Immobilization of catalase onto chitosan and cibacron blue F3GA attached chitosan beads

In this study, chitosan beads (Ch-bead) and cibacron blue F3GA attached chitosan beads (CB-Ch-bead) were prepared. Their characteristics were investigated with experiments of swelling, thermogravimetric analysis and Fourier transform infrared (FTIR) spectroscopic analysis. Catalase (CAT) was immobilized onto these beads. The adsorption isotherms have a Langmuirian shape for Ch-beads and CB-Ch-beads. The CAT adsorption capacity of Ch-beads is higher than that of CB-Ch-beads, but CB-Ch-CAT showed better activity according to the Ch-CAT. The values of apparent &, were found to be 18 and 41 mM for Ch-CAT and CB-Ch-CAT, respectively. However, V-max values were calculated as 4800 and 14,250 mu mol (mg protein)(-1) min(-1) for Ch-CAT and CB-Ch-CAT, respectively. Furthermore, various characteristics of immobilized catalase, such as the temperature profile, thermal stability, optimum pH, operational stability and storage stability were evaluated. Optimum temperature and optimum pH values were found as 35 degrees C and 7.0 for maximum activity of Ch-CAT and CB-Ch-CAT. It was observed that thermal, storage and operational stabilities of the enzyme were increased with immobilization. (c) 2007 Elsevier Inc. All rights reserved.