Hemicellulose fermentation by industrial yeast Saccharomyces cerevisiae

A major challenge in ethanol production using lignocellulosic feed stock is inefficient utilization of hemicellulose, which accounts for 20-40% of lignocellulosic biomass. Xylose, often comprises >60% of recoverable sugars from hemicellulose and is a major product of the hemicellulose hydrolysis. Utilization of this carbon source would significantly increase the ethanol yield from an estimated 60 gal/dry ton to 90 gal/dry ton. While xylose is not consumed and fermented efficiently by industrial yeast Saccharomyces cerevisiae, xylulose can be fermented by it. Isomerizing xylose to xylulose can provide an alternative to genetic modification of yeasts for xylose utilization. The objective of this research was to increase xylulose utilization during the fermentation process.