The Effect of Glucose Concentration on Tetrahymena Thermophila Growth Rate

Abstract

Tetrahymena Thermophila is a unicellular eukaryote with a doubling time of approximately 2 hours, making it ideal to study population growth. In the presence of nutrients, namely glucose, its growth rate can be further increased. The objective of our study was to determine how differing glucose concentrations would have an impact on the growth rate of T. Thermophila, using treatment concentrations of glucose at 0.2%, 1%, 3%, and 5%. We hypothesized that with increasing glucose concentration, growth rate would increase, with peak growth at 3% glucose. In this study, we placed T. Thermophila in media with varying glucose concentrations, and did trials at 3, 21, 24, and 27 hours, with cells kept incubated at 35℃ to promote optimal growth. Cell density was then determined using a haemocytometer. We found that the average population growth rate increased slightly from 0.2% glucose to 1%, before it significantly increased at 3% where it displayed the maximum growth rate, and then sharply declined at 5% glucose. Using a one-way ANOVA test, it was revealed that our results were not statistically significant (p=0.0768) therefore we were unable to reject our null hypothesis that there was no significant difference between increasing glucose concentrations on mean growth rate.