CARBON MONOXIDE AS A MICROBIAL ENERGY SOURCE ON MARS

CARBON MONOXIDE (CO) IS ABUNDANT IN PLANETARY ATMOSPHERES AND CAN POTENTIALLY BE A VALUABLE ENERGY SOURCE FOR MICROBES. DIVERSE MICROBES ON EARTH CAN METABOLIZE CO FOR ENERGY. RECENT STUDIES INDICATE THAT SOME CO METABOLIZERS CAN SURVIVE UNDER SELECT MARTIAN CONDITIONS. OTHER RESEARCH PROVIDES EVIDENCE THAT CO MAY BE USED IN PHOTOSYNTHESIS WHICH COULD HAVE BEEN FAVORABLE UNDER ANCIENT MARTIAN CONDITIONS. PHOTOSYNTHESIS WITH CO HAS NOT YET BEEN CONFIRMED. THIS RESEARCH WILL PROVIDE A COMPREHENSIVE EXAMINATION OF CO-ENABLED GROWTH UNDER MARTIAN CONDITIONS. IT WILL ALSO DETERMINE IF ELECTRONS FROM CO CAN BE USED IN PHOTOSYNTHESIS TO SUPPORT LIFE ON OTHER PLANETS. FINALLY WE WILL MODEL THE THERMODYNAMICS OF DIFFERENT CO METABOLISMS TO UNDERSTAND THEIR FAVORABILITY IN VARIOUS ENVIRONMENTS.TO ASSESS PRESENT MARTIAN HABITABILITY WE WILL CULTIVATE MICROBES IN A MARS SIMULATION CHAMBER TO RECREATE THE NEAR-SURFACE CONDITIONS ON MARS. THESE EXPERIMENTS WILL FOCUS ON CO AS THE PRIMARY ENERGY SOURCE. NEXT WE WILL EVALUATE WHETHER MICROBES CAN USE CO IN PHOTOSYNTHESIS. PHOTOSYNTHETIC MICROBES WITH KNOWN CO METABOLISMS WILL BE GROWN IN THE LIGHT AND DARK UNDER CO ATMOSPHERES WITHOUT ACCESS TO OTHER ELECTRON DONORS. WE WILL MEASURE CO MOLECULAR HYDROGEN AND PHOTOSYNTHETIC ACTIVITY TO ESTABLISH THE USECO IN PHOTOSYNTHESIS. LASTLY OUR THERMODYNAMIC MODEL WILL DETERMINE THE LIMITS OF ENVIRONMENTS IN WHICH VARIOUS CO METABOLISMS ARE FAVORABLE. IT WILL ALSO EXPLORE THE CONDITIONS IN WHICH CO-BASED PHOTOSYNTHESIS IS ENERGETICALLY FAVORABLE COMPARED TO OTHER CO METABOLISMS.THIS WORK IS RELEVANT TO NASA'S PLANETARY SCIENCE RESEARCH PROGRAM. OUR LABORATORY RESULTS WILL ESTABLISH WHETHER CO IS A PLAUSIBLE ENERGY SOURCE ON PRESENT OR PAST MARS. OUR MODELS OF CO METABOLISMS WILL PROVIDE INSIGHT INTO THE PLANETARY CONDITIONS IN WHICH CO MAY BE AN ENERGY SOURCE. COMBINED THESE RESULTS WILL EXPAND OUR UNDERSTANDING OF PLANETARY HABITABILITY AND HELP GUIDE THE SEARCH FOR LIFE BEYOND EARTH.