Carbon monoxide oxidation by anaerobic methanotrophic consortia

Anaerobic methanotrophic consortia, primarily constituting methane-oxidizing archaea (ANME) and sulfate-reducing bacteria (SRB), were a well-known example of importance in methane cycling and climate change. Besides methane, however, few studies have investigated the utilization of other electron donors for the consortia, of which carbon monoxide (CO) is predicted to be a potential electron source due to its low reduction potential and presence in the environment. Here this study explored the prediction for CO metabolism by ANME-SRB using microcosm experiments coupled with geochemical measurements and single-cell activity detection. CO metabolism across anaerobic methanotrophic consortia, which can be an important shunt for the methane cycling in the methane seep sediments. The versatile capability of CO oxidation by anaerobic methanotrophic consortia broadens the dimension of carbon cycling in the methane seeps and highlights the importance of microbes in the climate change.