title: Heterotrophic nitrification and aerobic denitrification at low nutrient conditions by a newly isolated bacterium, Acinetobacter sp. SYF26.
abstract: A new strain, named SYF26, was isolated from the Hei He oligotrophic drinking-water reservoir in China. Based on its phenotypic and phylogenetic characteristics, the isolate was identified as a species of genus Acinetobacter. Strain SYF26 was able to grow at low NH₄(+)-N concentrations (5.46 mg l(-1)), and the nitrification rate was 0.064 mg NH₄(+)-N l(-1) h(-1). Low accumulation of nitrate and nitrite was observed throughout the ammonium removal experiment. Strain SYF26 reduced NO₃(-)-N or NO₂(-)-N. Nitrite reductase and periplasmic nitrate reductase were detectable. The putative nitrogen removal process carried out by the strain SYF26 is as follows: NH₄(+)→NH₂OH→NO₂(-)→NO₃(-), then NO₃(-)→NO₂(-)→N₂. Response surface methodology analysis demonstrated that the maximum removal of ammonium occurred under the following conditions: NH₄(+)-N concentration of 22.05 mg l(-1), C/N ratio of 4.31, initial pH of 7.78 and temperature of 29.73 °C, where initial pH and temperature had the largest influence on ammonium removal.
authors: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, PR China State Environmental Protection Key Laboratory of Microorganism Application and Risk Control, Tsinghua University, Beijing 100084, PR China sjf1977518@sina.com.cn.
authors: Jun-feng
authors: JF
authors: Su
authors: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, PR China.
authors: Kai
authors: K
authors: Zhang
authors: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, PR China.
authors: Ting-lin
authors: TL
authors: Huang
authors: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, PR China.
authors: Gang
authors: G
authors: Wen
authors: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, PR China.
authors: Lin
authors: L
authors: Guo
authors: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, PR China.
authors: Shao-fei
authors: SF
authors: Yang
mesh_terms: D000150:Acinetobacter / Q000145:classification / Q000502:physiology*; D000332:Aerobiosis; D064751:Ammonium Compounds / Q000378:metabolism; D058440:Denitrification; D004777:Environment; D008969:Molecular Sequence Data; D058889:Molecular Typing; D009566:Nitrates / Q000378:metabolism; D058465:Nitrification; D009573:Nitrites / Q000378:metabolism; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S
chemical_list: D064751:Ammonium Compounds; D009566:Nitrates; D009573:Nitrites; D012336:RNA, Ribosomal, 16S