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Influence of residual ethanol concentration on the growth of Gluconacetobacter xylinus I2281

Kornmann, H. ; Duboc, P. ; Niederberger, P. ; Marison, I. ; von Stockar, U.

In: Applied Microbiology and Biotechnology, 2003, vol. 62, no. 2-3, p. 168-173

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    Titre
    • Influence of residual ethanol concentration on the growth of Gluconacetobacter xylinus I2281
    Auteur
    • Kornmann, H.. Laboratory of Chemical and Biological Engineering, Institute of Chemical Engineering, Swiss Federal Institute of Technology Lausanne, 1015, Lausanne, Switzerland
    • Duboc, P.. Nestlé Research Center, 1000, Lausanne 26, Switzerland
    • Niederberger, P.. Nestlé Research Center, 1000, Lausanne 26, Switzerland
    • Marison, I.. Laboratory of Chemical and Biological Engineering, Institute of Chemical Engineering, Swiss Federal Institute of Technology Lausanne, 1015, Lausanne, Switzerland
    • von Stockar, U.. Laboratory of Chemical and Biological Engineering, Institute of Chemical Engineering, Swiss Federal Institute of Technology Lausanne, 1015, Lausanne, Switzerland
    Type de document
    • Postprint
    Langue
    • Anglais
    Publié dans
    • Applied Microbiology and Biotechnology, 2003, vol. 62, no. 2-3, p. 168-173. Springer-Verlag
    Autre version électronique
    Classification
    • Biotechnologies
    Identifiant OAI-PMH
    • oai:doc.rero.ch:315083
    Summary
    The influence of residual ethanol on metabolism of food grade Gluconacetobacter xylinus I2281 was investigated during controlled cultivations on 35g/l glucose and 5g/l ethanol. Bacterial growth was strongly reduced in the presence of ethanol, which is unusual for acetic acid bacteria. Biomass accumulated only after complete oxidation of ethanol to acetate and carbon dioxide. In contrast, bacterial growth initiated without delay on 35g/l glucose and 5g/l acetate. It was found that acetyl CoA was activated by the acetyl coenzyme A synthetase (Acs) pathway in parallel with the phosphotransacetylase (Pta)-acetate kinase (Ack) pathway. The presence of ethanol in the culture medium strongly reduced Pta activity while Acs and Ack remained active. A carbon balance calculation showed that the overall catabolism could be divided into two independent parts: upper glycolysis linked to glucose catabolism and lower glycolysis liked to ethanol catabolism. This calculation showed that the carbon flux through the tricarboxylic cycle is lower on ethanol than on acetate. This corroborated the diminution of carbon flux through the Pta-Ack pathway due to the inhibition of Pta activity on ethanol