title: [Phylogenetic analysis and nitrogen removal characteristics of a heterotrophic nitrifying-aerobic denitrifying bacteria strain from marine environment].
abstract: OBJECTIVE
  We determined the phylogenetic position of a heterotrophic nitrifying-aerobic denitrifying bacterium X3, and detected its nitrogen removal characteristics for providing evidence to explain the principle of heterotrophic nitrification-aerobic denitrification and to improve the process in purification of marine-culture wastewater.
  
  
  METHODS
  The evolutionary position of the strain was determined based on its morphological, physiological, biochemical characteristics and 16SrRNA gene sequence. The nitrification-denitrification ability of this strain was detected by detecting its nitrogen removal efficiency and growth on different inorganic nitrogen source.
  
  
  RESULTS
  Strain X3 was identified as Halomonas sp. It grew optimally at salinity 3%, pH 8.5, C:N 10:1 at 28 degrees C, and it could still survive at 15% salinity. The removal of NH4+ -N, NO2(-) -N and NO3(-) -N was 98.29%, 99.07%, 96.48% respectively within 24 h. When three inorganic nitrogen existed simultaneously, it always utilized ammonia firstly, and the total inorganic nitrogen removal was higher than with only one nitrogen, suggesting that strain X3 has the ability of simultaneous nitrification and denitrification and completing the whole nitrogen removing process.
  
  
  CONCLUSIONS
  Strain X3 belonged to the genus of Halomonas. It had strong simultaneous nitrification and denitrification capability and could live in high-salinity environment.
authors.affiliation: Key Laboratory for Sustainable Utilization of Marine Fishery Resources, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, CAFS, Qingdao 266071, China. rose3260503@yahoo.com.cn
authors.forename: Xuemei
authors.initials: X
authors.lastname: Sun
authors.forename: Qiufen
authors.initials: Q
authors.lastname: Li
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Huaide
authors.initials: H
authors.lastname: Liu
authors.forename: Jun
authors.initials: J
authors.lastname: Zhao
authors.forename: Keming
authors.initials: K
authors.lastname: Qu
mesh_terms: D000332:Aerobiosis; D001673:Biodegradation, Environmental; D058440:Denitrification; D020632:Halomonas / Q000235:genetics* / Q000378:metabolism*; D052836:Heterotrophic Processes; D058465:Nitrification; D009584:Nitrogen / Q000378:metabolism*; D010802:Phylogeny; D012623:Seawater / Q000382:microbiology*
chemical_list: D009584:Nitrogen