A Mathematical Model to Evaluate the Kinetics of D-glucose and D-fructose Fermentations by Saccharomyces bayanus at Increasing Ethanol Concentrations

  • A. Zinnai Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy
  • F. Venturi Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy
  • C. Sanmartin Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy
  • M.F. Quartacci Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy
  • G. Andrich Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy

Abstract

In the cellar, slow and stuck fermentations occurring during winemaking are often successfully solved by
the addition of yeast strains like Saccharomyces bayanus. The kinetic behaviour shown by S. bayanus during
alcoholic fermentation was investigated using a mathematical model previously tested for S. cerevisiae, in
order to show which of the six functional parameters of the model differed significantly with the yeast
population. Although some parameters (hexose fractions converted to ethanol and glycerol) did not change,
the kinetic constant related to the inactivation rate of the yeast population showed by S. cerevisiae assumed
a value significantly higher (approximately 50-fold) than that observed for S. bayanus, while this latter
population was ten times less affected by ethanol than S. cerevisiae. Although no remarkable differences
could be found between the ability shown by the two yeast populations to convert hexoses (D-glucose and
D-fructose), the tolerance for ethanol accumulation changed strongly. The conversion rate of these two
hexoses by S. bayanus was affected less (about ten thousand-fold) by ethanol than that of S. cerevisiae.

Downloads

Download data is not yet available.
Published
2016-09-21
Section
Articles