Expression of 2 lipomyces kononenkoae alpha-amylase genes in selected whisky yeast strains

Nineteen whisky yeasts were evaluated according to their fermentation performance and ability to produce a palatable spirit. Four of these strains were selected and, together with a commercial wine yeast strain (control), were transformed with integration plasmids containing the LKA1 and LKA2 alpha-amylase genes from the yeast Lipomyces kononenkoae. Fermentation trials with starch-containing media indicated that the transformants produced between 47% and 66% of the theoretical ethanol yield. This study has resulted in progress toward the development of whisky yeast that could ultimately be used in a process during which production of amylases, hydrolysis of starch, and fermentation of resulting sugars to grain whisky occur in a single step.