Classification and examples of extremophiles
|
Environmental parameter |
type |
definition |
examples |
|
temperature |
hyperthermophile thermophile mesophile psychrophile |
growth >80°C growth 60-80°C 15-60°C <15°C |
Pyrolobus fumarii, 113°C Synechococcus lividis Homo sapiens Psychrobacter, some insects |
|
radiation |
Deinococcus radiodurans |
||
|
pressure |
barophile piezophile |
Weight loving Pressure loving |
unknown For microbe, 130 MPa |
|
gravity |
hypergravity hypogravity |
>1g <1g |
None known None known |
|
vacuum |
tolerates vacuum (space devoid of matter) |
tardigrades, insects, microbes, seeds. |
|
|
desiccation |
xerophiles |
anhydrobiotic |
Artemia salina; nematodes, microbes, fungi, lichens |
|
salinity |
halophile |
Salt loving (2-5 M NaCl) |
Halobacteriacea, Dunaliella salina |
|
pH |
alkaliphile
acidophile |
pH >9
low pH loving |
Natronobacterium, Bacillus firmus OF4, Spirulina spp. (all pH 10.5) Cyanidium caldarium, Ferroplasma sp. (both pH 0) |
|
oxygen tension |
anaerobe microaerophil aerobe |
cannot tolerate O2 tolerates some O2 requires O2 |
Methanococcus jannaschii Clostridium Homo sapiens |
|
chemical extremes |
gases metals |
Can tolerate high concentrations of metal (metalotolerant) |
Cyanidium caldarium (pure CO2) Ferroplasma acidarmanus(Cu, As, Cd, Zn); Ralstonia sp. CH34 (Zn, Co, Cd, Hg, Pb) |