Abstract:

Cold-adapted bacteria and archaea are widely distributed in cold environments on Earth, such as permafrost, cold soils and deserts, glaciers, lakes, sea ice in the Arctic, Antarctic and high mountains, as well as the deep sea, ice caves and the atmospheric stratosphere etc. Cold-adapted organisms inhabiting these environments exhibit rich diversity. Studies on the biogeography of psychrophiles will enable us to understand their biodiversity, distribution and origins. Due to long-term living in cold regions, cold-adapted bacteria and archeae have developed specific physiological mechanisms of adaptation to cold environments. These mechanisms include: regulating the fluidity of the cytoplasmic membrane through adjusting the composition of membrane lipids; achieving low-temperature protection through compatibility solute, antifreeze proteins, ice-binding proteins, ice-nucleation proteins and anti-nucleating proteins; production of heat-shock and cold- shock proteins, cold acclimation protein and DEAD-box RNA helicase at low temperatures; production of cold-active enzymes; increasing energy generation and conservation. With the rapid development of sequencing technology, various omics-based approaches have been used to reveal cold-adaptive mechanisms of psychrophiles at the genomic level.

Key words: psychrophiles, biodiversity, biogeography, cold-adaptive mechanisms