Interaction of Cellulase and Non-Cellulase Enzymes with Switchgrass Processed by Leading Pretreatment Technologies

Enzymes play important roles in hydrolyzing lignocellulosic biomass to sugars. Previous studies suggested that the accessibility and reactivity of cellulase and non-cellulase enzymes varied depending on substrates and pretreatment technologies. In this study, typical commercial cellulases (Spezyme CP, GC 220, and Accelerase 1000) and non-cellulases (beta-glucosidase, Multifect xylanase and pectinase) were applied to hydrolysis of pure cellulose and xylan. The sugar release patterns were tracked, compared and used to picture the enzyme properties. We further applied the enzymes to switchgrass solids pretreated through different pretreatment technologies as part of the CAFI project (ammonia fiber expansion, aqueous ammonia recycle, dilute sulfuric acid, lime, and neutral pH liquid hot water). The adsorption capacities of cellulase and non-cellulase enzymes as well as the initial hydrolysis rate were then investigated and correlated with the physical and compositional properties of pretreated switchgrass.