[The multiphase character of methane fermentation of cellulose]

An enrichment culture producing methane from cellulose was studied. The culture is a system of changing microbial populations realizing various pathways of methane formation. This change of microbial associations is expressed in three phases of growth; each phase is characterized by its maximum of methane production. The first maximum is related to accumulation and utilization of propionic acid. The second maximum is due to methane formation from acetate by Methanosarcina. One of the possible pathways regulating the methanogenous ecosystem is the action of concentrations of the main metabolites--glucose and the products of its fermentation.