title: Community analysis of ammonia oxidizer in the oxygen-limited nitritation stage of OLAND system by DGGE of PCR amplified 16S rDNA fragments and FISH.
abstract: OLAND (oxygen limited autotrophic nitrification and denitrification) nitrogen removal system was constructed by coupling with oxygen limited nitritation stage and anaerobic ammonium oxidation stage. Ammonia oxidizer, as a kind of key bacteria in N cycle, plays an important role at the oxygen limited nitritation stage of OLAND nitrogen removal system. In this study, specific amplification of 16S rDNA fragment of ammonia oxidizer by nested PCR, separation of mixed PCR samples by denaturing gradient gel electrophoresis (DGGE), and the quantification of ammonia oxidizer by fluorescence in situ hybridization (FISH) were combined to investigate the shifts of community composition and quantity of ammonia oxidizer of the oxygen limited nitritation stage in OLAND system. It showed that the community composition of ammonia oxidizer changed drastically when dissolved oxygen was decreased gradually, and the dominant ammonia oxidizer of the steady nitrite accumulation stage were completely different from that of the early stage of oxygen limited nitritation identified by DGGE. It was concluded that the Nitrosomonas may be the dominant genus of ammonia oxidizer at the oxygen limited nitritation stage of OLAND system characterized by nested PCR-DGGE and FISH, and the percentage of Nitrosomonas was 72.5% +/- 0.8% of ammonia oxidizer at the steady nitrite accumulation stage detected by FISH.
authors.affiliation: Department of Biology, Liaoning Normal University, Dalian 116021, China. zhangdanangel@hotmail.com
authors.forename: Dan
authors.initials: D
authors.lastname: Zhang
authors.forename: De-Min
authors.initials: DM
authors.lastname: Zhang
authors.forename: Yao-Ping
authors.initials: YP
authors.lastname: Liu
authors.forename: Wen-Wei
authors.initials: WW
authors.lastname: Cao
authors.forename: Guan-Xiong
authors.initials: GX
authors.lastname: Chen
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D017931:DNA Primers; D004275:DNA, Ribosomal / Q000235:genetics; D017753:Ecosystem; D004586:Electrophoresis; D017404:In Situ Hybridization, Fluorescence; D009584:Nitrogen / Q000302:isolation & purification*; D009606:Nitrosomonas / Q000235:genetics / Q000378:metabolism*; D010100:Oxygen / Q000032:analysis; D016133:Polymerase Chain Reaction; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D017931:DNA Primers; D004275:DNA, Ribosomal; D000641:Ammonia; D009584:Nitrogen; D010100:Oxygen