Applied Microbiology and Biotechnology

, Volume 77, Issue 5, pp 1083–1091

Correlation between glucose/fructose discrepancy and hexokinase kinetic properties in different Saccharomyces cerevisiae wine yeast strains

  • Nele J. Berthels
  • Ricardo R. Cordero Otero
  • Florian F. Bauer
  • Isak S. Pretorius
  • Johan M. Thevelein
Applied Microbial and Cell Physiology

DOI: 10.1007/s00253-007-1231-2

Cite this article as:
Berthels, N.J., Cordero Otero, R.R., Bauer, F.F. et al. Appl Microbiol Biotechnol (2008) 77: 1083. doi:10.1007/s00253-007-1231-2

Abstract

Grape juice contains about equal amounts of glucose and fructose, but wine strains of Saccharomyces cerevisiae ferment glucose slightly faster than fructose, leading to fructose concentrations that exceed glucose concentrations in the fermenting must. A high fructose/glucose ratio may contribute to sluggish and stuck fermentations, a major problem in the global wine industry. We evaluated wine yeast strains with different glucose and fructose consumption rates to show that a lower glucose preference correlates with a higher fructose/glucose phosphorylation ratio in cell extracts and a lower Km for both sugars. Hxk1 has a threefold higher Vmax with fructose than with glucose, whereas Hxk2 has only a slightly higher Vmax with glucose than with fructose. Overexpression of HXK1 in a laboratory strain of S. cerevisiae (W303–1A) accelerated fructose consumption more than glucose consumption, but overexpression in a wine yeast strain (VIN13) reduced fructose consumption less than glucose consumption. Results with laboratory strains expressing a single kinase showed that total hexokinase activity is inversely correlated with the glucose/fructose (G/F) discrepancy. The latter has been defined as the difference between the rate of glucose and fructose fermentation. We conclude that the G/F discrepancy in wine yeast strains correlates with the kinetic properties of hexokinase-mediated sugar phosphorylation. A higher fructose/glucose phosphorylation ratio and a lower Km might serve as markers in selection and breeding of wine yeast strains with a lower tendency for sluggish fructose fermentation.

Keywords

Wine yeastSugar preferenceSugar phosphorylationFermentation

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Nele J. Berthels
    • 1
    • 2
    • 3
  • Ricardo R. Cordero Otero
    • 1
    • 5
  • Florian F. Bauer
    • 1
  • Isak S. Pretorius
    • 1
    • 4
  • Johan M. Thevelein
    • 2
    • 3
  1. 1.Institute for Wine Biotechnology, Department of Viticulture & OenologyStellenbosch UniversityStellenboschSouth Africa
  2. 2.Laboratory of Molecular Cell Biology, Institute of Botany and MicrobiologyKatholieke Universiteit LeuvenLeuven-Heverlee, FlandersBelgium
  3. 3.Department of Molecular MicrobiologyVIBLeuven-Heverlee, FlandersBelgium
  4. 4.The Australian Wine Research InstituteAdelaideAustralia
  5. 5.Department of Biochemistry and BiotechnologyUniversity of Rovira I VirgiliTarragonaSpain