Comparative affinity immobilization of α-galactosidase on chitosan functionalized with Concanavalin A and its useability for the hydrolysis of raffinose

Abstract

A new enzyme immobilization strategy is bioaffinity immobilization that using biospecific affinity interactions between the enzyme and matrix. α-Galactosidase was immobilized with three different methods (Method I, II and III) on chitosan functionalized with Concanavalin A (ConA). In Method I, the chitosan was first activated with glutaraldehyde, derivatized with ConA and then utilized to immobilize the α-galactosidase. For Method II, chitosan was functionalized with ConA by adsorption at first and then used for the immobilization of the enzyme. In Method III, by using the optimized conditions of Method I affinity layers were prepared with α-galactosidase. The effect of various factors on α-galactosidase immobilization is searched to get perfect immobilization yields. Optimal immobilization conditions were determined for each method. At these conditions, α-galactosidase is immobilized with 53%, 64% and 58% activity yields by method I, II and III, respectively. α-Galactosidase immobilized with method I, II and III could hydrolyzed 52%, 94% and 30% of raffinose in 24 h at 50 °C, respectively. The biochemical characterization and stability studies confirm that these immobilized enzymes promise future in industry. Especially, the immobilized enzymes could be safely used because of their potential for the hydrolysis of raffinose and raffinose type oligosaccharides in food and feed industries.