Psychrophilic bacteria as possible models of life in Mars or Jovian moons: molecular analysis, a proposal

Bacteria,algae and also metazoans may live at temperatures below 0°C and survive ice formation in all body compartments1 ,2. In the Antarctic Dry Valleys, 3, microorganisms live at -35°C. Bacteria in culture metabolize and reproduce, 4, at -10°C. In order to identify and characterize new species we suggest, after having isolated microorganisms in culture from frozen samples, performing a selective cloning of 16S rRNA genes by PCR, electrophoresis to isolate genes, sequence analysis after subcloning and propagation in E. coli cells, building a phylogenetic tree of the bacterium. These devices are very common, being used for biomedical purposes in every country in the world. Ecology, evolutionary biology and astrobiology studies, as models of possible life on Mars or Jovian moons, or as microorganisms able to play important roles in terraforming perspectives, will benefit from a greater knowledge of these life forms and, last but not least, their enzymes, because of their low energy requirements, high specific activity at low temperature and thermolability, may provide a real spin-off for biotechnology. 1 Kohshima,S. (1984). Nature310, 225–227. 2 Wharton, D.A. & Ferns, D.J. (1995) J. Exp. Biol.198, 1381–1387. 3 Mahaney,W.C. et al. (2001). Icarus154, 113–130. 4 Bakermans, C. et al. (2003). Environ. Microbiol.5, 321–326