TitleEngineering Saccharomyces cerevisiae to release 3-Mercaptohexan-1-ol during fermentation through overexpression of an S. cerevisiae Gene, STR3, for improvement of wine aroma.
Publication TypeJournal Article
Year of Publication2011
AuthorsHolt, S, Cordente, AG, Williams, SJ, Capone, DL, Jitjaroen, W, Menz, IR, Curtin, CD, Anderson, PA
JournalAppl Environ Microbiol
Date Published2011 Jun
KeywordsDNA, Fungal, Fermentation, Gene Expression, Lyases, Molecular Sequence Data, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins, Sequence Analysis, DNA, Sulfhydryl Compounds, Vitis, Wine

Sulfur-containing aroma compounds are key contributors to the flavor of a diverse range of foods and beverages. The tropical fruit characters of Vitis vinifera L. cv. Sauvignon blanc wines are attributed to the presence of the aromatic thiols 3-mercaptohexan-1-ol (3MH), 3-mercaptohexan-1-ol-acetate, and 4-mercapto-4-methylpentan-2-one (4MMP). These volatile thiols are found in small amounts in grape juice and are formed from nonvolatile cysteinylated precursors during fermentation. In this study, we overexpressed a Saccharomyces cerevisiae gene, STR3, which led to an increase in 3MH release during fermentation of a V. vinifera L. cv. Sauvignon blanc juice. Characterization of the enzymatic properties of Str3p confirmed it to be a pyridoxal-5'-phosphate-dependent cystathionine β-lyase, and we demonstrated that this enzyme was able to cleave the cysteinylated precursors of 3MH and 4MMP to release the free thiols. These data provide direct evidence for a yeast enzyme able to release aromatic thiols in vitro that can be applied in the development of self-cloned yeast to enhance wine flavor.

Alternate JournalAppl. Environ. Microbiol.
PubMed ID21478306
PubMed Central IDPMC3127618