Short Communication

Applied Microbiology and Biotechnology

, Volume 19, Issue 6, pp 422-426

First online:

Influence of pH and undissociated butyric acid on the production of acetone and butanol in batch cultures of Clostridium acetobutylicum

  • Fréderic MonotAffiliated withLaboratoire des Sciences du Génie Chimique, CNRS-ENSIC Institut National Polytechnique de Lorraine
  • , Jean-Marc EngasserAffiliated withLaboratoire de Chimie Biologique, Université de Nancy
  • , Henri PetitdemangeAffiliated withLaboratoire de Chimie Biologique, Université de Nancy

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The kinetics of growth and acid and solvent production are examined in batch fermentation of Clostridium acetobutylicum at pH between 4.5 and 6.0. At the lower pH, growth occurs in two consecutive phases and solvents are the main excreted metabolites. At the higher pH, there is a single growth phase with only acid formation. The influence of the pH can be correlated with a critical role of the concentration of undissociated butyric acid in the medium: cellular growth is inhibited above 0.5 g/l and solvent production starts at an undissociated acid level of 1.5 g/l. Reducing the intracellular acid dissociation by lowering the intracellular pH also favours the production of acetone and butanol.