Development of co-immobilized enzyme pellets to replace GMOs for cellulosic ethanol

Economic bioethanol production is critically dependent upon the ability to convert both the hexose (C6) and pentose (C5) sugars resulting from cellulose and hemicellulose components of biomass. C5 sugars are not readily fermentable by native organisms. Genetically Modified Organisms (GMOs) are designed to ferment xylose, but their stability, ethanol yield, environmental impact, and survival under conditions of industrial fermentation are unproven. As an alternative, we developed a novel scheme for efficient fermentation of both C5 and C6 sugars using native yeasts. Rather than the traditional approach of genetically modifying yeast to ferment xylose, we pursue the unique approach of transforming xylose into a form that native yeast can successfully ferment. The projected economics of our process are very favorable in comparison to the costs associated with engineering, licensing and propogating GMOs. This novel fermentation technology is readily accessible to rural farming economies for implementation in cellulosic ethanol production facilities.