The Effect of Temperature on the Cell Density of Saccharomyces cerevisiae.

Abstract

We investigated how temperature affects the growth rate of Saccharomyces cerevisiae. We hypothesized that change in temperature would increase or decrease the abundance of S. cerevisiae over time. To conduct our study, we tested a total of 5 different temperatures; 17°C, 30°C, 35°C, 40°C, 45°C. On day one we used both incubators and water baths. We used 30°C as our control, found to be the optimal growing temperature in previous studies, and ran tests at 30°C in both the incubator and hot water bath to account for any differences in the two methods. On both days, we had 4 replicates at each temperature, growing for three hours, taking samples every hour. Our results showed that at 30°C, the cell density of S. cerevisiae cells was significantly higher than tubes incubated at the other temperatures, thus supporting our hypothesis. The reasoning we found to explain these results is that when the temperature is lower than 30°C, the kinetic processes within the cell slow down. In temperatures higher than 30°C, the functionality of the cell also decreases, due to increased ethanol accumulation.