Simple vs. Complex Sugars and Ethanol Production in Saccharomyces cerevisiae

Saccharomyces cerevisiae is used by Acme Baking & Brewing to produce ethanol. Since glucose is the basic unit of fermentation, our group wanted to test if different complexities of sugars affect the rate of ethanol production in S. cerevisiae. Our hypothesis was that glucose will have the highest rate of ethanol production because it is a monosaccharide, as compared to sucrose, a disaccharide, and starch, a polysaccharide. We mixed 2.0 g of each sugar into 78 mL of deionized water and 2 mL of S. cerevisiae. We ran three 12 minute trials for each sugar and tracked the ethanol production using an ethanol probe and Logger Pro. The data found revealed no significant difference in the average rate of ethanol production in glucose and sucrose, rejecting our hypothesis. However, starch produced a negative rate of ethanol production, signifying that starch cannot be used to produce ethanol.