Ethanol Production in Yeast in Relation to pH

Ethanol is an important biofuel around the world and Saccharomyces cerevisiae (baker’s yeast) s becoming an important ingredient in the ethanol production formula. With researchers improving the growth rate of S. cerevisiae , we are researching the role of pH in the growth process in order to maximize the amount of ethanol produced. Many researchers have tested the effects of pH levels along with temperature changes and osmotic pressure differences, but pH alone is not truly the focus. In order to test the effects of pH on ethanol production, we added vinegar to the yeast solution to make the solution more acidic and added baking soda to make the solution more basic while keeping the temperature and amount of sucrose (food) the same for each trial. We conducted four trials, one neutral one acidic, one basic, and one optimal pH and measured the ethanol production of the yeast solution over thirty minutes. As we predicted, ethanol production was highest at the optimal pH for the yeast and lowest at the highest pH level. We think this research will contribute in lowering the production cost of biofuels by improving culture conditions to best accommodate the yeast in order to optimize ethanol production.