title: Methanogenesis from acetate: enrichment studies.
abstract: An acetate enrichment culture was initiated by inoculating anaerobic sludge from a mesophilic methane digestor into a mineral salts medium with calcium acetate as the sole carbon and energy source. This enrichment was maintained indefinitely by weekly transfer into medium of the same composition. A study of this enrichment disclosed an unexpected age-dependent inhibition of methanogenesis by H2 and formate which apparently differed from the inhibition by chloroform and benzyl viologen. This age-dependent inhibition indicated that microbial interactions of the mixed enrichment population may play a regulatory role in methane formation. Futhermore, stimulation of methanogenesis in the acetate enrichment by addition of yeast extract showed a nutrient limitation which indicated that syntrophic interactions leading to formation of growth factors may also occur. A model is presented to illustrate the possible interrelationships between methanogenic and nonmethanogenic bacteria in their growth and formation of methane and carbon dioxide from acetate.
mesh_terms: D000085:Acetates / Q000378:metabolism*; D000693:Anaerobiosis; D001419:Bacteria / Q000378:metabolism*; D001594:Benzyl Viologen / Q000494:pharmacology; D002725:Chloroform / Q000494:pharmacology; D003470:Culture Media; D019605:Euryarchaeota / Q000378:metabolism*; D005561:Formates / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism; D006859:Hydrogen / Q000494:pharmacology; D008697:Methane / Q000096:biosynthesis*; D012722:Sewage; D014871:Water Microbiology
chemical_list: D000085:Acetates; D003470:Culture Media; D005561:Formates; D012722:Sewage; D001594:Benzyl Viologen; D002725:Chloroform; D006859:Hydrogen; D005947:Glucose; D008697:Methane