Journal Article

Artificial electron acceptors decouple archaeal methane oxidation from sulfate reduction

McGlynn, Shawn E., Chadwick, Grayson L., Scheller, Silvan, Orphan, Victoria J., Yu, Hang

2016

Overview

The oxidation of methane with sulfate is an important microbial metabolism in the global carbon cycle. In marine methane seeps, this process is mediated by consortia of anaerobic methanotrophic archaea (ANME) that live in syntrophy with sulfate-reducing bacteria (SRB). The underlying interdependencies within this uncultured symbiotic partnership are poorly understood. We used a combination of rate measurements and single-cell stable isotope probing to demonstrate that ANME in deep-sea sediments can be catabolically and anabolically decoupled from their syntrophic SRB partners using soluble artificial oxidants. The ANME still sustain high rates of methane oxidation in the absence of sulfate as the terminal oxidant, lending support to the hypothesis that interspecies extracellular electron transfer is the syntrophic mechanism for the anaerobic oxidation of methane.

• Publisher: American Association for the Advancement of Science,The American Association for the Advancement of Science
• Subject: Anaerobiosis / Bacteria / Carbon Cycle / Deep sea / Electron Transport / Electrons / Geologic Sediments - microbiology / Manganese / Marine sediments / Methane / Methane - metabolism / Methanosarcinales - classification / Methanosarcinales - genetics / Methanosarcinales - metabolism / Molecular Sequence Data / Ocean floor / Oxidation / Oxidation-Reduction / Oxidizing agents / Phylogeny / RNA, Archaeal - classification / RNA, Archaeal - genetics / Seawater - microbiology / Sediments / Stable isotopes / Sulfate reduction / Sulfates / Sulfates - metabolism / Sulfur-Reducing Bacteria - metabolism