Sulphate Uptake Plays a Major Role in the Production of Sulphur Dioxide by Yeast Cells during Oenological Fermentations

Sulphur dioxide (SO2) is mostly used as an antioxidant additive in winemaking, but excessive levels may be harmful to both wine quality and consumers health. During fermentation, yeast Saccharomyces cerevisiae contributes significantly final SO2 levels, low-producing strains become especially interesting for the industry. Recent evidence implicating impairment of sulphate transport decrease prompted us further investigate sulphate/sulphite metabolic connection multiple winery strains. Here, we inactivated by CRISPR/Cas9 high-affinity permeases (Sul1p Sul2p) four normally selected their different abilities produce SO2. Mutant were then perform fermentation assays types natural must, other secondary metabolites, crucial organoleptic properties, determined all products. Overall, data demonstrated double ΔSUL1/ΔSUL2 inactivation decreases produced mutant cells, without however altering fermentative properties ability release relevant metabolites. Since similar effects observed diverse must with features, strongly support that assimilation determining factor production during oenological fermentations.