23 research outputs found
Beta-galactosidase immobilization on chitosan microspheres
Application of solid-phase biocatalysts has become important
during the last decades. Enzymes could be immobilized on
various supports and by different methods. The properties of
immobilized biocatalysts are influenced by the characteristics
of enzyme, support material and the immobilization method.
A suitable support should have high affinity to proteins, reactive
functional groups, hydrophilicity, mechanical stability and
rigidity. Chitosan is a natural polyaminosaccharide which offers
the above characteristics, therefore it is often used for enzyme
immobilization (Martino et al., 1996; Sheu et al., 1998).
Chitosan microspheres suitable for enzyme immobilization
were prepared by emulsion cross-linking method (Agnihotri
et al., 2004). Aqueous chitosan solution was added dropwise
into an oil phase consisted of sunflower oil and n-hexadecane.
Cross-linking was performed with glutaraldehyde which make
possible the covalent attachment of enzymes. �-Galactosidase,
which is applied in dairy industry for lactose hydrolysis, was
immobilized onto the microspheres. The solid-phase biocatalyst
was characterized and the storage and operational stabilities
were investigated