The Nutritional Quality of the Culture Medium Influences the Survival of Non-<i>Saccharomyces</i> Yeasts Co-Cultured with <i>Saccharomyces cerevisiae</i>

Yeast-yeast interactions have been studied mainly using wine yeasts. However, studies are rare for native yeasts from agave juice fermentation. Therefore, this work used strains isolated from the alcoholic fermentation of agave to study the survival of non-<i>Saccharomyces</i> yeasts co-cultivated with <i>Saccharomyces cerevisiae</i> in media of different nutritional qualities. First, the feasibility of using simple and low-cost culture media was demonstrated to study the interactions between <i>Saccharomyces cerevisiae</i> and non-<i>Saccharomyces</i> yeasts. The results presented here demonstrated the antagonistic effect exerted by <i>S. cerevisiae</i> on <i>Torulaspora delbrueckii,</i> which showed a more significant loss of viability. However, the nutritional composition of the culture medium also influences this effect. It was clear that a nutritionally rich medium improved the survival of non-<i>Saccharomyces</i> yeasts. Lastly, the change in the survival of non-<i>Saccharomyces</i> yeasts also entails a variation in the concentration and diversity of minor volatile compounds produced during fermentation. This was observed in the variety and relative abundance of compounds belonging to the most numerous chemical families, such as alcohols, esters, and terpenes.