ИСТИНА

As the result of performed experiments, we determined the strains most resistant to wide range of extreme factor, the Halomonas sp. Н12b и Halorubrum sp. Н13a strains. The strains Salicola sp. H9b, Halomonas sp. H8b и Halorubrum sp. H3a were less resistant (in ascending order). In this case, archela strains were more tolerant to various salt concentrations, but less resistant to oscillations of various environmental parameters, while bacteria have can survive and reproduce in a very wide range of concentrations of various salts. Judging from the results of our experiments, we can suggest that halophilic archea and halotolerant bacteria could be the analogs of Martian organisms, since they can survive wide mineralization ranges and low temperatures with the lowest decline of viability. There are two other main harmful factors of martian subsurface environments limiting survival of terrestrial bacteria. The first is a low atmospheric pressure and the second is high level of ionizing radiation producing by cosmic rays. In previos experiments have been demonstrated that the wild strain of Vibrio sp are able to reproduce under very low atmospheric pressure even lower of modern mar- tian atmospheric pressure [9]. Also there are several types of high radiotoler- ant bacteria such as well known Deinococcus radiodurance. We are planning to study the impact both factors on halophilic bacteria. For future experiments on survival of microorganisms we are going to use Halomonas sp. H12b and Halorubrum sp. Н13a.