EXTREMOPHILES FOR ECOPOIESIS: DESIRABLE TRAITS FOR AND SURVIVABILITY OF PIONEER MARTIAN ORGANISMS

David J Thomas, John Boling, Penelope J Boston, Kathy A Campbell, Tiffany McSpadden, Laura McWilliams, Paul Todd

Abstract


Humanity is on the verge of having the capability of constructively directing environmental changes on a planetary scale. Within the foreseeable future, we will have the technology to modify Mars' environment, and make it a habitable planet. However, we do not have enough information to determine the course of such an event. To our knowledge, no known terrestrial organism has the capability of living on Mars' surface under present conditions. However, with some modification, Mars' environment could be brought into the survival and growth range of currently known microorganisms. Using the SHOT Ecopoesis Testbed, we performed survival/growth experiments to determine the suitability of potential pioneering life forms for Mars. Included among the potential pioneers were five genera of cyanobacteria (Anabaena, Chroococcidiopsis, Plectonema, Synechococcus and Synechocystis), three partially-characterized Atacama Desert heterotrophic eubacterial strains, and several desert varnish isolates. Microorganisms were exposed to a present-day mix of martian atmospheric gases, but at a pressure of 100 mbar (10 times Mars' current atmospheric pressure). Cultures were inoculated into samples of JSC Mars-1 soil stimulant and exposed to full-spectrum simulated martian sunlight. Day/night temperature cycled from 26°C to -80°C and back. Preliminary results indicate that both autotrophic and heterotrophic bacteria can survive in the simulated engineered martian environment.

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