This presentation will briefly guide you about the isolation of thermophiles and about their adaptation mechanism to the extreme environments. How do they respond to extreme heat and how do they survive at such high temperature. Also I've added a link for a You-tube video. And also shared the references used to make this Power-point presentation. Thank-you
Major project report on Tata Motors and its marketing strategies
Extremophiles and their adaptations to hot environments
1. EXTREMOPHILES AND THEIR ADAPTATIONS TO
HOT ENVIRONMENTS
NAME: ABHISHEK ANAND SHETYE
CLASS: M.Sc. MICROBIOLOGY PART 1
This Photo by Unknown Author is licensed under CC BY-NC
2. What are Extremophiles?
• Organisms living in extreme conditions that are mostly detrimental for other forms
of life.
• In another words, an extremophile is a microorganism, that lives in condition of
extreme acidity(pH), alkalinity, temperature, salinity, pressure, etc.
This Photo by Unknown Author is licensed under CC BY-SA
This Photo by Unknown Author is
licensed under CC BY-SA
4. Thermophiles
• Thermophiles is derived from Greek word “Thermotita” which means Heat and
“philia” means loving. i.e. Heat loving organisms.
• Types of Thermophiles:
1. Simple Thermophiles: optimum temperature for growth 50-64 ℃.
2. Extreme Thermophiles: optimum temperature for growth 65-79 ℃.
3. Hyperthermophiles: optimum temperature for growth 80 ℃ and beyond.
4. Thermotolerant: MOs that cannot grow but can tolerate high temperature.
• Isolation of Thermophiles:
1. Hot springs, volcanic exhalations, hydrothermal vents.
2. Smoldering coal refuse piles, Geothermally heated regions, deep sea hot
smokers.
6. Adaptation mechanism of Thermophiles
1. Chemolithoautotrophic mode of nutrition.
2. Membrane Lipids having Ether linkage.
3. Reverse DNA Gyrase enzyme.
4. High GC content.
5. Heat Shock Protein.
6. Histone like proteins.
7. Salts like Potassium and Magnesium.
7. 1.Chemolithoautotrophic mode of nutrition
• Most of the hyperthermophiles are adapted to chemolithoautotrophic mode of
nutrition i.e.
1. Inorganic redox reactions serves as energy source.
2. CO2 is the only carbon source.
3. H2 serves as important electron donor.
9. 2.Membrane Lipids having Ether linkage
• Membrane lipids have ether linkage in contrast to ester linkage in mesophiles.
• Membrane lipids of the bacterial hyperthermophile T. maritima contain a novel
glycerol ether lipid, 15,16-dimethyl-30-glyceryloxy-triacontanedioic acid.
• These lipids are more branched, more saturated and are of high molecular weight.
10. 3.Reverse DNA Gyrase Enzyme
• Unique type I DNA topoisomerase (DNA Gyrase) causes positive supertwist for
stabilization.
• Positive Supercoiling increases into linking number(LK) of topologically closed
DNA.
• Increase in linking number(LK) counteracts the effect of temperature elevation on
DNA molecule.
12. 4. High GC content
• Genomic structure is more stable in thermophiles rather than mesophiles.
• Guanine (G) and Cytosine (C) are important indicators of DNA stability.
• High GC content contributes to the thermostability of the genome, and is
correlated with the Optimum Growth Temperature(OGT).
• GC composition is non-universal. i.e. Different thermophiles have different GC
contents.
e.g. Thermus thermophilus ATCC 33923 with GC content of 69.41%,
Geobacillus kaustophilus with 52.1% .
13. 5. Heat shock proteins
• Heat shock proteins are essential for the growth of the hyperthermophiles.
• Pyrodictium occultum consisted of a heat inducible molecular chaperone
designated “Thermosome” at 108 ℃.
• With the thermosome fully induced P. occultum is able to survive autoclaving for
1 hour (121 ℃; 2 bar pressure).
• Survival of organisms growing at these temperatures may be ensured by rapid re-
synthesis of thermo-sensitive compounds.
• The upper temperature border of life is still unknown and depends on the stability
of the biomolecules.
