Bacteria Genomes - COLWELLIA PSYCHRERYTHRAEA

Colwellia psychrerythraea is an Arctic marine bacterium which thrives at temperatures below 5C.

Most of Earth's biosphere is cold and marine, with 90% of the ocean's waters at 5C or colder. 20% of Earth's surface environment is frozen, including permanently frozen soil (permafrost), terrestrial ice sheets (glacial ice), polar sea ice, and snow cover. A diversity of microorganisms can be recovered from these environments but only cold-adapted organisms can be active in them. Colwellia psychrerythraea 34H, is a model for the study of life in these permanently cold environments.

Colwellia psychrerythraea is a gamma proteobacteria, that is strictly psychrophilic (requiring temperatures of less than 20°C to grow on solid media). It is one of the Colwellia genus, members of which have been obtained from stably cold marine environments, including deep sea and Arctic and Antarctic sea ice. Many members of this genus produce extracellular polymeric substances relevant to biofilm formation and cryoprotection and enzymes capable of degrading high-molecular-weight organic compounds. These traits are likely to make the Colwellia species important to carbon and nutrient cycling wherever they occur in the cold marine environment, from contaminated sediments to ice formations under study as analogs for possible habitats on a younger Earth and other planets and moons (e.g., Mars).

The completion of the 5,373,180-bp genome sequence reveals capabilities important to carbon and nutrient cycling, bioremediation, production of secondary metabolites, and cold-adapted enzymes. Comparative genome analyses suggest that the psychrophilic lifestyle is most likely conferred not by a unique set of genes but by a collection of synergistic changes in overall genome content and amino acid composition.

References:

http://www.gi.alaska.edu/~eicken/he_publ/03JED.pdf
http://www.tigr.org/new/press_release_07-25-05.shtml