title: Microbial community structure of a simultaneous nitrogen and phosphorus removal reactor following treatment in a UASB-DHS system.
abstract: The anaerobic-anoxic sequence batch reactor (A2SBR) was applied to achieve nitrogen and phosphorus removal in an energy-saving sewage treatment system involving an up-flow anaerobic sludge blanket combined with a down-flow hanging sponge reactor to treat municipal sewage. After sludge acclimation, the A2SBR showed satisfactory denitrification and phosphorus removal performance with total phosphate and nitrate concentrations of the effluent of 8.4 ± 3.4 mg-N L⁻¹ and 0.9 ± 0.6 mg-P L⁻¹, respectively. 16S rRNA gene sequence and fluorescence in situ hybridization analyses revealed that 'Candidatus Accumulibacter phosphatis' was the dominant phosphate-accumulating micro-organism. Although a competitive bacterium for polyphosphate-accumulating organisms, 'Ca. Competibacter phosphatis', was not detected, Dechloromonas spp. were abundant. The ppk1 gene sequence analysis showed that the type II lineage of 'Ca. Accumulibacter' was dominant. The results suggest that denitrification and phosphorus removal in the A2SBR could be achieved by cooperative activity of 'Ca. Accumulibacter' and nitrate-reducing bacteria.
authors.affiliation: Department of Environmental Systems Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan E-mail: hatamoto@vos.nagaokaut.ac.jp.
authors.forename: Masashi
authors.initials: M
authors.lastname: Hatamoto
authors.affiliation: Department of Environmental Systems Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan E-mail: hatamoto@vos.nagaokaut.ac.jp.
authors.forename: Yayoi
authors.initials: Y
authors.lastname: Saito
authors.affiliation: Department of Environmental Systems Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan E-mail: hatamoto@vos.nagaokaut.ac.jp.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Dehama
authors.affiliation: Department of Environmental Systems Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan E-mail: hatamoto@vos.nagaokaut.ac.jp.
authors.forename: Nozomi
authors.initials: N
authors.lastname: Nakahara
authors.affiliation: Department of Environmental Systems Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan E-mail: hatamoto@vos.nagaokaut.ac.jp.
authors.forename: Kyohei
authors.initials: K
authors.lastname: Kuroda
authors.affiliation: Department of Civil and Environmental Engineering, Tohoku University, Sendai, Miyagi 980-8579, Japan.
authors.forename: Masanobu
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: Department of Environmental Systems Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan E-mail: hatamoto@vos.nagaokaut.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamaguchi
mesh_terms: D000693:Anaerobiosis; D001419:Bacteria / Q000145:classification* / Q000235:genetics; D019149:Bioreactors / Q000382:microbiology*; D058440:Denitrification; D017404:In Situ Hybridization, Fluorescence; D009566:Nitrates; D009584:Nitrogen / Q000737:chemistry / Q000378:metabolism*; D010758:Phosphorus / Q000737:chemistry / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012722:Sewage / Q000382:microbiology
chemical_list: D009566:Nitrates; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D010758:Phosphorus; D009584:Nitrogen