Subsurface carbon monoxide oxidation capacity revealed through genome‐resolved metagenomics of a carboxydotroph

Abstract

Summary Microbial communities play important roles in the biogeochemical cycling of carbon in the Earth's deep subsurface. Previously, we demonstrated changes to the microbial community structure of a deep aquifer (1.4 km) receiving 150 tons of injected supercritical CO2 (scCO2) in a geosequestration experiment. The observed changes support a key role in the aquifer microbiome for the thermophilic CO‐utilizing anaerobe Carboxydocella, which decreased in relative abundance post‐scCO2 injection. Here, we present results from more detailed metagenomic profiling of this experiment, with genome resolution of the native carboxydotrophic Carboxydocella. We demonstrate a switch in CO‐oxidation potential by Carboxydocella through analysis of its carbon monoxide dehydrogenase (CODH) gene before and after the geosequestration experiment. We discuss the potential impacts of scCO2 on subsurface flow of carbon and electrons from oxidation of the metabolic intermediate carbon monoxide (CO).

Biome-specific distribution of Ni-containing carbon monoxide dehydrogenases

“…However, some carboxydotrophs have also been isolated from samples not related to CO-emitting environments, suggesting their ubiquitous distribution (Inoue et al 2019b , 2020b ). Ni-CODH genes have been identified in metagenome-assembled genomes (MAGs) from various environmental samples (Evans et al 2015 ; Adam et al 2018 ; Inoue et al 2019a ; Mu et al 2020 ). These evidences have helped establish an enigmatic relationship between the physiology and ecology of carboxydotrophs.…”