title: Spatial distribution of some microbial trophic groups in a plug-flow-type anaerobic bioreactor treating swine manure.
abstract: Anaerobic digestion of swine manure is carried out by a consortium of microbial species, including volatile fatty acid (VFA) producers, VFA-degraders and methanogens. The distribution of five phylogenetic groups within a plug-flow-type anaerobic bioreactor consisting of eight serially-connected tanks was examined through the sequential digestion of swine manure. Quantification was carried out using reverse transcription real-time PCR (RT-Q-PCR) assays targeting the 16S rRNA of Clostridium (cluster XIVa), Peptostreptococcus, Syntrophomonas, Methanosaeta, and Methanosarcina spp. The VFA producers Peptostreptococcus spp. and Clostridium spp. were found predominantly in compartments where hydrolysis/acidogenesis took place. The spatial distribution of the aceticlastic methanogens, Methanosaeta and Methanosarcina, within the bioreactor was not correlated with methanogenic activity. In contrast the VFA-degrading genus Syntrophomonas spp. was more abundant in compartments with elevated methanogenic activity. Multivariate statistical analyses of the RT-Q-PCR data have provided new insights into our understanding of how the various trophic groups were distributed within this bioreactor system. While the distribution of clostridia, peptostreptococci and Syntrophomonas corresponded to their known metabolic functions, aceticlastic methanogens were not apparently linked to the methanogenesis stage occurring in latter compartments, suggesting that hydrogenotrophic methanogens were the primary methane generators in this bioreactor. However, aceticlastic methanogens could be involved in compartments related to the hydrolysis/acidogenesis stage.
authors.affiliation: Dairy and Swine Research and Development Centre, Agriculture and Agri-Food Canada, Lennoxville station, Sherbrooke, QC, J1M 1Z3, Canada. Guylaine.Talbot@AGR.GC.CA
authors.forename: Guylaine
authors.initials: G
authors.lastname: Talbot
authors.forename: Caroline S
authors.initials: CS
authors.lastname: Roy
authors.forename: Edward
authors.initials: E
authors.lastname: Topp
authors.forename: Martin L
authors.initials: ML
authors.lastname: Kalmokoff
authors.forename: Stephen P J
authors.initials: SP
authors.lastname: Brooks
authors.forename: Carole
authors.initials: C
authors.lastname: Beaulieu
authors.forename: Marie-France
authors.initials: MF
authors.lastname: Palin
authors.forename: Daniel I
authors.initials: DI
authors.lastname: Massé
mesh_terms: D000693:Anaerobiosis; D000818:Animals; D056804:Biofuels; D019149:Bioreactors; D017931:DNA Primers / Q000737:chemistry; D004867:Equipment Design; D008372:Manure; D008697:Methane; D015999:Multivariate Analysis; D012313:RNA / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012722:Sewage; D013552:Swine; D014871:Water Microbiology
chemical_list: D056804:Biofuels; D017931:DNA Primers; D008372:Manure; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D012313:RNA; D008697:Methane