Shift from Acetoclastic to H ₂ -Dependent Methanogenesis in a West Siberian Peat Bog at Low pH Values and Isolation of an Acidophilic <i>Methanobacterium</i> Strain

Abstract

Methane production and archaeal community composition were studied in samples from an acidic peat bog incubated at different temperatures and pH values. H(2)-dependent methanogenesis increased strongly at the lowest pH, 3.8, and Methanobacteriaceae became important except for Methanomicrobiaceae and Methanosarcinaceae. An acidophilic and psychrotolerant Methanobacterium sp. was isolated using H(2)-plus-CO(2)-supplemented medium at pH 4.5.