Optimized Method To Obtain Stable Food-Safe Recombinant Wine Yeast Strains

Pure Saccharomyces cerevisiae cultures are commonly used to inoculate fresh musts. The added active dry yeasts dominate the fermentation and produce wine of more reproducible quality. This microbiological simplification of the vinification process opens the way for the genetic modification of active dry yeasts. Industrial yeast strains have been successfully transformed, selecting for G418 resistance. The use of this method for integrative transformation facilitates the construction of food-safe recombinant yeast strains with high efficiency. To demonstrate the potential of the method, the two URA3 alleles of the wine yeast T 73 strain were disrupted in two consecutive steps, obtaining a stable recombinant strain that retains all of its useful wine-making properties.