title: Anaerobic ammonia oxidation in the presence of nitrogen oxides (NO(x)) by two different lithotrophs.
abstract: The anaerobic ammonia-oxidizing activity of the planctomycete Candidatus "Brocadia anammoxidans" was not inhibited by NO concentrations up to 600 ppm and NO2 concentrations up to 100 ppm. B. anammoxidans was able to convert (detoxify) NO, which might explain the high NO tolerance of this organism. In the presence of NO2, the specific ammonia oxidation activity of B. anammoxidans increased, and Nitrosomonas-like microorganisms recovered an NO2-dependent anaerobic ammonia oxidation activity. Addition of NO2 to a mixed population of B. anammoxidans and Nitrosomonas induced simultaneous specific anaerobic ammonia oxidation activities of up to 5.5 mmol of NH4+ g of protein(-1) h(-1) by B. anammoxidans and up to 1.5 mmol of NH4+ g of protein(-1) h(-1) by Nitrosomonas. The stoichiometry of the converted N compounds (NO2-/NH3 ratio) and the microbial community structure were strongly influenced by NO2. The combined activity of B. anammoxidans and Nitrosomonas-like ammonia oxidizers might be of relevance in natural environments and for technical applications.
authors.affiliation: Department of Microbiology, University of Nijmegen, 6525 ED Nijmegen, The Netherlands. i.schmidt@sci.kun.nl
authors.forename: Ingo
authors.initials: I
authors.lastname: Schmidt
authors.forename: Cristian
authors.initials: C
authors.lastname: Hermelink
authors.forename: Katinka
authors.initials: K
authors.lastname: van de Pas-Schoonen
authors.forename: Marc
authors.initials: M
authors.lastname: Strous
authors.forename: Huub J
authors.initials: HJ
authors.lastname: op den Camp
authors.forename: J Gijs
authors.initials: JG
authors.lastname: Kuenen
authors.forename: Mike S M
authors.initials: MS
authors.lastname: Jetten
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D000693:Anaerobiosis; D009585:Nitrogen Dioxide / Q000378:metabolism; D009589:Nitrogen Oxides / Q000378:metabolism*; D009606:Nitrosomonas / Q000378:metabolism*; D010084:Oxidation-Reduction
chemical_list: D009589:Nitrogen Oxides; D000641:Ammonia; D009585:Nitrogen Dioxide