Archives of Microbiology

, Volume 110, Issue 2, pp 257–262

Energy coupling and respiration inNitrosomonas europaea

Authors

  • Jan William Drozd
    • Woodstock Laboratory, Shell Research Ltd.Sittingbourne Research Centre
Article

DOI: 10.1007/BF00690236

Cite this article as:
Drozd, J.W. Arch. Microbiol. (1976) 110: 257. doi:10.1007/BF00690236

Abstract

Intact cells ofNitrosomonas europaea grown in an ammonium salts medium will oxidise ammonium ions, hydroxylamine and ascorbate-TMPD; there is no oxidation of carbon monoxide, methane or methanol. TheKm value for ammonia oxidation is highly pH dependent with a minimum value of 0.5 mM above pH 8.0. This suggests that free ammonia is the species crossing the cytoplasmic membrane(s). The measurement of respiration driven proton translocation indicates that there is probably only one proton translocating loop (loop 3) association with hydroxylamine oxidation. The oxidation of “endogenous” substrates is sometimes associated with more than one proton-translocating loop. These results indicate that during growth hydroxylamine oxidation is probably associated with a maximum P/O ratio of 1.

Key words

Nitrosomonas europaeaAutotrophic bacteriaEnergy couplingProton translocationChemiosmotic hypothesisAmmonia oxidation

Abbreviations

H+/O ratio

g equiv. H+ translocated/g atom O consumed

Copyright information

© Springer-Verlag 1976