title: Ammonium removal at low temperature by a newly isolated heterotrophic nitrifying and aerobic denitrifying bacterium Pseudomonas fluorescens wsw-1001.
abstract: A heterotrophic nitrifier wsw-1001 was isolated from Songhua River and identified as Pseudomonas fluorescens. Ammonium removal by the strain at low temperature was investigated. The effect of initial ammonium concentration (from 5 to 1000 mg/L) and culture temperature (from 4°C to 30°C) on ammonium removal efficiency was studied. Biodegradation product, [Formula: see text], [Formula: see text], N2, N2O and intercellular N were monitored. The results indicated that the strain had potential for water and wastewater treatment. Ammonium could be removed by the strain at low temperature. Ammonium removal efficiency increased with temperature from 4°C to 20°C and decreased with ammonium concentration from 5 to 1000 mg/L. The strain exhibited a capability of heterotrophic nitrification and aerobic denitrification using [Formula: see text] as the sole nitrogen source at 8°C. [Formula: see text] and [Formula: see text] were reduced by the strain. Nitrogen balance analysis in the presence of 39.7 mg/L [Formula: see text] indicated that 71.2% [Formula: see text] was removed by converting to N2 (46.3%) and assimilating as biomass (42.5%). Substances such as [Formula: see text], [Formula: see text] and N2O were detected at very low concentrations. Ammonium mono-oxygenase, hydroxylamine oxidase, nitrite reductase and nitrate reductase activity were measured. The ammonium removal pathway of the strain was speculated to be [Formula: see text].
authors.affiliation: a Institute of Microbiology, Heilongjiang Academy of Sciences , Harbin , Heilongjiang 150010 , People's Republic of China.
authors.forename: Shumei
authors.initials: S
authors.lastname: Zhang
authors.forename: Changqing
authors.initials: C
authors.lastname: Sha
authors.forename: Wei
authors.initials: W
authors.lastname: Jiang
authors.forename: Weiguang
authors.initials: W
authors.lastname: Li
authors.forename: Duoying
authors.initials: D
authors.lastname: Zhang
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Liqiang
authors.initials: L
authors.lastname: Meng
authors.forename: Yongjian
authors.initials: Y
authors.lastname: Piao
mesh_terms: D000332:Aerobiosis; D064751:Ammonium Compounds / Q000378:metabolism*; D003080:Cold Temperature; D004269:DNA, Bacterial / Q000235:genetics; D058440:Denitrification; D052836:Heterotrophic Processes; D058465:Nitrification; D010802:Phylogeny; D011551:Pseudomonas fluorescens / Q000235:genetics / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D064751:Ammonium Compounds; D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S
keywords: Pseudomonas fluorescens; aerobic denitrification; ammonium removal; heterotrophic nitrification; low temperature