of renewable resources as an alternative to fossil fuels has become a priority.

Efficient use of forest as a resource for energy and green chemistry purposes require the

development of suitable selected genotypes that are competitive and ready to meet the

challenges of global change. In this context, the black locust, Robinia pseudoacacia L., is a

very promising species which has many advantages in the context of current global change:

high phenotypic plasticity, drought resistance, high biomass production and fixation of

atmospheric nitrogen. The genetic improvement of woody species using traditional methods

can take between 20 to 30 years. These times can be greatly reduced with the development of

new selection methods such as genomic selection.

Before starting a genomic selection program, it is necessary to 1) develop new molecular

markers to achieve a very dense genetic map for genomic selection, 2) study the genetic

diversity of the species present in Belgium and compare it with that of the native area, 3)

study the structure and the relatedness of different populations, 4) establish a core-collection

gathering the most genetically diverse individuals, and 5) as black locust is an exotic species,

verify its invasiveness in Belgium.

These 5 steps will be detailed and the first results obtained will be discussed.

36

P29 - Aquatic vegetation growth and its effect on river resistance

in hydraulic modelling

Veerle Verschoren, Jonas Schoelynck and Stijn Temmerman

University of Antwerp, Belgium


The presence of aquatic vegetation in lowland rivers is time and space dependent: In spring

the vegetation starts growing and reaches maximal biomass around August, leading to

blockage and increased resistance in the river channel. During winter the vegetation dies and

disappears almost entirely. Also, the aquatic vegetation is not homogeneously distributed in

the river but forms spatial patterns.

These spatio-temporal changes were measured monthly (April - October 2013) in two

lowland rivers in the Nete catchment, NW Belgium. It was found that biomass, volume and

frontal area of the vegetation increased during the growing season. High friction values

coincided with high biomass, resulting in increased water levels and decreased flow

velocities. The manning, an indicator for flow resistance, reached a maximum in August with

0.26 and 0.17 for the two rivers respectively. After a certain threshold, further plant growth

did not lead to more friction because the channel was entirely blocked.

Based on these results, a 2 dimensional vegetation module was developed and the vegetation

resistance parameters were calibrated with the collected field data. The 2D hydraulic model

STRIVE ‘STReam RIVer Ecosystem’ was used for simulating water height and flow

velocities in the rivers. It was found that the gap between the vegetation top and water surface

plays a pivotal role for the velocity changes and consequently for the overall resistance of the

river.

37

P30 - Effect of dog breed "varieties" on population genetic

structure

Katrien Wijnrocx, Steven Janssens and Nadine Buys

KU Leuven, Belgium

Corresponding authors: [email protected], [email protected]

Breeding for specific characteristics in purebred dogs has resulted in a wide variety of breeds.

These breeding practices probably contributed to a reduced genetic variation within breeds.

The division of breeds into varieties or subpopulations is achieved by reproductive isolation.

The effects of the creation of varieties on population structure and diversity have not been

studied yet in Belgian breeds.

The reproductive isolation provided by this “variety-barrier” is likely to promote genetic

distance between subtypes. For this reason, we decided to study population structure in the

Belgian Shepherd Dog (comprising four varieties: Groenendael, Laekenois, Malinois and

Tervueren) and the small Belgian Griffons (currently managed as three different breeds:

Griffon Bruxellois, Griffon Belge and Petit Brabançon). These four varieties and three breeds

are identical in breed standard, but are mostly differentiated by coat color and texture. Some

registries consider these four varieties as separate breeds, or the three breeds as only one

breed with 3 varieties.

Population structure was analysed by means of sampling 1863 animals and 21 autosomal

microsatellite markers of the ISAG panel. We used a Bayesian method, implemented in

STRUCTURE, which assigns individuals probabilistically to a cluster, based on the genotype

of the marker loci. The aim of the study was to investigate the level of distinctiveness of breed

varieties and assess effects on genetic diversity.

38

BIOTECHNOLOGIES

39

P1 - Elevated CO2 reduces the impact of drought stress in

Arabidopsis thaliana

Abdelgawad Hamada, Zinta Gaurav and Asard Han

Antwerp University, Belgium Corresponding author: [email protected]

It is frequently observed that increased CO2 protects against stress impact. However, the

underlying molecular mechanisms are not well understood. Protection may be obtained by

altered defense mechanisms, or reduced ROS generation (i.e. relaxation). We found that

drought reduced plant growth by decreasing cell division and elongation. Elevated CO2

reduced the impact of mild drought on growth by increasing both cell number and size, and

the impact of severe drought by increasing cell size only.Moreover, drought inhibited

photosynthesis, respiration, stomatal conductance and chlorophyll fluorescence, and induced

oxidative stress. Elevated CO2 protected against stress, i.e., it induced photosynthesis and

decreased oxidative damage (low H2O2 and lipid peroxidation).This protective effect was

accompanied by changes in antioxidant defense mechanisms (e.g., FRAP, CAT, APX and

SOD).

40

P2 - Biofilms from entomopathogenic fungi in mosquito control

Bawin Thomas1, Boukraa Slimane

1, Seye Fawrou

2, Raharimalala Fara Nantenaina

3, Zimmer

Jean-Yves1, Delvigne Frank

4 and Francis Frédéric

1

1University of Liege - Functional and Evolutionary Entomology, Belgium 2University Cheik Anta Diop - Animal Biology, Senegal

3Pasteur Institute, Madagascar 4University of Liege - Bio-Industries/CWBI, Belgium


Mosquitoes (Diptera: Culicidae) are zoonotic vectors of medical and veterinary importance.

As part of an integrated vector control, metabolites secreted by entomopathogenic fungi could

be developed as biopesticides. In this context, filamentous microorganisms growing on a

support as biofilm in a liquid medium would offer several advantages in bioreactor regarding

performances and metabolites recovery.

The production of toxic metabolites by an entomopathogenic fungus Aspergillus flavus in

such conditions was assessed. Three initial inoculum levels, i.e. 10^1, 10^3 and 10^6

spores/ml of PYG medium, have been tested in shake flask with or without support. Toxicity

tests were performed on Culex quinquefasciatus larvae using dilutions of 1, 2, 4, 6, 8 and 10%

of liquid cultures.

The results indicated that A. flavus tends to form pellets in submerged culture; the size and

the amount of pellets was affected by the initial inoculum level of spores. Under similar

conditions, the filaments fixed on a support and didn’t appear in free form in the liquid.

Toxicity tests revealed differences between both free and fixed forms. All combined

conditions, LC50s ranging up to dilutions of 2.2 and 4.8% were observed within 48 hours.

Secretomes could be compared between these culture conditions by proteomic and

metabolomic approaches.

41

P3 - Using micro-injection technique to assess fungal toxicity in

mosquito control

Bawin Thomas1, Boukraa Slimane

1, Seye Fawrou

2, Raharimalala Fara Nantenaina

3, Zimmer

Jean-Yves1, Delvigne Frank

4 and Francis Frédéric

1

1University of Liege - Functional and Evolutionary Entomology, Belgium 2University Cheik Anta Diop - Animal Biology, Senegal

3Pasteur Institute, Madagascar 4University of Liege - Bio-Industries/CWBI, Belgium


Topical application of insecticidal compounds allows directly exposing these substances on

insect tissues and measuring their potential while ignoring many factors. However, this

technique remains difficult to apply on mosquito larvae considering their aquatic lifestyle.

Micro-injection could be used for the direct deposition of toxic compounds in the larvae.

Capillaries exhibiting an injection tip with an external diameter of 0.5 mm have been designed

from silica tubes. For each treatment, a capillary is mounted on a pump connected to a flow

rate regulator. Culex quinquefasciatus larvae were injected with 10^7 spores/ml of

entomopathogenic fungi (Aspergillus clavatus, Metarhizium anisopliae, Metarhizium sp.).

Mortalities were recorded daily for 72h. The distribution of spores stained with methylene

blue and injected into the body of larvae was also observed according to the system described.

Results showed that spores were distributed over the whole body. The injection of Aspergillus

clavatus, Metarhizium anisopliae and Metarhizium sp spores induced corrected mortalities of

62%, 53% and 57% after 72h, and differed statistically from control groups. Finally, post-

mortem emergences of filaments from dead larvae were observed in the case of the three

fungal strains confirming spores’ viability. Injection of inactivated spores (or inert bodies of

similar size) could help to reject the hypothesis of a response due to the presence of foreign

bodies.

42

P4 - Realized niche of 8 endemic plant species of katangan

Copperbelt (D.R.C.): implications for copper species conservation

Sylvain Boisson1, Maxime Séleck

2, Julie Lebrun

3, Grégory Mahy

1

1Ecological restoration, Biodiversity and Landscape Unit - Gembloux Agro-Bio Tech - University of Liege,

Gembloux (5030) – Belgium 2Ecological restoration, Biodiversity and Landscape Unit - Gembloux Agro-Bio Tech - University of Liege,

Gembloux (5030) - Belgium 3Project Manager Training-Information, FJA Management and Training, Gembloux (5030) – Belgium


South of the Katanga province (D.R. Congo), a unique vegetation grows on soils developed

on 100 Cu-Co outcrops among the most important in the world (katangan Copperbelt). These

outcrops form of isolated hills in the landscape hosting vegetal communities evolving along

the mineralization gradient. More than 600 metallophytes can be found in these communities

with some 32 strict endemics solely known from mineralized soils. These species present

physiological and biological adaptations allowing them to tolerate toxic levels of metals in

soils. The unique characteristics of most endemics are seriously threatened by the intense

mining activities in the region thus also threatening the high genetic potential to be used in

development of polluted soils’ restoration strategies.

In an effort to characterize the ecology of these species, we model ecological niches of eight

endemic species along copper-cobalt gradients. For each species, three sites were prospected

and transects set. Along these, five plots where the species occurred were selected: at both the

extremities of the gradient and at 1st quartile, median and 3rd quartile. In each plot,

individuals of the particular species were counted and composite soil samples collected.

Available EDTA Cu-Co values were determined and niches modeled for both metals through

the kernel density method in R 3.0.1 (package ‘vioplot’). Results show that ecological niches

of the selected endemics are distributed between Cu-soil values of 50 and 11 000 mg.kg-1 and

between Co values between four and 1500 mg.kg-1. Six species occur in the lower 100

mg.kg-1concentrations of Co. As for the Cu gradient, two species present ecological

optimums over 3000 mg.kg-1.

This variation of ecological niches along the gradients indicates a need of adequacy between

species conservation strategies and soils’ metal contents. Four of the eight studied species

should be conserved on soils contaminated with some 500 mg Cu.kg-1 and 30 mg Co.kg-1.

For others, precise conservation actions need to be undertaken.

43

P5 - Use of on-line flow cytometry for the characterization of

microbial stress dynamics during the bioprocess

Brognaux Alison1, Han Shanshan

2, Sorensen Soren

2, Lebeaux Frédéric

1, Thonart Philippe

3 and

Delvigne Frank1

1University of Liège, Belgium 2University of Copenhague, Denmark

3 Bio-Industry unit, Gembloux Agro Bio Tech, Liege University, Belgium

Corresponding authors: [email protected], [email protected], [email protected],

[email protected], [email protected], [email protected]

Microbial cell population heterogeneity is now recognized as a major source of issues for the

development and optimization of bioprocesses. Flow cytometry is a very powerful tool for the

follow up of physiological properties of microbial cells in process-related conditions at the

single cell level, and can be used to study the dynamics of segregation directly in bioreactors.

In this context, specific interfaces have been developed in order to connect flow cytometer

(FC) directly on bioreactor for automated analyses. In this work, we propose a simplified

version of such interface and demonstrated its usefulness for multiplexed experiments.

This automated FC system has been tested for the follow up of the dynamics of an E.coli

pfis::gfpAAV fluorescent bio-reporter and its PI uptake, correlated with membrane

permeability. This bioreporter is composed of a fis promoter, a growth dependent promoter-

indicator of the nutrient status of cells, fused to a gene expressing an unstable variant of GFP.

The results obtained showed that the dynamics of the GFP synthesis is complex and can be

attributed to a complex set of biological parameters. Segregation in the membrane

permeabilitity has been noticed.

This work demonstrates that a simplified version of on-line FC can be used at the process

level for the investigation of the dynamics of complex physiological mechanisms.

44

P6 - Bacteriotherapy to obtain a better body odour

Callewaert Chris1, Plaquet Tess

1, Bostoen Jessica

2, Van de Wiele Tom

1 and Boon Nico

1

1Universiteit Gent, Belgium 2 UZ Gent


In this research, we report a successful axillary bacteriotherapy to treat axillary malodour.

Bromhidrosis is caused by malodour causing bacteria that thrive in the region of the armpit.

At this moment, treatments include the application of deodorants, antiperspirants, antibiotics,

botulinum toxin or laser operations. These treatments focus on masking of the odour, reducing

the bacterial counts and reducing the sweat production. This research focused on applying

non-odour causing bacteria in the armpit to outcompete the existing malodour causing

bacteria. Subjects with significant body odour were selected for treatment. Odour assessment

was done by a trained odour panel. Axillary samples were analysed by means of denaturing

gradient gel electrophoresis (DGGE). A first case study was performed on a monozygotic

male twin who did not co-habit, in which one twin had a significant body odour and the other

one did not (p<0.05). Molecular analysis showed that one twin had mostly corynebacteria,

while the other twin mostly staphylococci as dominant species in the axillae. Typically, the

Corynebacterium spp. are known to cause body odour. An axillary bacterial transplantation

was executed from the non-odorous twin to the odorous twin. Only one axilla was treated,

whilst the other was used as a reference. Immediately after treatment, hedonic values

improved for the treated axilla. Three days after the treatment, the non-treated axilla improved

in hedonic values as well. The remarkable results were confirmed by DGGE as the

improvements in hedonic values were associated with an increase in abundance of

staphylococci and a decrease in abundance of corynebacteria. Bacteriotherapy was executed

for two other subjects from non-relatives and only held temporal changes. In these cases, the

autochthonous microbiome was able to recover completely. The initial results indicated that,

in one case, a permanent improvement was obtained, and in two case, a temporal

improvement was obtained. This treatment opens perspectives towards a medical solution for

bromhidrosis.

45

P7 - Optimization of heterologous protein production in Pichia

pastoris using a methanol/sorbitol co-feeding strategy

Carly Frédéric and Fickers Patrick

Université Libre de Bruxelles, Belgium


The methylotrophic yeast Pichia pastoris is currently one of the most interesting hosts for

production of heterologous proteins thanks to its short doubling time, its strong methanol-

induced pAOX1 promoter and the availability of extensive physiological and genetic

information. In the context of heterologous protein production optimization, recent studies

have highlighted the benefits of using a mixture of methanol and sorbitol as a feeding medium

for the cultivation of P. pastoris. These include reduced oxygen consumption, reduced heat

production and in some cases a higher induction level of the AOX1 promoter. Previous work

in our laboratory led to the identification of the optimal methanol/sorbitol proportion in the

feeding medium, with respect to heat production, oxygen consumption and induction level

(Niu et al. 2013).

In the present work, the influence of the feeding rate on the induction level of the AOX1

promoter has been studied. Fed-batch cultures at different feeding rates were performed in a 2

l bioreactor with a strain of P. pastoris carrying the pAOX1-lacZ reporter gene construct. The

effect of the feeding rate on the beta-galactosidase activity and thus on pAOX1 induction has

been investigated. Our results clearly shown a significant effect of the feeding rate on the

induction level, with an optimal feeding rate of 6,6 mmolC.gDCW.h-1. Results also shown

that P. pastoris tends to use methanol as the main carbon source in non-limiting oxygen

conditions, while sorbitol seems to be the main carbon source in oxygen-limiting conditions.

46

P8 - Identification of bacterial symbionts in the banana aphid

(Pentalonia nigronervosa) coupling genomics and proteomics

De Clerck Caroline1, Tsuchida Tsutomu

2, Massart Sébastien

1, Lepoivre Philippe

1, Francis

Frédéric3 and Jijakli M. Haissam

1

1 Gembloux Agro-bio Tech, Belgium 2 University of Toyama, Japan

3 Functional and Evolutionary Entomology, Gembloux Agro-Bio Tech, University of Liege, Gembloux, Belgium


The Banana Bunchy Top Virus (BBTV), transmitted by the aphid Pentalonia nigronervosa, is

one of the most harmful viral diseases of banana and plantains. The existing control methods

(mainly consisting in the vector chemical control) are not efficient enough, making this virus

a serious threat for the banana production worldwide.

Previous studies have yet considered the possibility of insects’ symbiont implication in the

transmission of some plant viruses. But studies have been mostly related to Luteoviridae and

the case of the BBTV (Nanoviridae) was never investigated in spite of its economic

importance.

As a first step in the characterization of a potential interaction between the virus and the

vector, this work aimed to determine the symbiotic population of several strains of P.

nigronervosa using complementary approaches.

Five aphid’s strains were studied: two were coming from Burundi, two from Madagascar and

one from Gabon. For the genomic approach, bacteria’s 16S DNA regions were amplified

using universal primers then sequenced. Results obtained were confirmed using specific

primers targeting the identified bacteria. For the proteomic approach, 2D DIGGE was used in

order to check for differences in protein content between a total P. nigronervosa protein

extraction, a symbiont protein extraction from the same aphid and a total protein extraction

from an Acyrthosiphon pisum aphid containing only B. aphidicola. The two approaches led to

the same results and to the detection of two bacterial symbionts in P. nigronervosa.

47

P9 - Biofilter in aquaponics

Delaide Boris, Lambrechts Paul-Emile and Jijakli Mohamed Haïssam

Laboratoire de Phytopathologie GxABT, Belgium Corresponding authors: [email protected], [email protected], [email protected]

Aquaponics is a combination of aquaculture (fish farming) and hydroponics (horticulture). In

this concept, the fish faeces and excreted ammonia are partially transformed into soluble

nutrients which then are available for plants. Wastewater from aquaculture is filtrated by

plants and so increases the economic efficiency with an additional production of plant, e.g.

vegetables. This combination allows an important decrease in chemical nutrients use. This is

the main difference between aquaponics and hydroponics.

A central part of this system is the biofilter. The microorganisms that colonize it are essential

to process the fish waste into soluble nutrients easily assimilated by plants. During this

process, nitrifying bacteria convert free ammonia into nitrite and then nitrate. The first

objective of this research will concern the identification and isolation of the main

microorganism species involved by the dilution plating and metagenomics technics. The

optimal conditions to process the fish waste will be determined for such microorganism. The

efficiency of nitrite and nitrate production by these micro-organisms will be tested in different

conditions (T°, pH, O2, water flow, support, etc..) in vitro at the lab scale and in aquaponics

prototypes.

48

P10 - Using Salix spp. in phytostabilization of metal pollution in

soils: an example of phytoremediation appropriate to the

brownfields of Wallonia

Evlard Aricia and Colinet Gilles

GxABT ULg, Belgium


Since the phytoremediation concept appeared, i.e. use of plants to stabilize and/or extract

pollutants, researches have mainly focussed on studying the efficiency of woody plants in

metal extraction. Willows, as fast growing plants and because of their tolerance to difficult

edaphic conditions, have been particularly well investigated. In our research, essays were

performed with Salix clones, which came from a Walloon collection (ECOLIRIMED project).

The first objective was to study the metal tolerance of these local clones by considering their

ability to extract the pollutants and their growth (phenotypic approach). The second value of

this study lies in the second objective which aims to complete these phenotypic criteria with

physiological and proteomic criteria. The combination of these approaches expands our view

about metal tolerance: as phenotypical parameters answer the extraction ability challenge,

physiological and proteomic ones give answers linked to the health of these Salix clones

growing in presence of metals. Our results indicate that the clones that produced less biomass

showed the highest metal concentrations. However, they showed the same tolerance as the

highest producers. Also, growth reduction indicates metal tolerance. Finally, by comparing

metal concentrations obtained in the twigs to results obtained from the literature of the last

two decades, we reconsidered the use of Salix potential in phytoextraction.

49

P11 - Promotor screening with reporter proteins for the yeast

Starmerella bombicola

Geys Robin, Roelants Sophie, De Maeseneire Sofie and Soetaert Wim

Laboratory of Industrial Biotechnology and Biocatalysis (Inbio.be), Faculty of Bioscience Engineering, UGent,

Belgium


Biosurfactants are surface active compounds produced by several micro-organisms. They are

known for their good biodegradability, low ecotoxicity and high molecular diversity. Still,

several challenges remain before biosurfactants can become an alternative to the chemically

produced surfactants. The most important aspect is the high production cost. Biosurfactants

tend to be at least ten times more expensive than classic petroleum-based surfactants. By

creating a platform organism, this problem could be circumvented. The yeast Starmerella

bombicola is an interesting candidate to be used as platform organism. It’s widely known for

its easy production of sophorolipids and high tolerance towards other biosurfactants. Further,

sophorolipids can be considered as a good example of a biosurfactant that has been

successfully commercialized. Using an organism as a production platform requires knowledge

about gene expression. One of the aspects involved in this are promotors. Reporter proteins

can be used to screen these promotors under several circumstances. During this research, both

intra- and extracellular proteins will be used in parallel expression strategies. The intracellular

strategy relies on fluorescent proteins like Green Fluorescent Protein (GFP) and Flavin

mononucleotide (FMN)-binding fluorescent protein (FbFP). The extracellular method relies

on screening for amylase expression and activity.

50

P12 - The effect of the electron beam treatment on polymer

surface characteristics

Grubova Irina1, Surmenev Roman

1, Surmeneva Maria

1, Koval Nicolay

2, Shugurov Vladimir

2

and Selezneva Irina3

1National Research Tomsk Polytechnic University, Russian Federation 2Institute of High Current Electronics, Russian Federation

3 Institute of Cell Biophysics RAS, Russian Federation


The purpose of the study is the analysis of the possibilities of electron beam treatment of

polymer (UHMWPE with GUR4022 doping) to fabricate stable hydrophilic or hydrophobic

surfaces for cardiovascular surgery and orthopedics. The effect of different electron beam

treatment conditions on physicochemical, mechanical properties and in vitro behavior of the

polymer was investigated. The samples were modified using the accelerator «Duet» by

irradiating the polymer surface with an electron beam at the atmospheric pressure. Three

distances 2, 7 and 15 cm were used from the electron beam to the samples. Treatment time

was varied from 5 to 50 min. Material characterization before and after surface modification

was carried out by water contact angle measurements, SEM, EDAX, IR-spectroscopy,

profilometry and in vitro test. The samples after the treatment revealed a higher surface

roughness and hydrophilicity (wetting angle value less than 10 degrees) compared to non-

treated surfaces. The molecular structure was not significantly altered over a period of 1-

month after surface treatment. In vitro studies revealed that treated surfaces provided good

adhesion, spreading and proliferation activity of epithelial cells (HEP-2) and fibroblast

(NCTC clone L929) as well as the absence of cytotoxic effect. The obtained results proved

the possibility of application of electron beam treatment at the atmospheric pressure to

produce stable hydrophilic surfaces for biomedical application.

51

P13 - Evaluation of the antifungal chitinase activity of two strains

of Bacillus subtilis

Hammadeh Ibrahim, Destain Jacqueline and Thonart Philippe

University of liege, Gembloux Agro Bio Tech, Belgium


Chitin, a ß-1, 4-linked polymer of N-acetyl-D-glucosamine, is major constituent of many

fungal cell walls. Chitinases (EC 3.2.1.14) are glycosyl hydrolases1, responsible for

biological conversion of chitin. Chitinase producing organisms can inhibit fungal growth

especially plant-pathogenic fungi and possible explanation is the action of chitinases and β-

glucanases on chitin or glucan present in the fungal cell walls, acting as protective agents. For

performing this study, we prepared

- Two strains of Bacillus subtilis B130 and B 114 both produce chitinase activity when

they grow in broth media containing colloidal chitin.

- Two fungal strains penicillium expansum and Aspergillus niger

- Petri dishs containing different solid medium PDA, MRS and CAP ( chitin Agar plate)

- Crude chitinases prepared from 96 h old broth culture

The antifungal chitinase activity was investigated in three tests are, well diffusion assay,

Inhibition of fungal growth by the crude-enzyme extract and test of antagonism.

The results obtained of this study showed

* The chitinase of BS114 (5U/ml) inhibited the growth of Aspergillus Niger whatever the

culture medium, but did not inhibit the growth of Penicillium expansum on PDA medium

* The chitinase of BS130 (5U/ml) did not inhibit the growth Penicillium expansum and

Aspergillus Niger in PDA medium. However, it shows an antifungal activity on MRS and

CAP medium

* The crude enzyme showed antifungal activity only at 5U/ml

The chitinases produced by two strains inhibited the growth of A.neger and P.expansum on

PDA, wherever, the chitinase of B130 did not show any antifungal activity against P.

expansum. In test of antagonism, the two strains showed strong antifungal activity.

52

P14 - Influence of steam explosion on crystallinity properties of

pure cellulose fiber

Jacquet Nicolas1, Richel Aurore

2 and Vanderghem Caroline

1

1Ulg-GxABT – CBI, Belgium 2 Ulg-GxABT, Belgium


The aim of the present study is to compare the effect of different steam explosion treatments

on crystallinity properties of a pure bleached cellulose. Steam explosion process is composed

of two distinct stages: vapocracking and explosive decompression. The treatment intensities is

determined by a severity factor, established by a correlation between temperature process and

retention time. The results show that steam explosion treatment has an impact on the

crystallinity properties of pure cellulose fiber. When the severity factor is below 5.2, an

increase of the overall crystallinity of the samples is observed with the treatment intensities.

For higher intensities, a significant thermal degradation of cellulose lead to an important

change in substrate composition, which lead to a further decrease of cellulose crystallinity.

53

P15 - Enzymes of Oenological interest from Wine Lactic Acid

Bacteria

Jamin Guilhem, Destain Jacqueline and Thonart Philippe

ULg, Belgium


Enzymes play a key role in the wine-making process. Indeed, wine is the result of two major

enzymatic biotransformations: the alcoholic fermentation achieved by yeasts (mainly

Sacharomyces cerevisiae) and the malolactic fermentation achieved by lactic bacteria (mainly

Oenococcus oeni). Oenococcus oeni also possess other enzyme activities implicated in the

must biotransformation such as β-glucanases. Those enzymes have two major oenological

applications. First one, must and wine both contain numerous polysaccharidic compounds

from grapes and wine microorganisms. Spoilage microorganisms also produce

exopolysaccharides (β-glucans) with high viscosity. Those molecules, mainly β-glucans,

induce filter clogging. Commercial β-glucanases from Trichoderma harzianium have been

authorized in wine to hydrolyze high viscosity molecules and thus improve must clarification

and wine filtration step instead of previous expensive and partially efficient physical

treatments. Unfortunately, those enzymes often exhibit secondary unwanted activities. Second

one, β-glucanases are also implicated in the yeasts autolysis, an enzymatic phenomenon

corresponding to the release of parietal and endogenous compounds in wine by hydrolysis of

yeast cells. Yeasts’ autolysis impacts on wine composition and organoleptic properties during

aging on yeast lees. There is an increasing interest for enzymes naturally existing in wine such

as β-glucanases produced by yeasts and lactic bacteria. The purpose of the project is to

characterize endogenous β-glucanases activities from wine lactic acid bacteria, able to realize

malolactic fermentation and to understand β-glucans hydrolysis mechanisms under

oenological conditions in order to improve wine clarification and aging.

Lactic acid bacteria have been isolated from enrichment cultures using Walloon producers

wine samples as inoculums. The observation of morphological and biochemical phenotypic

characteristics gave precious indications over the taxonomic identification of those strains.

Further genetic identification by sequencing 16S RNA will give a precise detail of the

taxonomy of isolated lactic bacteria. β-glucanases activities of commercial starters, isolated

bacteria and collections strains have been assessed by classic microbiological tests on agar

supplemented with β-glucans (fig. 1). Oenococcus oeni growth has been studied by liquid

cultures in batch bioreactors using optimum media (MRS supplemented with L-malic acid

and fructose) and optimum conditions (pH and Temperature respectively maintained at 4,8

and 30°C) (fig. 2). At the end of the log-phase, the cell culture contains around 1010 cfu/ml.

The production of β-glucanases in an optimum medium supplement with yeast cell wall as

inductor does not give satisfying results. A two-step culture including a first step of culture in

optimal medium and a second step of enzymatic induction with a minimum medium

supplemented by yeast cell wall is an alternative to produce the enzymes. Production levels of

β-glucanases have been determined during the second step log phase (fig. 3). In parallel, the

malolactic activity of isolated strains has been evaluated by a rapid test under optimal

conditions (fig. 3). Lactic bacteria can only achieve conversion of L-malic acid into L-lactic

54

acid in the specific medium used. Then, the ability to achieve malolactic fermentation and to

resist to wine physiological conditions will be assessed by Long-term malolactic fermentation

trials under oenological conditions (pH ~3-3,5 & 20°C) using synthetic wine medium (12%

ethanol (v/v), 5 g/l tartaric acid). Both previously mentioned tests permitted to select the two

“best” strains, one isolated from wine samples and one from a strains’ collection, for their

ability to produce β-glucanases and to achieve malolactic fermentation.

55

P16 - Effect of Two Volatiles Organic Compounds on wheat seeds

attacked by Fusarium

Kaddes Amine, Massart Sebastien and Jijakli M.Haissam

Laboratoire de Phytopathologie, Gembloux Agro-Bio Tech, Université de Liège, Passage des Déportés 2, B-

5030 Gembloux, Belgium

Corresponding authors: [email protected], [email protected], [email protected]

Barley is threatened by various edaphic fungal diseases. Common root rot, caused by

Fusarium culmorum and Cochliobolus sativus, is one of the major fungal diseases of barley,

causing between 9 and 23 % of yield losses. Since most of chemicals used for crop protection

are being forbidden, new ways of protection are needed. In a previous study, we showed that

barley roots infected by common root rot emitted 23 VOCs that were not emitted by healthy

barley roots. Amongst these VOC, two molecules, PG001 and PG002, decreased in vitro the

growth of F. culmorum by 50% and 70% respectively.

This objective of this study was to test the phytotoxicity and the efficiency of these two VOCs

on barley and wheat grains that are infected by Fusarium. We present here the first results

obtained from wheat grains. Bioassays carried out consisted in incubating wheat seeds in test

tubes containing water agar (+ the VOC) during 20 days at 23 °C.

The phytotoxicity of PG001 and PG002 applied alone on wheat germination has been

evaluated. A delay in seed germination has been observed for both molecules. When 100% of

the seeds were germinated with the control, there were 60 % and 10% of the seeds not

germinated for PG001 and PG002, respectively. Nevertheless, all the seeds treated were

germinating two days after. A delay in seed germination is therefore observed for both

molecules.

Moreover, the ability of both VOCs to control Fusarium infection was also evaluated.

Compared to plants from untreated seeds that were 100% infected, the addition of PG001 and

PG002 allows us to obtain only 7% and 15% of infected plants, respectively.

Further studies are currently undertaken to understand the cellular and molecular mechanisms

underlying the protective action of these VOCs.

56

P17 - Development of an anaerobic, thermophilic and cellulolytic

consortium to improve anaerobic digestion of lignocellulosic

biomass.

Kinet Romain1, Delvigne Frank

1, Destain Jacqueline

1, Hiligsmann Serge

2 and Thonart Philippe

1

1ULg – GxABT, Belgium 2ULg, Belgium


A thermophilic cellulolytic microbial consortium was obtained from high temperature

compost after enrichment cultures. In a first time the hydrolysis potential was tested on two

cellulosic reference substrates. The consortium was able to hydrolyze almost all the matter

present in the medium. After these tests on pure cellulosic substrates, tests were realized on

wheat bran. An important part of the biomass was also hydrolyzed by the consortium. After,

the cellulose degradation kinetics was studied. This kinetics is similar to sigmoidal microbial

growth curve. The consortium behavior during cellulosis degradation was also considered.

Different parameters (pH, biogas and fermentation products) have been followed during an

anaerobic degradation of filter paper in thermophilic conditions. No accumulation of glucose

was observed throughout the process but an important acidification of the medium going

along with biogas production was recorded. This decrease of the pH is due to the

accumulation of acetate and others fermentation products (butyrate, ethanol, and lactate). The

accretion of this type of by-products and the very low proportion of methane detected in

biogas indicate population present in the consortium can’t effectively complete anaerobic

digestion of cellulose (methane and carbon dioxide as end products). An analysis of

populations dynamic confirm the presence of efficient cellulolytic bacteria and the absence

(or the presence in no detectable amount) of an effective methanogen population. Finally, the

use of this consortium to remove the rate-limiting step in anaerobic digestion has been

assessed. A positive impact on the methanation of cellulosic products was highlighted.

57

P18 - Developing a formulation of elicitors to control bioagressors

of wheat: which interests?

Le Mire Geraldine and Jijakli Haissam

Gembloux Agro-Bio Tech, ULg, Belgium


Crop plants are constantly exposed to a wide range of environmental stresses that can cause

major productivity loss. Fungicide treatments are the most efficient disease control methods

used up to now. However, the environmental and health issues caused by these chemicals

make it urgent to develop safer methods for pathogen control. In the optic of a sustainable

agriculture, several biocontrol tools have been developed during the last decades. Elicitors are

increasingly subject to research as interesting alternatives to phytosanitary products. Yet, few

efficient formulations exist on the market, and no product has been designed specifically to

protect wheat crops. This study will thus focus on the the manipulation of host natural

defenses through the use of elicitors as a preventive treatment against major wheat diseases

such as Septoria tritici, Fusarium graminearum and Fusarium culmorum.

58

P19 - Screening of essential oils on rice pathogens isolated in

Madagascar

Mamiharisoa Razanakoto Léa1, Parisi Olivier

1, Massart Sébastien

1, De Clerck

Caroline1, Rabemanantsoa Christian

2, El Jaziri Mondher

3, Rakotozandrindrainy Raphaël

4

and Jijakli M Haïssam1

1Plant Pathology Unit, Gembloux Agro-Bio Tech, ULg, Belgium 2Institut Malgache de Recherche Appliquée, Madagascar

3Laboratory of vegetable Biotechnology, ULB, Belgium 4Ecole Supérieur des Sciences Agronomiques, Université d'Antananarivo, Madagascar

Corresponding authors: [email protected], [email protected], [email protected]

Four predominant isolated pathogens have been identified during survey of rice diseases in

three regions in Madagascar. These pathogens were the bacteria Xanthomonas oryzae pv.

oryzae and Pseudomonas fuscovaginae and the fungi Alternaria sp. and Curvularia lunata.

These pathogens are causing significant yield reduction on rice, which is the staple food in

this country. After the identification of those pathogens, the objective of this work was to

identify appropriate control measures against them.

Plants extracts has been traditionally used to control diseases in other plant species.

Nowadays, the problem of residues of phytopharmaceutical product, reinforce the need for

research on the development of natural plant extracts to control plant diseases. Madagascar

has many endemic plant of interest and we have evaluated the antimicrobial properties of

essential oils from Malagasy plants.

The main object of this study is the in-vitro screening of essential oils to control the pathogens

isolated on rice in Madagascar. Thirty nine essentials oils from Madagascar had been tested.

Activity of essentials oils on Pseudomonas fuscovaginae, Alternaria sp. and Curvularia lunata

had been tested using broth media and on agar medium for Xanthomonas oryzae pv. oryzae.

The growth of the pathogen (bacteria and conidia) in the presence of the essential oil was

evaluated and compared to a control. Nine of the 39 essentials oils showed interesting

antimicrobial activity with an efficiency more than 70% against at least one bacterial

pathogen. One essential oil inhibited the growth of the two pathogens tested. For fungal

pathogens, three essential oils presented an efficiency of more than 70% against at least one

fungal pathogen.

These results confirm that some essential oils present an interesting antimicrobial activity.

The in-situ confirmation on plant of this activity is currently ongoing.

59

P20 - Filamentous fungi (Trichoderma harzianum) behaviour in

biofilm culture for 6-pentyl-α-pyrone production us secondary

metabolite with coconut like aroma

Musoni Michel1, Telek Samuel

1, Zune Quentin

1, Destain Jacqueline

1, Fauconnier Marie-Laure

1,

Bahama Jean-Baptiste2, Thonart Philippe

1 and Delvigne Frank

1

1Liège University, Belgium 2Burundi University, Burundi


This study examines the production of the 6-pentyl-α-pyrone (6-PP), a compound which has a

strong coconut-like aroma, from Trichoderma spp. species in biofilm bioreactors. It gives the

aspect of fungus on inert support and in the liquid. The dextrose and castor oil were used as

carbon source when culture are conducted in flask bioreactor, and only oil in stirred

bioreactor, with castor oil being considered a precursor in lactones bioconversion processes.

The study point out that the aromatic compound is mainly produced when culture are

conducted in flask or in biofilm bioreactor. The biomass produced in the bioreactor is

immobilized on the inert support or at the wall in the flask without support. Microscopic

observations give three forms, filament (dispersed mycelia), pellets, and conidia. While, the

image analysis done with tomography suggest the surface colonization inside packing. The

analysis applies to the volatile compound using GC/FID reveals the production of the

compound, the concentration of the product was ranged from 0.22 g/l to 7.1 g/l.

It appears from the analysis that the system of producing the volatile using the biofilm

bioreactor leads to significant to increase of the production.

60

P21 - Impacts of organic matter type and biostimulant products

on the growth of wheat and the microbial communities of its

rhizosphere under contrasted production systems

Nguyen Minh Luan1, Bodson Bernard

1, Ongena Marc

1, Colinet Gilles

1, Vandenbol Micheline

1,

Spaepen Stijn2, Jijakli Haïssam

1, du Jardin Patrick

1 and Delaplace Pierre

1

1Gembloux Agro-Bio Tech (GxABT), University of Liège, Belgium 2Centre of Microbial and Plant Genetics, KU Leuven


[email protected], [email protected], [email protected], [email protected],

[email protected], [email protected]

Plant growth-promoting rhizobacteria (PGPR) formulations are one of the main biostimulant

classes due to their capacity to enhance root growth, mineral availability, and nutrient use

efficiency in crop rhizosphere. PGPR-containing biostimulants should, therefore, reduce

demand for chemical fertilizer and lessen their negative environmental impacts. The aim of

this project is to screen PGPR strains to (1) enhance wheat fitness level (growth,

photosynthesis efficiency, stress tolerance, and yield) in combination with an optimized

fertilizer level, (2) stimulate the increase in beneficial microorganism communities and

suppress pathogenic ones in the wheat rhizosphere, (3) link wheat productivity to the

composition of the microbial communities found in its rhizosphere, and (4) measure the

impacts of such changes on soil fertility. In order to assess changes in the rhizomicrobial

communities including fungi and bacteria (either pathogenic, neutral, or beneficial) under

controlled or field conditions, metagenomic approaches will be set up. Several levels of

nitrogen/ phosphorus supply will be tested to optimize agricultural practices and achieve the

highest yield. A soil analysis protocols will also be built up to measure the influence of those

PGPR strains on soil fertility changes and root uptake efficiency. Finally, a maximum of three

promising PGPR strains will be selected for practical agronomical application in the field

trials.

61

P22 - Susceptibility of avian pathogenic Escherichia coli from

laying hens in Belgium to antibiotics and disinfectants and

integron prevalence

Oosterik Leon, Peeters Laura and Butaye Patrick

CODA-CERVA, Belgium


Avian pathogenic Escherichia coli (APEC) cause huge annual losses in the poultry industry

worldwide. APEC from broilers are becoming increasingly resistant however, little is known

about strains from laying hens, where the use of antibiotics is limited. Also on the presence of

resistance against disinfectants, little is known. Ninety-seven APEC strains were isolated from

Belgian laying hens. Antimicrobial resistance was determined, as well as minimum inhibitory

concentrations (MIC) and minimum bactericidal concentrations (MBC) of five disinfectants

most often used in the poultry industry. The presence of integrons was determined by PCR.

Only resistance to ampicillin (35.1%), nalidixic acid (36.1%), sulfonamide (41.2%) and

tetracycline (53.6%) was high. The MIC of the disinfectants for the APEC strains showed a

Gaussian distribution, indicating that there was no acquired resistance. MBCs were similar to

MICs via the broth dilution method, showing the bactericidal effect of the disinfectants.

Twenty strains (20.6%) were found positive for integron type 1.

Susceptibility of APEC strains from laying hens to antibiotics is substantial but not as high as

reported for strains of broilers. Phenotypic resistance to commonly used disinfectants could

not be found, indicating that the current use of disinfectants in the laying hen industry did not

select for resistance.

62

P23 - Optimization of the methane production from Mangifera

Indica and Manihot Utilissima leaves in co-digestion

Philippe Mambanzulua Ngoma1, Serge Hiligsmann

1, Eric Sumbu Zola

2 and Philippe Thonart

1

1Gembloux Agro- Bio Tech, University of Liège, Belgium 2University of Kinshasa, The Democratic Republic of the Congo


Leaves of Mangifera Indica (MI, mango leaves) and Manihot Utilissima (MU, cassava leaves)

are available in tropical regions and are the most accessible vegetable waste of Kinshasa

Province, capital of the Democratic Republic of Congo. The main objective of this study was

to investigate the optimization of methane production from MI and MU leaves in co-digestion

by BMP tests at 30°C. The yields achieved from the anaerobic digestion of up to 61.3 g raw

matters in 1 l medium were 0.001 l/g and 0.100 l CH4/g volatile solids of MI and MU leaves

respectively.

By comparison to MI, MU leaves are generally characterized by a higher mineral content. The

total organic carbon and the total Kjeldahl nitrogen related to MU were slightly lower and 6-

fold higher respectively than the corresponding levels in MI. Therefore, the carbon to nitrogen

ratio C/N, i.e. about 7, was significantly different regarding the range from 20 to 30

commonly recommended for optimal anaerobic digestion. The reason why, MU and MI

leaves were mixed for correcting their C/N ratios.

Therefore, leaves yields of methane production in relation to volatile solids were improved.

The MU and MI yields in the mixture of MU (75%) and MI (25%) have increased; they were

0,380 l/g and 0,120 l CH4/g volatile solids respectively or nearly 3-fold higher and nearly

100-fold higher respectively than the corresponding leaves in the isolated digestion.

63

P24 - Interactions of a potential plant elicitor mannolipid with

plant model membranes

Polo Lozano Damien, Nasir Mehmet Naïl, Lins Laurence, Ongena Marc, Deleu Magali,

Fauconnier Marie-Laure and Jijakli Mohamed Haïssam

Gembloux Agro-Bio Tech - University of Liège, Belgium


The use of chemical pesticides causes problems for human health and environment. In this

context, there is an increasing interest for alternative products such as biopesticides. Among

them, elicitors act on the plants by inducing systemic resistance against diseases caused by

fungal, viral, bacterial agents and insects.

The target of the elicitors is supposed to be the plant plasma membranes (PPM). The main

mechanisms of interaction of many elicitors involve proteic receptors but lipid-based elicitors

(LBE) may preferably interact with the lipidic fractions of PPM. However there is no detailed

information at the molecular level on the PPM-LBE interactions.

Our work is focused on a original synthetic LBE composed of a mannoside linked to a

myristic acid. It has potential elicitor activities as shown by the assays on tobacco root cells.

These activities could be related to its interaction with the lipidic phase of PPM. Since PPM

are complex entities, the analyses of the PPM- molecule interactions are quite difficult. In this

context, these interactions were carried out using biomimetic membranes of PPM such as

Langmuir monolayers and multilayers. The effects of our molecule on these membranar

systems were investigated by biophysical and in silico approaches.

64

P25 - Kinetic resolution of lactid acid esters in heptane or in a

solvent free system

Richard Gaetan1, Nott Katherine

1, Nicks François

1, Paquot Michel

2, Blecker Christophe

3 and

Fauconnier Marie Laure1

1ULg - GxABT – CGO, Belgium 2ULg - GxABT - CBI

3ULg - GxABT – TIAA


Poly(lactic acid) (PLA) is a green plastic [1] of growing interest due to its mechanical

properties, its thermoprocessibility and its biological properties, such as biocompatibility and

biodegradability [2]. PLA is synthesized by polymerization of lactic acid (LA) obtained itself

by fermentation of carbohydrates such as corn or sugar cane starch [3]. However, PLA shows

interesting properties only if either L-LA or D-LA is used as starting material, hence, the need

of methods for the resolution of LA enantiomers.

Lipases are well-known biocatalysts described to catalyse the kinetic resolution of racemics

through acylation of primary or secondary alcohols. As enzymatic catalyst, they present the

advantage of working in mild conditions in comparison to chemical catalysts. But the

resolution efficiency of such a reaction is highly dependent on the lipase and the structure of

the reactants (both acyl donor and acceptor) implemented. This consequently requires a large

screening.

The aim of the present work was to develop a method for the resolution of lactic acid ester in

the presence of a lipase. In a first time, several enzymes and various acyl donors were

screened to determine the best catalyst and reactants. Once done, the reaction conditions

(reactants concentration, enzyme loading and temperature) were optimized. Finally, an

efficient and fast resolution of lactic acid ester was achieved [4].

[1] K. Ishimoto, M. Arimoto, H. Ohara, S. Kobayashi, M. Ishii, K. Morita, H. Yamashita, N.

Yabuuchi Biomacromolecules 2009, 10, 2719-2723

[2] B. Gupta, N. Revagade, J. Hilborn Progress in Polymer Science 2007, 32, 455-482

[3] R. Auras, B. Harte, S. Selke Macromolecular Bioscience 2004, 4, 835-864

[4] G. Richard, K. Nott, F. Nicks, M. Paquot, C. Blecker, M.L. Fauconnier Journal of

Molecular Catalysis B: Enzymatic 2013, 97, 289-296

65

P26 - Screening of two agricultural genomic DNA libraries to seek

new glycoside hydrolases

Stroobants Aurore, Portetelle Daniel and Vandenbol Micheline

ULg, Belgium


Soils are very rich environments where the diversity of microorganisms is very high. These

microorganisms play an important role in the degradation of organic matter with enzymes

able to degrade it. This work aims to discover, by functional screening, new microbial

glycoside hydrolases from soils collected in winter and spring in a winter wheat crop. The

genomic DNA was extracted from both soils to construct two libraries in Escherichia coli.

These libraries were then screened for beta-glucosidase activities on 2YT agar media

containing 0.5% esculin and 0.1% ammonium iron (III) citrate. At this time, about 250.000

clones from each library have been screened. Two beta-glucosidases have already been found

in the winter library while five beta-glucosidases and two glycosyltransferases were identified

in the spring library. Sequence analyses with the BLASTX program revealed putative

enzymes showing between 25% and 72% sequence identity with known enzymes and

belonging to three glycoside hydrolase families (GH1, GH3 and GH20) and to two probably

new glycosyltransferase families. Biochemical characterisation of the candidates at several pH

values and temperatures, and with four substrates, is in progress.

66

P27 - Role of exopolysaccharide excretion on Bifidobacterium

bifidum survival after heat stress

Thanh Nguyen1, Delvigne Frank

1, Thonart Philippe

1, N’yapo Charles

1 and Razafindralambo

Hary2

1Université de Liège, Gembloux Agro-Bio Tech, Unité de Bio-industries/CWBI, Belgium 2Université de Liège, Gembloux Agro-Bio Tech, Unité de Science des aliments et formulation


Exposure of Bifidobacterium bifidum THT 0101 cells, a stress sensitive probiotic bacteria, to

sub-lethal stresses is known to increase cell viability in to downstream processing operations

by the exopolysaccharide excretion in the scale-down reactor system. However, this

phenomenon is still not well characterized when cells will expose to heat shock stress during

stationary phase. In this work, scale-up reactors in which microbial cells are stochastically

exposed to sub-lethal temperature stresses in the stationary phase and fluctuating heat shock

temperature have been used in order to investigate the response of Bifidobacterium bifidum

THT 0101 to downstream processing operations. The scale-up reactor system (SUR) from the

200 (ml) to 200 (Liters) allows the exposure of microbial cells to sub-lethal temperature of

42°C for 1 hour in the stationary phase and the fluctuating regime temperature (37°C - 42°C).

This exposure resulted in a significant increase of cell resistance to freeze-drying (viability)

by comparison with cells cultivated in before and after stress (4-7 times more). The

mechanism behind this robustness seems to be related with the coating of microbial cells with

exopolysaccharide. In future, this technique will be applied to the industrial scale since this

strategy can be directly implemented in large-scale bioreactor during stationary phase

preceding cell recovery and freeze-drying and long-term conservation.

67

P28 - Molecular understanding of factors important for probiotic

lactobacilli outside the gut

van den Broek Marianne, Claes Ingmar, Petrova Mariya, Van Ham Leen and Lebeer Sarah

Universiteit Antwerpen, Belgium


Although Lactobacillus spp. are especially known for gastrointestinal applications, they are

also present in other mucosal niches of the human body including the skin, the

oronasopharynx and the urogenital tract, albeit in different numbers. Therefore, it is

interesting to investigate whether the same molecular framework to identify important

characteristics of gastro-intestinal probiotics can be translated to other niches. In agreement

with the main modes of action of beneficial gut probiotics, lactobacilli could also promote

health in other niches by (1) having antimicrobial actions against important pathogens, (3)

strengthening the mucosal barrier function; and (3) modulating host immunity. This PhD

work aims to optimize a molecular in vitro platform to identify factors important for probiotic

action in other niches. Hereby, the activity of lactobacilli against a panel of typical pathogens

is screened. In addition, the interaction with epithelial cell lines relevant for the various niches

in the human body is studied. Furthermore, important adaptation and probiotic factors of

lactobacilli are investigated by the phenotypic analyses of knock-out mutants in these assays.

68

P29 - Diatom silica-titania materials for photocatalytic air

purification

Van Eynde Erik1, Blust Ronny

2 and Lenaerts Silvia

1

1Universiteit Antwerpen, Belgium 2Systemic Physiological and Ecotoxicological Research, Universiteit Antwerpen, Belgium


Photocatalysis by porous silica supported titania materials is a promising technology for the

degradation of air pollutants. The present generation of photocatalysts possesses several

limitations and drawbacks: (1) inadequate immobilisation of the catalyst, (2) insufficient

activity of the photocatalyst and (3) environmentally burdening production process. There is

thus an urgent need for novel materials and production methods to overcome these issues.

Immobilisation of titanium dioxide by metabolic incorporation in the diatom silica skeleton

can deliver a proper solution for the aforementioned problems.

Controlled cultivation of the diatom Pinnularia sp. on soluble titanium in a fed-batch process

resulted in the metabolic incorporation of titanium dioxide in the porous 3D architecture of

the frustules. The chemical and physical resemblance between Si(OH)4 and Ti(OH)4 caused

titanium to act as a competitive inhibitor, displacing silicon in the metabolic reactions and

frustule formation. The as produced silica-titania material is evaluated towards photocatalytic

activity for acetaldehyde (C2H4O) abatement.

69

P30 - Effects of dietary α-lipoic-acid on feed intake and

hypothalamic AMPK activity of young broiler chicks

Wang Yufeng1, Franssens Lies

1, Koppenol Astrid

1, Lesuisse Jens

1, Willems Els

1, Decuypere

Eddy1, Everaert Nadia

2 and Buyse Johan

1

1KU Leuven, Department of Biosystems, Laboratory of Livestock Physiology, Belgium 2University of Liège, Gembloux Agro-Bio Tech, Animal Science Unit, Belgium


AMP-activated protein kinase (AMPK) is an evolutionarily conserved cellular energy sensor.

In the present study 0, 0.05% or 0.1% dietary α-lipoic-acid (α-LA), a central AMPK inhibitor

in mammals, was provided to young broiler chicks for 7 days. As a result, α-LA exerted an

anorexic effect which was due to the alteration in satiety but not taste aversion. However, the

curtailed feed intake induced by α-LA disappeared by the 7th supplementation day. After 7

days of treatment, hypothalamic AMPKα1 mRNA level was significantly decreased by the

dietary α-LA in concert with the reduced abundance of total AMPKα protein. The

phosphorylated AMPKα was also potently decreased, resulting in an unaltered

phosphorylation/non-phosphorylation ratio. In addition, hypothalamic corticotropin releasing

hormone (CRH) mRNA levels were enhanced by α-LA. Interestingly, the mRNA expressions

of hypothalamic orexigenic agouti-related peptide (AgRP) and neuropeptide Y (NPY) were

up-regulated, while the anorexigenic proopiomelanocortin (POMC) and its transcription

regulator hypoxia-inducible factor-1α (HIF 1α) were down-regulated, probably as a

physiological reaction in order to counteract the changed energy balance.

In conclusion, dietary α-LA decreased feed intake in broiler chicks. The anorexic effect was

due to the reduced hypothalamic phosphorylated AMPKα as reflected in decreased mRNA

and protein levels. However the anorexic effect of α-LA was progressively diminished after 7

days of treatment, likely by the physiological counteractive feedback via changing

neuropeptides related to energy balance.

70

SUSTAINABLE PRODUCTION

71

P1 - Impact of tillage systems and working depth on the

agronomic behavior of a biological potato crop

Khaoula Abrougui1, Hassina Hafida Boukhalfa

2, Meriem Nemri

3 and Sayed Chehaibi

1

1 Higher Institute of Agronomy, Tunisia 2 University Mohamed Khider- Biskra, Algeria

3 University of Liège, Gembloux Agro-Bio Tech, Belgium


Soil compaction and erosion are key factors limiting potato yield and quality. This study

evaluated the effects of tillage systems on the agronomic behavior of biological potato crop

(Solanum tuberosum L.) on a sandy loam soil (8.8% Clay, 61.8% Loam, 29% Sand) in the

Higher Institute of Agronomy (Sousse, Tunisia). Three different techniques were studied:

minimum tillage with discs harrow, medium tillage using discs plow and conventional deep

tillage with moldboard ploughing. Tillage was followed by a first resumption after 10 days

and a second one after 20 days. Emergence rate, fresh and dry weights of aerial and

underground parts of the plants and tubers yield were studied and compared for reduced,

medium and conventional tillage systems. The best results were obtained under conventional

deep tillage with highest values of emergence rate, fresh and dry weights of aerial and

underground parts and tubers yield of potato crop.

72

P2 - Effect of encapsulated nanoparticles on thermophillic

anaerobic digestion

Alaaeddin Al-Ahmad

CWBI, Belgium


Increased demand and progressive depletion of fossil fuels, and worldwide concerns about

greenhouse gas emissions have resulted in the development of promising technologies for

renewable energy production. Therefore, potential alternatives for energy generation are

intensively studied. One option is the use of biomass feedstock for the production of biogas

through anaerobic digestion. This process is a biochemical technological process for the

treatment of a wide range of feedstocks (e.g. organic fraction of municipal waste, animal

manure and slurry, agricultural crops, etc.) to produce methane-rich biogas which can be used

in replacement of fossil fuels in both heat and power generation and as a vehicle fuel.

However, there are critical issues, which need to be addressed to make the production of bio-

methane techno-economically viable and ecologically acceptable. One of the most important

issues is the effect of trace metals addition on anaerobic digestion. These metals can be

stimulatory, inhibitory, or even toxic for biochemical reactions, depending on their

concentrations. As reported in literature, Ni, Co and Fe are all involved in the methane

production biochemical process and serve as cofactors in enzymes which are involved in the

biochemistry of methane formation (Zandvoort et al., 2006).

Recently, enormous interest has been focused on biological applications of metal

nanoparticles NPs due to their small size, high specified surface and their great potential in

application to many science fields. The most studied process concerns zero valent palladium

and iron NPs improving anaerobic biodegradation of chlorinated hydrocarbons (Windt et al.,

2005). Moreover, investigation carried out in our lab showed that iron NPs encapsulated in

silicate matrix may enhance hydrogen production by Clostridium butyricum (Beckers et al.,

2013). Nevertheless the influences of metal NPs on methane producing anaerobic digestion

have seldom been investigated.

The present work investigates the enhancement effect of seven different metal NPs on

methane production during the thermophilic anaerobic digestion. NPs of Cu, Pd, Pt, Ni, Co,

Ag and Fe encapsulated in porous silica (SiO2) to prevent their coagulation and

agglomeration, were added at concentration of 10-5mol/L in batch test (125ml serum bottles

containing 70mL culture medium with 5g/L acetate monohydrate as the sole carbon

substrate).

Nickel, cobalt and iron NPs improved methane production from acetate. To confirm the

previous results, the NPs were tested at different concentrations (10-4, 10-5, and 10-6 mol/L)

with starch and glucose substrates. The results show that the impact increases with the

increase of NPs concentrations up to 10-4 mol/L. The modified Gompertz equation was

applied to describe the effect of NPs on anaerobic digestion. According to this model, the

kinetic of methane production was particularly affected by nanoparticles addition. The values

of the maximum methane production rate MPR (ml/day) was significantly higher 72.5% with

nickel NPs at a concentration of 10-4 mol/L than the control without NPs.

73

P3 - A diachronic analysis of the dynamic of two cities: Kisangani

and Lubumbashi (Democratic Republic of Congo). How do the

extension and/or of the densification of these cities impact the

urban internal and peripheral ecosystems?

Marie André1, Grégory Mahy

1, Philippe Lejeune

2 and Jan Bogaert

1

1 University of Liège, Gembloux Agro-Bio Tech, Unité Biodiversité et Paysage, Belgium 2 University of Liège, Gembloux Agro-Bio Tech, Unité de Gestion des ressources forestières et des milieux

naturels, Belgium


The dynamics of two cities between two years (2002 and 2010 for Kisangani; 2002 and 2008

for Lubumbashi, both part of the Democratic Republic of Congo) have been examined in

order to estimate how their extension and/or of the densification have impacted the urban

internal and peripheral ecosystems.

This study singularizes itself from the subjective ones by its quantified and objective approach

based on landscape ecology. This discipline assumes that the landscape pattern description is

important because, according to its central hypothesis called “pattern-process paradigm”, the

ecological processes influence landscape structure and vice versa. Composition metrics,

which are commonly used in landscape ecology, describe the pattern among other things in

quantifying the presence and the number of patches from the various classes within the

landscape.

For each city two SPOT 5 images were classified with a oriented-object supervised approach;

then built area proportion index, a composition landscape metric, has been evaluated in order

to 1) identify the extent of each area (urban, suburban, rural) within the urban-rural gradient,

2) quantify the dynamic of the different areas in the urban-rural gradient during the last

decade and 3) quantify the effect of a decade of urban and suburban growth on ecosystems.

The similarities and differences between these cities, relevance and gaps in the method have

then been identified and discussed.

74

P4 - Analyzing relationships between cattle grazing behavior and

pasture attributes using the inertial measurement unit of a mobile

phone.

Andriamasinoro L. Herinaina Andriamandroso1, Jérôme Bindelle

2 and Fréderic Lebeau

3

1 University of Liège, Gembloux Agro-Bio Tech, Agriculture Is Life, Belgium 2 University of Liège, Gembloux Agro-Bio Tech, Animal Science Unit, Belgium

3 University of Liège, Gembloux Agro-Bio Tech, Mechanics and Construction Unit, Belgium


The recent technological developments are boosting the opportunities of accurate method to

monitor resource use efficiency in agriculture and in their wake, precision livestock farming

(PLF) has experienced huge developments over the past decade. These developments focus on

the optimization of individual performances of farm animals as opposed to herd management.

The aim of this paper is to explore a method to detect accurately and to analyze changes in

cattle's behaviors on pasture during grazing time using signals from the inertial measurement

unit (IMU) of mobile devices as a possible tool to manage individual grazing behavior.

Commercial iPhones or iPods, which include a 3-axis accelerometer, a gyroscope and a GPS

sensor, are fitted on a halter and placed on the neck of grazing cows. The acquired IMU data

are recovered using an open source application (Sensor Data, Wavefrontlabs) and analyzed in

a “white-box” model of the cows’ movements. First results using time-domain analysis

allowed the detection of grazing behaviors showed accuracies ranging between 84% and 96%,

attesting the relevancy of the method. Refined signal processing method will improve the

detection but will also inform more about the relative link between the behaviors and the

pasture attributes such as sward height, composition and nutritive value.

75

P5 - Estimating daily yield of major fatty acids from single

milking

Valerie Arnould1, Romain Reding

1, Charles Delvaux

1, Jeanne Bormann

2, Alain Gillon

3, Carlo

Bertozzi3, Nicolas Gengler

4 and Hélène Soyeurt

4

1 CONVIS s.c., Luxembourg 2 ASTA, Luxembourg

3 AWE a.s.b.l., Belgium 4 University of Liège, Gembloux Agro-Bio Tech, Belgium


Reducing the frequency of milk recording and the number of recorded samples per test-day

could be a solution in order to reduce costs of official milk recording. However, fewer

samples lead to a decrease in the accuracy of predicted daily yields. Unfortunately, the current

published equations use the milking interval that is often not available and/or reliable in

practice. The first objective of this study was to propose models using easily available traits.

Therefore the milking interval was replaced by a combination of data easily recorded by milk

recording. The second objective of this study was to enlarge the previous investigations to

milk fatty acids (FA) in order to propose a practical method for estimating accurate daily

milk, fat and major FA yields from single milking. The fit goodness of proposed models was

evaluated based on the correlation values between the estimated and observed daily yields in

addition to the calculation of the mean square error. Obtained results are promising.

Correlation values were comprised between 96.4% and 97.6% when daily yield were

estimated from morning milking, and from 96.9% to 98.3% when daily yield were est imated

from evening milking. The combination of records related to lactation stage, month of test,

milk yield, and fat could replace the milking interval effect. Because of their simplicity,

proposed models would be easy to implement.

76

P6 - How much light is a tree allowed to take from a crop?

Sidonie Artru, Ludivine Lassois and Sarah Garré

University of Liège, Gembloux Agro-Bio Tech, Belgium Corresponding author: [email protected]

Modern agriculture faces a range of challenges, which are partly due to the strong

intensification of production during the past decades. Currently, agroforestry is often

proposed to improve regulating, social and cultural ecosystem services of the agricultural

landscape. Agroforestry research is in full expansion. Nevertheless, uncertainty remains about

the performance of combinations of species at different sites and at different stages of growth.

In Belgium, climate, cultural practices and literature suggest that light might be the principal

tree/crop competitiveness resource in an agroforestry context. In fact, in every agroforestry

system, the tree canopy reduces the incident radiation for crop. Responses induced by this

stress condition may converge toward a systematic reduction of crop final yield. However, the

behavior of wheat to the shade is highly dependent on environmental conditions, including

climate and soil. Therefore, we the presented project will study in detail the effect of shading

degree and timing on wheat.

We will monitore wheat productivity and development on the fields of the experimental farm

of Gembloux Agro-Bio Tech during 3 subsequent years under artificial shade conditions. We

designed an artificial shade structure to mimics the light environment observed under a tree in

an agroforestry context. This means periodic fluctuation in radiation transmittance and

discontinuous light quantity. The aim of this work is to evaluate the influence of light

availability and the efficiency with which this radiation is converted into wheat dry matter

under artificial shade treatment.

77

P7 - Rhizobacterial volatile organic compounds implication in

Brachypodium distachyon response to phosphorus deficiency

Caroline Baudson, Magdalena Saunier de Cazenave, Patrick du Jardin and Pierre Delaplace

University of Liège, Gembloux Agro-Bio Tech, Plant Biology Unit, Belgium


In agriculture, phosphorus (P) is considered as the second most growth-limiting macronutrient

after nitrogen. However, P fertilizers are produced from non-renewable resources. In this

context, sustainable production strategies have to be developed to enhance P use efficiency of

crops, e.g. based on naturally occurring biotic interactions that limit the negative impacts of P

deficiency in soils. Plant growth-promoting rhizobacteria (PGPR) have already revealed their

ability to promote plant growth and tolerance to abiotic stresses through many mechanisms.

Among them, the bacterial volatile organic compounds-mediated communication between

plants and PGPR is still poorly documented. Our research project aims at studying the

capacity of a model cereal plant (Brachypodium distachyon (L.) Beauv. Bd21) to face P

deficiency in interaction with PGPR. The prerequisite of this project consists in characterizing

Bd21 response to P deficiency by measuring plant biomass production and allocation, root

system architecture, total phosphorus content, root-secreted and intracellular acid phosphatase

activity under various P concentrations. Those results will allow us to define P-limiting

conditions, in order to assess PGPR volatiles influence on plant response to P deficiency. This

approach will use an ex-vitro co-cultivation system allowing volatiles-mediated interaction

and should help us to unravel the ability of rhizobacterial volatiles to enhance plant tolerance

to P deficiency.

78

P8 - Pivot ramps irrigation constraints in southern Algeria

Hassina Hafida Boukhalfa1, Khaoula Abrougui

2 and Meriem Nemri

3

1 Université Mohamed khider Biskra, Algeria 2 Higher Institute of Agronomy, University of Sousse. Department of Horticultural Systems Engineering, 4042

Chott Meriem, Tunisia 3 University of Liège, Gembloux Agro-Bio Tech, Belgium


Irrigation by pivot ramp in southern Algeria allows the evaporation of 40 % of the volume of

irrigation water under the influence of high temperatures, low humidity and very frequent

winds . This is also due to the very fine size of water droplets and the distance between the

nozzle and the target that must go through the droplet.

This loss increases the salt concentration of the amount of water reaching the ground.

What is the salinity after each irrigation? How many do we add after each watering? And

what is the lethal dose?

The operating principle of the pivot required for each span a running time and a stop time. In

a water tower pivot, the first bay waters while it is in motion for only the 1/8 time in the water

tower and continues to water on site with the same speed and the same pressure during the 7/8

time. What we have to recognize as a loss: the water increasingly scarce, the electrical energy

or soil degradation under the influence of overwatering?

79

P9 - Contribution of splashing drops in spray retention by barley

leaves

Hassina Hafida Boukhalfa1, Mathieu Massinon

2, Mohamed Belhamra


2

1 Université Mohamed Khider Biskré, Algeria 2 University of Liège, Gembloux Agro-Bio Tech, Belgium


Drop behaviour during impact affects retention. The increase of adhesion is usually seen as

the objective when applying crop protection products, while bouncing and shattering are seen

as detrimental to spray retention. However, observation of drop impacts using high speed

shadowgraphy shows that fragmentation can occur in Wenzel wetting regime. In this case, a

part of the drop sticks on the surface, what contributes to retention. Using simultaneous

measurements of drop impacts with high speed imaging and of retention with fluorometry for

3 spray mixtures on excised barley leaves allowed us to observe that about 50% of the drops

fragmented in Wenzel state remain on the leaf. Depending on spray mixture, these impact

outcomes accounted for 25 to 50% of retention, the higher contribution being correlated with

bigger VMD (Volume Median Diameter). This contribution is non-negligible and should be

considered when a modelling of spray retention process is performed.

80

P10 - Coupling shadowgraphy and spectrofluorometry to measure

spray retention

Hassina Hafida Boukhalfa1, Mathieu Massinon

2, Mohamed Belhamra


2

1 Université Mohamed Khider Biskré, Algeria 2 University of Liège, Gembloux Agro-Bio Tech, Belgium


Study of spray retention should take into account target surface properties and impact

behaviour. The aim of this experiment is to combine simultaneously conventional method

based on the dosage of a tracer to quantify retention, and imaging method focusing on droplet

behaviour during impact to gain the individual contribution of each droplet impact on

effective retention.

Measurements were performed with a high-speed camera coupled with a retro-LED lighting.

Size and velocity of the drops were extracted by image analysis. Drops impact types were

determined by the operator. Sprays were produced with a flat-fan nozzle Teejet 11003

mounted on a movable ramp at the speed of 2m/s. Two surfactants (Break-Thru® S240 and

Li700®) were sprayed on BBCH 12 excised barley leaves(0,3cm²) and compared to water

spray. Relative volume proportions were computed within of an energy scale.

After spraying, leaves samples were washed in a buffer solution for quantifyingthe amount of

fluorescent tracer and so the effective volume of spray mixture retained by leaf surface.

Coupling of these two approaches offers a thorough understanding of how the various impact

outcomes contribute to spray retention by a leaf and how adjuvant acts on droplet impact.

81

P11 - Impact of agricultural practices on bacterial and fungal

communities in soil

Florine Degrune1, Bernard Taminiau

2, Carine Nezer

3, Georges Daube

2, Marc Dufrêne

4 and

Micheline Vandenbol1

1 University of Liège, Gembloux Agro-Bio Tech, Microbiology and Genomics Unit, Belgium 2 University of Liège, Food Microbiology Unit, Belgium

3 Quality Partner s.a., Belgium 4 University of Liège, Gembloux Agro-Bio Tech, Unité Biodiversité et Paysage, Belgium


The use of fertilizers in agricultural soils is becoming a real environmental issue (an obvious

example is eutrophication caused by leaching of phosphorus and nitrates). Much research has

focused on finding ways to reduce the use of chemicals, and investigating microbial life may

lead to solutions. We know that bacteria and fungi are deeply involved in nutrient cycles.

Recently the emergence of massive parallel sequencing has enabled us to realize that

microbial diversity is huger than we expected. With such a tool it should be possible to study

how soil management practices affect the microbial diversity of agricultural soils. A few such

studies have been conducted, most of them focusing on bacteria. For Belgium in particular,

there is a lack of data on this topic. Here the aim was to see how residue management and

tillage practices affect communities of both bacteria and fungi in Belgian agricultural soils.

For this we used 454 pyrosequencing of 16S bacterial and 28S fungal rRNA genes. Soil

samples came from an experiment in which faba beans were grown with four soil

management practices (tillage and no tillage, with and without crop residues), each repeated

four times in a Latin square. Several chemical and physical characteristics were measured on

each sample. The experiment is ongoing and results will be presented at the meeting.

82

P12 - Quantitative gas chromatography - mass spectrometry

profiling of volatile organic compounds produced by barley

(Hordeum distichon L.) roots according to plant age

Benjamin M. Delory1,3

, Pierre Delaplace1, Patrick du Jardin

1 and Marie-Laure Fauconnier

2

1 University of Liège, Gembloux Agro-Bio Tech, Plant Biology Unit, Belgium 2 University of Liège, Gembloux Agro-Bio Tech, General and Organic Chemistry Unit, Belgium

3 National Fund for Scientific Research, Bruxelles, Belgium


In chemical ecology, the roles played by root-emitted volatile organic compounds (VOCs) in

biotic interactions and the quantitative analysis of such chemicals in root tissues remain

poorly documented. In this context, this study aims at developing a fully automated analytical

methodology allowing both identification and accurate quantification of VOCs produced by

roots of a monocotyledon plant species. Briefly, VOC emitted by crushed barley roots are

successively trapped by dynamic headspace sampling on Tenax TA adsorbents, thermally

desorbed and cryofocused, separated by gas chromatography (GC) and finally analysed by

mass spectrometry (MS) in both SCAN and selected ion monitoring modes. Results show that

barley roots mainly produce four volatile aldehydes, namely hexanal, (E)-hex-2-enal, (E)-non-

2-enal and (E,Z)-nona-2,6-dienal. These molecules are well-known linoleic (C18:2) and

linolenic (C18:3) acid derivatives produced via the lipoxygenase and the hydroperoxide lyase

pathways of higher plants. Our findings contrast with analyses documented on aboveground

barley tissues that mainly emit C6 aldehydes, alcohols and their derivative esters. Moreover,

preliminary results indicate quantitative changes in the volatile profile contained in barley

roots according to plant age. Multivariate statistical analyses are currently underway to

quantitatively assess these changes using plants at five selected developmental stages ranging

from germination to the end of tillering.

83

P13 - Old inks: pigments extracted from plants

Jessica Despy1, Noémie Wymeersch

1, Isabelle Bouchat

1, Caroline Destree

1, Anne Burette

2,

Aurore Richel3 and Gilles Olive

1

1 Ecole Industrielle et Commerciale de la Ville de Namur, Belgium 2 Abbaye de Villers-la-Ville ASBL, Belgium

3 University of Liège, Gembloux Agro-Bio Tech, Unit of Biological and Industrial Chemistry, Belgium


Thousands of years ago, natural pigments were discovered and they have been used ever

since. Indeed, prehistoric people already used them to paint the walls of the caves in which

they were living. A significant example of this is the Cosquer cave (-19,000 to -27,000 years)

located near Marseilles.

Pigments and dyes can be classified into two broad categories and five families: natural

pigments and dyes and those called artificial. The first one of these five families includes the

mineral pigments. Among these we can find the clays (yellow ochre, red ochre, green clay,

brown clay) and the stones like lapis lazuli (blue). The second and third families gather the

organic dyes and pigments. Those that have vegetal origins like indigo (blue) and madder

(red) compose the second family and those that have animal origins like cochineal (red) and

kermes dyers (carmine) form the third family. One family includes pigments and dyes

stemming from chemical reactions such as verdigris or red lead (family 4) and the other one is

made of the miscellaneous inks such as iron-gall type who are vegetal and mineral one

(family 5).

All these pigments, although they have been used for centuries, have been replaced by

synthetic dyes from the oil industry at the end of the 19th century. Indeed, they have the

advantage of reproducibility of the properties unlike natural pigments. But the scarcity of oil

causes a renewed interest in natural preparations. We report the extraction of pigments from

plants.

84

P14 - Impact of abiotic stresses on volatile organic compound

production of field crops

Anthony Digrado1, Ahsan Mozaffar

2, Aurélie Bachy

2, Niels Schoon

3, Crist Amelynck

3, Marie-

Laure Fauconnier4, Marc Aubinet

2, Bernard Heinesch

2, Patrick du Jardin

1 and Pierre

Delaplace1

1 University of Liège, Gembloux Agro-Bio-Tech, Plant Biology Unit, Belgium 2 University of Liège, Gembloux Agro-Bio-Tech, Biosystems Physics Unit, Belgium

3 Belgian Institute for Space Aeronomy, Belgium 4 University of Liège, Gembloux Agro-Bio-Tech, General and Organic Chemistry Unit, Belgium


Abiotic and biotic stresses are known to alter biogenic volatile organic compounds (BVOCs)

emission from plants. These BVOCs are involved in a wide range of interactions of plants

with their environment and play a key role in the atmospheric chemistry. Yet, there are few

studies examining the impact of stresses on BVOCs emission at the ecosystem scale.

In the CROSTVOC (for CROp STress VOC) project, the impact of abiotic stresses (e.g. heat,

drought, O3 and mechanical damage) on BVOCs emission will be investigated for field crops

(maize, wheat and grassland) while biotic stresses will be monitored and controlled only. For

that purpose, measurements will be made both at the ecosystem and plant scales. BVOCs

fluxes will be measured by an on-line proton-transfer-reaction mass-spectrometer both in the

field and in growth chamber and complemented by eddy-covariance measurements in field.

BVOCs identification will be achieved through an off-line gas-chromatography mass

spectrometer coupled with dynamic headspace sampling. The stress level experienced by the

ecosystems will be monitored weekly based on environmental, non-destructive (i.e.

chlorophyll fluorescence and content ; stomatal conductance) and destructive physiological

measurements (i.e. antioxidant measurements) in order to identify stress episodes. This

ecophysiological dataset will be linked to BVOCs fluxes to define environmental conditions

responsible for altered BVOCs emissions and to reproduce them in growth chamber.

85

P15 - Soil seed bank: a poorly know component of forest

regeneration.

Chauvelin Douh1, Kasso Daïnou

1, Jean Joël Loumeto

2, Adeline Fayolle

1 and Jean-Louis Doucet

1

1 Université de Liège, Gembloux Agro Bio Tech, Belgium 2 Université Marien NGOUABI, Congo

Corresponding author : [email protected]

The resilience of African forest ecosystems to disturbances is poorly known. The ability of

tropical forests to recover their original aspect depends on regeneration dynamics. As

observed in other vegetation types, the soil seed bank could play a fundamental role in the

regeneration dynamics of tropical forests. Therefore, knowledge on seed bank characteristics

may help to assess forest dynamics and develop strategies to improve forest recovery after

disturbances. Unfortunately, as claimed by many authors, the literature review we have

produced related to tropical forest seed banks proved that seed bank does not receive enough

attention from African scientists. Thus the aim of our research is to improve our knowledge

on the role of soil seed bank in the resilience of Central African forests in particular. Our

project emphasizes three aims: (1) assessing the extent to which the standing vegetation

contributes to the formation of the soil seed bank, (2) understanding the relative contributions

of both seed rain and seed bank to the regeneration of the forest, and (3) testing dormancy of

various seeds through burial experiments. We think that the achievement of our project will

provide valuable information on mechanisms that act to the forest recovery.

86

P16 - Use of GC-MS in SIM-Scan mode for a selective

quantitation of pollutant volatile organic compounds (VOC) in

food industries

Pierre Patrick Eloundou Mballa, Bérénice Dethier and Marie-Laure Fauconnier



The control of atmospheric emission discharges by food industries is classically achieved in

two phases. The first one consists of sampling the target atmosphere followed by

concentrating the volatile organic compounds (VOC) contained in a defined volume of this

atmosphere on an adsorbing agent. These compounds are then thermally desorbed (TD) or

desorbed with a solvent. In the second phase, the gas phase chromatograph (GC) will be

coupled with mass spectrometry (MS) or flame ionization detector (FID) for compounds

analysis. Quantitative analysis (without identification) are usually achieved with solvent

desorption followed by GC-FID. This mode imposes the dilution of the sample by a solvent

and consequently may cause high detection thresholds as well as important matrix effect and

possible interferences due to chemical reactions between analytes and the solvent. Besides, a

preliminary qualitative analysis (GC-MS identification) is necessary.

Combining TD-GC-MS allows very low detection thresholds to be reached, and the matrix

effect and the interferences caused by products of the reactions between analytes and the

solvent to be eliminated. The use of this combination in selected ion monitoring (SIM) mode

allows targeting analytes via their characteristic ions, increasing their sensitivity and

repeatability insuring more accuracy for simultaneous qualitative and quantitative analysis.

This technique was experimented for seeking VOC in the atmosphere around food industries.

87

P17 - Use of Near Infrared Hyperspectral Imaging (NIR-HSI) to

discriminate wheat roots and straws in soil

Damien Eylenbosch1, Juan Antonio Fernandez Pierna

2, Vincent Baeten

2 and Bernard Bodson

1

1 University of Liège, Gembloux Agro-Bio Tech, Belgium 2 Walloon Agricultural Research Centre (CRA-W), Belgium


In agricultural research, studying the effect of tillage in agriculture, quantification of roots and

straw residues in each soil horizons is very interesting and should allow monitoring the

development of root systems and the decomposition of crop residues. Current quantification

methods need to wash the soil cores to extract these elements, then to manually separate and

to weight them. These methods are time consuming and completely dependent of the operator.

The use of Near Infrared (NIR) combined with Hyperspectral Imaging has been proposed in

this study in order to cope with such problems. This technique provides simultaneously

spectral and spatial information and allows predictions based on infrared spectra of each pixel

of the image, spectra which are directly linked to chemical nature of elements. Main

advantages of such technique are the non-destructive analyses, the rapidity, the ease of use

and the possibility of online prediction.

The first step before quantification is to detect the presence of the different elements in a

sample of soil. This step needs the development of spectral libraries containing spectra of

each element. These libraries will be used to build chemometric discrimination models that

should allow, for future samples, discriminate the elements only according to their NIR

spectra.

In this work, particular interest is put in the discrimination of wheat roots and straws in soil. A

library including thousands of spectra from soil samples, wheat roots and straw has been built.

After washing, drying and sorting of these elements, they were spread, without grinding, on

the conveyor belt installed at a NIR hyperspectral line scan camera. The chemometric tool,

Principal Component Analysis (PCA), was then used to choose, amongst the spectra, those

which were most representative of the diversity in order to create, for each element, a matrix

incorporating the maximum variability. This matrix has then used to build a Partial Least

Squares Discriminant Analysis (PLS-DA) model to make clear distinction between the spectra

of background, soil, wheat roots and straw.

In order to quantify these elements in a sample of soil, further research has to be done to rely

the number of pixels detected, on the NIR images, as belonging to a certain element, to the

corresponding weight of this element in the sample.

88

P18 - Agroecology: a framework to rethink academic research in

agriculture

Séverin Hatt, Sidonie Artru, Fanny Boeraeve, David Brédart, Florine Degrune, Marce Dufrêne,

Pierre Stassart, Sarah Garré, Micheline Vandenbol, Ludivine Lassois and Frédéric Francis



Critics are rising about conventional farming and its consequences on biodiversity, human

health and society. As alternatives, new farming concepts have been proposed.

Agroecology was born in applying knowledge of ecology to the agricultural production. This

led to the development of more ecological practices favoring biodiversity and ecosystem

services at multiple scales. However, Agroecology went further in considering that the

agricultural production is integrated in a global food system. This latter one takes into account

the socio-economical and political dimensions to develop new production systems to assure

food security worldwide while preserving resources for future generations.

Facing these ambitious objectives, academics are invited to develop new approaches such as

the participatory and the multidisciplinary approach.

AgricultureIsLife is a research platform built up in Gembloux AgroBio-Tech. 18 junior

researchers, from social sciences, agronomy, ecology, soil sciences, physics, genetics,

biochemistry and immunology, were already working closely together in 2013 in a

multidisciplinary approach. The platform has also the ambition to discuss its results to a large

comity gathering the actors of the agricultural development.

The aim of our work is thus to present how Agrocology is an interesting framework to

develop solutions to conventional farming limits. The concept of the research platform

AgricultureIsLife will be discussed within this framework.

89

P19 - Impact of cover crop management on crop production: a

field experiment in Wallonia context.

Marie-Pierre Hiel and Bernard Bodson



Minimal soil tillage methods, crop rotation, cover crop and continuous plant residue cover are

the main pillars of sustainable agriculture. Lower energy consumption, costs and time are

some direct benefit in favor to the adaptation of this agriculture. This practices aims also

directly at protecting the soil from wind and water erosion by covering the soil. Lower

disruption of the soil aims at developping the micro- and macro-fauna activity that increases

soil fertility and carbon and nitrogen sequestration in soils. Unfortunately, some of the great

constraints to the adaptation of conservation agriculture remain weed management, fungal

diseases and pest management, that has been shown to be a problem in non-ploughed fields.

The aim of our study is to evaluate, on a same field (Wallonia context), contrasted tillage

methods for managing the cover crop and the implantation of the following main crop. On the

experimental field, four tillage methods are tested (Latin square design). Two commonly used

conventional practices were selected: (i) winter ploughing and (ii) spring ploughing to destroy

the cover crop as well as two reduced tillage practices: (iii) a decompaction before implanting

the cover crop, the cover crop is destroyed by frost (or chemical intervention if needed), the

main crop is implanted with just a shallow tillage and (iv) the strip till in which only the

sowing line is tilled. In 2013, first year of this experiment, the cultivated crop was sugar beet

implanted after a cover crop composed of oats and peas. The following measurements were

taken: germination rate, root and shoot biomass development, root notation (size and shape),

leaf area index and quality of harvested product.

Preliminary results indicate that the different tillage methods did not have a significant impact

on crop production or development. However changes in germination dynamics were

observed, the reduced tillage inducing slower germination. Regarding weeds populations,

some difference were observed in weed occurrences. No plant diseases were observed during

the experiment, most probably due to a favorable climate for sugar beet production.

Since a field experiment rely on weather and one the continuous adaptation of soils, we will

continue for further years.

90

P20 - Plasmon activated photocatalysts for soot degradation

Maarten Keulemans and Silvia Lenaerts

University of Antwerp, Belgium Corresponding author: [email protected]

Every year, approximately 2000 kiloton of particulate matter is emitted in Europe, of which a

large contribution is delivered by combustion processes. One of the main constituents of

particulate matter is soot, which consists of finely dispersed carbon particles, hydrocarbons

and tar formed by incomplete fuel combustion.

Current soot concentrations in the atmosphere keep posing a considerable threat to human

health and environment. Therefore, new strategies are necessary to alleviate the damaging

impact of soot emissions. In this regard, photocatalysis is a very promising technique. The

photocatalytic process is based on the light-induced generation of electron-hole pairs in the

photocatalyst, which drives the reduction and oxidation reactions of pollutants. Commonly,

UV-light has to be used to induce this process. Although the photocatalytic soot degradation

has already been shown under UV-light[1], it would be far more interesting to have a working

photocatalyst under visible light.

The goal of this research is therefore to synthesize a visible light active TiO2 photocatalyst

that can be used for soot degradation. An attempt to achieve this visible light activity will be

made by modifying the TiO2 photocatalyst with plasmonic noble metal alloy nanoparticles.

This way, a more energy efficient process can be obtained.

[1]Smits M., Chan kit C., Tytgat T., Craeye B., Costarramone N., Lacombo S., Lenaerts S.,

Chemical Engineering Journal 222 (2013) 441-418.

91

P21 - Introduction of new species of fodder shrubs in Manombo

(Southern part of Madagascar): The importance of

endomycorrhizae symbiosis

Razafimandimby Lanto Andriantsara1, Jerôme Bindelle

1 and Rado Rasolomampianina

2

1 University of Liège, Gembloux Agro-bio Tech, Belgium 2 CNRE, Madagascar


In the Southern part of Madagascar (Manombo) where malnutrition and poverty prevail, small

ruminant breeding is promoted. Consequently, new species of fodder shrubs were introduced

among farmers to feed livestock such as : Leucaena leucocephala (Lam), L. pallida Britton et

Rose, L. diversifolia (Schlecht) Benth, Cajanus cajan (L.) Druce, and Morus alba L. To

enhance the adaptation of those perennial forage species, the development of a favourable

consortium of soil microorganisms, especially endomycorrhizae is an option. With this

respect, the first step is to characterize existing consortiums in situ. In order to achieve this, a

visual and gravimetric method has been used on forages shrubs implanted since 2010 on an

experimental plot. This method based on color and membrane conformation of spores

revealed that 5 types of spores have been identified under the introduced species of forage

shrubs. an inegal repartition. Some types dominate (type I, II, III) while others remain in very

low proportion (type IV, V). In addition, fodder shrubs promoted spores in the soil as well as

the emergence of a new type (type IV) in comparison with non planted soils . The structure of

the communities has been compared using the Shannon-Wiener (H') and Simpson (D) indices.

This preliminary determination the general structure of the fungal community and their

impact of shrubs growth have still to be further detailed using a.o. molecular characterization

techniques.

92

P22 - The role of bacterial endotoxins in airborne particulate

matter

Serena Moretti, Eline Oerlemans and Sarah Lebeer

Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen,

Belgium


With the expanding awareness of health-threatening concentrations of air pollutants, the

European Commission has declared 2013 as the year of air. A complex mixture of air-

suspended particles known as particulate matter (PM) is known to affect more people than

any other pollutant, and can be associated with e.g. asthma exacerbations and heart and

vascular diseases. The World Health Organization estimates that PM air pollution contributes

to approximately 1.3 million premature deaths each year, ranking it the 13th leading cause of

mortality worldwide. Belgium and Flanders are unfortunately important hotspots for traffic-

related air pollution, with particulate air pollution in Belgium being one of the highest of

Western Europe. In 2004, 5.5% of all deaths in cities such as Antwerp were attributable to

PM10 concentrations exceeding European standards (Remy et al., 2011).

Mechanistic studies indicate that many of the observed health effects are related to the

capacity of inhaled PM to induce airway inflammation, for which various factors can be

attributed, including its (a) physicochemical characteristics; (b) its capacity to elicit oxidative

stress; (c) and the capacity of PM to act as vectors for pro-inflammatory microbiological

compounds such as bacterial endotoxins (lipopolysaccharides- LPS) (Frampton, 2006). There

is conflicting evidence in the literature as to the predominant mechanisms and also the

compositional element(s) that drive the inflammatory response of ambient PM. In addition,

the presence of bacteria and bacterial derived products in airborne PM has not yet been

systemically studied. This study therefore investigates the role of endotoxins in PM samples

collected within Flanders. Detailed mechanistic studies in cell models are used to investigate

the relative pro-inflammatory capacity of different PM components (with special attention to

endotoxins, metals and polycyclic aromatic hydrocarbons), their associated immune receptors

and response genes, and their possible synergistic effects with other toxic PM components.

Preliminary results indicate that the presence of endotoxins and the pro-inflammatory capacity

of the airborne samples do not always correlate with the measured PM10 concentrations at

these sites (VMM). This highlights that it is important that current regulations not only

monitor not the PM concentrations and size, but also the pro-inflammatory capacity of its

components.

93

P23 - Impact of GLOBALG.A.P. and Organic Certifications on

farmers health : case of Tunisia

Meriem Nemri



As food products export from Tunisia targets almost the European market, which regulations

are becoming stricter due to the emergence of food-borne outbreak problems, export standards

like GLOBALGAP and Organic Farming Certifications are required to Tunisians producers

and exporters. These standards are primarily designed to guarantee a safe food production

process, minimising harmful environmental impacts of farming operations, reducing the use

of chemical inputs and ensuring a responsible approach to worker health, safety and welfare.

So the purpose of this study is to determinate the impact of GLOBALG.A.P. and Organic

Certifications on farmers health. A survey was carried out at July-August 2013, in 5 Tunisians

public health organizations, also in the major dates and tomatoes areas of Gabes South district

of Tunisia. A sample of 70 farms, randomly selected and interviewed through a questionnaire,

was taken and stratified in two kind of farmers: 30 certified and 40 uncertified farmers.

Preliminaries results of this study shows that since certified, Tunisians producers use less

chemical pollutants especially pesticides (compliance with MRL), which absolutely have

positive effects on their health and safety and even their families also. In fact, uncertified

interviewed farmers confirm that they have many problems like water point pollution, field

accidents due to contact with chemicals products, and especially pest resistance. These results

were confirmed by Tunisian ministry of public health witch affirm that field accidents are

decreasing by 30% since 2007.

Finally, adopting certifications and respecting standards can lead to improvement in

agricultural efficiency, tending towards more sustainable production.

94

P24 - Paints based on renewable materials

Gilles Olive and Aurore Richel

University of Liège, Gembloux Agro-Bio Tech, Unit of Biological and Industrial Chemistry, Belgium Corresponding author: [email protected]

Paints, at the coating meaning, are known since a long time. Typically, paint is a dispersion of

one or more powders (pigments and fillers) in a macromolecular substance ("resin"), called

film-forming material, diluted in solvents.

Pigments are solid particles, used to give opacity and/or color. Today almost all pigments

have a synthetic origin. The fillers are often natural compounds. Unlike pigments, fillers have

low opacity and are colorless. These very cheap products achieve the required solid content

under satisfactory economic conditions.

Resins used in paints have the property of forming a continuous solid (hard or flexible) film

under specific conditions. They are often called “resins”. They can be solid or liquid at room

temperature. The solvents are used to control the viscosity of the paint in order to facilitate its

production and application. The solvents used are volatile compounds.

Additives are minor compounds (a few percent), whose function is to either promote or

prevent some developments of the product. For example, surfactants improve the

homogeneity of the dispersion. Some additives protect the film against mold or ultraviolet

radiation, or against the formation of free radicals under the action of sunlight.

Since the end of the 18th century most of those paints are petroleum-based. But the near

disappearance of the petroleum causes a renewed interest in bio-based preparations. In this

communication, we present an overview of bio-based alternatives.

95

P25 - An attempt to optimize spray retention on black grass leaves

using a shielded rotary atomizer

Sofiene Ouled Taleb Salah, Mathieu Massinon, Bruno Schiffers and Frederic Lebeau



Controlled Droplet Application using rotary atomizer results in better control of droplet size

and trajectory comparatively to hydraulic nozzles. On recent literature, it was stated that using

60° forward angled spray combined with the narrow drop size distribution of a rotary

atomizer could lead to low drift and high retention on monocotyledonous and

superhydrophobic weeds at early stage. A Micromax120 rotary atomizer, equipped with a

shield to capture spray outside the 120° spray opening, was set to emit 270 µm VMD, 60°

angled forward in order to increase interception by the canopy structure of black grass. This

device was benchmarked to a Teejet XR11002 and a Hardi anti-drift nozzle which are of

widespread use in early stage weed control. A superspreader adjuvant Break Thru S-240 was

added to spray mixture to avoid drop bouncing. An increase of spray retention comparatively

to a Teejet 11002 and the anti-drift nozzle was observed, although not proved statistically

significant for the Teejet. On the drift side, the tilted rotary atomizer seemed to be

advantageous since droplet size distribution contains a low percentage of droplets under 100

µm and presents an ejection velocity of 25 m.s-1 at 5000 RPM. The drift was reduced about

50% compared to the Teejet. However, these setting were not found as efficient as expected

since the Micromax produce more drift than the anti-drift nozzle. Indeed, angled spray proved

to be more sensitive to advection and turbulence, as the spray was more exposed to the

airflow than for the vertical position. It appears that angling the spray and choosing drops as

big as 270 µm is not sufficient to reduce significantly this issue. Some alternatives as

decreasing the emission height are possible with angled sprays but require height control that

seems difficult to reach in practical situations.

96

P26 - Soil infrastructure evolution and its effect on water transfer

processes under contrasted tillage systems

Nargish Parvin and Aurore Degré



The heterogeneity of soil has high spatial variability in soil structure and porosity and this

diverse nature of soil is highly influenced by external factors like tillage systems and other

land management approaches. To understand the changes in soil architecture and structural

evolution under different tillage systems we need to recognize the conditions in these systems

that affect soil hydrological behavior and consequently nutrient losses, microbial activities

and water availability for crop production. The aim of this project is to investigate the effect

of soil tillage along with residue management on the changing pattern of soil structure. This

investigation will help to emphasize the different water flow pattern especially the preferential

flow processes through the soil profile that are influenced by the changes in soil structural

distribution in the soil profile. Mostly the preferential flow of water is addressed at the pore

scale but this study will focus on soil structure along with soil moisture dynamic at aggregate

scale or more specifically at pedon scale. The experimentation has been started from June

2013 in the research field known as Solcouvert (objects: strip-till versus winter ploughing)

and Solresidus (objects: no-till with organic matter restitution versus no-till without organic

matter restitution). Soil profile description has been done in the four objects of land

management. Soil sampling has been done in different depths of soil according to the soil

profile description. Soil samples will be used for the measurement of water retention curve,

hydraulic conductivity and x-ray microtomography. In addition there will be soil moisture

sensors (Decagon 10HS, 5TM and ML3 Thetaprobe) in the field under four different trials.

The soils from the different trials and also from different depths (0-15, 25-30 and 50-60 cm)

were calibrated with the sensors. The calibration results were significantly (p<0.05) different

between Solcouvert and Solresidus and there was also significant (p<0.05) difference among

depths of same field especially between 0-15 and 50-60 cm. To capture the dynamic of soil

moisture the moisture sensors will be in the field in the beginning of winter untill spring 2014.

All the experiment will be repeated twice a year. For the specific spatio-temporal comparison,

the monitoring results from electrical resistance tomography will be available from the

collaborated project of the same faculty.

97

P27 - Lignin as a raw material for industrial materials

applications

Aurore Richel, Caroline Vanderghem, Mario Aguedo and Nicolas Jacquet

University of Liège, Belgium


Native lignin is an abundant biopolymer on earth and represents 15-30% by weight of the

lignocellulosic biomass. Lignin is a heterogeneous cross-linked polymer composed of

phenylpropane units linked together by a panel of specific ether or carbon-carbon bonds.

Nowadays, large amounts of lignins and lignin-based wastes are available and originate either

from the pulp and paper manufacturing or from the production of bioethanol from

lignocellulose. Typically, these lignins are dedicated to energetic purposes by combustion. In

recent years however, novel axes for high added value applications have emerged and

concern, notably, the use of lignin as performance products or specialty chemicals for

materials applications.

Herein, several applications of lignin in materials sciences with industrial issues are

presented. A correlation is established between the extraction processes from lignocellulosic

materials and the chemical structure and physico-chemical properties of lignins. Our research

group has also developed new methodologies for the extraction of highly pure lignins from

several starting materials, including food wastes, herbaceous raw materials and wood

biomass. These methodologies are described in this presentation.

98

P28 - Development of an ex-vitro system allowing plant-bacteria

interactions through VOCs in the context of water stress

Magdalena Saunier de Cazenave, Caroline Baudson, Benjamin M. Delory, Patrick du Jardin

and Pierre Delaplace

University of Liège, Gembloux Agro-Bio Tech, Plant Biology Unit, Belgium


Water stress is one of the major environmental factors limiting the productivity of crops. Plant

stress responses are very complex and drought tolerance may be linked to the presence of

specific microorganisms in the rhizosphere. Indeed, some plant growth promoting bacteria

(PGPR) strains have been found to improve plant growth under abiotic stresses. Among the

many mechanisms by which those PGPR can support plant growth, the emission of volatile

organic compounds (VOCs) and their biological impact are still under study.

The aim of this work is to evaluate the interaction between the model grass Brachypodium

distachyon (Bd21) and two strains of PGPR. The impact of volatile emission on Bd21 growth

was studied using an ex-vitro cocultivation system without physical contact between plant and

bacteria during 10 days. This peculiar system was developed to assess bacterial VOCs

impacts on plants under realistic growth and stress conditions. In parallel, the response of

Bd21 seedlings to water deficit induced by polyethylene glycol 6000 (PEG 6000) was studied

to establish contrasted growth conditions regarding water availability.

The first results show that the VOCs emitted by both strains promote total biomass

production, modulate biomass partitioning and affect root system architecture of

Brachypodium. Regarding water stress, the identification of stress-inducing water potential

values is in progress.

99

P29 - Airborne microorganisms for the biodegradation of air

pollutants

Wenke Smets1, Serena Moretti

2, Siegfried Denys

1 and Sarah Lebeer

1

1 University of Antwerp, Belgium 2 University of the Free State, South Africa


Over the past decades, outdoor air pollution has become a serious problem worldwide,

causing at least 1.3 million premature deaths annually. Even though measures such as

catalytic filters and motor adaptations have induced an overall emission decrease in Europe, it

is not enough: the ambient air remains polluted and health problems due to air pollution

persist. This calls for alternative strategies to combat air pollution. In this project, a novel

approach is explored: the potential application of airborne microorganisms to degrade specific

air pollutants in ambient air. Airborne microbes are considered for two reasons. Because

research on atmospheric microbiology is still in its infancy compared to other niches, many

species, genes and reactions are still to be discovered and described among airborne microbes.

However, many indications point toward a great diversity and potential of these airborne

microbes. Furthermore, these microbes continuously come in contact with air pollutants and

so they may have developed suitable mechanisms for the biodegradation of the considered

pollutants. Airborne microbes were sampled using a Coriolis®µ air sampler at locations with

high traffic density. Microorganisms that grow under selective conditions (i.e. presence of air

pollutants) will be identified and tested for their biodegradation efficiency.

100

P30 - Plasma catalysis: the integration of a photocatalytic coating

in a corona discharge unit

Karen Van Wesenbeeck, Birger Hauchecorne and Silvia Lenaerts

University of Antwerp, Belgium


The use of corona discharge (CD) in an electrostatic precipitator offers a unique way to

remove pollutants from indoor air. There are, however, some disadvantages, like the

formation of by-products and the occurrence of irreversible deposition on the collector

surface, resulting in a declined removal efficiency. Applying a photocatalytic coating on the

collector electrode, to obtain plasma catalysis, can resolve the disadvantages.

Before combining photocatalysis and CD, an optimal window of operation for the plasma

reactor must be determined. This window will then be used to study possible adverse effects

of the coating on the overall efficiency.

The plasma reactor is configured as a conventional wire-to-cylinder type with a set of pinpairs

equally distributed on the discharge electrode. The conversion of NO and ethylene is used as

case study to confirm the activity of the plasma. To obtain an optimal window of operation,

the polarity, applied voltage, relative humidity (RH) and configuration were studied. To

determine the influence of the coating on the plasma efficiency, a coating is prepared based

on the P25 powder modified sol-gel method. By applying this coating on the collector

electrode, it was possible to see its influence on the performance of the plasma system,

operating in the previously found optimal window. The coating does not have a significant

influence on the conversion efficiency of the reactor.

With this study, we have illustrated that the implementation of a photocatalytic coating within

an corona discharge reactor, also referred to as plasma catalysis, has high potential as an

integrated and sustainable indoor air purification technology.

101

P31 - Is the behavior of grazing cattle influenced by the presence

of a hedge in the pasture?

Sophie Vandermeulen1, Emile Yando

1, Christian Marche

2, Carlos Ramirez-Restrepo

3 and

Jérôme Bindelle1

1 University of Liège, Gembloux Agro-Bio Tech, Animal Science Unit, Belgium 2 Centre de Technologies Agronomiques, Belgium

3 CSIRO, Australia


The interest in using shrubs and trees as forage for cattle is raising in temperate regions, along

with the environmental measures promoting hedges along pasture. This study aimed at

determining the influence of the presence of a woody hedge on grazing cattle behavior as well

as the evolution of this behavior during the grazing season.

Twelve heifers were set to graze a standard ryegrass and clover meadow during the grazing

season of 2013. The animals were divided in 2 groups : one with a free access to a hedge

composed by 10 temperate shrub and tree species, the other with no access to a hedge

(control). Their behavior (grazing, browsing and other activities) was monitored during 14h d-

1 replicated 3d week-1 during 3 periods (May, July and September).

Results suggest that both season and presence of a hedge have an influence on the behavior of

heifers. Grazing, resting and rumination varied between the two groups in each period

(P<0.05). The time spent browsing was influenced by the season (P<0.001); the heifers with

an access to the hedge could browse 19.3% of the total time in May against 5.9 and 5.4% in

July and September. Both control and experimental heifers grazed more with the progressing

season, but the animals without the hedge grazed always more than the heifers that could

graze and browse (49.6 vs 43.0%).

In conclusion, browsing woody species represents a significant part of the time spent for

forage ingestion, and variation in this behavior over the whole grazing season requires to

investigate the influence of both pasture and browse availability and composition.

102

P32 - Testing the stability of a ZSM-5 catalyst under biomass fast

pyrolysis conditions

Guray Yildiz, Frederik Ronsse and Wolter Prins

Universiteit Gent, Belgium


Fast pyrolysis is a thermochemical process that contributes to the conversion of biomass into

a variety of fuels and chemicals. It is defined as the rapid thermal decomposition of matter in

absence of oxygen and followed by a quick condensation of the generated vapours. The target

of this process is to produce a liquid mixture of organic molecules that is called pyrolysis oil

or bio-oil, and which can be used as feed for fuels and chemicals production. The objective of

the research carried out is to validate a fully controlled, semi-continuously operated pyrolysis

set-up (PYReactor) and to investigate the effects of a repeatedly regenerated ZSM-5 catalyst

(in total, eight regeneration cycles) on the yields and compositions of the pyrolysis products in

relationship with the applied process conditions. The experimental reproducibility of the setup

has been checked by repetition of several non-catalytic and in situ experiments under identical

conditions. The changes in the performance of the continuously regenerated catalyst has been

observed via detailed bio-oil (2D-GC/MS, Karl-Fischer analysis, total acid number), non-

condensable gases (micro-GC) and carbonaceous solids (elemental analyzer, BET SA)

analyses. The main observation was that the catalyst partially loses its activity along the

regeneration sequence due to catalyst poisoning by ash components and the degradation of the

physical and the chemical structure of the catalyst during several regeneration cycles.

103

FEED, FOOD AND HUMAN HEALTH

104

P1 - Angiotensin-Converting Enzyme Inhibitory Effects by Plant

Phenolic Compounds

Al Shukor Nadin, Van Camp John, Gonzales Gerard Bryan, Staljanssens Dorien, Struijs Karin,

Zotti Moises, Raes Katleen and Smagghe Guy

Gent University, Belgium


A wide range of phenolic compounds belonging to different classes and subclasses with a

potency to inhibit angiotensin converting enzyme (ACE) were investigated in vitro. Structure-

activity relationship analysis and molecular docking were used to understand the key

structural elements influencing ACE inhibitory activity.

Tannic acid showed the highest activity with an IC50 value of 0.23 mM. In the class of

phenolic acids, both hydroxybenzoic and hydroxycinnamic acids resulted in ACE inhibition

with IC50 values ranging from 2 to 9.3 mM. The IC50 values obtained for flavonoids ranged

from 0.41 to 1.4 mM with quercetin, kaempferol and rutin being the most active ones. Our

structure-activity relashionship analysis showed that the numbers of hydroxyl groups on the

benzene ring play an important role for activity of phenolic compounds, and that substitution

of hydroxyl groups by methoxy groups decreased activity. Docking studies indicated that

phenolic acids and flavonoids inhibit ACE via interaction with the zinc ion in the active site.

Other compounds such as resveratrol and pyrogallol may inhibit ACE via interactions with

amino acids at the active site and thereby blocking the catalytic activity of ACE. These

structure-function relationships are useful to design new ACE inhibitors based on phenolic

compounds.

105

P2 - Effect of sun-drying on flavonoid composition and

antioxidant activity of three dark fig varieties

Bachir Bey Mostapha1, Richard Gaëtan

2, Fauconnier Marie-Laure

2 and Louaileche Hayette

1

1Universty of Bejaia, Algeria 2Gembloux Agro bio-Tech, Belgium


The aim of the study was to investigate the effect of sun-drying on individual flavonoid and

antioxidant activities of three dark fig varieties (Azenjar, Bouankik, and Aberkane).

Flavonoid compounds were identified and quantified using high-performance liquid

chromatography. Antioxidant capacity of fig samples was evaluated by DPPH (1,1-Diphenyl-

2-picrylhydrazyl) radical scavenging activity and β-carotene bleaching assay. The results

showed that all samples significantly differed in their flavonoid composition. The analysed fig

varieties had high quercetin 3-glucoside and rutin concentrations but contain moderate levels

of catechin, epicatechin, and quercetin. The sun-drying effect dramatically decreased all

analysed flavonoid except epicatechin which significantly enhanced after drying. Good

antioxidant activities were expressed by the fig varieties before drying. The antiradical

activities of fig varieties were about 80 mg gallic acid equivalent/100g of dry mater and can

protect the degradation of β-carotene with 24%. After drying these activities were

considerably decreased for both activities with an average of 32%. The elaboration of dried

fig using sun-drying method affects dramatically the flavonoid composition and antioxidant

activity of dark fig.

106

P3 - Effect of wheat bran fiber components on intestinal mucosal

barrier function in the weaned piglet

Chen Hong1, Michiels Joris

1, De Smet Stefaan

1 and Chen Daiwen

2

1UGent, Belgium 2Sichuan Agricultural University, China


[email protected]

The objective was to determine the effects of the major fiber components in wheat bran on

intestinal mucosal barrier function in the piglet model. Thirty weaned piglets were assigned to

5 dietary treatments and each treatment was replicated in 2 pens of 3 pigs each. The piglets

were fed synthetic diets, including one basal diet without fiber components (CON) and four

fibrous diets, i.e. wheat bran diet (WB, 10% wheat bran), arabinoxylan diet (AX, amount of

arabinoxylan equivalent to that in WB), cellulose diet (CEL, amount of cellulose equivalent to

that in WB) and combination diet (CB, amount of arabinoxylan and cellulose equivalent to

that in WB). Feeds and water were available ad libitum for 30 d. At the distal small intestine,

pigs fed WB had an elevated number of goblet cells per villus and a higher ratio of villus

height to crypt depth compared to CON. However, lower active transport was observed in the

WB group. Supplemental AX reduced intestinal permeability (HRP as macromolecular

marker) compared to CON. The pH in caecum, except for CEL group, was higher for pigs fed

fibrous diets as compared to CON. Concomittant, higher acetate, propionate and total SCFA

and lower BCFA concentrations were observed in pigs fed AX and higher propionate,

butyrate and total SCFA concentrations in pigs fed CB as compared to CON. In the mid-

colon, a higher goblet cell number per villus occurred for pigs fed AX diet. A reduction in

colonic permeability and an increase in propionate and total SCFA concentrations was found

when pigs were fed the AX and CB diet. These results confirmed that arabinoxylan, not

cellulose, is responsible for this effect, probably by improving intestinal barrier function,

increasing the number of goblet cells and SCFA, especially in the hindgut.

107

P4 - Can phytoestrogen-rich plants restore the image of livestock

products in terms of human health?

Daems Frédéric1, Jasselette Christophe

1, Lognay Georges

2, Romnee Jean-Michel

1 and

Froidmont Eric1

1Walloon Agricultural Research Center, Belgium 2University of Liège-Gembloux Agro-Bio Tech, Belgium


In a project entitled PhytoHealth, analytical methods are being developed for studying the

impact of a phytoestrogen-rich diet on the ‘health value’ of animal products. Despite the

ambiguous image surrounding phytoestrogens, some of their metabolites appear to have

potentially beneficial effects on human health. In an original study, a microbial metabolite

(equol) was selected and its metabolism in dairy cows is being studied. A new method using

UPLC®-MS/MS technology was validated and applied to screening the equol content of milk

consumed in Wallonia. Equol was found in all milk samples analyzed and a significant

difference among farming methods was revealed. A second analytical method to quantify

equol precursors was then developed and a study of forage plants consumed by dairy cows in

Belgium will be conducted in order to select the richest fodder varieties. Other methods will

be developed to better understand the metabolism of phytoestrogens in dairy cows and assess

the impact of enriched milk on human health. A new approach involving the use of minipigs

will be considered. Ultimately, the production of animal products of differing quality could

serve consumer interests as well as being viable for producers.

108

P5 - A stochastic spatial individual-based model for three

competitively interacting microbial populations

Daly Aisling, Baetens Jan and De Baets Bernard

Universiteit Gent, Belgium


One of the most important aims in ecology is to identify and comprehend the mechanisms that

sustain biodiversity - often critically important for the viability of ecosystems. Many

theoretical models have shown that species in competition can coexist – and thus maintain the

system’s biodiversity - if ecological processes such as competition and movement take place

over small spatial scales. This is also true in the case of communities with non-transitive

competition between species – that is, communities where a strict competitive hierarchy does

not exist. The classic example of non-transitive competition is the rock-paper-scissors game.

There exist many examples of communities in nature that demonstrate this type of

competitive relationship.

We present a stochastic, spatial individual-based model simulating a community of three

bacterial species. Interactions take place on a two-dimensional lattice. The model incorporates

three processes: reproduction, competition and mobility. Competition between the three

species is cyclic (thus non-hierarchical) and non-deterministic – that is, competition outcomes

are not completely certain. We are also working towards the inclusion of other, more realistic

competition structures. In addition, the model allows the initial evenness of the community to

be varied in order to investigate the consequent effects on the system’s biodiversity.

109

P6 - Weaning induces oxidative stress in pigs

Degroote Jeroen1, Wang Wei

1, Vergauwen Hans

2, van Ginneken Chris

2, De Smet Stefaan

1 and

Michiels Joris1

1Ghent University, Belgium 2Antwerp University, Belgium



Weaning is a critical proces in the life of piglets and several authors indicate that weaning

influences the oxidative status. Oxidative stress has been associated with immune-

suppression, changes of the intestinal barrier function and a disturbed intestinal growth. The

aim of this study was to assess the effect of birth weight, weaning treatment and days post-

weaning on the oxidative status in piglets. Therefore, ninety pairs of low birth weight (0,84 ±

0,09 kg) and normal birth weight (1,37 ± 0,18 kg) sex-matched littermates were selected and

assigned to one of three weaning systems; i.e. weaning at 3 weeks of age (19,6 ± 0,50 d), at 4

weeks of age (26,5 ± 0,50 d) and removal from the sow at 3 days of age and fed a milk

replacer until weaning at 3 weeks of age (19,8 ± 0,38 d). After weaning, piglets were fed a

starter diet ad libitum and were sampled at 0, 2, 5, 12 and 28 days post-weaning. Plasma and

small intestinal tissue samples were collected to characterize glutathione peroxidase (GSH-

Px) activity, glutathione transferase (GST) activity, malondialdehyde (MDA) concentration,

glutathione (GSH) and glutathione disulfide (GSSG) concentration. Results show clear

significant effects of days post-weaning and weaning system. The interaction term of these

two main factors was significant in a select number of cases. Unlike weaning treatment and

days post-weaning, type of piglet had minor effect on these parameters. These findings

provide fresh insight into the complex changes in response to weaning.

110

P7 - Intrauterine growth retardation does not affect the intestinal

barrier function in weaning piglets

Degroote Jeroen1, Wang Wei

1, Vergauwen Hans

2, van Ginneken Chris

2, De Smet Stefaan

1 and

Michiels Joris3

1Ghent University, Belgium 2Antwerp University, Belgium

3University College Ghent, Belgium



As a common problem in human and other mammals, intrauterine growth retardation can

inhibit normal growth after birth for a long time. Compared with normal piglets, intra-uterine

growth retarded (IUGR) piglets have smaller organs and dysfunction in the gastrointestinal

tract. Also, weaning of piglets is associated with many kinds of stress. Several studies

reported a decreased barrier function when normal pigs are weaned at 3 weeks of age. How

intestinal barrier function evolves in relation to weaning in IUGR piglets is still unknown.

Therefore, thirty pairs of IUGR (0.86±0.28 kg at birth) and normal birth weight(NBW)

(1.38±0.30 kg at birth) sex matched litter-mates weaned at 19.6±0.50 d of age were selected

and euthanized at 0, 2, 5, 12 and 28 days post-weaning. Mucosa of 5% and 75% of the total

length of small intestine (SI) were collected and both para- and transcellular permeability

were investigated with fluorescein isothiocyanate-dextran 4 (FD4, MW 4 kDa) and

horseradish peroxidase (HRP, MW 40 kDa) in Ussing Chambers. Data were analyzed by SAS

using a mixed model for testing the type of piglet (IUGR vs. NBW), days post-weaning and

interaction; for each intestinal site. Results showed that IUGR has no effect on the

permeability of neither FD4 nor HRP on both sites of the small intestine (P > 0.05). However,

days post-weaning had a significant effect on the FD4 permeability on both sites of small

intestine (P = 0.0171 and P = 0.0026, at 5% and 75% of SI, respectively) while no changes

occurred for HRP permeability. FD4 permeability peaked on day 2 post-weaning. To

conclude, in contrast to the period before weaning, IUGR piglets did not show a deterioration

of the permeability for macromolecular markers in the post-weaning period.

111

P8 - Contribution to the study of alliinase, the active principle of

garlic

Dethier Bérénice1 and Fauconnier Marie-Laure

2

1University of Liège, Belgium 2GX ABT (ULg), Belgium


Alliinase is a crucial enzyme in the Allium genus. The conversion of its substrates, cysteine

sulfoxides, into volatile thiosulfinates is an important mechanism in the defence of the plant.

It also provides the typical pungent flavour of garlic. As a matter of fact, the thiosulfinates

decompose in a range of organosulfur compounds (OSC) known for their biological activities

(antioxidant, anticancer, anti-diabetes properties, etc.). The environment of the decomposition

of the thiosulfinates determines the type and amount of products released. A deeper

knowledge of the conditions that form each OSC could help us in the preparation of garlic-

based nutraceutics in the perspective of healthier food consumption.

This study aims to improve the extraction and purification the enzyme alliinase in order to

perform the reaction between the enzyme and its substrates and assess the potentialities of

garlic preparations.

Three methods have been applied to evaluate the efficiency of the extractions and

purifications of the enzyme. A first idea of the purity of the enzyme is given by an

electrophoresis separation of each sample on a polyacrylamide gel (SDS-PAGE). The protein

content is then measured by UV-vis spectrometry with Lowry-Folin reagent for the coloration

and BSA as an external standard. Finally, the specific activity is assessed by an indirect

measure of the pyruvate (released as a co-product): the addition of NADH and lactate

dehydrogenase turns the pyruvate in lactate, and the disappearance of NADH is measured by

UV-vis spectrometry at 340 nm.

The extraction of the enzyme from garlic was performed either by PEG 8000 precipitation or

by ammonium sulphate precipitation. Two purifications were tested: affinity chromatography

(on ConA) and size-exclusion chromatography. The combination of the ammonium sulphate

process with the ConA chromatography provided the purest enzyme, with the best activity but

a lower yield than the size-exclusion process.

Finally the stability of the enzyme has been assessed at 4, -20 and -80 °C, showing that the

enzyme could be kept at -80 °C for over 4 months without deterioration, while activity loss

was observed at higher temperature.

112

P9 - Profiles of the volatile organic compounds emitted by the

masses of Abies nordmanniana somatic embryos at maintenance

and maturation stages.

Druart Philippe1, Michels Franck

2, Misson Jean-Pierre

1, Seffer Xavier

1, Wathelet Jean-Paul

2

and Fauconnier Marie-Laure2

1CRAW- Département Sciences du vivant « Unité Génie biologique », Belgium 2Gembloux Agro-Bio-Tech, University of Liege, Belgium


Somatic embryogenesis is the only way to propagate well-shaped Abies nordmanniana

clonally. It would also be the most promising technology for breeding such woody species

without genetic re-combinations. As Christmas tree, the aromatic trait is a priority and the

lines putatively improved require a precocious identification. That is the reason why the

emissions of the volatiles organic compounds have been considered at the most important

stages of the in vitro process: the maintenance of immature embryos masses and their

maturation, respectively.

The masses of immature embryos were grown on maintenance culture medium before their

transfer to different maturation media. Two weeks after growth, the volatile organic

compounds (VOCs) accumulating in the head-space of in vitro culture jars were trapped in

sterile nondestructive quantitative conditions on tenax ®columns. The VOCs were desorbed

from the adsorbent in a thermodesorption unit and then separated by gas chromatography on a

polar column. The identification of the VOCs was performed by mass spectrometry and by

comparisons with mass spectra libraries and calculated retention indexes to the one of

literature. The embryos masses emitting VOCs as a function of culture media were compared

on the base of total VOCs emission and individual compound relative percentages.

Total VOCs emission was clearly influenced by the composition of the culture medium

especially when masses were transferred from maintenance to maturation stage. The

individual compound relative percentages were also impacted by the transfer of one culture

medium to another.

113

P10 - Rapid method for the structural characterization of

flavonoid-O-glycosides from plant extract using UPLC-ESI-IMS-

HDMS/MSE

Gonzales Gerard Bryan, Raes Katleen, Coelus Sofie, Struijs Karin, Smagghe Guy and Van

Camp John

Ghent University, Belgium


Flavonoids belong to a large family of secondary plant metabolites, which often occur as

flavonoid-O-glycosides (FG) in nature. The structures of these polyphenols are popularly

identified using LC-MS/MS. However, it involves multiple injections and manual

identification of pseudo-molecular ions that are subjected to succeeding MS experiments

(MSn), thus time-consuming and unsuitable for routine analysis and screening of a wide array

of samples. In this paper, a strategy for the structural elucidation of FG from a plant extract in

one chromatographic run using UPLC-ESI-IMS-HDMS/MSE is presented. This system

operates using alternate low and high energy voltages that is able to perform the task of

conventional MS/MS in a rapid, data-independent manner. Also, ion mobility separation

(IMS) was employed as an additional separation technique for compounds that are co-eluting

after LC separation. First, the fragmentation of FG standards were observed and criteria was

set for structural elucidation of FG in cauliflower waste extract. Based on chromatographic

and MS characteristics, such as abundances of product ions and the presence of radical ions

([Y0-H]•-), a total of 19 FG, 8 non-acylated and 11 acylated, were structurally characterized.

Kaempferol was the main aglycone detected while sinapic and ferulic acids were the main

phenolic acids. The proposed method can be used as a rapid technique for flavonoid

identification and for routine analysis of plant extracts.

114

P11 - Functional differences of storage proteins are reflected in

their mobilization patterns from protein bodies in cotyledon cells

during olive (Olea europaea L.) seed germination

Jimenez-Lopez Jose C.1 and Hernandez-Soriano Maria C.

2

1National Council for Scientific Research (CSIC), Spain 2Katholieke Universiteit Leuven (KULeuven), Belgium


Olive tree is one of the most extensive, economically and agricultural important crop in

Mediterranean countries, and the sixth most important cultivated plant in the world. Despite

this fact, knowledge about mobilization process of storage materials during seed germination

remains scarce.

We performed morphometric and immunohistochemistry analyses of protein bodies (PBs) in

olive seed storage tissues using 11S-type globulins as molecular marker. We have observed

differences in the populations of PBs, which may reflect their differential biogenesis during

seed development and maturation, and the differences in seed storage proteins (SSPs)

functionality in cotyledon and endosperm.

Up to three different cytological mobilization patterns of legumin-like proteins were

distinguishable in PBs of cotyledon cells during in vitro seedling germination. Features of

SSPs deposited in different PBs, cell types and enzyme composition and/or differential

activation may play a fundamental role in determining the proteins mobilization from PBs and

further degradation in cotyledon cells.

This study will add new knowledge and will help understanding the complexity of

physiological processes such as seed reserve proteins mobilization supporting physiological

events, i.e. seedling growth and plant development. This knowledge will be useful for

potential development and utilization of olive seed bypass product (proteins) of nutritional

value as complementary source in animal (livestock) feeding.

115

P12 - Design of a low-cost, vision-based robot for automated weed

destruction

Krishna Moorthy Parvathi Sruthi Moorthy1, Mercatoris Benoît

1 and Boigelot Bernard

2

1Gembloux Agro-Bio Tech, University of Liège, Belgium 2Faculty of applied Sciences, University of Liège, Belgium


Weed destruction plays a significant role in crop production, and its automation has both

economic and environmental benefits by minimizing the usage of chemicals in the field. Our

aim is to design a small low-cost versatile robot allowing the destruction of weeds that lie

between the crop rows by navigating in the field autonomously. Major challenges foreseen

are: mapping the unknown geometry of the field, high-level planning of efficient and

complete coverage of the field, controlling the low-level operations of the robot, and ensuring

security. Sensors like odometers that are being used for localisation are not well suited for

real-world environments such as crop fields. Specialized sensors like cameras will therefore

be investigated and the plethora of image recognition algorithms will be explored and fine-

tuned to enable Simultaneous Localisation And Mapping (SLAM) in real time on a mobile

platform. Vision-based localisation is not always viable because of the varying weather

conditions and to overcome that, intelligent stochastic data fusion and machine learning

algorithms will be used to combine data from heterogeneous sensors. The image sensors for

localisation will optionally be re-used to differentiate crop rows from the weeds, which are cut

when they grow. Finally, logic-based methods and reinforcement learning techniques will be

explored, to exploit the generated map of the field and other sensorial information, to

efficiently plan and execute weed elimination.

116

P13 - Hesperidin conversion in the Simulator of the Human

Intestinal Microbial Ecosystem (SHIME)

Matthijs Bea1, Van Rymenant Evelien

1, Scheirlinck Ilse

2, Van der Saag Hans

3, Voorspoels

Stefan4, Possemiers Sam

2, Grootaert Charlotte

1 and Van Camp John

1

1University of Gent, Belgium 2Prodigest, Belgium

3Bioactor, Netherlands 4Vito, Belgium


Hesperidin is a polyphenol that is present in oranges, and has been associated with beneficial

effects on cardiovascular health. Limited bioavailability of these polyphenols, including the

difficult release from the food matrix by human digestive enzymes and microbial metabolism,

greatly affects the bioactivity of these compounds. In this study, hesperidin conversion was

investigated in the Simulator of the Human Microbial Ecosystem (SHIME), as well as its

impact on microbial community composition and metabolic activity. It was observed that the

hesperidin structure was not altered by gastric and small intestinal conditions, but was

converted to hesperitin (the aglycon) by the intestinal microbiota. Hesperidin supplementation

maintained the proper functioning of the intestinal microbial community.

Acknowledgements

The research leading to these results received funding the Agency for Innovation by Science

and Technology (IWT-Flanders) and from the European Union Seventh Framework

Programme (FP7/2007-2013) under Grant Agreement 312090 (BACCHUS). This publication

reflects only the authors’ views, and the Community is not liable for ant use made of the

information contained therein.

117

P14 - From wood charcoal to trees: pitfalls and successes of the

taxonomic identification in tropical contexts

Morin-Rivat Julie1, De Weerdt Joëlle

2, Hubau Wannes

3, Tshibamba John

4, Doucet Jean-Louis

5

and Beeckman Hans2

1ULg - Gembloux Agro - Bio Tech and Royal Museum for Central Africa, Belgium 2Royal Museum for Central Africa, Belgium

3University of Leeds, United Kingdom 4University of Kisangani and Royal Museum for Central Africa, The Democratic Republic of the Congo

5ULg - Gembloux Agro - Bio Tech, Belgium Corresponding author: [email protected]

So as to document the past history of tropical forests, several palaeoenvironmental proxies

have been used. For instance, charcoals from soil deposits provide a local signal of the

evolution of the vegetation together with snapshots of human interactions with their

environment. As charcoal analyses are rare in tropical contexts, here we aim at presenting the

different aspects of charcoal studies through their pitfalls and successes as well as the needs

for further research. Charcoal analysis (anthracology) is a discipline initially from

archaeobotany that consists in the analysis of pieces of charred wood primarily found in

archaeological contexts but also in natural soil layers. Its goal is to identified the species that

burnt during the past through the observation of the charred wood structure. Indeed

carbonization, as the incomplete combustion of the ligneous material, preserves the wood

structure. The identifications obtained through microscopic observations allow assessing past

uses of wood and human impacts on the forest landscape. However, issues typically tropical

exist: difficulties related to fieldwork accessibility, to sampling, to soil processing so as to

collect the charcoals, difficulties related to the taxonomic identification because of the huge

number of species and of the limited number of anatomical descriptions. New developments

are nonetheless emerging for Central Africa with original anatomical descriptions,

identification protocols and visual keys.

118

P15 - Reduction of furan formation by high pressure-high

temperature treatment of singular vegetable purées

Palmers Stijn, Grauwet Tara, Tamiru Kebede Biniam, Hendrickx Marc and Van Loey Ann

Laboratory of Food Technology, KU Leuven, Belgium


The present study addressed the need for furan mitigation measures at the level of food

production, where effects of extrinsic (process related) and intrinsic (product related)

properties on the furan formation in vegetable-based systems were investigated. For the first

time in literature, the effect of high pressure-high temperature (HPHT) processing on the

formation of furan was demonstrated. HPHT processing was proven to be an interesting

alternative for furan reduction in vegetable-based systems, when aiming for sterilization

intensities. Following HPHT treatment, the furan concentrations of a wide range of singular

vegetable purées dropped to levels close to the analytical limits. A higher processing cost

might limit the use of HPHT processing to high-value added products, which means that for

many other products, conventional heating would remain the standard technology. As a first

step towards control of the furan formation in the latter products, mixed model regression was

used to identify the major precursors in vegetable-based systems. Significant correlations

were observed for vitamin C and sugars, which were attributed to the efficiency of the

conversion and high concentrations, respectively. Next to furan, the HPHT and thermally

treated purées were analyzed for 2- and 3-methylfuran, which are likely to undergo the same

metabolic fate as furan. For most of the vegetables tested, the total amount of methylfuran

found in the thermally treated purées could not be ignored. Similar to furan, there was a clear

reduction of the concentrations found in the HPHT treated purées.

119

P16 - Field Bordering Flower Strips as Source of Lipids

Paul Aman1, Danthine Sabine

1 and Frederich Michel

2

1Gembloux Agro-Bio Tech, Belgium 2Department of Pharmacy, University of Liege, Belgium


Field bordering flower strips not just only improves the biodiversity but also serves as a

source of beneficial compounds. Some of the plants in these strips can be really interesting

source of lipids, the oils extracted from their seeds can be important for food, pharmaceutical

and cosmetics industries. Six species of plants from flowering strips in Belgium were

investigated for their seed oil content. The oil from seeds was extracted by cold extraction

technique using chloroform/methanol in 2:1 ratio as solvent. Oil extraction from seeds of red

clover (Trifolium pratense), rough hawkbit (Leontodon hispidus), cow parsley (Anthriscus

sylvestris), st john’s wort (Hypericum perforatum), common yarrow (Achillea millefollium)

and birdsfoot trefoil (Lotus corniculatus) plant species was done on wet weight which came

out to be 8%, 12%, 15%, 24%, 20% and 7% respectively. The physicochemical properties of

the extracted oils were analysed. Some of these oils can be of great commercial value.

120

P17 - Spoilage potential of psychrotrophic lactic acid bacteria

(LAB) Leuconostoc gasicomitatum and Lactococcus piscium

under different packaging conditions

Pothakos Vasileios, Nyambi Clarice, Zhang Baoyu, Papastergiadis Antonios, De Meulenaer

Bruno and Devlieghere Frank



Leuconostoc gasicomitatum and Lactococcus piscium constitute two major spoilage-related

psychrotrophic LAB species. Based on previous studies conducted in our laboratory these

species are unable to grow at 30oC, hence remain undetermined during microbiological

routine analysis implementing mesophilic enumeration. However they have been consistently

isolated from food products of vegetable and meat origin using a psychrotrophic enumeration

method (i.e. incubation at 22oC). Additionally they were found to dominate in a source

tracking analysis carried out in a vegetable processing plant. Unequivocally, the supplied

sweet bell peppers were carriers of the microbes into the plant. Determination of the spoilage

potential of two LAB species was conducted through single strain inoculation experiments on

sweet bell pepper juice (SBPJ) simulation medium. The medium was packaged in trays,

sealed with low permeability barrier film, subsequently packaged under 4 different gas

compositions: 1.- vacuum (100% N2), 2.- air (21% O2:79% N2¬), 3.- MAP1 (30% CO2:70%

N¬2), 4.- MAP2 (50% O2:50% CO2) and stored at 7oC, for 20 days. Growth, acidification,

gas composition in the headspace were monitored, as well as the production of volatile

organic compounds (VOCs) using Gas Chromatography (GC-MS) and Selected Ion Flow

Tube (SIFT-MS) analysis. This study aims at determining the spoilage potential of the two

LAB taxa. A selection of 4 Leuconostoc gasicomitatum and 3 Lactococcus piscium strains,

isolated from different food sources, possessing characteristic phenotypes and genotypic

fingerprints were tested in single culture inoculation studies. Each strain was considered an

independent repetition of the experiment for each species. This way the intraspecific diversity

of spoilage potential was assessed. All 4 Leuconostoc gasicomitatum strains exhibited a very

potent growth and no inhibition under any packaging condition tested, reaching 9 logs CFU/g

within 5 days of storage, extreme acidification, emission of large amounts of off-odor

compounds like acetic acid, diacetyl, acetaldehyde, 2-3 butanediol etc. The spoilage potential

was congruent to the O2 concentration making MAP2 - which was selected as the most

promising protective atmosphere - the worst case for quality properties. Ethanol, acetoin and

slime production were proved to be strain specific. On the other hand the 3 Lactococcus

piscium strains showed a great intraspecies diversity. This species was more sensitive to

MAP2 (super-atmospheric O2 and high CO2) therefore inhibited, had a slower growth in the

other conditions but produced considerably greater amounts of diacetyl, formic acid, ethanol

and acetoin compared to Leuconostoc gasicomitatum. Apparently the metabolism and

survival of strains belonging to the same species could be influenced by many factors.

121

P18 - Life Cycle Evaluation of using insect-derived proteins as

animal feed

Roffeis Martin

KU Leuven, Belgium


For the next few decades, the global agricultural sector faces major challenges. By the year of

2050 the global population is expected to be grown up to 9.2 billion, which is predicted to

boost the global food demand by 70-100% [1, 2]. The expected increase in per capita real

income by factor 2.4, will affect consumption patterns of future generations as well which

will most likely be displayed in dietary shifts towards higher proportions of meat [2, 3]. Feed

production and animal husbandry are by far the most important contributors to the

environmental impacts [4-7]. In order to meet the expected demand scenarios without

comprising an increase of environmental damage beyond present levels, current agricultural

research has to focus on solutions of achieving productivity increment from less per capita

arable land and fewer input of scarce resources [8, 9]. Especially Recycling of livestock waste

streams shows high potential for efficiency augmentation [7, 10, 11]. In search for more

efficient recycling methods, latest thinking on manure management intend to recover nutrients

from livestock-borne waste streams by the means of insects. Insects are not only capable to

extract highly valuable proteins and functional feed ingredients, they also facilitate significant

reductions in waste volumes [12, 13]. Hence key elements (N,P,K,C) remain by 40-60%.

Reuse of residuals as fertilizer, soil remediation material or as a substrate in anaerobic

digestion create the potential to add value in subsequent process stages [14], while the reared

insects can be used as a resource for other value adding products. Existing and well

established refining and extraction processes from the feed and food industry offer several

conceivable refining options for insect-derived product scenarios (e.g. as feed, food or for

chemicals) [15, 16]. While the underlying conception allows to expect great utility potential

and economic vigour and attract a lot of attention from the scientific, policy and public world

[15, 16], the actual environmental impact and socio-economic performance of production

processes and product offerings of that origin remain widely unexplored [15, 16]. However,

encouraging research results of rearing dipteran fly species on waste streams, indicate that

highly automated and efficient production systems are not aberrant to assume.

While the underlying concept of using insects as a novel protein source in feedstuffs allows to

expect great utility potential and economic vigour, the actual environmental impact and socio-

economic performance of production processes and product offerings of that origin remain

widely unexplored. Aiming for sustainable production and consumption patterns,

consideration must be given to the environmental, economic and social implications.

To indicate sustainable insect production systems that are suitable for adoption by small and

large-scale operations in different regions, I will perform comparative Life Cycle

Assessments on a wide range of different production systems in different biophysical and

socioeconomic environments. The concept of Life Cycle Assessment is based on an

evaluation of impacts of products and services over their complete life cycle, i.e. from

extraction of raw materials, transport, processing and assembly to distribution, end use, and

122

waste disposal. To address all of sustainability’s dimension, I will employ different methods

of life cycle assessments including environmental Life Cycle Assessment (env. LCA),

assessing environmental impacts, and Life Cycle Costing (LCC) and Social Life Cycle

Assessments (S-LCA) to assess socioeconomic impacts. Apart from making informed choices

on products, Life Cycle Thinking methodologies are particular suitable to detect efficiency

deficits and yet untapped improvement potentials and thus are highly pertinent in product

development and policy change consultation. In order to guarantee comparability with other

protein supplying feedstuffs, the evaluation will be made on the functional utility of 1 kg of

crude protein for relevant livestock. The nutritional performance and ileal digestibility of 1kg

of insect borne crude protein will be evaluated in respective feeding trials.

These comprehensive and informed LCA analyses shall yield information that help to consult

political decision makers on customized measures that ease implementation or counter yet

unforeseen negative externalities.

References

1. Tscharntke, T., et al., Global food security, biodiversity conservation and the future of

agricultural intensification. Biological Conservation, 2012. 151(1): p. 53-59.

2. Godfray, H.C.J., et al., Food Security: The Challenge of Feeding 9 Billion People. Science,

2010. 327(5967): p. 812-818.

3. Tilman, D., et al., Agricultural sustainability and intensive production practices. Nature,

2002. 418(6898): p. 671-677.

4. Nijdam, D., T. Rood, and H. Westhoek, The price of protein: Review of land use and

carbon footprints from life cycle assessments of animal food products and their substitutes.

Food Policy, 2012. 37(6): p. 760-770.

5. Petersen, S.O., et al., Recycling of livestock manure in a whole-farm perspective. Livestock

Science, 2007. 112(3): p. 180-191.

6. Sandars, D.L., et al., Environmental Benefits of Livestock Manure Management Practices

and Technology by Life Cycle Assessment. Biosystems Engineering, 2003. 84(3): p. 267-281.

7. Lesschen, J.P., et al., Greenhouse gas emission profiles of European livestock sectors.

Animal Feed Science and Technology, 2011. 166–167(0): p. 16-28.

8. Crosson, P. and J.R. Anderson, Demand and supply: trends in global agriculture. Food

Policy, 1994. 19(2): p. 105-119.

9. Lal, R., Food security in a changing climate. Ecohydrology & Hydrobiology, 2013. 13(1):

p. 8-21.

10. Elferink, E.V., S. Nonhebel, and H.C. Moll, Feeding livestock food residue and the

consequences for the environmental impact of meat. Journal of Cleaner Production, 2008.

16(12): p. 1227-1233.

11. de Vries, M. and I.J.M. de Boer, Comparing environmental impacts for livestock

products: A review of life cycle assessments. Livestock Science, 2010. 128(1-3): p. 1-11.

12. Miller, B.F., J.S. Teotia, and T.O. Thatcher, Digestion of poultry manure by Musca

domestica 1. British Poultry Science, 1974. 15(2): p. 231-234.

13. Sheppard, C., House Fly and Lesser Fly Control Utilizing the Black Soldier Fly in Manure

Management Systems for Caged Laying Hens. Environmental Entomology, 1983. 12(5): p.

1439-1442.

123

14. Newton, L., et al., Using the black soldier fly, Hermetia illucens, as a value-added tool for

the management of swine manure. Animal and Poultry Waste Management Center, North

Carolina State University, Raleigh, NC, 2005: p. 17.

15. Huis, A.v., et al., Edible insects Future prospects for food and feed security, in FAO

Forestry Paper2013, FAO.

16. Rumpold, B.A. and O.K. Schlüter, Potential and challenges of insects as an innovative

source for food and feed production. Innovative Food Science & Emerging Technologies,

2013. 17(0): p. 1-11.

124

P19 - Isolation and in vitro characterization of skeletal muscle

myoblasts from chronic heart failure patients

Sente Tahnee1, Van Berendoncks An M.

1, Jonckheere Ann I.

2, Rodenburg Richard J.

3, Lauwers

Patrick4, Hoymans Vicky Y.

4, Vrints Christiaan J.

4 and Conraads Viviane M.

1

1University of Antwerp, Belgium 2University Hospital Brussels, Belgium

3Radboud University Nijmegen, Netherlands 4Antwerp University Hospital, Belgium


Purpose: To develop a protocol for obtaining pure populations of human chronic heart failure

(CHF) myoblasts that can be studied under standardized conditions. Background: Peripheral

muscle wasting is a common finding in CHF. Recent advances in clinical research have

confirmed the negative impact of muscle wasting on patient survival. Although innovative

research in molecular biology is improving our understanding of how muscle mass is

maintained, effective treatment for muscle wasting in CHF has yet to be developed.

Consequently, primary skeletal myoblasts cultures from fresh human skeletal muscle biopsies

are an attractive tool for investigating skeletal muscle atrophy. Methods: In vitro myoblasts

(n=5 CHF patients) were efficiently isolated and expanded in a controlled environment.

Myogenic phenotype and their ability to differentiate into myotubes in vitro was verified by

immunostaining and flow cytometry. Cellular viability (Annexine-V) and apoptosis (7-AAD)

were assessed using flow cytometry. Results: Primary muscle cells cultured on single plates

revealed a large cell population (≥ 10 mm) consisting of 90% desmin-positive myoblasts.

Immunohistochemistry results showed that desmin and α-actinin proteins were expressed in

the cytoplasm of CHF myoblasts. Differentiation of human CHF myoblasts was analyzed

until day 6 and myogenesis was characterized by expression pattern of the paired box (Pax)

transcription factor Pax7 and by the myogenic regulatory factors (MRFS) myogenic

determination factor 1 (MyoD1), Myogenin and MRF4, indicating their skeletal muscle cell

identity. Pax7 (72,7% ± 11,80%) and MyoD1 (82,9% ± 6,73%) are highly expressed in

myoblast cells from CHF patients. CHF myoblast differentiation is marked by the onset of

Myogenin expression (13,0% ± 3,60%) on day 2, whereas levels of MRF4 (72,19% ±

14,11%) remains stable throughout the process of myogenesis. CHF myoblast cells formed

well-developed, multinucleated myotubes. Cell viability ranged from 84,4% to 98,2%.

Conclusion: Overall, satellite cell-derived myoblasts from CHF patients demonstrated a

robust proliferation and an excellent differentiation. Skeletal muscle myoblast cell cultures

offer the potential for the in vitro study of mechanisms that underlie skeletal muscle wasting

in CHF.

125

P20 - Microbial ecology of Vietnamese Tra fish (Pangasius

hypophthalmus) fillets during processing

Tongthi Anhngoc



Distribution microbiota of tropical-farmed Pangasius hypophthalmus fish during processing

was examined by culture-dependent techniques and 16S rRNA gene sequencing. Two

Vietnamese companies (BC: large scale factory, chlorine-based process, BW: large scale

factory, water-based process and SC: small scale factory, chlorine-based process) processed

Pangasius for intend-exporting to Western market was sampled. A total of 252 isolates

originating from beginning, intermediate and final steps of the production line were then

identified by 16S rRNA gene sequencing. The results of microbial profile showed no

significant difference (p > 0.05) between two processing lines of BC and BW. Surprisingly,

chlorine treated fillets from the SC line were revealed to have significantly higher microbial

counts than potable water treated fillets at BW line due to probably temperature abuse during

processing. Along the processing chains, 131 of Gram negative and 43 of Gram positive

bacteria were identified consisting of 20 different genera and 38 different species. Contrary to

microbial counts, the type of spoilage related microbiota present on the BC and BW line was

more diverse than that on the SC line. Enterobacteriaceae (as spoilage and hygiene indicators)

such as Providencia, Shigella, Klebsiella, Enterobacter and Wautersiella were isolated from

fillets sampled on the SC line whereas Serratia was only observed on fillets sampled on the

BC and BW lines. The results can be used to improve Good Manufacturing Practices for

processed Pangasius fillets.

126

P21 - Microbiological safety of Vietnamese Tra fish (Pangasius

hypophthalmus) fillets during processing

Tongthi Anhngoc



Vietnamese Tra fish (Pangasius hypophthalmus) have become highly appreciated by

consumers in the European Union, USA, Canada, etc. and are therefore of worldwide

economic importance. The availability of data in microbiological quality and safety of this

fish species is however limited. Therefore; the dynamics of microbiological performance of

Vietnamese processing company between large and small scale plants was evaluated from

raw material until final product by microbial assessment scheme. The total of 279 samples

(144 samples in large scale plant) were taken for monitoring: overall microbial quality

(psychrotrophic aerobic count), hygiene indicators (E. coli and S. aureus), and relevant

pathogens (Listeria monocytogenes and Vibrio cholerae). The low levels of total

psychrotrophic bacteria and E. coli on final products sampled from large scale plant was ca. 3

log CFU/g and below detection limit, respectively. In addition, the pathogen of Listeria

monocytogenes and Vibrio cholerae was absent in all samples analysed, indicating that the

food safety management system applying to the large scale plant was effective. On the

contrary, high numbers of total psychrotrophic bacteria (ca. 6 log CFU/g on fish and ca. 6 log

CFU/ 100 cm2 on food contact surface) were found on the small scale plant during

processing. Additionally, the foodborne pathogen was present in water, hands and fish;

especially the presence of L. monocytogenes on a final Pangasius product. We suggest that

both the preventive measures and monitoring systems design should be improved to avoid a

potential food safety problem.

127

P22 - Functional traits and speciation of tropical African species:

the case of genus Guibourtia Benn

Tosso Félicien1, Daïnou Kasso

1, Hardy J. Olivier

2, Lejeune Philipe

1 and Doucet Jean-Louis

1

1 Laboratoire de Foresterie des Régions Tropicales et Subtropicales, Unité de Gestion des Ressources

Forestières et des Milieux Naturels, Gembloux Agro-Bio Tech, Université de Liège, Belgium 2 Evolution Biologique et Ecologique, Département de Biologie des Organismes, Université Libre de Bruxelles,

Belgium


Nowadays, comparative ecology approach is widely used to understand mechanisms of

speciation. In evolutionary biology, few studies take into account the importance of

physiological traits as criteria for interspecific differentiation, although such an approach is

particularly suited to infer the adaptive capacities of taxa. The genus Guibourtia Benn

(Fabaceae / Caesalpinioideae), composed of 13 species in Africa, seems an ideal candidate for

this study. As a matter of fact, this model includes not only species of different vegetation

ecosystems (forest and savanna) but also morphologically very similar species found in

various areas with different climates and soils (sandy, clayloam, limestone, hydromorph).

Addressing speciation issues, our study seeks to test the hypothesis that populations of closely

related species should be studied in terms of both functional traits and phylogeny. In this

research, two questions are asked: (i) what are the phylogenetic differences within the genus

Guibourtia? (ii) To what extent phylogeny, functional traits and bioclimatic envelope are

linked?

The results of the study will help to realize the distribution modeling of different evolutionary

units of Guibourtia using a dynamic vegetation model (CARAIB) in order to propose

strategies for conservation and sustainable management in the context of Central African

forests.

128

P23 - Prebiotic Effects of Novel Nondigestible Carbohydrates on

Bacterial Community with Challenge of S. Typhimurium in Pigs

Tran Tham, Blaise Yannick, Bindelle Jérôme, Théwis André and Boudry Christelle

Zootechnie, Gembloux Agro-Bio Tech, Belgium


An intestinal imbalance is mostly caused by the overgrowth of enteric pathogens. Prebiotics

are more and more used to tight against these pathogens by favouring the beneficial microbes.

The aim of this study is to evaluate the effect of two new carbohydrates:

isomaltooligosaccharides (IMO) and pecticoligosaccharides (POS) on bacterial populations

with challenge of S. Typhimurium in pigs. The POS increased bifidobacteria (p=0.008) and

lactobacilli compared to saccharose. Whereas, in trojan pigs, lower Lactobacillus counts were

observed for IMO compared to control (p=0.002). Both IMO and POS had no effects on

Bacteroides and Clostridium cluster I populations.

129

P24 - The intestinal matrix modulates polyphenol transport and

metabolism by Caco-2 cells

Van Rymenant Evelien1, Grootaert Charlotte

1, Scheirlinck Ilse

2, Gonzales Gerard Bryan

1,

Matthijs Bea1, Kamiloglu Senem

1, Possemiers Sam

2 and Van Camp John

1

1 Laboratory of Food Chemistry and Human Nutrition, Faculty of Bioscience Engineering, Ghent University,

Coupure Links, 653, 9000 Ghent, Belgium 2 Prodigest, Technologiepark-Zwijnaarde 4, 9052 Zwijnaarde, Belgium


Introduction and objectives

Polyphenols are a diverse group of plant compounds with beneficial effects on cardiovascular

health. However, their bioactivity is often limited by their bioavailability. Although many in

vitro models describe polyphenol transport through the intestinal epithelium-like Caco-2 cell

line, the impact of the intestinal matrix on this process is relatively unknown. Therefore, in

this study, we want to compare the transport and metabolism of hesperitin, the main

polyphenol metabolite from oranges, by the Caco-2 cell line in the presence of an intestinal

matrix from the Simulator of the Human Intestinal Microbial Ecosystem (SHIME).

Materials and methods

Caco-2 cell cultures from different origin (ATCC and three morphologically different

subcultures) were exposed to an intestinal matrix from the stomach, small intestine,

ascending, transverse and descending colon compartments of the SHIME. The cellular

response was characterized based on cell morphology, cytotoxicity, transepithelial electrical

resistance (TEER) and glucuronidation and sulphation potential of hesperitin. Finally the

impact of the intestinal matrix on hesperitin transport was assessed using UPLC-DAD.

Results and discussion

A difference in toxicity response towards SHIME suspension was observed as well as an

effect on glucuronidation and sulfation potential of the cell lines.

These results show the importance of cell culture practices and the presence of an intestinal

matrix in the development of a screening model for bioavailability of polyphenols that

combines in vitro digestion with enterocyte transport.

Acknowledgements

The research leading to these results received funding the Agency for Innovation by Science

and Technology (IWT-Flanders) and from the European Union Seventh Framework

Programme (FP7/2007-2013) under Grant Agreement 312090 (BACCHUS). This publication

reflects only the authors’ view(s), and the Community is not liable for ant use made of the

information contained therein. We also thank the Special Research Fund (BOF-Bijzonder

Onderzoeksfonds Basisuitrusting BAS/2012) with Guy Smagghe as representative of the

CWO Host-Microbe Interactions Consortium – Animal Cell for funding the REMS TEER

equipment

130

P25 - Scaling-up adoption of improved technologies: The impact

of the promotion of row planting on farmers’ teff yields in

Ethiopia

Vandercasteelen Joachim1, Dereje Mekdim

2, Minten Bart

2 and Taffesse Alemayehu Seyoum

2

1 KULeuven, Belgium 2 LICOS, Ethiopia


Adoption of yield increasing technologies is seen as a key driver to increase agricultural

production in Sub-Saharan Africa. There is, however, a lack of empirical evidence on the

impact of programs aiming to scale-up the adoption of improved technologies from research

settings to the farm level. To fill this gap, this paper assesses the impact of the promotion of a

new agricultural technology, i.e. row planting at reduced seed rate, on farmers’ teff yields in

Ethiopia. Teff is Ethiopia’s most important staple crop, but the national average yield level is

low. The results of a randomized control trial show that the program to scale-up row planting

on average has a positive effect on teff yield. Depending on the measure of yield used, we

find increases between 2 percent—but not statistically significant—and 22 percent. These

findings are in contrast with larger yield increases found on village demonstration plots and in

more controlled settings, as well as with the yield increase expected by teff farmers. The

differences seemingly are linked to problems in implementation of the program and of its

recommendations, methodological issues, and likely over-optimism on the potential of row

planting in real farm settings. The results of our research point to several important

implications as more effort should be put in design and implementation of the extension

campaigns for promoting such technologies and on-farm constraints towards adoption should

be further assessed.

131

P26 - Perceptions of traditional food and European food in

Chinese consumers' minds

Wang Ou, Gellynck Xavier and Verbeke Wim

Department of Agricultural Economics, Ghent University, Belgium


China is one of the most important Asian emerging markets. There are opportunities and

challenges for European local food products in the huge and potential market. This study

elicits Chinese consumers' perceptions of European food and their own traditional food . Two

online qualitative research methods were carried out for data collection,a web-based free word

association test and an online asynchronous focus group. Findings show that Chinese

consumers defined European food and traditional food through similar dimensions: sensory,

health, origin, marketing, safety, variety, heritage, symbolic meanings, simplicity and special

occasions. Additionally, they associated traditional food with the dimensions ‘elaboration’

and ‘habit’ and European food with dimensions ‘convenience’ and ‘unfamiliarity’. The

concept associations of traditional food in Chinese consumers’ minds appeared to be rather

similar to documented perceptions of traditional food among Europeans, despite cultural

differences. Furthermore, traditional food was perceived positive in general, while perceptions

were more ambiguous with respect to European food (positive or negative). Result of this

study is helpful for European food producer and marketer to better understand Chinese

consumer so that they can develop effective marketing strategy dealing with the opportunities

and challenges for their products in Chinese market.

132

P27 - Effects of intrauterine growth retardation on intestinal

barrier function in neonatal piglets

Wang Wei1, Degroote Jeroen

1, Vergauwenb Hans

2, Van Ginneken Chris

2, De Smet Stefaan

1 and

Michiels Joris1

1 Ghent University, Belgium 2 University of Antwerp, Belgium



Intrauterine growth retardation (IUGR) is a common problem in human and other species

because it increases the risk of death of the fetus and affects development during the perinatal

period. Compared with normal piglets, neonatal IUGR piglets grow slower due to the delay in

gastrointestinal development.

Little is known about the postnatal effects of IUGR on the barrier function of the small

intestine. In the current experiment, the barrier function was determined by assessing the

permeability for macro-molecular markers ex vivo. Twenty-four pairs of IUGR (0.81±0.08 kg

at birth) and normal birth weight (NBW, 1.30±0.15 kg at birth) sex matched litter-mates were

selected and euthanized at 0, 3, 8 and 19 days of age. Mucosa at 5% and 75% of the total

length of small intestine (SI) were collected and both para- and transcellular permeability

were investigated using fluorescein isothiocyanate-dextran 4 (FD4, MW 4 kDa) and

horseradish peroxidase (HRP, MW 40 kDa) in Ussing Chambers. Data were analyzed by SAS

using a mixed model for testing the type of piglets (IUGR vs. NBW), age and interaction; for

each intestinal site. IUGR piglets showed a higher permeability for FD4 and HRP on both

sites (P = 0.008 and P = 0.015 for FD4 and HRP, respectively at 5% of SI, P = 0.0123 and P =

0.029 for FD4 and HRP, respectively at 75% of SI) while age did not affect permeability (P >

0.05). There was only an interaction effect for FD4 permeability at 75% of SI (P = 0.049).

Increased fluxes of FD4 and HRP in IUGR piglets might reflect increased trans- and

paracellular permeability and thus impaired intestinal barrier function. These findings indicate

that impaired intestinal barrier function might contribute to the retarded growth of IUGR

piglets.

133

P28 - Assessment of lipoxygenase activity in seeds and leaves of

Nigella sativa L. and Cassia absus L

Zribi Ines1, Le Maire Nathalie

2, Fauconnier Marie Laure

2 and Haouala Rabiaa

1

1Higher Agronomic Institute of Chott-Mariem. Agrobiodiversity Unit, Tunisia 2Gembloux Agro bio tech. General and Organic Chemistry Unit, Belgium


Nigella sativa (family: Ranunculaceae), commonly known as black cumin and Cassia absus

(family: Fabacea) commonly known as Chaksu are two important medicinal plants used in the

treatments of many diseases. The aim of the study was to investigate lipoxygenase (LOX)

activity in seeds and leaves at different growth stages of these plants, which were grown

under normal crop conditions. LOX activity was determined spectrophotometrically at 234

nm at pH7 on the basis of hydroperoxide (HPO) using 20mM of linolenic or linoleic acid as

substrates. The results referring to the extracted protein content show that all extracts

exhibited LOX activity. Nigella sativa LOX showed a preference for linolenic acid than for

linoleic acid. Leaves at fruiting stage of Tunisian and Indian Nigella sativa varieties exhibited

the highest specific activity [151,2 and 108,3 µmole/g protein.s respectively]. Cassia absus

seed LOX showed a high affinity for linoleic acid [162,8 µmole/g protein.s] rather than

linolenic acid. Cassia absus leaves at vegetative stage showed the highest level of biosynthetic

capabilities using linolenic acid as substrate [153,5µmole /g protein.s]. In conclusion, this

study shows that LOX is involved in growth and development of Nigella sativa and Cassia

absus especially in fruit ripening.

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