The Effects of Tap Water on Saccharomyces cerevisiae (Baker’s Yeast) CO2 Production

Abstract

Saccharomyces cerevisiae, otherwise known as baker’s yeast, is used by humans in a host of ways including baking, alcoholic beverages, industrial ethanol production, and even biofuel production. Different conditions such as temperature, sugar type and concentration, and even minerals present can affect how efficiently yeast grows. In this experiment, we hypothesized that tap water would increase yeast activity, thus increasing CO2 output, while deionized water would see lower growth activity and, therefore, a lower CO2 output. To test this hypothesis, we compared the CO2 output when using DI water compared to tap water, adding a mixture of sugar and sodium phosphate to a sample of yeast and allowed it to ferment for ten minutes. Our study demonstrated a higher level of CO2 production for our yeast samples using tap water compared to a lower output in our DI group by a difference of 15.86ppm/min, thus supporting our hypothesis that yeast growth would increase in our experimental group.