title: Bacterial community dynamics in an anaerobic plug-flow type bioreactor treating swine manure.
abstract: A plug-flow type anaerobic reactor consisting of eight sequential compartments was used to study shifts in a bacterial community adapted to degrade swine manure at 25 degrees C. The investigation was carried out during the first 6 months of reactor operation. The reactor successfully separated the hydrolysis/acidogenesis stage from the methanogenesis stage. Bacterial 16S rDNA- and rRNA-based fingerprints obtained through amplicon length heterogeneity PCR (LH-PCR) were analyzed with a view to characterizing the bacterial community structure and the metabolically active community, respectively. Multivariate statistical tools showed that the rDNA-based fingerprints described a more temporal than compartmentalized distribution of similar bacterial communities. By contrast, the rRNA-based multivariate analyses described a distribution that was linked more to reactor performance parameters, especially during short time periods. Diversity indices calculated from fingerprint data were used to assess overall diversity shifts. The decrease in rRNA-based diversity observed through the reactor compartments was greater than the decrease in rDNA-based diversity. This finding indicates that the analysis of metabolically active bacteria diversity was more discriminative than the analysis based on the mere presence of bacteria. The observed decrease in diversity suggests that the bacterial community became specialized in degrading less diversified substrates through the compartments. All these findings suggest that rRNA-based analyses are more appropriate for monitoring reactor performance.
authors.affiliation: Dairy and Swine Research and Development Centre, Agriculture and Agri-Food Canada, 2000 College Street, Sherbrooke, QC J1M 0C8, Canada. roycarol@agr.gc.ca
authors.forename: Caroline S
authors.initials: CS
authors.lastname: Roy
authors.forename: Guylaine
authors.initials: G
authors.lastname: Talbot
authors.forename: Edward
authors.initials: E
authors.lastname: Topp
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: D000332:Aerobiosis; D000818:Animals; D001419:Bacteria / Q000378:metabolism*; D044822:Biodiversity; D019149:Bioreactors; D016000:Cluster Analysis; D004275:DNA, Ribosomal / Q000235:genetics; D005232:Fatty Acids, Volatile / Q000032:analysis; D008372:Manure; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D034421:Sus scrofa
chemical_list: D004275:DNA, Ribosomal; D005232:Fatty Acids, Volatile; D008372:Manure