title: Hydrogen sulfide production during yeast fermentation causes the accumulation of ethanethiol, S-ethyl thioacetate and diethyl disulfide.
abstract: Hydrogen sulfide (H2S) is produced by yeast during winemaking and possesses off-flavors reminiscent of rotten eggs. The production of H2S during fermentation has also been associated in the finished wine with the rise of additional volatile sulfur compounds (VSCs) with strong aromas of cooked onions and vegetables. To characterize these more complex VSCs produced from H2S, we performed fermentations in synthetic grape juice. H2S production was manipulated experimentally by feeding increasing concentrations of sulfate to mutant strains that are unable to incorporate H2S efficiently as part of the sulfur assimilation pathway. In finished wines from these mutants, three VSCs - ethanethiol, S-ethyl thioacetate and diethyl disulfide - increased proportionally to H2S. (34)S-labeled sulfate fed to the MET17-deleted strain was incorporated into same three VSCs, demonstrating that they are formed directly from H2S.
authors.affiliation: School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand. Electronic address: mkin586@aucklanduni.ac.nz.
authors.forename: Matias I
authors.initials: MI
authors.lastname: Kinzurik
authors.affiliation: School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand.
authors.forename: Mandy
authors.initials: M
authors.lastname: Herbst-Johnstone
authors.affiliation: School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand.
authors.forename: Richard C
authors.initials: RC
authors.lastname: Gardner
authors.affiliation: School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand. Electronic address: b.fedrizzi@auckland.ac.nz.
authors.forename: Bruno
authors.initials: B
authors.lastname: Fedrizzi
mesh_terms: D000085:Acetates / Q000032:analysis*; D003547:Cysteine Synthase / Q000235:genetics; D005285:Fermentation; D005638:Fruit / Q000378:metabolism; D006862:Hydrogen Sulfide / Q000032:analysis*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D013431:Sulfates / Q000737:chemistry; D013438:Sulfhydryl Compounds / Q000032:analysis*; D013440:Sulfides / Q000032:analysis*; D027843:Vitis / Q000378:metabolism*; D014920:Wine / Q000032:analysis*
chemical_list: D000085:Acetates; D029701:Saccharomyces cerevisiae Proteins; D013431:Sulfates; D013438:Sulfhydryl Compounds; D013440:Sulfides; D003547:Cysteine Synthase; C103381:MET17 protein, S cerevisiae; C007638:ethanethiol; D006862:Hydrogen Sulfide
keywords: Diethyl disulfide (PubChem CID: 8077); Ethanethiol (PubChem CID: 6343); Hydrogen sulfide (PubChem CID: 402); MET17; S-ethyl thioacetate (PubChem CID: 61171); Saccharomyces cerevisiae; Sulfate assimilation; Volatile sulfur compounds; Wine aroma