[Xerophytic microorganisms multiplying under conditions close to Martian ones].

The xerophytic cultures Bacillus megaterium and Mycococcus ruber can grow in the imitated Martian conditions. Therefore, they are resistant to the extreme factors of the environment: the composition of atmosphere, low pressure, the maximum hygroscopicity of a substrate, periodic freezing-thawing.

[Physiology of xerophytic microorganisms that grow under very dry conditions].

The biology of xerophytic microorganisms surviving and growing under conditions imitating Martian ones was studied, as well as the zone of tolerance of several microorganisms towards the activity of water. The xerophytic nature of microorganisms is suggested to be evaluated by means of quantitative determination, using gas chromatography, of carbon dioxide which is evolved when microorganisms are cultivated on media with different values of aw.