The use of complex microbial soil communities in Mars simulation experiments

Abstract

Mars simulation studies have in the past mainly investigated the effect of the simulation conditions such as UV radiation, low pressure and temperature on pure cultures and much has been learnt about the survival potential of sporeformers such as Bacillus subtilis. However, this approach has limitations as the studies only investigate the properties of a very limited number of microorganisms. In this paper we propose that Mars simulations should be carried out with complex microbial communities of Martian analogues such as permafrost or the deep biosphere. We also propose that samples from these environments should be studied by a number of complementary methods and claim that these methods in combination can provide a comprehensive picture of how imposed Martian conditions affect the microbial community and in particular the survival of its constituents -microbes as well as biological material in general. As an interesting consequence this approach can lead to the isolation of bacteria, which are more recalcitrant to the imposed Martian conditions than the pure cultures that have previously been studied.