Authors: Patricia DíazHellín Victoria Naranjo Juan Úbeda Ana Briones
Publish Date: 2016/10/12
Volume: 32, Issue: 12, Pages: 196-
Abstract
When exposed to mixtures of glucose and fructose as occurs during the fermentation of grape juice into wine Saccharomyces cerevisiae uses these sugars at different rates Moreover glucose and fructose are transported by the same hexose transporters HXT which present a greater affinity for glucose so that late in fermentation fructose becomes the predominant sugar Only a few commercial fermentation activators are available to optimally solve the problems this entails The aim of this study was to investigate the relation between HXT3 gene expression and fructose/glucose discrepancy in two different media inoculated with a commercial wine strain of S cerevisiae in the presence of three metabolic activators Fermentation kinetics vitality and major metabolites were also measured Rehydration with ergosterol improved the area under the curve and the growth rate µ max in both studied media Also the fructose/glucose discrepancy values were improved with all activator treatments highlighting rehydration in the presence of ascorbic acid The yeast rehydration process was demonstrated to influence HXT3 expression under the studied conditions Tetrahydrofolic acid treatment greatly influenced HXT3 gene expression especially on the 12th day of the fermentation process To a lesser extent ergosterol and ascorbic acid also improved this parameter
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