The Effects of Sugar Processing on Ethanol Production Rate in Saccharomyces cerevisiae

Abstract

Saccharomyces cerevisiae is a type of yeast that is used in the production of bread, alcohol, and fuel because it produces ethanol and carbon dioxide as a product of fermentation. Fermentation is an anaerobic and metabolic process that takes place after glycolysis when oxygen is not present for cellular respiration. Because of its many uses, determining what conditions are best for this organism’s metabolism is an important question to answer. We chose to test how the processing of sugar affects the production of ethanol by putting yeast in three different growth media. Each of these contained sugar that had been refined to a different extent. Going in descending order of processing, we used white sugar, turbinado sugar, and golden-brown sugar. We found that less refined sugars led to a higher average rate of ethanol production. This may have been because the molasses in the less refined sugars contained simpler molecules that could be used faster by the yeast.