title: Functional bacterial and archaeal community structures of major trophic groups in a full-scale anaerobic sludge digester.
abstract: Functional Bacteria and Archaea community structures of a full-scale anaerobic sludge digester were investigated by using a full-cycle 16S rRNA approach followed by microautoradiography (MAR)-fluorescent in situ hybridization (FISH) technique and micromanipulation. FISH analysis with a comprehensive set of 16S and 23S rRNA-targeted oligonucleotide probes based on 16S rRNA clone libraries revealed that the Gram-positive bacteria represented by probe HGC69A-hybridized Actinobacteria (8.5+/-1.4% of total 4', 6-diamidino-2-phenylindole (DAPI)-stained cells) and probe LGC354-hybridized Firmicutes (3.8+/-0.8%) were the major phylogenetic bacterial phyla, followed by Bacteroidetes (4.0+/-1.2%) and Chloroflexi (3.7+/-0.8%). The probe MX825-hybridized Methanosaeta (7.6+/-0.8%) was the most abundant archaeal group, followed by Methanomicrobiales (2.8+/-0.6%) and Methanobacteriaceae (2.7+/-0.4%). The functional community structures (diversity and relative abundance) of major trophic groups were quantitatively analyzed by MAR-FISH. The results revealed that glucose-degrading microbial community had higher abundance (ca. 10.6+/-4.9% of total DAPI-stained cells) and diversity (at least seven phylogenetic groups) as compared with fatty acid-utilizing microbial communities, which were more specialized to a few phylogenetic groups. Despite the dominance of Betaproteobacteria, members of Chloroflexi, Smithella, Syntrophomonas and Methanosaeta groups dominated the [(14)C]glucose-, [(14)C]propionate-, [(14)C]butyrate- and [(14)C]acetate-utilizing microorganism community, and accounted for 27.7+/-4.3%, 29.6+/-7.0%, 34.5+/-7.6% and 18.2+/-9.5%, respectively. In spite of low abundance (ca. 1%), the hitherto unknown metabolic functions of Spirochaeta and candidate phylum of TM7 as well as Synergistes were found to be glucose and acetate utilization, respectively.
authors.affiliation: Department of Urban and Environmental Engineering, Graduate School of Engineering, Hokkaido University, North-13, West-8, Kita-ku, Sapporo 060-8628, Japan.
authors.forename: Herto Dwi
authors.initials: HD
authors.lastname: Ariesyady
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Ito
authors.forename: Satoshi
authors.initials: S
authors.lastname: Okabe
mesh_terms: D001105:Archaea / Q000235:genetics*; D001345:Autoradiography; D001421:Bacteria, Anaerobic / Q000235:genetics*; D001483:Base Sequence; D044822:Biodiversity; D003001:Cloning, Molecular; D016000:Cluster Analysis; D017931:DNA Primers; D017404:In Situ Hybridization, Fluorescence; D007564:Japan; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012722:Sewage / Q000382:microbiology*; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D017931:DNA Primers; D012336:RNA, Ribosomal, 16S; D012722:Sewage