the applications of halophilic bacteria
TRANSCRIPT
THE APPLICATIONS OF
HALIPHILIC BACTERIA IN
ENVIRONMENTAL
ENGENEERING
Prepared by:
Shaimaa ALSAADAWI
Supervisor: Dr. Gulşad USLU SENEL
Content1. Introduction
2. Definition of Halophiles
3. The halophiles habitat
4. mechanisms of Halophilic bacteria
5. The halophilic bacteria isolation
6. halophilic bacteria enzymes
7. Halophiles applications
8. Industrial application
9. Environmental applications
10.Conclusion
Introduction
Halophilic microorganisms have recently been re-discovered to
possess advantages for environmental and industrial treatment
processes. The spectrum of organisms that thrive in such saline
biotopes is mainly determined by parameters such as salinity,
solubility, ionic composition and, in some cases, temperature and
pH. Modern uses of halophiles include the production of natural
nutritional supplements, β-carotene, vitamins, and other components
from green algal Dunaliella species for human consumption, and for
the manufacturing of two-dimensional films of purple membrane
containing the bacteriorhodopsin protein from archaeal
Halobacterium species for biosensor applications.
HALOPHILES
DEFINITON
Halophiles are referred to those microorganisms that require salt
(NaCl) for growth, and they can be found in all three domains of
life: Archaea, Bacteria, and Eukarya which include a great
diversity of organisms, like moderately halophilic aerobic
bacteria, cyanobacteria, sulphur-oxidizing bacteria, heterotrophic
bacteria, anaerobic bacteria, archaea, protozoa, fungi, algae and
multicellular eukaryotes. They can be found in hypersaline
environments which are widely distributed in various
geographical areas on earth, such as saline lakes, salt pans or salt
marshes.
HALOPHILES DEFINITON Conn..
Halophiles can be roughly divided into two groups:
I- extremely halophile grows at salt concentration of 15% w/v
NaCl (2.5 M).
HALOPHILES DEFINITON Conn..
II- A moderate halophile grows at salt concentration of
3 to15% (w/v) and can tolerate 0- 25%(w/v). Both
Salinivibrio and Halomonas are moderate halophiles.
HALOPHILES DEFINITON Conn..
THE HALOPHILES HABITAT
Hypersaline environments constitute typical examples of environments with extreme conditions due to their high salinity, temperatures, low oxygen conditions and high pH values.
they are found in salt lakes, the Great Salt Lake and the Dead Sea, and in pools and flats along the seashore where seawater has been concentrated by drying in the sun.
These locations that effected by climatic conditions, water retention time and status of the deposited nutrients allows variety of halophilic biota to thrive.
Often extensive growth of pigmented microbes imparts red color to these crystallizer ponds.
Saline soils mostly assist the growth of halotolerant microbes rather than halophiles.
Other halophiles have been successfully isolated from meat, salted fish, desert plants and animals.
THE HALOPHILES HABITAT Conn..
Salinity and Temperature Measurements for Saline
Environments
Dead Sea, Jordan
Great Salt Lake, USA
Deep Lake, Antarctica
Pacific Ocean
31.5 - 34.2%12-33%21-28% 3.4 - 3.7%NaCl Percent (g/L)
21 - 36 °C5 - 35 °C0 - 11.5 °C1.4 - 30 °CTemperature
(C)
MECHANISMS OF HALOPHILIC BACTERIA
In order to survive in salt-rich environments, the cytoplasm ofhalophiles must be isotonic with the environment. In order toreach this state, they use two different methods:
- The first method , organic compounds are accumulated in the
cytoplasm which are known as compatible solutes. The most
commonly used solutes in this process are neutral amino acids and
sugars. These can be either synthesized or accumulated from the
environment. An important disadvantage of this method is that it
requires the organism to use considerable amounts of energy.
-The second, and less common adaptation to salt, involves the selective intake of potassium (K+) ions into the cytoplasm. In exchange, the organism pumps sodium (Na+) ions out with the help of the sodium-potassium pump. The main disadvantage with this approach is that all of the machinery within the cell (enzymes, structural proteins, etc.) must be adapted to high levels of non-organic ions and high salt levels.
THE
HALOPHILIC
BACTERIA
ISOLATION
All isolates grew optimally in media containing between 5
and 15% (w/v) total salts. Characteristics of the isolates were
either studied on nutrient agar or in nutrient broth. For
isolation of halophilic microorganisms (bacteria) and
enzyme production, salts-added culture medium is used. One
of the best media for isolation of halophilic bacteria is
named halophilic medium (HM). In all cases, pH should be
adjusted at 7.0.
THE HALOPHILIC BACTERIA
ISOLATION Conn..
The samples were collected during October andNovember (early wet season), April and May (dryseasons) from different sites which representing thesaline environments.
Samples were collected in sterile plastic containersand must be ere cultured through 18 h after collection.
All samples were cultured in a saline nutrient brothwith a final concentration of 10 % sea salt formoderately halophilic bacteria and 20 % sea salt forextremely halophiles.
Then the samples incubated at 34°C in an orbitalshaker for 3–7 days or more depending on the growthrate of the isolates
For long term storage; the samples were stored insealed plates at 4°C for some months by using Liquidnitrogen for longtime preservation
HALOPHILIC BACTERIA ENZYMES
Most environmental isolates able to produce hydrolytic enzymes that have diverse potential usage in biomedical science and chemical industries belonged to the Gram-negative genera Salinivibrio or Halomonas
Among the Gram-positive, representatives of the genera Bacillus. In general,
A wide diversity of enzymes found among the isolates that producing Lipolytic, Proteases, Amylases, Nucleases (DNA), Cellulase and Xylanases were chosen for the study, considering their high industrial usage.
ApplicationsMicroorganisms (examples)
Enzyme
Detergent additives, in the food and paper industries, enantioselective biocatalysis
Natrococcus sp.Lipases
Peptide synthesis, preparation detergents formulations.
Bacillus sp., Halobacillussp.
Proteases
starch hydrolysis and textile, food, brewing and distilling industries
Halobacterium salinarum Amylases
Acid 5′-guanilic and acid 5′-inosinic as flavor agents.
Microccocus varians,Bacillus sp.
DNase
Pulp and paper industry, baking industry for increasing loaf volume.
Halobacillus sp.Xylanases
Biocatalysis in organic solvents and super critic fluids.
Bacillus sp.Cellulases
Halophiles applications
Since the last decades and still, Halophiles have been qualified in
biotechnological and industry applications. These applications
includes: food industry pigment, organic osmotic stabilizers,
surfactants, enzymes that able to function at low water activates.
Various halophilic enzymes in different enzymatically processes,
compatible solutes as macromolecule stabilizers, biopolymers,
biofertilizers and pharmaceutically active molecules from halophilic
bacteria are among the important applications of these group.
Additionally, they have many potential in bioremediation of various
organic and inorganic pollutants from environment.
Halophiles applications Conn..
INDUSTRIAL BIOTECHNOLOGY
Recently, halophiles have shown promises to overcome in industrial
biotechnology shortcomings such as: chemicals, materials and biofuel
to alleviate the challenges of shortage on petroleum.
Although the disadvantages of bioprocesses including energy
consuming sterilization.
Some halophiles are able to grow in high pH and high NaCl containing
medium under higher temperature, allowing fermentation processes to
run contamination under unsterile conditions and continuous way.
At the same time, genetic manipulation methods have been
developed for halophiles. So far, halophiles have been used to
produce bioplastics polyhydroxyalkanoates (PHA), ectoines,
enzymes, and bio-surfactants.
Increasing effects have been made to develop halophiles into a
low cost platform for bioprocessing with advantages of low
energy, less fresh water consumption, low fixed capital
investment, and continuous production.
ENVIRONMENTAL BIOTECHNOLOGY
Environmental pollution due to anthropogenic activity has spread to
all types of ecosystems. Marine and fresh water or soils have been
impacted by the dispersion of contaminants.
Extremophilic microorganisms adapted to thrive in such hostile
environments identification of both individual and groups of
halophiles in saline wastewater from paper, textile, and oil industry
processes hasled to the exploration of specific enzymes that could be
exploited in treatment.
Contamination and biodegradation in extreme environments has
received little attention although many contaminated ecosystems
present high or low temperatures, extreme acidic or alkaline pH,
high pressures or high salinity.
Since halophiles are diverse and widespread and the large
numbers of contamination sites are often saline to hypersaline,
environmental applications of halophiles hold significant
promise.
It's been used for bioremediation and biodegradation of various
materials from industrial effluents to soil contaminants and
accidental spills are being widely explored
Biodegradation of Organic Pollutants
The degradation or transformation of
organic pollutants by halophilic and
halotolerant microorganisms has received
little attention. All the isolates were
moderately halophilic bacteria mainly from
the genus Halomonas that able to degrading
phenol as the sole source of carbon and
energy in a model industrial saline
wastewater. There have been some factors
that are effects on biodegradation processes
including temperature, season variation,
amount of the bacteria, and many more
factors.
Biodegradation of Sulfur Compounds
Organic sulfur is one of the compounds that have important role in
acid precipitation, global sulfur cycle, and global warming. They
have been identified as predominant odorants in several industrial
gaseous emissions. The use of haloalkaliphilic sulfur-oxidizing
bacteria in a biotechnological process designed to remove hydrogen
sulfide (H 2 S) from gaseous emissions of petroleum industry has
been recently described. However, Alkaliphilic halophilic and
methylotrophic methanogens from the Methanohalophilus genus
are able to degrade dimethyl sulfide (DMS). and grow in medium
with a methyl group-containing substrate (methanogenic substrate,
such as methanol or trimethylamine) as organic substrate
As the most produced waste waters have high concentration of salt, use of
halophiles offers a promise alternative in treatment of these wastes.
Bioremediation is a technology is being used for treatment the large-area of
environmental, also to remove the pollutants from soil, groundwater, waste
water, and sludge, industrial waste and waste gas. The purpose of
bioremediation is to put organic pollutants concentration down below the
limit of detection or below the environmental protection department of the
concentration range. A moderately halophilic chromium tolerant bacterium,
Vigribacillus sp. was isolated from saline soil
Bioremediation
Production of PHA
Poly-β-hydroxyalkanoate (PHA) is a polymer that accumulated by
many prokaryotes, Bacteria as well as archaea. It is used for the
production of biodegradable plastics (‘biological polyesters’) with
properties resembling that of polypropylene. Some halophilic
Archaea and Bacteria produce PHA. The archaea on Haloferax
mediterranei can accumulate the compound to up to 38% of its dry
weight; H. mediterranei grows in simple media with sugars or
starch as cheap carbon sources.
Conclusion
According to significant studies, it is important to estate the
potential of the halophilic bacteria which have been successfully
applied in several environmental and biotechnological
applications.
Halophilic bacteria is the most suitable with low disadvantage
solution for the processes of bioremediation, drinking water
treatment, and biodegradation processes.
Conclusion Conn.
Though the halophilic bacteria enzymes for some industrial
processes is still challenging due to some disadvantage of
halophiles.
Otherwise the uses of these microorganisms expend although as
for future it could be used in renewable and alternative energy.
As well as , these organisms will aid a tool for genetic and
biochemical analysis in the future.