Use of commercial or indigenous yeast impacts the <i>S. cerevisiae</i> transcriptome during wine fermentation

Understanding microbial functions during wine fermentation, particularly the role of <i>Saccharomyces cerevisiae</i>, is crucial for enhancing wine quality. While commercially available <i>S. cerevisiae</i> strains are commonly used, indigenous strains can offer unique flavors, potentially reflecting vineyard terroir. By leveraging high-throughput DNA sequencing and transcriptomic analysis, we explored the impact of vine age on the grape mycobiome and characterized microbial functions during grape fermentation. Our findings revealed that older vines harbor higher fungal loads, but fungal diversity remains similar across vine ages. Additionally, uninoculated fermentations exhibited diverse fungal dynamics, including the beneficial wine yeasts Metschnikowia and Pichia. Transcriptomic analysis uncovered significant differences in <i>S. cerevisiae</i> gene expression between inoculated and uninoculated fermentations, highlighting the potential of indigenous yeast to enhance wine diversity and inform winemaking practices.