The Saccharomyces cerevisiae through increasing the expression of membrane transporter to produce more GSH inhibit the browning of pear wine

This study aimed to combine the strong fermentation capacity with enhanced glutathione (GSH) production of the Saccharomyces cerevisiae. Using laboratory-preserved S. cerevisiae and commercial S. cerevisiae as the initial strains, after chemical mutagenesis and H2O2 resistance domestication, obtained S. cerevisiae JN32-9 with the GSH yield of 47.47 % higher than that of the initial strain. JN32-9 was used to ferment Dangshan pear wine and reduced the browning degree of pear wine by 27.68 % during storage. Genome resequencing results showed that extracellular GSH production might be related to the genes such as MAL31, MPH2 and HXT13 of S. cerevisiae. After high expression of MAL31, MPH2 and HXT13 gene, the extracellular GSH yield of S. cerevisiae increased by 23.41 %, 21.53 % and 24.85 %. The transporters encoded by MAL31, MPH2 and HXT13 gene formed multiple hydrogen bonds to interact with GSH, and then transport GSH to the outside of the cells. In this study, the browning of pear wine was effectively inhibited by biological methods, which provided a possibility for the industrial production of fermented pear wine, and provided a reference for the research of browning of other fruit wines.