Psychrophiles and Psychrotrophs

Psychrophiles are extremophilic bacteria or archaea which are cold-loving, having an optimal temperature for growth at about 158C or lower, a maximal temperature for growth at about 208C and a minimal temperature for growth at 08C or lower. Psychrotrophs are cold-tolerant bacteria or archaea that have the ability to grow at low temperatures, but have optimal and maximal growth temperatures above 15 and 208C, respectively. The Earth has extensive cold ecosystems that do not reach temperatures greater than 58C (e.g. worldwide deep oceans, polar surface, polar ice-cap regions, permafrost). Psychrophiles and psychrotrophs are cold-loving extremophiles adroitly adapted to these environmental conditions, and are often capable of enduring extended periods of cryobiosis.