Knockout of the high-coupling cytochrome aa3 oxidase reduces TCA cycle fluxes in Bacillus subtilis

Authors

  • Nicola Zamboni,

    1. Institute of Biotechnology, ETH Zürich, CH-8093 Zürich, Switzerland
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  • Uwe Sauer

    Corresponding author
    1. Institute of Biotechnology, ETH Zürich, CH-8093 Zürich, Switzerland
      *Corresponding author. Tel.: +41 (1) 633 3672; Fax: +41 (1) 633 1051, E-mail address: sauer@biotech.biol.ethz.ch
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*Corresponding author. Tel.: +41 (1) 633 3672; Fax: +41 (1) 633 1051, E-mail address: sauer@biotech.biol.ethz.ch

Abstract

The metabolic impact of electron rerouting in the respiratory chain of Bacillus subtilis was quantitatively assessed during batch growth of quinol oxidase mutants by 13C-tracer experiments. While disruption of the low-coupling cytochrome bd oxidase was without any apparent phenotype, deletion of the high-coupling cytochrome aa3 oxidase caused a severe reduction of tricarboxylic acid cycle fluxes and increased overflow metabolism. Since the product-corrected biomass yields were identical in mutants and parent, the results show that efficient ATP generation is not overly important for exponential growth of B. subtilis in batch culture.

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