Impact of sugar complexity on the process of fermentation in Saccharomyces cerevisiae

Abstract

Baker’s yeast (Saccharomyces cerevisiae) yields commercially important alcohol and carbon dioxide through fermentation, a type of anaerobic cellular respiration. There is a need to optimize the yeast fermentation affected by factors such as growth media composition and yeast strain, to maximize industrial output. Our hypothesis states that as sugar complexity increases from glucose to starch, the CO2 production indicative of efficiency of cellular respiration and yeast growth would decrease directly. To test this, we used three sugars of increasing complexity(glucose, sucrose, and starch) as the independent variable, and monitored the respiration rate of yeast in each media. We calculated the CO2 output in ppm of the solution over a time period of ten minutes. Our results concluded that the CO2 output was highest in the glucose medium, lower in sucrose and lowest in the starch medium confirming our hypothesis. We reasoned that due to its simple structure, glucose can be readily utilized in the fermentation process. Sugars of higher complexity such as sucrose and starch have to be further reduced to glucose before entering the process, thus diminishing their efficiency as growth media. This substantiates that sugar complexity plays a major role in optimizing the growth media for maximum yeast growth and byproduct output. While many similar studies have shown similar results, a few others have produced contradictory findings, necessitating further research in this domain.