(191m) Electricity from Methane By Reversing Methanogenesis Using an Engineered Consortium

Wood, T. K., Pennsylvania State University
Given our vast methane reserves and the difficulty in transporting methane without substantial leaks, the conversion of methane directly into electricity would be beneficial. Microbial fuel cells harness electrical power from a wide variety of substrates through biological means; however, the greenhouse gas methane has not been used with much success previously as a substrate in microbial fuel cells to generate electrical current. Here we construct a synthetic consortium consisting of (i) an engineered archaeal strain to produce methyl-coenzyme M reductase from unculturable anaerobic methanotrophs for capturing methane and secreting acetate, (ii) microorganisms from methane-acclimated sludge (with the active population identified as Paracoccus denitrificans through genomic sequencing) to facilitate electron transfer by providing electron shuttles (confirmed by replacing the sludge with humic acids), and (iii) Geobacter sulfurreducens to produce electrons from acetate, to create the first microbial fuel cell that converts methane directly into significant electrical current (Nature Communications in press, 2017). Notably, this methane MFC operates at high Coulombic efficiency.