Stability of β-galactosidase immobilized on composite microspheres of artemisia seed gum and chitosan

In this work, composite microspheres were prepared by using artemisia seed gum and chitosan as a source. The composite microspheres have activated aldehyde groups by using glutaraldehyde. β‐Galactosidase was covalently bound on these activated microspheres. The properties of the immobilized enzyme were investigated and compared with those of the free enzyme, for which o‐nitrophenol β‐D‐galactopyranoside (ONPG) was chosen as a substrate. The results showed that the pH and thermal stability of the immobilized β‐galactosidase were higher than those of the soluble one. Apart from these, the Michaelis constant Km was evaluated for the immobilized β‐galactosidase and the soluble enzyme. The immobilized β‐galactosidase exhibited better environmental adaptability and reusability than the soluble one. POLYM. COMPOS., 29:9–14, 2008. © 2007 Society of Plastics Engineers