Competition for nitrate between denitrifying Pseudomonas stutzeri and nitrate ammonifying enterobacteria |
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Authors: | Bert Rehr Jobst-Heinrich Klemme |
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Institution: | Institut für Mikrobiologie der Universität Bonn, Bonn, F.R.G. |
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Abstract: | Abstract Competition for nitrate between nitrate ammonifying enterobacteria and a denitrifying pseudomonad was studied in electron acceptor-limited chenostats. In pure cultures, using different carbon and energy sources, the C/N-ratio needed for denitrification is far lower than that required for nitrate ammonification. In mixed cultures of Citrobacter freundii and Pseudomonas stutzeri , competing for nitrate with l -lactate as electron donor, the nitrate ammonifying organism dominated at dilution rates of D ≤ 0.14 h−1. Competition for both nitrate and l -lactate at a dilution rate of D = 0.05 h−1 always resulted in the coexistence of both species. Using glucose as additional carbon source, the final ratio of nitrate ammonifying and denitrifying organism depended on the C/N-ratio as well as on the dilution rate. The results of the study are discussed with respect to field data. |
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Keywords: | Denitrification Nitrate ammonification Microbial competition Chemostat |
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