This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Jensen, M. M.
Right arrow Articles by Dalsgaard, T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Jensen, M. M.
Right arrow Articles by Dalsgaard, T.
Agricola
Right arrow Articles by Jensen, M. M.
Right arrow Articles by Dalsgaard, T.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, May 2007, p. 3151-3158, Vol. 73, No. 10
0099-2240/07/$08.00+0     doi:10.1128/AEM.01898-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Effects of Specific Inhibitors on Anammox and Denitrification in Marine Sediments{triangledown}

Marlene Mark Jensen,1* Bo Thamdrup,1 and Tage Dalsgaard2

Nordic Center for Earth Evolution, Institute of Biology, University of Southern Denmark, DK-5230 Odense M,1 National Environmental Research Institute, DK-8600 Silkeborg, Denmark2

Received 9 August 2006/ Accepted 8 March 2007

The effects of three metabolic inhibitors (acetylene, methanol, and allylthiourea [ATU]) on the pathways of N2 production were investigated by using short anoxic incubations of marine sediment with a 15N isotope technique. Acetylene inhibited ammonium oxidation through the anammox pathway as the oxidation rate decreased exponentially with increasing acetylene concentration; the rate decay constant was 0.10 ± 0.02 µM–1, and there was 95% inhibition at ~30 µM. Nitrous oxide reduction, the final step of denitrification, was not sensitive to acetylene concentrations below 10 µM. However, nitrous oxide reduction was inhibited by higher concentrations, and the sensitivity was approximately one-half the sensitivity of anammox (decay constant, 0.049 ± 0.004 µM–1; 95% inhibition at ~70 µM). Methanol specifically inhibited anammox with a decay constant of 0.79 ± 0.12 mM–1, and thus 3 to 4 mM methanol was required for nearly complete inhibition. This level of methanol stimulated denitrification by ~50%. ATU did not have marked effects on the rates of anammox and denitrification. The profile of inhibitor effects on anammox agreed with the results of studies of the process in wastewater bioreactors, which confirmed the similarity between the anammox bacteria in bioreactors and natural environments. Acetylene and methanol can be used to separate anammox and denitrification, but the effects of these compounds on nitrification limits their use in studies of these processes in systems where nitrification is an important source of nitrate. The observed differential effects of acetylene and methanol on anammox and denitrification support our current understanding of the two main pathways of N2 production in marine sediments and the use of 15N isotope methods for their quantification.

* Corresponding author. Mailing address: Institute of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark. Phone: 45 6550 2739. Fax: 45 6593 0457. E-mail: mmj{at}biology.sdu.dk

{triangledown} Published ahead of print on 16 March 2007.

Applied and Environmental Microbiology, May 2007, p. 3151-3158, Vol. 73, No. 10
0099-2240/07/$08.00+0     doi:10.1128/AEM.01898-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Dong, L. F., Smith, C. J., Papaspyrou, S., Stott, A., Osborn, A. M., Nedwell, D. B. (2009). Changes in Benthic Denitrification, Nitrate Ammonification, and Anammox Process Rates and Nitrate and Nitrite Reductase Gene Abundances along an Estuarine Nutrient Gradient (the Colne Estuary, United Kingdom). Appl. Environ. Microbiol. 75: 3171-3179 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»