Integration of the Yeast K1 Killer Toxin Gene into the Genome of Marked Wine Yeasts and Its Effect on Vinification

Abstract

The yeast K1 killer toxin gene was integrated into the genome of laboratory and commercial wine yeasts by gene replacement technology that generated recombinants containing only yeast DNA. Integration of the K1 killer gene into two K2 wine yeasts generated stable K1/K2 double killer strains which have a wider spectrum of killing and a potential competitive advantage over other sensitive and killer strains of Saccharomyces cerevisiae in wine fermentations. The fermentation characteristics of several killer integrant strains were examined in microvinification tests. The results indicate that wine fermentations and products from such yeasts can be similar to those obtained from fermentations by the parental strains.