(461f) Biofuel Production: Performance of New Generation of Cellulase Enzymes in Combination with Esterases On Ionic Liquid Pretreated Lignocellulosic Biomass

Successful commercialization of lignocellulosic biofuels mandates the cost-effective release of fermentable sugars from the biomass substrate. A process based on enzymatic hydrolysis and fermentation is a promising route in converting the biomass to ethanol with high yields and low production cost. However, the components of biomass (cellulose, hemicellulose, and lignin) are intricately bound together, thereby requiring suitable pretreatment of the substrate prior to hydrolysis. Pretreatment and enzymatic hydrolysis are critical steps, and most of the current pretreatment methods do not effectively disrupt the crystallinity of cellulose, which is a major barrier for efficient enzymatic hydrolysis. Ionic liquids (ILs) being non volatile, non-flammable, recyclable and designer friendly, are gaining wide recognition as green solvents, and their unique solvating properties make them ideal for pretreating lignocellulosic substrates like corn stover and poplar. Strategic addition of enzyme mixtures can produce enhanced enzymatic hydrolysis yields of glucan to glucose and xylan to xylose. In our earlier studies, we reported the use of complex cellulase enzyme mixtures in the hydrolysis step. Covalent lignin-carbohydrate linkages exist in lignocellulose from wood and herbaceous plants. The addition of esterases can help in breaking the ester linkages that bind lignin to carbohydrates. In this study, we address the following: (1) the pretreatment of lignocellulosic biomass using different ionic liquids, and (2) a comparative assessment of the efficiency of old generation and new generation of cellulase enzymes, and the effect of addition of esterases on hydrolysis yields.