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Topic : General characteristics of extremophiles presented by :- Gaurav Kumar pal M.Sc. Applied microbiology.
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Topic : General characteristics of extremophiles presented by :- Gaurav Kumar pal M.Sc. Applied microbiology
Contents :- EXTREMOPHILES 1.Thermophiles 2.Psychrophiles 3.Osmophiles 4. Methanogens 5. METHYLOTROPHS 6. Alkaliphiles 7. Acidophiles 8. Halophiles 9. Reference
EXTREMOPHILES :- • Having optimal condition outside the normal environment. • These organism are not only survive in extreme or unusual enviroment on the earth but also reproduced & grow. • Mostly extremophiles are ARCHAEA. • They are used in BIOTECHNOLOGY &VARIOUS INDUSTRIES
THERMOPHILES • CHARACTERISTICS :- • "Thermopiles" are heat loving microorganisms which can grow in the temperature 55-65 °C • minimum growth temperature:- 45°C • optimal growth temprature:-55- 65°C • Maximum growth temperature:- 110 °C • They contain heat-stable enzymes. • Used in biotechnology & medicine. • Example:-Thermos aquatics and Thermococcus littorals are used as sources of the enzyme DNA polymerase, for the PCR technique in DNA fingerprinting.
PSYCHROPHILES :- CHARACTERISTICS :- Most psychrophiles are bacteria or archaea. Psychrophiles are also called as Cryophiles . found in Arctic and Antarctic oceans & deep ocean. They are capable of growth and reproduction in cold temperatures, ranging from 4°C to +15°C. They having the cold –active enzyme. Having special proteins or cryoprotectants called antifreeze proteins. Examples are Arthrobacter sp., psychrobacter sp., and members of the genera Halomonas, Pseudomonas, Hyphomonas,andSphingomonas . Used Psychrophilic bacteriaRhodococcus sp. in biodegradation. Also used in pharma, baking , & fermentation industry .
OSMOPHILES • Osmophillic organisms are extremophiles that are able to grow in high sugar concentration . • osmophiles protect themselves against this high osmotic pressure by the help of osmoprotectants such as alcohols and amino acids . • Osmophile are important because they cause spoilage in the sugar and sweet goods industry. • Example of osmophiles is Aspergillus, Saccharomyces, Enterobacter aerogenes and Micrococcus.
METHANOGENS :- • Methanogens belong to the Archaea group of the Prokaryotes. • Methanogens are bacteria that produce methane gas. • Methanogens require anaerobic conditions. • Many require warm conditions to work best. • Methanogens are chemoautotrophs. • They can be used as sources of biogas gas. • This would be a renewable source of energy.
Using acetate that may be derived from the decomposition of cellulose: CH3COO+ + H- CH4 + CO2 +36 kJ mol-1 OR • Using hydrogen and carbon dioxide produced by the decomposers: 4 H2 + CO2 CH4 + 2 H2O +130.4 kJ mol-1 • Examples:- • Methanobacterium formicum • Methanococcus deltae
METHYLOTROPHS:- They are aerobic organism . are microorganisms that can use to reduced one carbon compounds, such as methanol or methane. The used carbon source for their growth. may grow on other organic molecules including Organic acids Ethanol And sugars . can degrade the methane, and called methanotrophs. Methylococcus capsulatus is used to degrade methane and other pollutants . Example: Methylosinus sp.& Methylococcus capsulatus
Alkalophiles:- • They grow at the Ph 9 and above. • isolated from alkaline environments. • cell surface play a key role in keeping the intracellular pH value in the range between 7 and 8.5 . • Used:- Biological detergents. Enzyme production. • Example:- bacillus okhensis ,alkalibacterium iburiense
Acidophiles:-acid loving organism • They grow at pH 3 or below . • these organisms have the ability to pump hydrogen ions out of their cells . • The internal ph of the cell is about 6.5 & external ph is about 2.5 or less • Used:- Enzyme production. • Example:-sulfolobus ,picrophilus ,ferroplasma
Halophiles:-salt loving organism • are organisms that live in high salt concentrations. • halophile means “salt loving”. • most halophiles are aerobic and heterotrophic. • some are anaerobic and photosynthetic. • They are pinkish in colour. • Having carotenoids for ultraviolet protection. • Example :- halobacterium , halococcus
Reference • Prescott & harley ,klein (2002) ,Microbiology second edition ,Arehaeobacteria, wm.C.brown publishers(497-504). • Tortora J.G., Funke R.b. ,Christine l. case, (1997),microbiology an introduction sixth edition ,microbial growth ,Addison wesley longman (154-158). • ALCAMO I. EDWARD(2001), Fundamentals of microbiology fifth edition ,bacterial structure and growth ,jones and bartlett publishers (112-115,122 ). • Wistreich A.G.,MAX. D.lechtman(1988) Microbiology fifth edition ,microbial ecology and environmental activities, Collier macmillan publishers LANDON(406-408). • http://en.wikipedia.org/wiki/Extremophile. • http://www.daviddarling.info/encyclopedia/H/halophile.html