The MicroWine group from ICVV found indications that extracellular vesicles contribute to communication between different wine yeast species.
There is a growing trend for introducing non-Saccharomyces species as additional starters, in combination with Saccharomyces cerevisiae. The use of more than one wine yeast starter in the same fermentation process raises the question of whether there are interactions that may affect their performance and the fermentation outcome. In previous works the group showed that S. cerevisiae gene expression was affected by the presence of other yeasts, even after very short contact times (2-3 hours). One prominent metabolic pathway affected by the presence of other yeasts was glycolysis. Also previously, the group showed wine yeasts of several species release extracellular vesicles to the medium. Since extracellular vesicles are known to mediate communication between different cell types in animals or plants, the question was if this was also the case for interspecific communication between wine yeasts.
In this work, it was found that the gene expression profile of S. cerevisiae was almost identical whether they were confronted to the fraction enriched in extracellular vesicles, or to whole cells of Metschnikowia pulcherrima. In both cases, the transcription profile indicates accelerated carbon metabolism and low expression of autophagy genes, suggesting that the challenged cells are trying to resume growth faster, to outgrow perceived competitors.
All this constitute strong evidence of the existence of interspecific communication mechanisms between wine yeasts, by one side; and that extracellular vesicles may play a role in them, on the other side. There are still few reports on the involvement of extracellular vesicles (or other extracellular entities) in interspecific microbial communication, and none in a biotechnological context. So, these findings have broad interest for our understanding of microbial interactions in general. In addition, being aware of these interactions might help develop better combinations of yeast strains, suited for specific oenological aims (including biocontrol), and better winemaking practices.
Further information: https://doi.org/10.1111/1751-7915.14240