Factors affecting the enzymatic hydrolysis of bagasse and rice straw

Abstract

This study was initiated to determine the effects of substrate composition, cellulose crystallinity, and particle size on the yields of enzymatic hydrolysis for two agricultural crop wastes, bagasse and rice straw. The data indicate that each individual lignocellulosic substrate requires a specific pretreatment in order to achieve maximum enzymatic hydrolysis. The crystallinity of lignocellulosics may be altered either upward or downward, but does not appear to have a direct relationship in determining susceptibility of the β-1,4-glucosidic bonds to enzymatic hydrolysis. The absolute change in the crystallinity of rice straw following pretreatment did, however, appear to correlate with conversions to either glucose or ethanol. Substrate particle size was determined and found not to be a major factor in enzymtic hydrolysis within the range studied. However, modification of the lignocellulose matrix from its native state by caustic pretreatment resulted in the most significant increases in enzymatic hydrolysis reinforcing the concept that the nature of the native lignocellulose matrix is a major limiting factor in enzymatic hydrolysis of bagasse and rice straw.