Editing Thermophile

{{short description|Organism that thrives at relatively high temperatures}}
{{distinguish|Thermopile|Thermopylae (disambiguation){{!}}Thermopylae}}
[[Image:Aerial image of Grand Prismatic Spring (view from the south).jpg|right|thumb|300px|Thermophiles produce some of the bright colors of [[Grand Prismatic Spring]], [[Yellowstone National Park]]]]
A '''thermophile''' is a type of [[extremophile]] that thrives at relatively high temperatures, between {{convert|41|and|122|C|F}}.<ref>{{cite book |title=Brock Biology of Microorganisms |date=2006|author=Madigan MT|author2=Martino JM |edition=11th |pages=136 |publisher=Pearson |isbn=0-13-196893-9}}</ref><ref>{{Cite journal |author= Takai T |display-authors= etal |title=Cell proliferation at 122°C and isotopically heavy CH<sub>4</sub> production by a hyperthermophilic methanogen under high-pressure cultivation |journal=PNAS |volume=105 |issue=31 |pages=10949–51 |date=2008 |doi= 10.1073/pnas.0712334105 |pmid=18664583 |pmc=2490668|bibcode=2008PNAS..10510949T |doi-access= free }}</ref> Many thermophiles are [[archaea]], though some of them are [[bacteria]] and [[fungi]]. Thermophilic [[eubacteria]] are suggested to have been among the earliest bacteria.<ref name="pmid19000750">{{cite journal |author=Horiike T |author2=Miyata D |author3=Hamada K |display-authors=etal |title=Phylogenetic construction of 17 bacterial phyla by new method and carefully selected orthologs |journal=Gene |volume=429 |issue=1–2 |pages=59–64 |date=January 2009 |pmid=19000750 |pmc=2648810 |doi=10.1016/j.gene.2008.10.006 }}</ref>

Thermophiles are found in [[Geothermal energy|geothermal]]ly heated regions of the [[Earth]], such as hot springs like those in [[Yellowstone National Park]] and [[deep sea]] [[hydrothermal vent]]s, as well as decaying plant matter, such as [[peat bogs]] and [[compost]]. They can survive at high temperatures, whereas other bacteria or archaea would be damaged and sometimes killed if exposed to the same temperatures.

The [[enzyme]]s in thermophiles function at high temperatures. Some of these enzymes are used in [[molecular biology]], for example the [[taq polymerase|''Taq'' polymerase]] used in [[polymerase chain reaction|PCR]].<ref>{{cite journal |last1=Vieille |first1=Claire |last2=Zeikus |first2=Gregory J. |date=March 2001 |title=Hyperthermophilic Enzymes: Sources, Uses, and Molecular Mechanisms for Thermostability |journal=Microbiology and Molecular Biology Reviews |volume=65 |issue=1 |pages=1–43 |doi=10.1128/MMBR.65.1.1-43.2001 |issn=1092-2172 |pmid=11238984|pmc=99017 }}</ref> "Thermophile" is derived from the {{langx|el|θερμότητα}} (''thermotita''), meaning [[heat]], and {{langx|el|φίλια}} (''philia''), [[love]].

Comparative surveys suggest that thermophile diversity is principally driven by pH, not temperature.<ref>Power, J.F., Carere, C.R., Lee, C.K., Wakerley, G.L., Evans, D.W., Button, M., White, D., Climo, M.D., Hinze, A.M., Morgan, X.C. and McDonald, I.R., 2018. Microbial biogeography of 925 geothermal springs in New Zealand. Nature communications, 9(1), p.2876.</ref>

==Classification==
Thermophiles can be classified in various ways.  One classification sorts these organisms according to their optimal growth temperatures:<ref>{{cite journal|author=Stetter, K.|title=History of discovery of the first hyperthermophiles|journal=Extremophiles|year=2006|volume=10|issue=5|pages=357–362|doi=10.1007/s00792-006-0012-7|pmid=16941067|s2cid=36345694}}</ref>
# Simple thermophiles: {{convert|50–64|C|F}}
# Extreme thermophiles {{convert|65–79|C|F}}
# Hyperthermophiles {{convert|80|C|F}} and beyond, but not below {{convert|50|C|F}}

In a related classification, thermophiles are sorted as follows:
# Facultative thermophiles (also called moderate thermophiles) can thrive at high temperatures, but also at lower temperatures (below {{convert|50|C}}), whereas
# Obligate thermophiles (also called extreme thermophiles) require such high temperatures for growth.
# [[Hyperthermophile]]s are particularly extreme thermophiles for which the optimal temperatures are above {{convert|80|C}}.

[[File:Thermophilic bacteria.jpg|thumb|A colony of thermophiles in the outflow of [[Mickey Hot Springs]], [[Oregon]],  the water temperature is approximately
{{convert|60|C}}.]]

Many hyperthermophilic [[Archaea]] require elemental [[sulfur]] for growth. Some are [[anaerobe]]s that use the sulfur instead of [[oxygen]] as an [[electron acceptor]] during [[anaerobic respiration|anaerobic cellular respiration]]. Some are [[lithotroph]]s that oxidize sulphur to create [[sulfuric acid]] as an energy source, thus requiring the microorganism to be adapted to very low [[pH]] (i.e., it is an [[acidophile (organisms)|acidophile]] as well as thermophile). These organisms are inhabitants of hot, sulfur-rich environments usually associated with [[volcanism]], such as [[hot springs]], [[geysers]], and [[fumaroles]].  In these places, especially in Yellowstone National Park, [[wikt:zonation|zonation]] of microorganisms according to their temperature optima occurs. These organisms are often colored, due to the presence of [[photosynthetic]] pigments.{{cn|date=February 2023}}

==Thermophile versus mesophile==
Thermophiles can be discriminated from [[mesophile]]s from genomic features. For example, the [[GC-content]] levels in the coding regions of some signature genes were consistently identified as correlated with the temperature range condition when the association analysis was applied to mesophilic and thermophilic organisms regardless of their phylogeny, oxygen requirement, salinity, or habitat conditions.<ref>{{cite journal |author=Zheng H |author2=Wu H |title=Gene-centric association analysis for the correlation between the guanine-cytosine content levels and temperature range conditions of prokaryotic species |journal=BMC Bioinformatics |volume=11 |pages=S7 |date=December 2010 |issue=Suppl 11 |doi=10.1186/1471-2105-11-S11-S7 |pmc=3024870 |pmid=21172057 |doi-access=free }}</ref>

== Fungal thermophiles ==
Fungi are the only group of organisms in the Eukaryota domain that can survive at temperature ranges of 50–60&nbsp;°C.<ref>{{Cite journal |last1=Rajasekaran |first1=A. K. |last2=Maheshwari |first2=R. |date=1993-09-01 |title=Thermophilic fungi: An assessment of their potential for growth in soil |url=https://doi.org/10.1007/BF02702992 |journal=Journal of Biosciences |language=en |volume=18 |issue=3 |pages=345–354 |doi=10.1007/BF02702992 |s2cid=46013720 |issn=0973-7138}}</ref> Thermophilic fungi have been reported from a number of habitats, with most of them belonging to the fungal order [[Sordariales]].<ref>{{Citation |last1=Patel |first1=Hardi |title=Thermophilic fungi: Diversity, physiology, genetics, and applications |date=2021 |url=http://dx.doi.org/10.1016/b978-0-12-821005-5.00005-3 |work=New and Future Developments in Microbial Biotechnology and Bioengineering |pages=69–93 |publisher=Elsevier |access-date=2022-06-02 |last2=Rawat |first2=Seema|doi=10.1016/b978-0-12-821005-5.00005-3 |isbn=9780128210055 |s2cid=224847697 }}</ref> Thermophilic fungi have great biotechnological potential due to their ability to produce industrial-relevant thermostable enzymes, in particular for the degradation of plant biomass.<ref>{{Cite journal |last1=van den Brink |first1=Joost |last2=Facun |first2=Kryss |last3=de Vries |first3=Michel |last4=Stielow |first4=J. Benjamin |date=December 2015 |title=Thermophilic growth and enzymatic thermostability are polyphyletic traits within Chaetomiaceae |url=http://dx.doi.org/10.1016/j.funbio.2015.09.011 |journal=Fungal Biology |volume=119 |issue=12 |pages=1255–1266 |doi=10.1016/j.funbio.2015.09.011 |pmid=26615748 |bibcode=2015FunB..119.1255V |issn=1878-6146}}</ref>

== Gene transfer and genetic exchange ==

''[[Sulfolobus solfataricus]]'' and ''[[Sulfolobus acidocaldarius]]'' are [[Hyperthermophile|hyperthermophilic]] [[Archaea]].  When these organisms are exposed to the [[DNA damaging agent]]s [[UV radiation|UV irradiation]], [[bleomycin]] or [[mitomycin C]], species-specific cellular aggregation is induced.<ref name=Frols08>{{cite journal |display-authors=6 |author=Fröls S |author2=Ajon M |author3=Wagner M |author4=Teichmann D |author5=Zolghadr B |author6= Folea M |author7=Boekema EJ |author8=Driessen AJ |author9=Schleper C |author10=Albers SV |title=UV-inducible cellular aggregation of the hyperthermophilic archaeon Sulfolobus solfataricus is mediated by pili formation |journal=Mol. Microbiol. |volume=70 |issue=4 |pages=938–52 |date=November 2008 |pmid=18990182 |doi=10.1111/j.1365-2958.2008.06459.x |url=https://www.rug.nl/research/portal/files/56956856/UV_inducible_cellular_aggregation_of_the_hyperthermophilic_archaeon_Sulfolobus_solfataricus_is_mediated_by_pili_formation.pdf |doi-access=free }}</ref><ref name=Ajon>{{cite journal |author1=Ajon M |author2= Fröls S |author3=van Wolferen M |author4=Stoecker K |author5=Teichmann D |author6=Driessen AJ |author7=Grogan DW |author8=Albers SV |author9=Schleper C |display-authors=5 |title=UV-inducible DNA exchange in hyperthermophilic archaea mediated by type IV pili |journal=Mol. Microbiol. |volume=82 |issue=4 |pages=807–17 |date=November 2011 |pmid=21999488 |doi=10.1111/j.1365-2958.2011.07861.x |url=https://pure.rug.nl/ws/files/6771142/2011MolMicrobiolAjon.pdf |doi-access=free }}</ref>  In ''S. acidocaldarius'', UV-induced cellular aggregation mediates chromosomal marker exchange with high frequency.<ref name=Ajon />  Recombination rates exceed those of uninduced cultures by up to three orders of magnitude.  Frols et al.<ref name=Frols08 /><ref>{{cite journal |author=Fröls S |author2=White MF |author3=Schleper C |title=Reactions to UV damage in the model archaeon Sulfolobus solfataricus |journal=Biochem. Soc. Trans. |volume=37 |issue=Pt 1 |pages=36–41 |date=February 2009 |pmid=19143598 |doi=10.1042/BST0370036 }}</ref> and Ajon et al.<ref name=Ajon />(2011) hypothesized that cellular aggregation enhances species-specific DNA transfer between ''Sulfolobus'' cells in order to provide increased repair of damaged DNA by means of [[homologous recombination]].  Van Wolferen et al., in discussing DNA exchange in the hyperthermophiles under extreme conditions, noted that DNA exchange likely plays a role in repair of DNA via homologous recombination.  They suggested that this process is crucial under DNA damaging conditions such as high temperature.  Also it has been suggested that DNA transfer in ''Sulfolobus'' may be a primitive form of sexual interaction similar to the more well-studied [[bacterial transformation]] systems that are associated with species-specific DNA transfer between cells leading to homologous recombinational repair of DNA damage.<ref>{{cite journal |author=van Wolferen M |author2=Ajon M |author3=Driessen AJ |author4=Albers SV |title=How hyperthermophiles adapt to change their lives: DNA exchange in extreme conditions |journal=Extremophiles |volume=17 |issue=4 |pages=545–63 |date=July 2013 |pmid=23712907 |doi=10.1007/s00792-013-0552-6 |s2cid=5572901 }}</ref>

==See also==

* [[Mesophile]]
* [[Psychrophile]]
* [[Anaerobic digestion]]
* [[Pyrolobus fumarii|Pyrolobus fumarri]]

==References==
{{reflist}}

==External links==
* {{cite web |url=https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Tree&id=183924 |title=Thermoprotei : Extreme Thermophile |work=NCBI Taxonomy Browser }}
* [https://deepcarbon.net/feature/how-hot-is-too-hot#.V9Fp-4WASfE/ How hot is too Hot? T-Limit Expedition]
{{Extremophile}}

[[Category:Anaerobic digestion]]
[[Category:Biodegradation]]
[[Category:Biodegradable waste management]]
[[Category:Thermophiles| ]]
[[Category:Thermozoa]]
[[Category:Geysers]]
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