Transcriptomic profiling of yeast in response to increasing corn syrup and reduced molasses levels

Molasses, a byproduct of raw sugar production, is widely used as a cost effective carbon and nutrient source for industrial fermentations, including the production of yeast. Due to the cost and limited availability of molasses, efforts have been made to replace molasses with cheaper and more readily available substrates such as corn syrup. However, the quality of dry yeast drops upon inclusion of corn syrup despite the same amount of total sugar provided. Our understanding of how molasses replacement affects yeast physiology, especially during the dehydration step, is limited. Here, we examined changes in gene expression of a strain of baker's yeast during fermentation with increasing corn syrup to molasses ratios at the transcriptomic level.