Immobilization of Commercial Cellulase and Xylanase by Different Methods Using Two Polymeric Supports

Abstract

Industrial applications require enzymes highly stable and economically viable in terms of reusability. Enzyme immobilization is an exciting alternative to improve the stability of enzymatic processes. The immobilization of two commercial enzymes is reported here (cellulase and xylanase) using three chemical methods (adsorption, reticulation, and crosslinking-adsorption) and two polymeric supports (alginate-chitin and chitosan-chitin). The optimal pH for binding was 4.5 for cellulase and 5.0 for xylanase, and the optimal enzyme concentrations were 170 μg/mL and 127.5 μg/mL respectively, being the chitosan and the ideal support. In some cases, a low concentration of crosslinking agent (glutaraldehyde) improved stability of the immobilization process. Biotechnological characterization showed that the reusability of enzymes was the most striking finding, particularly of immobilized cellulase using glutaraldehyde, which after 19 cycles retained 64% activity. These results confirm the economic and biotechnical advantages of enzyme immobilization for a range of industrial applications.