Effect of Gamma Radiation on Viability of a Soil Microbial Community under Conditions of Mars

Abstract

It is supposed that the biosphere could be formed under conditions of early Mars, and it is cryo-conserved up to now. The period of its preservation is limited by the effect of ionizing radiation. The viability of a soil microbial community thtat underwent gamma radiation (100 kGy) under simulated conditions (‒50°C, 1 Torr) of the surface layer of the Martian regolith is studied. Irradiation did not result in the death of the microbial community: the number of living cells, metabolic activity, and functional diversity remained high. The data obtained suggest that microorganisms could be preserved in regolith of Mars for no less than 1.3 m.y. and in general contribute to the modern concepts concerning radiation resistance of the Earth’s life form.