title: Methanosarcina as the dominant aceticlastic methanogens during mesophilic anaerobic digestion of putrescible waste.
abstract: Taking into account isotope (13)C value a mathematical model was developed to describe the dynamics of methanogenic population during mesophilic anaerobic digestion of putrescible solid waste and waste imitating Chinese municipal solid waste. Three groups of methanogens were considered in the model including unified hydrogenotrophic methanogens and two aceticlastic methanogens Methanosaeta sp. and Methanosarcina sp. It was assumed that Methanosaeta sp. and Methanosarcina sp. are inhibited by high volatile fatty acids concentration. The total organic and inorganic carbon concentrations, methane production, methane and carbon dioxide partial pressures as well as the isotope (13)C incorporation in PSW and CMSW were used for the model calibration and validation. The model showed that in spite of the high initial biomass concentration of Methanosaeta sp. Methanosarcina sp. became the dominant aceticlastic methanogens in the system. This prediction was confirmed by FISH. It is concluded that Methanosarcina sp. forming multicellular aggregates may resist to inhibition by volatile fatty acids (VFAs) because a slow diffusion rate of the acids limits the VFA concentrations inside the Methanosarcina sp. aggregates.
authors.affiliation: Cemagref, UR-HBAN, Parc de Tourvoie, 92163, Antony Cedex, France. vavilin@aqua.laser.ru
authors.forename: Vasily A
authors.initials: VA
authors.lastname: Vavilin
authors.forename: Xian
authors.initials: X
authors.lastname: Qu
authors.forename: Laurent
authors.initials: L
authors.lastname: Mazéas
authors.forename: Melanie
authors.initials: M
authors.lastname: Lemunier
authors.forename: Christian
authors.initials: C
authors.lastname: Duquennoi
authors.forename: Pinjing
authors.initials: P
authors.lastname: He
authors.forename: Theodore
authors.initials: T
authors.lastname: Bouchez
mesh_terms: D019342:Acetic Acid / Q000378:metabolism*; D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology; D008697:Methane / Q000378:metabolism*; D017019:Methanosarcinaceae / Q000235:genetics / Q000378:metabolism*; D008962:Models, Theoretical; D012722:Sewage / Q000382:microbiology*; D018505:Waste Management
chemical_list: D012722:Sewage; D008697:Methane; D019342:Acetic Acid