A balance between hydrolysis and methanogenesis during the anaerobic digestion of organic matter

The "Methane" simulation model was used to analyze the functioning of anaerobic microbial communities during the digestion of municipal sewage sludge and the decomposition of organic matter in tundra soil. In both cases, the rate of organic matter decomposition was limited by the stage of hydrolysis. The dynamics of methane production by tundra soil was sigmoidal due to changes in the biomass of hydrolytic microorganisms. The dynamics of solid waste digestion in a reactor with recycled leaching liquid was also analyzed. Cessation of digestion at pH 5.2 could be attributed to the inhibition (either direct or indirect) of both methanogenesis and hydrolysis at this pH value. At pH 5.8, intense methanogenesis promoted hydrolysis.