Hydrothermal features are habitats for microscopic organisms called thermophiles: "thermo" for heat, "phile" for lover. So the heat lovers. So temperature is one of the most important factors that influences the growth and survival of microorganisms. If the temperature increases: they speed up the biochemical and enzymatic reactions. But at the low temp. enzymatic activities and microbial growth can continue more slowly. As the temperature increases, molecules move faster, enzymes speed up metabolism and cells rapidly increase in size. But, above a certain value, all of these activities are proceeding at such high rates, enzymes start to denature, and the total effect is detrimental. Cellular growth ceases. But thermophilic microorganisms/heat lovers can tolerate and survive these high temperatures. High temperature grown microbe types can be classified mainly into 02 categories. Prokaryotes and eukaryotes. Thermophilic bacteria- Thermus aquaticus is one of the most advantageous species of bacteria that can tolerate high temperatures, isolated from Yellowstone national park hydrothermal vent. source of the Taq DNA polymerases, one of the major discoveries now its use for PCR. Technique. It is difficult to imagine life without PCR. Here are some examples of cyanobacterial species also. Archaea are the most extreme of all extremophiles. These single-celled organisms have no nucleus but have a unique, tough outer cell wall. This tough wall contains molecules and enzymes. And also they have many adaptations. Fig shown as the lSulfolobus is the genus most often isolated. THERMOPHILIC FUNGI Although they aren’t visible like mushrooms, several thermophilic fungi thrive in Yellowstone. Curvularia protuberata lives in the roots of hot springs panic grass. This association helps both survive higher temperatures than when alone. In addition, researchers have recently discovered a virus inside the fungus that is also essential to the grass’s ability to grow on the hot ground. thermophilic algae Tolerate & thriving at high temperatures ( 50- 70 C ) zygogonium is the most often isolated species. Here are some examples of thermophilic protista belonging to the eukarya. These are some habitats of thermophilic extremophiles. Classified into 03 groups. Extreme thermophiles – mostly archaea but some bacteria too belong to this category. (Ex thermotoga./ bacteria) Then, adaptations., Prokaryotes accept higher temperatures than eukaryotes. Above 70° C - Only prokaryotes able to grow. Above 100°C - Only archaea able to grow. Because they have many adaptations.

1. High temperature on
microbial growth
Dinithi Vihanga De Silva

2. Content
1. Life in extreme heat
2. Temperature stress
3. High temperature grown microbe types
i)Thermophilic bacteria
ii) Thermophilic archaea
iii) Thermophilic fungi
iv) Thermophilic algae
v) Thermophilic Protista (eukaryotic)
4. Habitats of thermophilic microbes
5. Adaptations to high temperature
6.Thermophiles & their applications
7.Conclusion
8.References

3.  Extremophile: A microorganism living in extreme conditions such as heat and
acid, that cannot survive without these conditions.
 Thermophile: Heat-loving extremophile. ("thermo" for heat, "phile" for lover)
Fig 01- Thermophiles, or heat-loving microscopic organisms, are nourished by the extreme habitat at hydrothermal features in Yellowstone National
Park. They also color hydrothermal features shown here at Firehole Spring. https://www.nps.gov/yell/learn/nature/life-in-extreme-heat.htm
Life in Extreme Heat

4. Temperature stress
 Majority of microorganisms
living at temperatures average
between 15 and 45 °C
 Optimum growth between 25
and 37 °C: Mesophilic
 But, thermophiles able to
develop at temperature above
45- 50 °C

5. High temperature grown microbe types
1.Bacteria
2.Archaea
3.Microalgae
4.Fungi
5.Protista
Prokaryotes
Eukaryotes

6. Thermophilic Bacteria
• Thermus aquaticus is a species of bacteria that can
tolerate high temperatures and source of the Taq
DNA polymerases.
• Thermophilic cyanobacteria, arbitrarily defined, are
those that grow well or best above 45°.
• They may also be present in nongeothermal
environments.
• such as desert soils and rocks, intertidal flats and
sabkhas, tropical ponds and pools, cliff faces, and
other habitats where temperatures often reach the
40-50 ° range.
Fig 02- Thermus aquaticus

7. Cyanobacteria Calothrix
pH : 6–9
Temperature : 30–45°C (86–113°F)
Color : Dark brown mats
Metabolism : Photosynthesis by day; fermentation by night.
Location : Mammoth Hot Springs, Upper, Midway, and
Lower geyser basins
Cyanobacteria Oscillatoria
pH: 6–8
Temperature: 36–45°C (96–113°F)
Color: Orange mats
Metabolism: Photosynthesis; oscillating moves it closer to or
away from light sources.
Location: Mammoth Hot Springs and Chocolate Pots
Cyanobacteria Synechococcus
pH : 7–9
Temperature: 52–74°C (126–165°F)
Colour : Green mats
Metabolism : Photosynthesis by day; fermentation by night.
Location : Mammoth Hot Springs, Upper, Midway, and Lower
geyser basins
Green Sulfur Chlorobium
pH : 6–9
Temperature : 32–52°C (90–126°F)
Color: Dense, dark green mats
Metabolism : Anoxygenic photosynthesis— produces sulfate and
sulfur, not oxygen.
Location: Mammoth Hot Springs and Calcite Springs
Aquifex Hydrogenobaculum
pH: 3–5.5
Temperature: 55–72°C (131–162°F)
Color: Yellow and white streamers
Metabolism: Uses hydrogen, hydrogen sulfide and carbon dioxide
as energy sources; can use arsenic in place of hydrogen sulfide.
Location: Norris Geyser Basin, Amphitheater Springs
Aquifex- Thermocrinis
pH: 5–9
Temperature: 40–79°C (104–174°F)
Color: Bright red or orange streamers; contains carotenoid
pigments that act as sunscreen.
Location: Lower Geyser Basin
Thermophilic Bacteria in Yellowstone National Park

8. Thermophilic Archaea
Thermophilic Archea found in Yellowstone
National Park
Domain : Archaea
pH : 0.9–9.8
Temperature : up to 92°C (197.6°F)
Color : Cream or yellow-colored
Metabolism : Chemosynthesis, using hydrogen, sulfur, carbon
dioxide
Form : Unicellular, tough cell membrane
Location : In many of Yellowstone’s hydrothermal features
Sulfolobus is the genus most often isolated
pH : 0–4
Temperature : ~50-80°C (104–131°F)
Color : Cream or yellow-colored
Metabolism : Chemosynthesis
Location : Norris Geyser Basin and Lemonade Creek
Fig 03 - Sulfolobus solfataricus , Yellowstone
Nationalpark, described by T. Brock as the first
hyperthermophilic microorganism (Brock et al. 1972)
http://www.sulfosys.com/sulfolobus-solfataricus.html

9. Thermophilic fungi
 Thermophilic fungi – thrive at 45- 55 ‘C
 Higher stability & better catalytic rates.
 Ex: Myceliophthora thermophila (Ascomycete fungi)
Fig 04- The fungi Curvularia proturberata lives in the roots of hot
springs panic grass.
https://www.nps.gov/yell/learn/nature/thermophilic-eukarya.htm
Fungi (Curvularia protuberata)
Temperature : ≤65°C (149°F) with panic grass
<55°C (131°F) without
Description : Grows in roots of hot springs
panic grass (Dichanthelium lanuginosum), enabling
both to survive high temperatures; the plant also
produces sugars that the fungus feeds on.

10. Thermophilic Algae
Red algae Cyanidioschyzon
pH : 0–4
Temperature : 40–55°C (104–131°F)
Color : Bright green
Metabolism : Photosynthetic
Form : Coating on top of formations; mats
Location : Norris Geyser Basin, Lemonade Creek,
and Nymph Creek
Green algae Zygogonium
pH : 0–4
Temperature : 32–55°C (90–131°F)
Color : Appears black or dark purple in sunlight
Metabolism : Photosynthetic
Form : Filaments and mats
Location : Norris Geyser Basin, Lemonade Creek,
and Nymph Creek
Fig 05- Eukarya, like these waving streamers of Zygogonium
live in the extreme environments of Yellowstone.
https://www.nps.gov/yell/learn/nature/thermophilic-
eukarya.htm

11. Protozoa Naegleria (amoeba)
pH: Alkaline
Temperature: Warm
Description: Predator of Bacteria; can infect humans
when ingested through nose.
Location: Huckleberry Hot Springs and Boiling River
Protozoa Vorticella (ciliate)
pH: Alkaline
Temperature: Warm
Description: Consumer; single-celled ciliate (feathery
appendages swirl water, bringing prey).
Location: Obsidian Creek
Euglenids Mutablis
pH: 1–2
Temperature: <43°C (109°F)
Description: Single-celled; photosynthetic; moves by
waving one or two strands called flagella.
Thermophilic protista
Fig 06- extremophilic Euglenids Mutablis

12. Habitats of thermophilic microbes
Fig 07- Geysers
Fig 10- Hot springs
Fig 09- Volcanos
Fig 08- Fumaroles
https://www.frommers.com/slideshows/848448-beyond-old-
faithful-a-geyser-gazing-guide-to-yellowstone-national-park
https://www.flickr.com/photos/usgeologicalsurvey/23998018863
https://www.scmp.com/week-asia/explained/article/3041783/explained-
asias-deadliest-eruptions-and-four-volcanoes-watch https://www.quora.com/Is-it-safe-to-swim-in-drink-
from-the-colorful-hot-springs-in-Yellowstone

13. Adaptations to high temperature
Prokaryotes accept higher temperature than eukaryotes.
• Above 70° C - Only prokaryotes able to grow.
• Above 100°C - Only archaea able to grow.
Prokaryotes classified into 03 groups of
thermophiles.
Facultative
thermophile
Strict
thermophiles
Extreme
thermophiles
Maximum temp. 50-60 °C
Don’t grow below 40°C.
Optimum at 60-65°C.
Optimum at 80- 115°C.

14. Life at high temperature
adaptations
Protein stability
DNA stability
Membrane
lipids
 Thermostable proteins
 Small amino acid sequence will
result in the protein folding
 More folding makes more
resistance to temperature.
 Hyperthermophiles possess a
reverse DNA Gyrase
 It produces positive supercoiling of
DNA.
 That ensure better stability to high
temperature.
 Composed of bi-phytanyl tetra-
ethers & they are resistant to
high temperature.
 Due to the presence of
covalent link between the
phytanyl units.

15. Fig 11- Lipids of hyperthermphilic Archaea
Fig 12- Lipids of non- hyperthermophilic prokaryots.

16. Thermophiles
& their
applications
DNA
polymerases
Biofuel
production
Bioleaching
Detergent
Proteases &
Lipases

17. Conclusion
Heat-loving microorganisms have different
survival adaptations. Among them, prokaryotes
show great adaptations than Eukaryotes. They
produces different enzymes, proteins & etc.
These are used for the many advantageous
biotechnological applications. And a lot more
open for discover.

18. References…..
 Wang, Q., Cen, Z. and Zhao, J., 2015. The survival mechanisms of thermophiles at high
temperatures: an angle of omics. Physiology, 30(2), pp.97-106.
 Ward, D.M., Castenholz, R.W. and Miller, S.R., 2012. Cyanobacteria in geothermal habitats. In
Ecology of cyanobacteria II (pp. 39-63). Springer, Dordrecht.
 Lowe, S.E., Jain, M.K. and Zeikus, J.G., 1993. Biology, ecology, and biotechnological applications
of anaerobic bacteria adapted to environmental stresses in temperature, pH, salinity, or
substrates. Microbiological reviews, 57(2), pp.451-509.
 Wiegel, J., Ljungdahl, L.G. and Demain, A.L., 1985. The importance of thermophilic bacteria in
biotechnology. Critical Reviews in Biotechnology, 3(1), pp.39-108.

19. Thank you….

20. Acknowledgement