skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Nitric oxide is an obligate bacterial nitrification intermediate produced by hydroxylamine oxidoreductase

Journal Article · · Proceedings of the National Academy of Sciences of the United States of America

Ammonia (NH3)-oxidizing bacteria (AOB) emit substantial amounts of nitric oxide (NO) and nitrous oxide (N2O), both of which contribute to the harmful environmental side effects of large-scale agriculture. The currently accepted model for AOB metabolism involves NH3 oxidation to nitrite (NO2) via a single obligate intermediate, hydroxylamine (NH2OH). Within this model, the multiheme enzyme hydroxylamine oxidoreductase (HAO) catalyzes the four-electron oxidation of NH2OH to NO2. In this paper, we provide evidence that HAO oxidizes NH2OH by only three electrons to NO under both anaerobic and aerobic conditions. NO2 observed in HAO activity assays is a nonenzymatic product resulting from the oxidation of NO by O2 under aerobic conditions. Finally, our present study implies that aerobic NH3 oxidation by AOB occurs via two obligate intermediates, NH2OH and NO, necessitating a mediator of the third enzymatic step.

Research Organization:
Cornell Univ., Ithaca, NY (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
SC0013997
OSTI ID:
1371603
Alternate ID(s):
OSTI ID: 1465961
Journal Information:
Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Vol. 114 Journal Issue: 31; ISSN 0027-8424
Publisher:
Proceedings of the National Academy of SciencesCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 257 works
Citation information provided by
Web of Science

References (35)

Principles of structure, bonding, and reactivity for metal nitrosyl complexes journal September 1974
Nitrite Reductase of Nitrosomonas europaea Is Not Essential for Production of Gaseous Nitrogen Oxides and Confers Tolerance to Nitrite journal May 2002
Oxidation of Inorganic Nitrogen Compounds journal June 1970
A review of chemical reactions of nitrification intermediates and their role in nitrogen cycling and nitrogen trace gas formation in soil: Chemical reactions of nitrification intermediates in soil journal November 2015
The metabolism of hydroxylamine to nitrite by Nitrosomonas journal April 1964
Characterization of Hydroxylamine-Cytochrome c Reductase from the Chemoautotrophs Nitrosomonas europaea and Nitrosocystis oceanus journal October 1965
Interaction of Nitric Oxide with Catalase: Structural and Kinetic Analysis journal May 2011
Bidirectional Catalysis by Copper-Containing Nitrite Reductase journal August 2004
Spectroscopic Characteristics and Some Chemical Properties of N-Methylphenazinium Methyl Sulfate (Phenazine Methosulfate) and Pyocyanine at the Semiquinoid Oxidation Level journal November 1964
Hydroxylamine oxidoreductase of Nitrosomonas journal November 1979
Nitrosomonas europaea cytochrome P460 is a direct link between nitrification and nitrous oxide emission journal November 2016
Hydroxylamine metabolism of Nitrosomonas europaea. I. Purification of hydroxylamine oxidase journal January 1968
Nitrous Oxide (N2O): The Dominant Ozone-Depleting Substance Emitted in the 21st Century journal August 2009
Processes regulating nitric oxide emissions from soils journal July 2013
Nitroxyl and its anion in aqueous solutions: Spin states, protic equilibria, and reactivities toward oxygen and nitric oxide journal May 2002
Identification of the sources of nitrous oxide produced by oxidative and reductive processes in Nitrosomonas europaea journal March 1972
The reaction of NO· with O2·− and HO2·−: A pulse radiolysis study journal October 1995
Energy Metabolism in Chemolithotropic Bacteria journal October 1960
Properties of 5-methylphenazinium methyl sulfate. Reaction of the oxidized form with NADH and of the reduced form with oxygen. journal February 1982
Clarifying the regulation of NO/N2O production in Nitrosomonas europaea during anoxic–oxic transition via flux balance analysis of a metabolic network model journal September 2014
Hydroxylamine oxidoreductase of Nitrosomonas. Oxidation of diethyldithiocarbamate concomitant with stimulation of nitrite synthesis journal October 1977
Hydroxylamine as an Intermediate in Nitrification journal January 1952
Oxidation of hydroxylamine by cytochrome P-460 of the obligate methylotroph Methylococcus capsulatus Bath. journal October 1994
The Crystal Structure of Cytochrome P460 of Nitrosomonas europaea Reveals a Novel Cytochrome Fold and Heme−Protein Cross-link , journal July 2007
Preliminary characterization of a variant co-binding heme protein from Nitrosomonas journal August 1972
Mössbauer, EPR, and optical studies of the P-460 center of hydroxylamine oxidoreductase from Nitrosomonas. A ferrous heme with an unusually large quadrupole splitting. journal June 1984
Kinetic and product distribution analysis of NO· reductase activity in Nitrosomonas europaea hydroxylamine oxidoreductase journal June 2008
Oxidation of hydroxylamine to nitrite catalyzed by hydroxylamine oxidoreductase purified fromNitrosomonas europaea journal July 1980
Nitrous oxide production by nitrification and denitrification in soil aggregates as affected by O2 concentration journal April 2004
Autoxidation kinetics of aqueous nitric oxide journal July 1993
Nitrogen Cycles: Past, Present, and Future journal September 2004
Structural Basis of Biological NO Generation by Octaheme Oxidoreductases journal December 2013
Complete Genome Sequence of the Ammonia-Oxidizing Bacterium and Obligate Chemolithoautotroph Nitrosomonas europaea journal May 2003
Revision of N 2 O-Producing Pathways in the Ammonia-Oxidizing Bacterium Nitrosomonas europaea ATCC 19718 journal June 2014
Spectrophotometric Method for Determining Hydroxylamine Reductase Activity in Higher Plants journal October 1955