title: Phylogenetic diversity and ecophysiology of Candidate phylum Saccharibacteria in activated sludge.
abstract: Candidate phylum Saccharibacteria (former TM7) are abundant and widespread in nature, but little is known about their ecophysiology and detailed phylogeny. In this study phylogeny, morphology and ecophysiology of Saccharibacteria were investigated in activated sludge from nine wastewater treatment plants (WWTPs) from Japan and Denmark using the full-cycle 16S rRNA approach in combination with microautoradiography (MAR) and fluorescence in situ hybridization (FISH). Phylogenetic analysis showed that Saccharibacteria from all WWTPs were evenly distributed within subdivision 1 and 3 and in a distinct phylogenetic clade. Three probes were designed for the distinct saccharibacterial groups, and revealed morphotypes representing thin filaments, thick filaments and rods/cocci. MAR-FISH results showed that most probe-defined Saccharibacteria utilized glucose under aerobic-, nitrate reducing- and anaerobic conditions. Some Saccharibacteria also utilized N-acetylglucosamine, oleic acid, amino acids and butyrate, which are not predicted from available genomes so far. In addition, some filamentous Saccharibacteria exhibited β-galactosidase and lipase activities determined using a combination of enzyme-labeled fluorescence and FISH (ELF-FISH). No uptake of acetate, propionate, pyruvate, glycerol and ethanol was observed. These results indicate that Saccharibacteria is a phylogenetically diverse group and play a role in the degradation of various organic compounds as well as sugar compounds under aerobic-, nitrate reducing- and anaerobic conditions.
authors.affiliation: Department of Civil and Environmental Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima, 739-8527 Japan Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, DK-9220 Aalborg E, Denmark.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Kindaichi
authors.affiliation: Department of Civil and Environmental Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima, 739-8527 Japan.
authors.forename: Shiro
authors.initials: S
authors.lastname: Yamaoka
authors.affiliation: Department of Civil and Environmental Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima, 739-8527 Japan.
authors.forename: Ryohei
authors.initials: R
authors.lastname: Uehara
authors.affiliation: Department of Civil and Environmental Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima, 739-8527 Japan.
authors.forename: Noriatsu
authors.initials: N
authors.lastname: Ozaki
authors.affiliation: Department of Civil and Environmental Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima, 739-8527 Japan.
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Ohashi
authors.affiliation: Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, DK-9220 Aalborg E, Denmark.
authors.forename: Mads
authors.initials: M
authors.lastname: Albertsen
authors.affiliation: Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, DK-9220 Aalborg E, Denmark.
authors.forename: Per Halkjær
authors.initials: PH
authors.lastname: Nielsen
authors.affiliation: Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, DK-9220 Aalborg E, Denmark jln@bio.aau.dk.
authors.forename: Jeppe Lund
authors.initials: JL
authors.lastname: Nielsen
mesh_terms: D001345:Autoradiography; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D003718:Denmark; D004734:Energy Metabolism / Q000235:genetics*; D005696:Galactosidases / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D007564:Japan; D008049:Lipase / Q000378:metabolism; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012722:Sewage / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D008049:Lipase; D005696:Galactosidases; D005947:Glucose
keywords: FISH; Saccharibacteria; activated sludge; candidate division TM7; exoenzyme activity; microautoradiography