IMMOBILIZATION OF CELLULASES ON CHITOSAN: APPLICATION FOR SUGARCANE BAGASSE HYDROLYSIS

Abstract

In this work, a commercial cellulolytic cocktail was immobilized on glutaraldehyde activated chitosan gel. The chitosan concentration in the gel preparation, pH, immobilization time and enzymatic loading were evaluated. Immobilized cellulases showed better hydrolysis performance when an enzyme loading of 134 mg protein/g carrier was used for immobilization at pH 9.0 for 30 minutes. Hydrolysates with a glucose content of 13.43 and 10.35 g/L were obtained when Avicel and pretreated sugarcane bagasse were used as substrate, respectively. Immobilized cellulase lost 60% of its hydrolysis performance after 8 cycles using Avicel, and 75% after 6 cycles for sugarcane bagasse. The hydrolysis performance associated with the reuse of the immobilized cellulases indicates that an improvement in the immobilization of cellulases, coupled with an improvement in the pretreatment of lignocellulosic biomass, will allow the development of a continuous hydrolysis system with the enzyme retained in the reactor.