Immobilization of Candida Rugosa Lipase on the Glutaraldehyde-Activated Chitosan Beads

Abstract

An immobilized enzyme is a biocatalyst that speeds up the conversion of a chemical reaction. The application of enzymes for chemical synthesis is an effort toward a responsible production initiative to ensure the sustainability of chemical synthesis. Therefore, in the present work, Candida rugosa lipase was immobilized onto glutaraldehyde-activated chitosan beads through covalent bond linkages. Chitosan is biodegradable and contains amine groups, which serve as bases for lipase binding via cross-linking with bifunctional cross-linkers like glutaraldehyde. The immobilization of lipase on the chitosan beads was confirmed by determining lipase activity through the hydrolysis of a standard substrate. The effect of lipase and glutaraldehyde concentrations on the immobilization and activity yield was investigated. In general, lipase and glutaraldehyde concentrations have a significant effect on immobilization and activity yield. The interaction between the investigated parameters is significant toward the activity yield rather than the immobilization yield. The optimized immobilization procedures give lipase activity up to 46 IU by using 0.013 g/mL lipase and 2 %/v/v glutaraldehyde. It was found that the immobilized enzyme was rather stable and could be recycled 7 times. Therefore, immobilization of lipase onto glutaraldehyde-activated chitosan support is feasible.