title: Biokinetic and molecular studies of methanogens in phased anaerobic digestion systems.
abstract: The influence of differing operational conditions of two-stage digesters on biokinetic characteristics and communities of methanogenic archaea was evaluated. Operating temperature of each phase influenced the archaeal communities significantly. Also, a strong correlation was observed between community composition and temperature and pH. The maximum specific substrate utilization rates (k max) of acetoclastic methanogens in the mesophilic and thermophilic 1st phases were 11.4 and 22.0 mgCOD mgCOD(-1)d(-1), respectively, whereas significantly lower k max values were estimated for the mesophilic and thermophilic 2nd-phase digesters which were 7.6 and 16.6 mgCOD mgCOD(-1)d(-1), respectively. It appeared that the biokinetic characteristics of the acetoclastic methanogen communities were reliant on digester loading rates. Also, higher temperature dependency coefficients (θ) were observed for the long retention time digesters when compared to the values computed for the 1st-phase digesters. Accordingly, the implementation of two sets of biokinetic parameters for acetoclastic methanogen will improve modeling of phased anaerobic digesters.
authors.affiliation: Department of Civil and Environmental Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada. Electronic address: mzamanza@uwaterloo.ca.
authors.forename: Mirzaman
authors.initials: M
authors.lastname: Zamanzadeh
authors.forename: Wayne J
authors.initials: WJ
authors.lastname: Parker
authors.forename: Yris
authors.initials: Y
authors.lastname: Verastegui
authors.forename: Josh D
authors.initials: JD
authors.lastname: Neufeld
mesh_terms: D000085:Acetates / Q000378:metabolism; D000693:Anaerobiosis; D001105:Archaea / Q000235:genetics* / Q000378:metabolism*; D001673:Biodegradation, Environmental; D018533:Biomass; D019149:Bioreactors; D058645:Denaturing Gradient Gel Electrophoresis; D007700:Kinetics; D008697:Methane / Q000378:metabolism*; D008969:Molecular Sequence Data; D012037:Refuse Disposal / Q000295:instrumentation / Q000379:methods*; D013696:Temperature
chemical_list: D000085:Acetates; D008697:Methane
keywords: Acetoclastic methanogens; Anaerobic digestion; DGGE; Kinetics; Modeling