Methane-driven perchlorate reduction by a microbial consortium

The phenomenon of methane oxidation linked to perchlorate reduction has been reported in multiple studies, yet the underlying microbial mechanisms remain unclear. Here, we enriched suspended cultures performing methane-driven perchlorate reduction under oxygen-limiting conditions in a membrane bioreactor (MBR). Batch test results proved perchlorate reduction was coupled to methane oxidation, in which acetate was predicted as the potential intermediate and oxygen played an essential role in activating methane. By combining DNA-based stable isotope probing incubation and high-throughput sequencing analyses of 16S rRNA gene and functional genes (pmoA, pcrA and narG), we found synergistic interactions between aerobic methanotrophs (Methylococcus and Methylocystis) and perchlorate-reducing bacteria (PRB, Denitratisoma and Dechloromonas) played active roles in mediating methane-driven perchlorate reduction.