Bacteria Genomes - PSYCHROBACTER ARTICUM

Psychrobacter arcticum is a member of the gamma Proteobacteria family. This genera is commonly isolated from cold environments, including soil, sea-ice, and the skin and gills of fish. It is a psychrobacteria, ie a microorganism capable of thriving at temperatures as low as 0°C.

The sequenced strain, Psychrobacter 273-4 was isolated from the 20-40 thousand-year-old Siberian permafrost core in the Kolyma-Indigirka lowland. It is a small, non-motile coccoid rod, they are often found in pairs.

This strain was selected for sequencing based on its excellent survival after exposure to a long-term freeze, rapid growth at low temperatures and age of the permafrost sediment from which it was cultured.

Completion of this bacterial genome sequence represents a milestone in bacterial genome sequencing as it is the first complete genome sequence to be obtained for any pyschroactive bacterium. It is of particular interest to astrobiologists studying the growth of organisms in potentially "lifeless" space environments. Understanding the genetic and physiological adaptations that Psychrobacter has made to inhabit permafrost will enable hypothesis about potential microbial life in extraterrestrial cryo environments.

Initial analysis reports that Psychrobacter has adapted to use oxidized substrates, and suggests the glyoxylate bypass (involving icl) plays an important role in low temperature energy metabolism.

References:

http://genome.jgi-psf.org/finished_microbes/psy24/psy24.home.html
http://nai.nasa.gov/nai2005/abstracts/793%20-%20Bergholz-NAI2005-2.doc.pdf
http://astrobiology.msu.edu/research/res_yr2.html