Controls on Interspecies Electron Transport and Size Limitation of Anaerobically Methane-Oxidizing Microbial Consortia
Xiaojia He, Grayson L. Chadwick, Christopher P. Kempes, Victoria J. Orphan, Christof Meile
Abstract
Anaerobic oxidation of methane is a globally important, microbially mediated process reducing the emission of methane, a potent greenhouse gas. In this study, we investigate the mechanism of how a microbial consortium consisting of archaea and bacteria carries out this process and how these organisms interact with each other through the sharing of electrons. We present a process-based model validated by novel experimental measurements of the metabolic activity of individual, phylogenetically identified cells in very large (>20-μm-diameter) microbial aggregates. Model simulations indicate that extracellular electron transfer between archaeal and bacterial cells within a consortium is limited by potential losses and suggest that a flexible use of electron donors can provide energetic advantages for syntrophic consortia.