Optimization of the alcoholic fermentation of organic solid waste, by means of temperature control and the addition

of Zn as a cofactor or limiting reagent of the coenzyme alcohol dehydrogenase.

Marco Javier Puente*, David Puente,* Scarlet Cisneros and* Edison Criollo.

Universidad Central del Ecuador- Quito

xavierpuente4@gmail.com ,mjpuente@uce.edu.ec, edimani@hotmail.com

1, Introduction and objetive

The present study was conducted independently

and in a certain way at the Central University of

Ecuador, in order to give new use and

productive value to the urban organic waste from

Quito Metropolitan District, thus contributing to

the change of the matrix energetic and

productive of Ecuador, for which the alcoholic

fermentation of residues was optimized, by

means of the temperature control obtaining an

optimum point of work for brewing yeasts of high

fermentation and the addition of Zn as a cofactor

or limiting reagent of the coenzyme alcohol

dehydrogenase was also analyzed.

2, Methodology

2.1Temperature control at 18 ° C-24 ° C

Macerated the mixture is passed to the

fermentors once it has reached a temperature of

20-30 ° C. A temperature variation was taken to

evaluate the performance of the fermentation in

terms of speed every two degrees to

verify what would be most convenient in the city

of Quito introducing a controlled sauna room by

measuring the temperature with the digital

kitchen thermometer to verify the concordance

with the sauna thermometer.

2.2 Addition of Zn as limiting reagent

Zn is an essential part of the formation of alcohol

and is the active part in this formation, this is the

central part of the enzyme alcohol

dehydrogenase responsible for the generation of

Bio-ethanol (Hammes-Schiffer, 2006). Zinc is

absolutely essential for yeast, since it is a

cofactor of said enzyme and also intervenes in

the protection against stress and other

biochemical reactions. Lallemand, in

collaboration with the Technical University of

Munich Weihenstephan, has created a

completely natural yeast enriched with zinc of

the lager type of low fermentation. Taking this

last as a reference, it has been enriched with

zinc to high fermentation yeasts type ale,

creating a subspecies similar to the lager

created by this university, but focused on a

different range of temperatures between 18 and

24 ° C to which they work the yeasts used in the

present study, since due to the geographical

location and the climatological characteristic.

3. Results

3.1Temperature

3.1.1Table 1: Optimization of the speed of the

reactor when digesting, controlling the

temperature

Optimization of temperature

18°C 20°C 22°C 24°C

Retention

in days

Retention in

days

Retention in

days

Retention

in days

5 5 5 6

5 5 6 6

6 5 5 6

6 5 6 6

5 5 5 6

Average Average Average Average

5,4 5 5,4 6

Source: self made

3.1.2 Figure 1: Reaction behavior of thereactor by controlling the temperature

4,8

5

5,2

5,4

5,6

5,8

6

6,2

0 10 20 30

Ret

enci

ón

del

rea

cto

r en

día

s

Temperatura en °C

Temperature Control

Both table 1 and figure 1 show that we have an

optimum working point of these high fermentationyeasts at 20 ° C since the tendency to lower the

temperature to 18 ° C as when rising to 22 ° C and

24 ° C that temperature is to increase the retention

time, which would worsen the work of the reactor,this is because at 20 ° C the yeasts are not in

stress because they are closer to the limits of the

optimum range of work with regarding thetemperature.

3.1.3 Table 2 Composition with temperaturecontrol

Composition with temperature variable

%v/v ethanol a

20°C

%v/v methanol

20°C

%v/v ethanol

a 18°C

%v/v

methan

ol a18°C

11 1,5 9 2

11 1,5 9 1,5

10 1,5 10 1,5

10 1 9 1,5

10 2 10 1

promedio promedio promedio

promedi

o

10.4 1,5 9,4 1,5

Composition with temperature variable

%v/v ethanol

22°C

%v/v methanol

a22°C

%v/v

ethanol

24°C

%v/v

methanol

24°C

9 1 9 1,5

10 1,5 8 2

9 1,5 10 1

9 2 9 1,5

10 1,5 10 2

promedio promedio promedio promedio

9,4 1,5 9,2 1,6

3.1.4Figure 2: Composition behavior of ethanol with respect to temperature

9

9,5

10

10,5

0 5 10 15 20 25 30

%v/

v d

e et

ano

l

Temperatura °C

temperature control -generation of ethanol

You can see in this graph a similar behavior but the

opposite with respect to the retention in the reactor

since the decrease in stress due to environmental

conditions increases the speed decreasing the

retention time but at the same time increases the

production of ethanol by of the yeasts for the same

reduction of stress.

1,451,5

1,551,6

1,65

0 10 20 30

%v/

vde

met

ano

l

temperatura en °C

temperature control -generation of methanol

It can be observed that the composition of methanol

with respect to the fermentation temperature does not

change the point of 1.6, it may be due to human errors

in the measurement but a tendency to keep in a

straight line or constant in 3 points of the line is

observed, which indicates that in fact the generation of

methanol by pectins are part of an adjunct reaction

parallel to the fermentation depending on the amount

of pectins in the mixture but not the conditions

analyzed and evaluated in the ranges established inthe present study for fermentation .

3.2 Table 3: optimization of the retention time with

respect to the addition of limiting reagent (trace

element) Zn adapted to high fermentation ale typeyeas

Optimization with Zn

Retention in days

5

4

4

5

4

Average

4,4As can be seen by adding a Zn enrichment in

fermented beer type yeasts, there is an increase in the

digestion rate of the yeasts and a decrease in the

retention time with respect to the last temperature

optimization of 0.6 days which 12% increase in the

reduction of the stress of the molecules to the

bioavailability of this element that forms an essential

part of the enzyme Alcohol Dehydrogenase responsiblefor the generation of bioethanol.

3.2.1Table 4: Composition with enrichment

optimization with Zn to yeasts of high alefermentation.

Optimization with Zn

%v/v ethanol %v/v methanol

11,5 1,5

13 2

12 2

12,5 2

13 1,5

Average Average

12,4 1,8

There is evidence of an increase in the percentages of

ethanol and methanol due to the bioavailability and

affinity that exists for the enzyme alcohol

dehydrogenase in methanol, evidencing an increase

of 0.2% V / V methanol, increasing total methanol

generation by 12.5% while in ethanol, although the

affinity can be up to 20 times greater in ethanol for

said ethanol, an increase of 2.6% v / v of ethanol is

evidenced, which would correspond to an increase of

26.53% in yield with respect to to 9.8% v / v of ethyl

alcohol generated with the previous optimization.

Methanol is slowly oxidized by this enzyme at a rate of

25 mg / kg / hr, more slowly than the rate of ethyl

alcohol which is 175 mg / kg / hr (Olson K.R.2007).

4.Bibliography

1.Gil, C. M. Q., & Quijano, H. R. (2008). Optimización de las

condiciones de proceso para la elaboración de la esponja líquida de

pan de molde a través de un diseño factorial deexperimentos. Publicaciones e Investigación, 2(1), 43-65.

2.Puerta, G. I., & Echeverry, J. G. (2015). Fermentación controlada del

café: Tecnología para agregar valor a la calidad.

3.Criollo, J., Criollo, D., & Aldana, A. S. (2010). Fermentación de la

almendra de copoazú (Theobroma grandiflorum [Willd. ex Spreng.]

Schum.): evaluación y optimización del proceso. Corpoica Ciencia y

Tecnología Agropecuaria, 11(2), 107-115.

4.Ruíz-Leza, H. A., Rodríguez-Jasso, R. M., Rodríguez-Herrera, R.,

Contreras-Esquivel, J. C., & Aguilar, C. N. (2007). Diseño de

biorreactores para fermentación en medio sólido. Revista Mexicana de

ingeniería química, 6(1).

5.Empresa pública metropolitana de Quito. (2012). Consultoría para la

realización de un estudio de caracterización de residuos sólidos

urbanos domésticos y asimilables a domésticos para el distrito

metropolitano de Quito. Recuperado de:www.emaseo.gob.ec/documentos/pdf/Caracterizacion_residuos.pdf

6. Kjeldsen, P., Barlaz, M. A., Rooker, A. P., Baun, A., Ledin, A.,

Christensen, T. H. (2002) Present & long-term composition of MSW

landfill leachate: a review. Critical Reviews in Environmental Scienceand Technology 32 (4): 297–336.

7. Jorstad, L. B., Jankowski, J., Acworth, R. I. (2004) Analysis of the

distribution of inorganic constituents in a landfill leachatecontaminated

aquifer Astrolabe Park, Sydney, Australia. Environmental Geology 46(2): 263-272.

8. Constitución del ecuador 2008. artículo 15 recuperado de :

http://www.oas.org/juridico/PDFs/mesicic4_ecu_const.pdf ConvenciónMarco sobre el

9.Cambio Climático acuerdo de París, Conferencia de las Partes 21er

período de sesiones París, 30 de noviembre a 11 de diciembre de 2015

Tema 4 b) del programa Plataforma de Durban para una Acción

Reforzada (decisión 1/CP.17): Aprobación del protocolo, otro

instrumento jurídico o una conclusión acordada con fuerza legal en el

marco de la Convención que sea aplicable a todas las Partes. Objetivo

fundamental. Recuperado de :https://unfccc.int/resource/docs/2015/cop21/spa/l09s.pdf

10.Montoya, D., Sierra, J., Silva, E. D., Buitrago, G., & Ramos, J.

(1999). Optimización de un medio de cultivo industrial para la

fermentación acetobutilica (abe). Revista Colombiana de

Biotecnología, 2(2), 37-42.

11.Rodríguez, Z., Elías, A., Boucourt, R., & Núñez, O. (2001). Efectos de

los niveles de nitrógeno ureico en la síntesis proteica durante la

fermentación de mezclas de caña (Saccharum officinarum) y boniato

(Ipomea batata Lam.). Revista Cubana de Ciencia Agrícola, 35(1).

12. López, R. M. (2008). Las paredes celulares de levadura de

Saccharomyces cerevisiae: un aditivo natural capaz de mejorar la

productvidad y salud del pollo de engorde (Doctoral dissertation,

Universitat Autònoma de Barcelona).

13. Ruiz, B. O., Castillo, Y., Anchondo, A., Rodríguez, C., Beltrán, R., La,

O., & Payán, J. (2009). Efectos de enzimas e inoculantes sobre la

composición del ensilaje de maíz. Archivos de zootecnia, 58(222), 163-

172.

14. Rodríguez, Z., Boucourt, R., Elías, A., & Madera, M. (2001).

Dinámica de fermentación de mezclas de caña (Saccharum officinarum)

y boniato (Ipomea batata). Revista Cubana de Ciencia Agrícola, 35(2).

15.Repetto, J. L., & Cajarville, C. (2009). ¿ Es posible lograr la

sincronización de nutrientes en sistemas pastoriles intensivos. XXXVII

Jornadas Uruguayas de Buiatría, 12, 60-67.

16. Afanador, A. M. (2005). El banano verde de rechazo en la

producción de alcohol carburante. Revista EIA, (3), 51-68.

17. Franco, Y., Gómez, G., Núñez, R., & Martínez, J. (2009).

Optimización de las condiciones de fermentación para la producción de

polihidroxibutirato por Rhizobium tropici. Revista CENIC. Ciencias

Biológicas, 40(1).