Sugar, Rice, and Everything Nice: The Effect of Sugar Concentration on Yeast Growth Rate

Saccharomyces cerevisiae is a type of yeast whose growth rate can be affected by several conditions—including sugar concentration. It is necessary to investigate which conditions result in an increased growth rate of this yeast because of how important this element is in the production of food products today. The concentration of D-glucose in a yeast-containing dough was the manipulated variable, and CO2 emission and cell count indicate growth. We hypothesized that the addition of less than 5% D-glucose in the dough would cause the yeast to grow because the sugar would provide an immediate energy source. This hypothesis was supported by the data. The cell growth rates and CO2 emission increased significantly following the addition of some D-glucose, but the growth slowed as a greater concentration of D-glucose was added. This investigation showcases the ideal concentration of D-glucose in a yeast dough.