Effect of sulfate and nitrate on acetate conversion by anaerobic microorganisms in a freshwater sediment
UNSPECIFIED. (2002) Effect of sulfate and nitrate on acetate conversion by anaerobic microorganisms in a freshwater sediment. FEMS MICROBIOLOGY ECOLOGY, 42 (3). pp. 375-385. ISSN 0168-6496Full text not available from this repository.
Acetate is quantitatively the most important substrate for methane production in a freshwater sediment in The Netherlands. In the presence of alternative electron acceptors the conversion of acetate by methanogens was strongly inhibited. By modelling the results, obtained in experiments with and without C-13-labelled acetate, we could show that the competition for acetate between methanogens and sulfate reducers is the main cause of inhibition of methanogenesis in the sediment. Although nitrate led to a complete inhibition of methanogenesis, acetate-utilising nitrate-reducing bacteria hardly competed with methanogens for the available acetate in the presence of nitrate. Most-probable-number enumerations showed that methanogens (2 x 10(8) cells cm(-3) sediment) and sulfate reducers (2 x 10(8) cells cm(-3) sediment) were the dominant acetate-utilising organisms in the sediment, while numbers of acetate-utilising nitrate reducers were very low (5 x 10(5) cells cm(-3) sediment). However, high numbers of sulfide-oxidising nitrate reducers were detected. Denitrification might result in the formation of toxic products. We speculate that the accumulation of low concentrations of NO (< 0.2 mM) may result in an inhibition of methanogenesis. (C) 2002 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.
|Item Type:||Journal Article|
|Subjects:||Q Science > QR Microbiology|
|Journal or Publication Title:||FEMS MICROBIOLOGY ECOLOGY|
|Publisher:||ELSEVIER SCIENCE BV|
|Official Date:||December 2002|
|Number of Pages:||11|
|Page Range:||pp. 375-385|
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