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

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dc.contributor.authorBerthels, N. J.en_ZA
dc.contributor.authorCordero Otero, R. R.en_ZA
dc.contributor.authorBauer, Florianen_ZA
dc.contributor.authorPretorius, I. S.en_ZA
dc.contributor.authorThevelein, J. M.en_ZA
dc.date.accessioned2011-05-15T15:56:36Z
dc.date.available2011-05-15T15:56:36Z
dc.date.issued2008
dc.description.abstractGrape 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 K m for both sugars. Hxk1 has a threefold higher V max with fructose than with glucose, whereas Hxk2 has only a slightly higher V max 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 K m might serve as markers in selection and breeding of wine yeast strains with a lower tendency for sluggish fructose fermentation. © 2007 Springer-Verlag.
dc.description.versionArticle
dc.identifier.citationApplied Microbiology and Biotechnology
dc.identifier.citation77
dc.identifier.citation5
dc.identifier.issn1757598
dc.identifier.other10.1007/s00253-007-1231-2
dc.identifier.urihttp://hdl.handle.net/10019.1/9942
dc.subjectEnzyme activity
dc.subjectFermentation
dc.subjectFructose
dc.subjectKinetics
dc.subjectPhosphorylation
dc.subjectYeast
dc.subjectSugar phosphorylation
dc.subjectSugar preference
dc.subjectWine yeast
dc.subjectGlucose
dc.subjectfructose
dc.subjectglucose
dc.subjecthexokinase
dc.subjectenzyme activity
dc.subjectfermentation
dc.subjectfruit
dc.subjectlaboratory method
dc.subjectsucrose
dc.subjectyeast
dc.subjectarticle
dc.subjectcorrelation analysis
dc.subjectenzyme activity
dc.subjectfermentation
dc.subjectglucose intake
dc.subjectnonhuman
dc.subjectSaccharomyces cerevisiae
dc.subjectwine
dc.subjectyeast
dc.subjectFermentation
dc.subjectFructose
dc.subjectGlucose
dc.subjectHexokinase
dc.subjectKinetics
dc.subjectSaccharomyces cerevisiae
dc.subjectWine
dc.subjectSaccharomyces cerevisiae
dc.subjectVitaceae
dc.titleCorrelation between glucose/fructose discrepancy and hexokinase kinetic properties in different Saccharomyces cerevisiae wine yeast strains
dc.typeArticle
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