title: Isolation and nitrogen removal characteristics of an aerobic heterotrophic nitrifying-denitrifying bacterium, Bacillus subtilis A1.
abstract: Bacterium A1, isolated to enhance nitrogen removal from ammonium-rich wastewater in situ, exhibited an amazing ability to convert ammonium to gaseous nitrogen compounds under fully aerobic conditions, while growing autotrophically or heterotrophically. A1 was identified as Bacillus subtilis by morphological and physiological characteristics, and phylogenetic analysis of its 16S rDNA gene sequence. Nitrogen removal by A1 was analyzed in relation to the ammonium concentration, presence of organic carbon, carbon source, and carbon-to-nitrogen ratio (C/N). The nitrogen balance during 120 h of autotrophic growth in the presence of 104.12±1.27 mg/L NH4+N showed that 20.4±2.7% of NH4+N was removed as gaseous nitrogen compounds, and A1 removed 58.4±4.3% of NH4+N within 60 h of growth in acetate medium at a C/N of 6. A mean ammonium removal rate of 3.52 mg NH4+N/(L h) was achieved in an open wastewater system, indicating great potential of A1 for future full-scale applications.
authors.affiliation: College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Xin-Ping
authors.initials: XP
authors.lastname: Yang
authors.forename: Shi-Mei
authors.initials: SM
authors.lastname: Wang
authors.forename: De-Wei
authors.initials: DW
authors.lastname: Zhang
authors.forename: Li-Xiang
authors.initials: LX
authors.lastname: Zhou
mesh_terms: D000332:Aerobiosis; D001412:Bacillus subtilis / Q000254:growth & development / Q000302:isolation & purification*; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology; D002244:Carbon / Q000378:metabolism; D058440:Denitrification / Q000502:physiology*; D052836:Heterotrophic Processes / Q000502:physiology*; D008969:Molecular Sequence Data; D058465:Nitrification / Q000502:physiology*; D009584:Nitrogen / Q000302:isolation & purification*; D000644:Quaternary Ammonium Compounds / Q000302:isolation & purification; D014865:Waste Disposal, Fluid; D018508:Water Purification
chemical_list: D000644:Quaternary Ammonium Compounds; D002244:Carbon; D009584:Nitrogen