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.