Synthesis of Aroma Compounds as a Function of Different Nitrogen Sources in Fermentations Using Non- Wine Yeasts.

Non- yeasts are prevalent at the onset of grape must fermentations and can have a significant influence on the final wine product. In contrast to , the biosynthetic pathways leading to aroma compound formation in these non-conventional yeasts, in particular those that are derived from amino acid metabolism, remains largely unexplored. Within a synthetic must environment, we investigated the amino acid utilization of four species (, , , ) and . We report on the differential uptake preferences for amino acids with displaying the most rapid uptake of most amino acids. To investigate the fate of amino acids and their direct contribution to aroma synthesis in , and , musts were supplemented with single amino acids. Aroma profiling undertaken after three days showed the synthesis of specific aroma compounds by the respective yeast was dependent on the specific amino acid supplementation. showed similarities to in both amino acid uptake and the synthesis of aroma compounds depending on the nitrogen sources. This study shows how the uptake of specific amino acids contributes to the synthesis of aroma compounds in wine fermentations using different non- yeasts.