Extremophiles
Extremophiles are micro-organisms that inhabit some of earth's most hostile environments of temperature (-2C to 15C and 60C to 120C), salinity (3-5M NaCl), pH (<4 and >9), and/or pressure (>400 atmospheres). Many extremophiles identified to date are members of the Domain Archaea, although extremophilic members of the Domain Bacteria are known. Phylogenetic analyses of environmentally-derived DNA indicate that mesophilic archaea are also abundant. To thrive in such environmental extremes, these organisms require cellular components that are naturally resistant to, and functional in, conditions that were once thought incompatible with life. Thus many extremophiles, particularly the thermophiles, are an excellent source of hyperstable macromolecules, and there is no doubt that the discovery of extremophiles, and especially of Archaea, has stimulated a wealth of fundamental and applied research into these organisms and their cellular constituents.
Scott's Hut Ross Island, Antarctica
Artist's palette Waiotapu, New Zealand