Fumeroles
Thermophiles,hyperthermophiles
Athermophileisanorganism—atypeofextremophile—thatthrivesatrelativelyhightemperatures,between45and122°C(113and252°F).[1][2]Manythermophilesarearchaea.Thermophiliceubacteriaaresuggestedtohavebeenamongtheearliestbacteria.[3]
Thermophilesareclassifiedintoobligateandfacultativethermophiles:Obligatethermophiles(alsocalledextremethermophiles)requiresuchhightemperaturesforgrowth,whereasfacultativethermophiles(alsocalledmoderatethermophiles)canthriveathightemperatures,butalsoatlowertemperatures(below50°C).Hyperthermophilesareparticularlyextremethermophilesforwhichtheoptimaltemperaturesareabove80°C.
Psychrophilesorcryophiles(adj.cryophilic)areextremophilicorganismsthatarecapableofgrowthandreproductionincoldtemperatures,rangingfrom−15°Cto+10°C.Temperaturesaslowas−15°Carefoundinpocketsofverysaltywater(brine)surroundedbyseaice.Theycanbecontrastedwiththermophiles,whichthriveatunusuallyhottemperatures.TheenvironmentstheyinhabitareubiquitousonEarth,asalargefractionofourplanetarysurfaceexperiencestemperatureslowerthan15°C.Theyarepresentinalpineandarcticsoils,high-latitudeanddeepoceanwaters,polarice,glaciers,andsnowfields.Theyareofparticularinteresttoastrobiology,thefielddedicatedtotheformulationoftheoryaboutthepossibilityofextraterrestriallife,andtogeomicrobiology,thestudyofmicrobesactiveingeochemicalprocesses.InexperimentalworkatUniversityofAlaskaFairbanks,a1000litrebiogasdigesterusingpsychrophilesharvestedfrom"mudfromafrozenlakeinAlaska"hasproduced200–300litresofmethaneperday,about20–30%oftheoutputfromdigestersinwarmerclimates.[1]
Extremophiles
Therearemanyclassesofextremophilesthatrangeallaroundtheglobe,eachcorrespondingtothewayitsenvironmentalnichediffersfrommesophilicconditions.Theseclassificationsarenotexclusive.Manyextremophilesfallundermultiplecategoriesandtermedaspolyextremophiles.Forexample,organismslivinginsidehotrocksdeepunderEarth'ssurfacearethermophilicandbarophilicsuchasThermococcusbarophilus.[9]ApolyextremophilelivingatthesummitofamountainintheAtacamaDesertmightbearadioresistantxerophile,apsychrophile,andanoligotroph.PolyextremophilesarewellknownfortheirabilitytotoleratebothhighandlowpHlevels.
Acidophile
AnorganismwithoptimalgrowthatpHlevelsof3orbelow
Alkaliphile
AnorganismwithoptimalgrowthatpHlevelsof9orabove
Anaerobe
AnorganismthatdoesnotrequireoxygenforgrowthsuchasSpinoloricusCinzia.Twosub-typesexist:facultativeanaerobeandobligateanaerobe.Facultativeanaerobecantolerateanaerobicandaerobiccondition;however,anobligateanaerobewoulddieinpresenceofeventracelevelsofoxygen.
Cryptoendolith
Anorganismthatlivesinmicroscopicspaceswithinrocks,suchasporesbetweenaggregategrains;thesemayalsobecalledEndolith,atermthatalsoincludesorganismspopulatingfissures,aquifers,andfaultsfilledwithgroundwaterinthedeepsubsurface.
Halophile
Anorganismrequiringatleast0.2Mconcentrationsofsalt(NaCl)forgrowth[10]
Hyperthermophile
Anorganismthatcanthriveattemperaturesbetween80–122°C,suchasthosefoundinhydrothermalsystems
Hypolith
Anorganismthatlivesunderneathrocksincolddeserts
Lithoautotroph
Anorganism(usuallybacteria)whosesolesourceofcarboniscarbondioxideandexergonicinorganicoxidation(chemolithotrophs)suchasNitrosomonaseuropaea;theseorganismsarecapableofderivingenergyfromreducedmineralcompoundslikepyrites,andareactiveingeochemicalcyclingandtheweatheringofparentbedrocktoformsoil
Metallotolerant
capableoftoleratinghighlevelsofdissolvedheavymetalsinsolution,suchascopper,cadmium,arsenic,andzinc;examplesincludeFerroplasmasp.,CupriavidusmetalliduransandGFAJ-1.[11][12][13]
Oligotroph
Anorganismcapableofgrowthinnutritionallylimitedenvironments
Osmophile
Anorganismcapableofgrowthinenvironmentswithahighsugarconcentration
Piezophile
Anorganismthatlivesoptimallyathighhydrostaticpressure;commoninthedeepterrestrialsubsurface,aswellasinoceanictrenches
Polyextremophile
Apolyextremophile(fauxAncientLatin/Greekfor'affectionformanyextremes')isanorganismthatqualifiesasanextremophileundermorethanonecategory.
Psychrophile/Cryophile
Anorganismcapableofsurvival,growthorreproductionattemperaturesof-15°Corlowerforextendedperiods;commonincoldsoils,permafrost,polarice,coldoceanwater,andinorunderalpinesnowpack
Radioresistant
Organismsresistanttohighlevelsofionizingradiation,mostcommonlyultravioletradiation,butalsoincludingorganismscapableofresistingnuclearradiation
Thermophile
Anorganismthatcanthriveattemperaturesbetween45–122°C
Thermoacidophile
Combinationofthermophileandacidophilethatprefertemperaturesof70–80°CandpHbetween2and3
Xerophile
Anorganismthatcangrowinextremelydry,desiccatingconditions;thistypeisexemplifiedbythesoilmicro
Amesophileis anorganismthat grows best in moderatetemperature, neither too hot nor too cold, typically between 20 and 45°C(68 and 113°F).[1]The term is mainly applied tomicroorganisms.
The habitats of these organisms include especiallycheese,yogurt, and mesophile organisms are often included in the process ofbeerandwinemaking.
Organismsthat prefer cold environments are termedpsychrophilic, those preferring warmer temperatures are termedthermophilicand those thriving in extremely hot environments arehyperthermophilic. All bacteria have their own optimum environmental surroundings and temperatures in which they thrive the most. A genome-wide computational approach has been designed by Zheng, et al. to classify bacteria into mesophilic and thermophilic.[2]