Corey Wolf, Westminster College
Life Sciences
The yeast species Saccharomyces cerevisiae is used in numerous industries including brewing, baking, and winemaking. In recent years an increased demand for low ethanol beers has pushed breweries to develop a beer that is both rich in flavor and low in alcohol content. The current strategies employed to decrease the ethanol concentration in beer are costly, time intensive, and result in less flavorful beers. In this study, a method for decreasing alcohol content in the brewing process through the use of metabolic inhibitors of Alcohol Dehydrogenase is tested. Alcohol Dehydrogenase is the enzyme responsible for the conversion of acetaldehyde, an intermediate in the metabolic pathway of yeast, into ethanol. Two competitive inhibitors of Alcohol Dehydrogenase, Pyrazole and Fomepizole, were applied to small scale fermentations in varying concentrations in an attempt to decrease the overall ethanol yield of the beer. The application of either inhibitor resulted in an initial decreased rate of fermentation overall, measured as a change of sugar and ethanol concentration. In the later stages of fermentation, the rate of ethanol production returned to normal, suggesting the inhibitors were either catalyzed or removed by the cell. While this method for manipulating the products of fermentation did not yield the desired effects, this study did highlight the importance of the fermentation pathway for maintaing healthy Saccharomyces cerevisiae cultures. This research may be helpful in understanding the complete metabolic pathway of brewer’s yeast, with further application to organisms with conserved pathways.