On the other hand, mixed fermentation can have positive or negative interactions with analytical compounds, in comparison with monoculture fermentation. Acetaldehyde reduction was shown in mixed fermentation using T. delbrueckii and L. thermotolerans, as well as the exchange of acetaldehyde between S. cerevisiae and Saccharomyces bayanus [35]. The influence of S. bombicola in mixed fermentation with S. cerevisiae is not limited to a synergistic or additive effect on the analytical profile of the wine. Significant modifications to alcohol dehydrogenase (ADH1) and pyruvate decarboxylase (PDC1) gene expression and the enzymatic activity of the S. cerevisiae strain in mixed fermentation with S. bombicola immobilised cells has been showed [36•].