Protein Biosynthesis and Carbon Catabolite Repression Are Transcriptionally Upregulated in <i>Saccharomyces cerevisiae</i> by Extracellular Fractions From Several Wine Yeast Species

Non-Saccharomyces yeast species are increasingly used in winemaking in combination with Saccharomyces cerevisiae to modulate sensory attributes or as processing aids. Consequently, there is academic and practical interest in understanding how different yeast species interact with each other in grape must. Although interactions will depend on the metabolic capabilities of the strains involved, there are other possible interaction mechanisms between wine yeasts. In this work we used extracellular vesicle (EV)-enriched fractions from different non-Saccharomyces species to challenge S. cerevisiae inoculated in synthetic grape must. The results show that the previously described response to EVs of Metschnikowia pulcherrima was not an isolated phenomenon, but that S. cerevisiae responds in a general way to EVs of other yeast species. Meta-analysis of the results points to protein biosynthesis and carbon catabolite repression as general targets; both being stimulated by the interaction, beyond the acclimatisation to the synthetic juice experienced by the control cells. The intensity of the response showed differences between the four species; while the transcriptional response to M. pulcherrima EVs clearly diverges from that to EVs of the other yeast species, which show greater similarity to each other.