(76c) Optimization of Enzyme Formulation On Pretreated Switchgrass

Achieving high enzymatic yields is one of the most important factors in making lignocellulosic biomass a viable feedstock for ethanol production. Switchgrass is a promising crop to be used in cellulosic ethanol production due to its relative ease of growth and high yields. In previous CAFI studies, the optimal reaction conditions for a variety of pretreatment technologies (ammonia fiber expansion, aqueous ammonia recycle, dilute sulfuric acid, lime, and neutral pH liquid hot water) were determined for switchgrass using a consistent cellulase loading. Glucan enzymatic yields after pretreatment were shown to be high (>80%) but xylan enzymatic yields were not as promising. Switchgrass is comprised of approximately 20% xylan so successful hydrolysis would be economically very beneficial and should not be ignored. In this study, the effect of differing enzyme formulations on enzymatic digestibility yields was investigated. Through manipulation of the combination and concentration of cellulase (Spezyme CP, Accelerase) and non-cellulase (Multifect xylanase) enzymes, the optimum enzyme formulation, which maximizes glucan and xylan enzymatic yields, were determined.