Influence of Product Addition on the Oxidation of D-Sorbitol to L-Sorbose by the Strain Acetobacter suboxydans

Abstract

The kinetics of the D-sorbitol to L-sorbose biotransformation catalysed by the strain Acetobacter suboxydans is studied. The product inhibits the bacterial growth but the transformation is an autocatalytic process. However, higher initial concentrations of sorbose lead to a considerable decrease of the rate constant of the reaction, although the autocatalytic process takes place too. The addition of sorbose in the exponential phase of bacterial growth, or in the stationary phase, leads to a considerable shortening of the process duration, compared to the traditional fermentation.The rate constants calculated from the kinetic curves are dependent on the initial dry substances concentration and there is a correlation between these levels and the biomass concentration in the stationary phase.