Archives of Microbiology

, Volume 188, Issue 4, pp 349–354 | Cite as

Role of nitrite reductase in the ammonia-oxidizing pathway of Nitrosomonas europaea

Original Paper


Metabolism of ammonia (NH3) and hydroxylamine (NH2OH) by wild-type and a nitrite reductase (nirK) deficient mutant of Nitrosomonas europaea was investigated to clarify the role of NirK in the NH3 oxidation pathway. NirK-deficient N. europaea grew more slowly, consumed less NH3, had a lower rate of nitrite (NO2) production, and a significantly higher rate of nitrous oxide (N2O) production than the wild-type when incubated with NH3 under high O2 tension. In incubations with NH3 under low O2 tension, NirK-deficient N. europaea grew more slowly, but had only modest differences in NH3 oxidation and product formation rates relative to the wild-type. In contrast, the nirK mutant oxidized NH2OH to NO2 at consistently slower rates than the wild-type, especially under low O2 tension, and lost a significant pool of NH2OH–N to products other than NO2 and N2O. The rate of N2O production by the nirK mutant was ca. three times higher than the wild-type during hydrazine-dependent NO2 reduction under both high and low O2 tension. Together, the results indicate that NirK activity supports growth of N. europaea by supporting the oxidation of NH3 to NO2 via NH2OH, and stimulation of hydrazine-dependent NO2 reduction by NirK-deficient N. europaea indicated the presence of an alternative, enzymatic pathway for N2O production.


Ammonia oxidation Hydroxylamine oxidation Nitrifier denitrification Nitrite reductase Nitrosomonas europaea Nitrous oxide 



Hydroxylamine oxidoreductase


Ammonia monooxygenase


  1. Anderson IC, Poth M, Homstead J, Burdige D (1993) A comparison of NO and N2O production by the autotrophic nitrifier Nitrosomonas europaea and the heterotrophic nitrifier Alcaligenes faecalis. Appl Environ Microbiol 59:3525–3533PubMedGoogle Scholar
  2. Beaumont HJE et al (2002) Nitrite reductase of Nitrosomonas europaea is not essential for production of gaseous nitrogen oxides and confers tolerance to nitrite. J Bacteriol 184:2557–2560PubMedCrossRefGoogle Scholar
  3. Beaumont HJE, Lens SI, Reijnders WNM, Westerhoff HV, van Spanning RJM (2004) Expression of nitrite reductase in Nitrosomonas europaea involves NsrR, a novel nitrite sensitive transcription repressor. Mol Microbiol 54:148–158PubMedCrossRefGoogle Scholar
  4. Beaumont HJE, Lens SI, Westerhoff HV, van Spanning RJM (2005) Novel nirK cluster genes in Nitrosomonas europaea are required for NirK-dependent tolerance to nitrite. J Bacteriol 187:6849–6851PubMedCrossRefGoogle Scholar
  5. Bremner JM, Blackmer AM (1980) Mechanisms of nitrous oxide production in soils. In: Trudinger PA, Walter MR, Ralph BJ (eds) Biogeochemistry of ancient and modern environments. Australian Academy of Science, Canberra, pp 279–291Google Scholar
  6. Cantera JJL, Stein LY (2007) Molecular diversity of nitrite reductase (nirK) genes in nitrifying bacteria. Environ Microbiol 9:765–776PubMedCrossRefGoogle Scholar
  7. Cho CM-H, Yan T, Liu X, Wu L, Zhou J, Stein LY (2006) Transcriptome of Nitrosomonas europaea with a disrupted nitrite reductase (nirK) gene. Appl Environ Microbiol 72:4450–4454PubMedCrossRefGoogle Scholar
  8. Clesceri LS, Greenberg AE, Eaton AD (1998) Standard methods for the examination of water and wastewater, 20th edn. American Public Health Assoc, Washington, D.CGoogle Scholar
  9. DiSpirito AA, Taaffe LR, Lipscomb JD, Hooper AB (1985) A ‘blue’ copper oxidase from Nitrosomonas europaea. Biochim Biophys ACTA 827:320–326Google Scholar
  10. Dundee L, Hopkins DW (2001) Different sensitivities to oxygen of nitrous oxide production by Nitrosomonas europaea and Nitrosolobus multiformis. Soil Biol Biochem 33:1563–1565CrossRefGoogle Scholar
  11. Frear DS, Burrell RC (1955) Spectrophotometric method for determining hydroxylamine reductase activity in higher plants. Anal Chem 27:1664–1665CrossRefGoogle Scholar
  12. Goreau TJ, Kaplan WA, Wofsy SC, McElroy MB, Valois FW, Watson SW (1980) Production of NO2 and N2O by nitrifying bacteria at reduced concentrations of oxygen. Appl Environ Microbiol 40:526–532PubMedGoogle Scholar
  13. Hooper AB, Terry KR (1979) Hydroxylamine oxidoreductase of Nitrosomonas, production of nitric oxide from hydroxylamine. Biochim Biophys Acta 571:12–20PubMedGoogle Scholar
  14. Hyman MR, Arp DJ (1992) 14C2H2- and 14CO2-labeling studies of the de novo synthesis of polypeptides by Nitrosomonas europaea during recovery from acetylene and light inactivation of ammonia monooxygenase. J Biol Chem 267:1534–1545PubMedGoogle Scholar
  15. Lipschultz F, Zafiriou OC, Wofsy SC, McElroy MB, Valois FW, Watson SW (1981) Production of NO and N2O by soil nitrifying bacteria. Nature 294:641–643CrossRefGoogle Scholar
  16. Logan MSP, Hooper AB (1995) Suicide inactivation of hydroxylamine oxidoreductase of Nitrosomonas europaea by organohydrazines. Biochemistry 34:9257–9926PubMedCrossRefGoogle Scholar
  17. Schmidt I, van Spanning RJM, Jetten MSM (2004) Denitrification and ammonia oxidation by Nitrosomonas europaea wild-type, and NirK- and NorB-deficient mutants. Microbiology 150:4107–4114PubMedCrossRefGoogle Scholar
  18. Snell FD, Snell CT (1949) Colorimetric methods of analysis, 3 edn. Van Nostrand, PrincetonGoogle Scholar
  19. Stein LY, Yung YL (2003) Production, isotopic composition, and atmospheric fate of biologically produced nitrous oxide. Annu Rev Earth Planet Sci 31:329–356CrossRefGoogle Scholar
  20. Whittaker M, Bergmann D, Arciero D, Hooper AB (2000) Electron transfer during the oxidation of ammonia by the chemolithotrophic bacterium Nitrosomonas europaea. Biochim Biophys ACTA 1459:346–355PubMedCrossRefGoogle Scholar
  21. Yoshida N et al (1989) Nitrification rates and 15N abundances of N2O and NO3 in the western North Pacific. Nature 342:895–897CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  1. 1.Department of Environmental Sciences, Geology 2207University of CaliforniaRiversideUSA

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