Two-Stage Screening of spp. Bioprotective Properties: From Grape Juice to Fermented Must by .

(Go) and (Bb) are detrimental micro-organisms compromising wine quality through the production of acetic acid and undesirable aromas. Non- yeasts, like species, offer a bioprotective approach to control spoilage micro-organisms growth. Antagonist effects of forty-six strains in a co-culture with or in commercial grape juice were assessed.

Copper-based grape pest management has impacted wine aroma.

Despite the high energetic cost of the reduction of sulfate to HS, required for the synthesis of sulfur-containing amino acids, some wine Saccharomyces cerevisiae strains have been reported to produce excessive amounts of HS during alcoholic fermentation, which is detrimental to wine quality. Surprisingly, in the presence of sulfite, used as a preservative, wine strains produce more HS than wild (oak) or wine velum (flor) isolates during fermentation. Since copper resistance caused by the amplification of the sulfur rich protein Cup1p is a specific adaptation trait of wine strains, we analyzed the link between copper resistance mechanism, sulfur metabolism and HS production.

QTL mapping reveals novel genes and mechanisms underlying variations in H2S production during alcoholic fermentation in Saccharomyces cerevisiae.

Saccharomyces cerevisiae requirement for reduced sulfur to synthesize methionine and cysteine during alcoholic fermentation, is mainly fulfilled through the sulfur assimilation pathway. Saccharomyces cerevisiae reduces sulfate into sulfur dioxide (SO2) and sulfide (H2S), whose overproduction is a major issue in winemaking, due to its negative impact on wine aroma. The amount of H2S produced is highly strain-specific and also depends on SO2 concentration, often added to grape must.