First Results from Mars Simulator LISA

We present the first results obtained from experiments performed with the Martian simulator LISA (Laboratorio Italiano Simulazione Ambienti, Galletta et al., 2006, 2007). The research was carried out at the University and Astronomical Observatory of Padua, Italy. LISA environmental chamber has been designed to simulate the conditions on the surface of planet Mars (atmospheric pressure, 6–9 Mb; temperature ranging from 133 to 293 K, atmospheric composition, 95% of carbon dioxide; strong UV radiation). We have studied the survival of the microorganisms exposed to the above described conditions. The microorganisms used in our experiments are bacterial strains belonging to the genus Deinococcus, and to the endospore forming genera Bacillus and Clostridium (D’Angelo, 2007). Cellular suspensions or endospores suspensions were layered on sterile coverslip dehydrated under sterile air flux, introduced in dedicated plates and then exposed to the Martian condition inside the LISA chamber. One of our Bacillus strains has shown a particular capability to survive in Martian conditions without screening by dust or other shields, in fact we noticed a capability to survive (as endospores suspension) at least 4 h and in some cases to 28 h of Martian conditions, in the longest experiment we performed until now.