Psychrobacter sp. 273-4
   
   
 
Psychrobacter is a member of the gamma Proteobacteria family. This genera is commonly isolated from cold environments, including soil, sea-ice [1], and the skin and gills of fish [2]. It has also been associated with food spoilage and is often resistant to irradiation used for food preservation [3]. Psychrobacters have also been identified from a variety of human sources[4].

The sequenced strain, Psychrobacter 273-4 was isolated from a 20-40 thousand-year-old Siberian permafrost core[5]. The permafrost samples were obtained from the Kolyma-Indigirka lowland, Siberia by David Gilichinsky (Russian Academy of Sciences, Pushchino, Russia).

Psychrobacter 273-4 is a small, non-motile coccoid rod often found in pairs. On TSA it produces smooth, non-pigmented colonies. 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.

Through analysis of the transcriptome, experiments can be designed to study microbial survival under a variety of harsh conditions. The issue of long-term survival is of interest in the field of astrobiology. Organisms that survive such hostile environments may be used as models for understanding cellular responses on astral bodies.

  1. Bowman, J.P., et al., Diversity and association of Psychrophilic bacteria in Antarctic sea ice. Applied and Environmental Microbiology, 1997. 63(8): p. 3068-3078.
  2. Scholes, R.B. and J.M. Shewan, The present status of some aspects of marine microbiology. Advances in Marine Biology, 1964. 2: p. 133-169.
  3. Firstenberg-Eden, R., D.B. Rowley, and G.E. Shattuck, Factors affecting inactivation of Moraxella- Acientobacter cells in an irradiation process. Applied and Environmental Microbiology, 1980. 40: p. 480-485.
  4. Moss, C.W., et al., Cultural and chemical characterization of CDC groups EO-2, M-5 and M-6, Moraxella(Moraxella) species, Oligella urethralis, Acientobacter sp. and Psychrobacter immobilis. Journal of Clinical Microbiology, 1988. 26: p. 484-492.
  5. Vishnivetskaya, T., et al., Low temperature recovery strategies for the isolation of bacteria from ancient permafrost sediments. Extremophiles, 2000. 4. 165-173.