Analysis of the NCR Mechanisms in and During Winemaking.

There is increasing interest in the use of non- yeasts in winemaking due to their positive attributes. The non- yeast is an apiculate yeast that has been associated with the production of wine with good fermentation capacity and an increase in aromatic properties. However, this yeast represents a concern in mixed culture fermentation because of its nutrient consumption, especially nitrogen, as its mechanisms of regulation and consumption are still unknown. In this study, we analyzed the nitrogen consumption, as well as the nitrogen catabolism repression (NCR) mechanism, in two genome-sequenced strains, using synthetic must fermentations. The use of synthetic must with an established nitrogen content allowed us to study the NCR mechanism in , following the amino acid and ammonia consumption, and the expression of genes known to be regulated by the NCR mechanism in , , , , and . exhibited a similar amino acid consumption and gene expression profile to . However, the wine strain of QA23 consumed ammonia and valine more quickly and, in contrast, tyrosine and tryptophan more slowly, than the strains. Our results showed a similar behavior of nitrogen regulation in and , indicating the presence of the NCR mechanism in this yeast differentiated before the whole genome duplication event of the complex. Future study will elucidate if the NCR mechanism is the only strategy used by to optimize nitrogen consumption.