Toward Genetic Improvement of Wine Yeast

Abstract

Planned genetic improvement programs for wine yeasts should be successful, as wine strains contain a great deal of variability. The genetic groundwork which has been undertaken indicates that the methods in current use in yeast genetics and molecular biology research can be readily applied to them. Most wine strains appear to be homothallic and to contain a great deal of heterozygosity for lethal genes or genes affecting growth rate. Some may be polyploid or aneuploid. A number of auxotrophic mutants have been induced in the Montrachet strain and certain of these have been used to produce tetraploid strains through cell mating or protoplast fusion techniques. There is a high degree of genetic homology between Montrachet and laboratory strains. Although in many cases it is easy to specify desirable genetic improvements in wine yeasts, it likely that one of the major problems which will be encountered in attempts to improve flavor and aroma characteristics will be identification of those biochemical changes which would result in better wine.