1 research outputs found
Microbial Selenate Reduction Driven by a Denitrifying Anaerobic Methane Oxidation Biofilm
Anaerobic
oxidation of methane (AOM) plays a crucial role in controlling
the flux of methane from anoxic environments. Sulfate-, nitrite-,
nitrate-, and iron-dependent methane oxidation processes have been
considered to be responsible for the AOM activities in anoxic niches.
We report that nitrate-reducing AOM microorganisms, enriched in a
membrane biofilm bioreactor, are able to couple selenate reduction
to AOM. According to ion chromatography, X-ray photoelectron spectroscopy,
and long-term bioreactor performance, we reveal that soluble selenate
was reduced to nanoparticle elemental selenium. High-throughput 16S
rRNA gene sequencing indicates that <i>Candidatus</i> Methanoperedens
and <i>Candidatus</i> Methylomirabilis remained the only
known methane-oxidizing microorganisms after nitrate was switched
to selenate, suggesting that these organisms could couple anaerobic
methane oxidation to selenate reduction. Our findings suggest a possible
link between the biogeochemical selenium and methane cycles