The Effect of pH and Time on Aerobic CO2 Production in S. cerevisiae

Abstract

This experiment sets out to find the effect of pH and time on aerobic respiration in Saccharomyces cerevisiae blooming in different pH treatments. S. cerevisiae were added to four bottles with different pH mediums – a pH of 2, 4, 8 and a control (pH 7). Balloons attached to the bottles would collect the CO₂ gas released by the yeast, and the balloon height would be considered a measure of respiration. Data was collected in two intervals separated by an hour to measure the effect of time. Yeast in the control (pH 7) had significantly greater aerobic respiration compared to the other pH groups (p < 0.0001). Only the yeast in the control (pH 7) group showed a significant increase in respiration with time (p < 0.0001), while the rest showed no change with time. These results are discordant with what is known in studies conducted for anaerobic respiration. Consequently, this suggests that the baking industry (which focuses on aerobic respiration) should follow different guidelines for the usage of yeast than the liquor industry (which focuses on anaerobic respiration) in order to maximize profit.