Piezophile

A piezophile (also called a barophile) is an organism which thrives at high pressures, such as deep sea bacteria or archaea. They are generally found on ocean floors, where pressure often exceeds 380 atm (38 MPa). Some have been found at the bottom of the Pacific Ocean where the maximum pressure is roughly 117 MPa. The high pressures experienced by these organisms can cause the normally fluid cell membrane to become waxy and relatively impermeable to nutrients. Evolution has forced these organisms to adapt in novel ways to become tolerant of these pressures in order to colonize deep sea habitats.

"Barotolerant" bacteria are able to survive at high pressures, but can exist in less extreme environments as well. "Obligate barophiles" cannot survive outside of such environments. For example, the Halomonas species "Halomonas salaria" requires a pressure of 1000 atm (100 MPa) and a temperature of 3 degrees Celsius. Most piezophiles grow in darkness and are usually very UV-sensitive; they lack many mechanisms of DNA repair.

References

*cite journal
author=Sharma, A.
coauthors=Scott, J. H.; Cody, G. D.; Fogel, M. L.; Hazen, R. M.; Hemley, R. J.; and Huntress, W. T.
title=Microbial activity at gigapascal pressures
journal=Science
volume=295
issue=5559
pages=1514–16
year=2002
month=Feb
pmid=11859192
doi=10.1126/science.1068018

ee also

*Archaea
*Bacteria
*Cell membrane