title: Diversity of ammonium-oxidizing bacteria in a granular sludge anaerobic ammonium-oxidizing (anammox) reactor.
abstract: The ammonium-oxidizing microbial community was investigated in a granular sludge anaerobic ammonium-oxidizing (anammox) reactor that was operated for about 1 year with high anaerobic ammonium oxidation activity (up to 0.8 kg NH(4)(+)-N m(-3) day(-1)). A Planctomycetales-specific 16S rRNA gene library was constructed to analyse the diversity of the anaerobic ammonium-oxidizing bacteria (AnAOB). Most of the specifically amplified sequences (15/16) were similar to each other (> 99%) but were distantly related to all of the previously recognized sequences (< 94%), with the exception of an unclassified anammox-related clone, KSU-1 (98%). An ammonia monooxygenase (amoA) gene library was also analysed to investigate the diversity of 'aerobic' ammonium-oxidizing bacteria (AAOB) from the beta-Proteobacteria. Most of the amoA gene fragments (53/55) clustered in the Nitrosomonas europaea-Nitrosococcus mobilis group which has been reported to prevail under oxygen-limiting conditions. The quantitative results from real-time polymerase chain reaction (PCR) amplification showed that the dominant AnAOB comprised approximately 50% of the total bacterial 16S rRNA genes in the reactor, whereas the AAOB of beta-Proteobacteria represented only about 3%. A large fragment (4008 bp) of the rRNA gene cluster of the dominant AnAOB (AS-1) in this reactor sludge was sequenced and compared with sequences of other Planctomycetales including four anammox-related candidate genera. The partial sequence of hydrazine-oxidizing enzyme (hzo) of dominant AnAOB was also identified using new designed primers. Based on this analysis, we propose to tentatively name this new AnAOB Candidatus'Jettenia asiatica'.
authors.affiliation: Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai, China.
authors.forename: Zhe-Xue
authors.initials: ZX
authors.lastname: Quan
authors.forename: Sung-Keun
authors.initials: SK
authors.lastname: Rhee
authors.forename: Jian-E
authors.initials: JE
authors.lastname: Zuo
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.forename: Jin-Woo
authors.initials: JW
authors.lastname: Bae
authors.forename: Ja Ryeong
authors.initials: JR
authors.lastname: Park
authors.forename: Sung-Taik
authors.initials: ST
authors.lastname: Lee
authors.forename: Yong-Ha
authors.initials: YH
authors.lastname: Park
mesh_terms: D000693:Anaerobiosis; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics; D044822:Biodiversity; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D020459:Genes, rRNA; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000235:genetics; D010802:Phylogeny; D000644:Quaternary Ammonium Compounds / Q000378:metabolism; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D012722:Sewage / Q000382:microbiology*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D000644:Quaternary Ammonium Compounds; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D010088:Oxidoreductases; C045582:ammonia monooxygenase