title: Conversion of ammonia to dinitrogen in wastewater by Nitrosomonas europaea.
abstract: Because Nitrosomonas europaea contains ammonia-oxidizing enzyme, nitrite reductase, and nitrous oxide reductase, the conversion of ammonia to dinitrogen was tried with different reaction conditions. In aerobic reaction conditions, ammonium was converted to nitrite (NO2-), while under oxygen-limiting or oxygen-free conditions, NO2(-)-N formed from ammonia oxidation by N. europaea was reduced to N2O and dinitrogen with 22% conversion. During denitrification, optimal pH for the production of N2O and dinitrogen was found to be 7.0-8.0. Dinitrogen was not produced in acidic pH <7.0. A low partial oxygen pressure as well as oxygen-free conditions are favorable for high production of dinitrogen.
authors.affiliation: Department of Bioengineering, Tokyo Institute of Technology, Nagatsuta, Yokohama, Japan.
authors.forename: N K
authors.initials: NK
authors.lastname: Shrestha
authors.forename: S
authors.initials: S
authors.lastname: Hadano
authors.forename: T
authors.initials: T
authors.lastname: Kamachi
authors.forename: I
authors.initials: I
authors.lastname: Okura
mesh_terms: D000641:Ammonia / Q000737:chemistry* / Q000378:metabolism*; D009573:Nitrites / Q000737:chemistry; D009584:Nitrogen / Q000378:metabolism*; D009606:Nitrosomonas / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D013997:Time Factors; D014866:Waste Products; D014867:Water / Q000737:chemistry*
chemical_list: D009573:Nitrites; D014866:Waste Products; D014867:Water; D000641:Ammonia; D009584:Nitrogen; D010100:Oxygen