title: Microbial community changes in biological phosphate-removal systems on altering sludge phosphorus content.
abstract: Biomarkers (respiratory quinones and cellular fatty acids) and denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA genes were used to characterize the microbial community structure of lab-scale enhanced biological phosphate-removal (EBPR) systems in response to altering sludge phosphorus (P) content. All the data suggest that the microbial community structures of sludge samples with a P content between 8 and 12.3% (sludge dry weight) (i.e. good EBPR activity) were very similar, but differed from those with 2% P content (i.e. no EBPR activity). For all samples analysed, ubiquinones Q-8 and Q-10, menaquinone MK-8(H4), and fatty acids C16:0, C16:1 omega9c and C18:1, omega11c were the major components. The dominance of Q-8, Q-10 and MK-8(H4) suggested that large numbers of organisms belonging to the beta and alpha subclasses of the Proteobacteria and the Actinobacteria from the high G+C Gram-positive bacteria, respectively, were present. DGGE analysis revealed at least 7-9 predominant DNA bands and numerous other fragments in each sample. Five major DGGE fragments from each of the 2% and 12% P-containing sludge samples, respectively, were successfully isolated and sequenced. Phylogenetic analysis of the sequences indicated that both 2% and 12% P-containing sludge samples shared three common phylotypes that were separately affiliated with a novel bacterial group from the gamma subclass of the Proteobacteria, two MK-8(H4)-containing actinobacteria previously isolated from the 2% P-containing sludge, and a Caulobacter spp. in the alpha subclass of the Proteobacteria. The phylogenetic analysis also revealed phylotypes unique to both sludge samples. Changes in sludge P content therefore had an effect on the composition and abundance of the predominant microbial populations, though specific phylotypes could not be unequivocally associated with EBPR.
authors.affiliation: Department of Urban Engineering, University of Tokyo, Tokyo 113, Japan3.|Center for Microbial Ecology, Michigan State University, East Lansing, MI 48824, USA2.|Institute of Environmental Engineering, National Central University, Chungli 32054, Taiwan1.
authors.forename: Wen-Tso
authors.initials: WT
authors.lastname: Liu
authors.affiliation: Center for Microbial Ecology, Michigan State University, East Lansing, MI 48824, USA2.
authors.forename: Katrina D
authors.initials: KD
authors.lastname: Linning
authors.affiliation: National Institute of Bioscience and Human Technology, Agency of Industrial Science and Technology, 1-1 Tsukuba, Ibaraki, 305-8566 Japan4.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Department of Urban Engineering, University of Tokyo, Tokyo 113, Japan3.
authors.forename: Takashi
authors.initials: T
authors.lastname: Mino
authors.affiliation: Department of Urban Engineering, University of Tokyo, Tokyo 113, Japan3.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Matsuo
authors.affiliation: Center for Ecological and Evolutionary Studies, University of Groningen, The Netherlands5.
authors.forename: Larry J
authors.initials: LJ
authors.lastname: Forney
mesh_terms: D039903:Actinobacteria / Q000302:isolation & purification / Q000378:metabolism; D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D001673:Biodegradation, Environmental; D015415:Biomarkers / Q000032:analysis; D016934:Caulobacter / Q000302:isolation & purification / Q000378:metabolism; D004269:DNA, Bacterial / Q000032:analysis; D004275:DNA, Ribosomal / Q000032:analysis; D004783:Environmental Microbiology; D005227:Fatty Acids / Q000032:analysis; D008969:Molecular Sequence Data; D010710:Phosphates / Q000032:analysis* / Q000378:metabolism; D010758:Phosphorus / Q000032:analysis* / Q000378:metabolism; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D020560:Proteobacteria / Q000302:isolation & purification / Q000378:metabolism; D011809:Quinones / Q000032:analysis; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012722:Sewage / Q000032:analysis / Q000382:microbiology*
chemical_list: D015415:Biomarkers; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005227:Fatty Acids; D010710:Phosphates; D011809:Quinones; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D010758:Phosphorus