RRC ID 40959
著者 King GM.
タイトル Carbon monoxide as a metabolic energy source for extremely halophilic microbes: implications for microbial activity in Mars regolith.
ジャーナル Proc Natl Acad Sci U S A
Abstract Carbon monoxide occurs at relatively high concentrations (≥800 parts per million) in Mars' atmosphere, where it represents a potentially significant energy source that could fuel metabolism by a localized putative surface or near-surface microbiota. However, the plausibility of CO oxidation under conditions relevant for Mars in its past or at present has not been evaluated. Results from diverse terrestrial brines and saline soils provide the first documentation, to our knowledge, of active CO uptake at water potentials (-41 MPa to -117 MPa) that might occur in putative brines at recurrent slope lineae (RSL) on Mars. Results from two extremely halophilic isolates complement the field observations. Halorubrum str. BV1, isolated from the Bonneville Salt Flats, Utah (to our knowledge, the first documented extremely halophilic CO-oxidizing member of the Euryarchaeota), consumed CO in a salt-saturated medium with a water potential of -39.6 MPa; activity was reduced by only 28% relative to activity at its optimum water potential of -11 MPa. A proteobacterial isolate from hypersaline Mono Lake, California, Alkalilimnicola ehrlichii MLHE-1, also oxidized CO at low water potentials (-19 MPa), at temperatures within ranges reported for RSL, and under oxic, suboxic (0.2% oxygen), and anoxic conditions (oxygen-free with nitrate). MLHE-1 was unaffected by magnesium perchlorate or low atmospheric pressure (10 mbar). These results collectively establish the potential for microbial CO oxidation under conditions that might obtain at local scales (e.g., RSL) on contemporary Mars and at larger spatial scales earlier in Mars' history.
巻・号 112(14)
ページ 4465-70
公開日 2015-4-7
DOI 10.1073/pnas.1424989112
PII 1424989112
PMID 25831529
PMC PMC4394273
MeSH Atmosphere Bacteria / metabolism* Carbon Dioxide / chemistry Carbon Monoxide / chemistry* Energy-Generating Resources Extraterrestrial Environment Halobacteriales / metabolism* Mars Molecular Sequence Data Soil Microbiology* Temperature Water / chemistry
IF 9.412
引用数 20
WOS 分野 MICROBIOLOGY
リソース情報
一般微生物 JCM 13488 JCM 10635 JCM 14089 JCM 17497