Potential for Aerobic Methanotrophic Metabolism on Mars

• DOI: 10.1089/ast.2018.1943
• Publication Date: 2019-06-07T18:28:43Z
• Authors: Mayumi Seto; Katsuyuki Noguchi; Philippe Van Capp...
• Keywords: Atmosphere of Mars; Biogeochemical Cycle; Early Earth

Observational evidence supports the presence of methane (CH4) in martian atmosphere on order parts per billion by volume (ppbv). Here, we assess whether aerobic methanotrophy is a potentially viable metabolism upper regolith, calculating metabolic energy gain rates under assumed conditions surface temperature, pressure, and atmospheric composition. Using kinetic parameters for 19 terrestrial methanotrophic strains, show that even imposed low temperature pressure extremes (180-280 K 6-11 hPa), oxidation oxygen (O2) should principle be able to generate minimum production rate required support endogenous (i.e., cellular maintenance). Our results further indicate corresponding activity would extremely low, with cell doubling times excess 4000 Earth years at present-day ppbv-level CH4 mixing ratios Mars. Thus, while microorganisms similar those found could theoretically maintain their vital functions, they are unlikely constitute prolific members hypothetical soil communities.