Stir it Up: A Study of the Effect of Agitation on CO2 Output in Saccharomyces cerevisiae Yeast

Abstract

One of the ways yeast’s, particularly Saccharomyces cerevisiae, carbon dioxide output is affected is through its relationship with the amount of agitation it endures through methods like stirring. The levels of stirring, (level 3, 2, 1, and 0), are key components in increasing CO₂ output, which varies directly with the growth of yeast. This led us to conduct this experiment in order to determine which level of agitation causes the CO₂ output in yeast to be the greatest. We hypothesized that the yeast will produce the most CO₂ when stirred on level 3 (250 rpm), since it is going through the highest level of agitation. To find the answer to our hypothesis, we used a mixture of 39 mL of water, 80 μL of sodium phosphate twice, 0.80g of sugar, and 1 mL of yeast solution. Putting the mixture through different levels of stirring on the stir station like levels 3 (250 rpm), 2 (150 rpm), and 1 (50 rpm) to determine the greatest rate of CO₂ output, along with level 0 as the control group. We found that level 3 had the greatest CO₂ output, while level 2 had the lowest CO₂ output. This means that our hypothesis is somewhat valid and aligns with the final results. It follows our hypothesis that the higher the level/rpm the more CO₂ will be produced; however, level two does not follow this trend.