title: Characterization of microbial community in granular sludge treating brewery wastewater.
abstract: The diversity and distribution of microbes within brewery-degrading anaerobic sludge granules were studied using various molecular techniques. Molecular cloning of small-subunit rRNA gene sequences indicated that all archaeal clones were affiliated with Methanosaeta concillii (>99% sequence similarity), and the bacterial clones were mostly affiliated with a not-yet-cultured Clostridium cluster (48 out of 99 clones) in the low G + C gram-positive group, Xanthomonas spp. in the gamma-subclass of Proteobacteria (30 clones), and Desulfovibrio spp. (16 clones) in the delta-subclass of Proteobacteria. Slot-blot hybridization indicated that archaeal cells from the Methanomicrobiales (58.4% of total rRNA), Methanobacterials (3.3%) and Methanococcales (1.0%) accounted for 62.4% of the total community rRNA. The rest of the microbial populations were the clostridial cluster (27.3% of total rRNA) and Desulfovibrio spp. (9.4%). Fluorescence in-situ hybridization with domain and group-specific oligonucleotide probes further revealed a multi-layer granular architecture. On the surface layer, the hydrolytic clostridial species and hydrogenotrophic Methanobacteriales were the predominant. In the middle layer, mostly H2-producing acetogens from the delta-Proteobacteria (i.e., Desulfovibrio spp.), hydrogenotrophic Methanobacteriales and aceticlastic Methanosaeta were observed to presumably form a syntrophic association. Finally, the center core consisted of microcolonies of Methanosaeta cells.
authors.affiliation: Graduate Institute of Environmental Engineering, National Central University, Taiwan. cveliuwt@nus.edu.sg
authors.forename: Wen-Tso
authors.initials: WT
authors.lastname: Liu
authors.forename: On-Chim
authors.initials: OC
authors.lastname: Chan
authors.forename: Herbert H P
authors.initials: HH
authors.lastname: Fang
mesh_terms: D001105:Archaea / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D003013:Clostridium / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D019649:Food Industry; D017404:In Situ Hybridization, Fluorescence; D010802:Phylogeny; D020560:Proteobacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D012335:RNA, Ribosomal / Q000235:genetics; D012722:Sewage / Q000382:microbiology*; D014871:Water Microbiology; D018508:Water Purification
chemical_list: D012335:RNA, Ribosomal; D012722:Sewage