مشخصات پژوهش

Cellulases are third industrial enzymes in the world. Endoglucanases have received considerable attention among cellulases family, because they cut internal amorphous sites in the cellulose polysaccharide Chain randomly and generate substrates for cellobiohydrolase and β-glucosidase enzymes to complete the hydrolysis of cellulose. The cellulases are widely used in textile, detergent, paper industry and biofuel production. Enzyme immobilization on support is the best technique among different method for enzymatic stabilization. An advantage of immobilization is enzymatic reusability, which have an economical advantage for enzyme using in industry. Chitosan is polycationic support that is deacetylated form of chitin. Due to its unique biological properties such as biocompability, biodegradability and affordability, chitosan is an attractive support for immobilization. In this investigation, expression vector that contains the sequence encoding AaCel9A enzyme was transferred into expression host. After enzyme expression and purification, the enzyme was immobilized on chitosan macrobeads. Glutaraldehyde used as a cross-linker between enzyme and support. Biochemical properties like optimum pH and temperature properties of immobilized enzyme were investigated. The study of temperature profile shows that the immobilized enzyme has higher activity over a wide range of temperatures compared to the free form of enzyme. Moreover, optimal pH of the immobilized enzyme shift to basic pH relative to the free form of enzyme.