Abstract
The obligately ammonia-oxidizing bacterium Nitrosomonas europaea was incubated in medium containing 50 mM ammonium. Changes in the concentration of nitrite, the pH, and the NH(inf4)(sup+)- and NH(inf2)OH-dependent O(inf2) uptake activities of the cell suspension were monitored. The NH(inf4)(sup+)-dependent O(inf2) uptake activity doubled over the first 3 h of incubation and then slowly returned to its original level over the following 5 h. The extent of stimulation of NH(inf4)(sup+)-dependent O(inf2) uptake activity was decreased by lowering the initial pH of the medium. Radiolabeling studies demonstrated that the stimulation of NH(inf4)(sup+)-dependent O(inf2) uptake activity involved de novo synthesis of several polypeptides. Under O(inf2)-limited conditions, the stimulated NH(inf4)(sup+)-dependent O(inf2) uptake activity was stabilized. Rapid, controlled, and predictable changes in this activity could be caused by acidification of the medium in the absence of ammonia oxidation. These results indicate that the NH(inf4)(sup+)-dependent O(inf2) uptake activity in N. europaea is strongly regulated in response to NH(inf3) concentration.
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Selected References
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- Hyman M. R., Arp D. J. 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. 1992 Jan 25;267(3):1534–1545. [PubMed] [Google Scholar]
- Hyman M. R., Arp D. J. Effects of ammonia on the de novo synthesis of polypeptides in cells of Nitrosomonas europaea denied ammonia as an energy source. J Bacteriol. 1995 Sep;177(17):4974–4979. doi: 10.1128/jb.177.17.4974-4979.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hyman M. R., Arp D. J. The small-scale production of [U-14C]acetylene from Ba14CO3: application to labeling of ammonia monooxygenase in autotrophic nitrifying bacteria. Anal Biochem. 1990 Nov 1;190(2):348–353. doi: 10.1016/0003-2697(90)90206-o. [DOI] [PubMed] [Google Scholar]
- McTavish H., Fuchs J. A., Hooper A. B. Sequence of the gene coding for ammonia monooxygenase in Nitrosomonas europaea. J Bacteriol. 1993 Apr;175(8):2436–2444. doi: 10.1128/jb.175.8.2436-2444.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Prosser J. I. Autotrophic nitrification in bacteria. Adv Microb Physiol. 1989;30:125–181. doi: 10.1016/s0065-2911(08)60112-5. [DOI] [PubMed] [Google Scholar]
- Sayavedra-Soto L. A., Hommes N. G., Russell S. A., Arp D. J. Induction of ammonia monooxygenase and hydroxylamine oxidoreductase mRNAs by ammonium in Nitrosomonas europaea. Mol Microbiol. 1996 May;20(3):541–548. doi: 10.1046/j.1365-2958.1996.5391062.x. [DOI] [PubMed] [Google Scholar]
- Suzuki I., Dular U., Kwok S. C. Ammonia or ammonium ion as substrate for oxidation by Nitrosomonas europaea cells and extracts. J Bacteriol. 1974 Oct;120(1):556–558. doi: 10.1128/jb.120.1.556-558.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]