Pelotomaculum-Methanothermobacter Syntrophic Consortium

A thermophilic syntrophic, obligate two-member anaerobic consortium consisting of Pelotomaculum thermopropionicum, which oxidizes propionate and other organic acids (ethanol, lactate, alcohols) to acetate, CO2, and H2, and Methanothermobacter thermautotrophicus, a hydrogen-utilizing thermophilic methanogen. P. thermopropionicum oxidizes propionate only in coculture with H2-using methanogens, as it uses protons as the electron acceptor with H2 as the electron sink product. The removal of H2 by M. thermautotrophicus is thermodynamically essential for continued propionate oxidation by P. thermopropionicum. This thermophilic syntrophic relationship is fundamental to understanding propionate degradation and methane production at elevated temperatures (55°C) in anaerobic environments such as thermophilic digesters and hot springs.