Grafted carrageenan: alginate gel beads for catalase enzyme covalent immobilization

Abstract

A new matrix formulation was devised for catalase immobilization. Carrageenan-alginate beads different ratios were developed and soaked into different ratios of CaCl₂-KCl as a hardening solution. The best formulation for loading capacity was selected, treated with polyethylene imine followed by glutaraldehyde and further studied. The best concentration of catalase for immobilization was 300U/ml and the best loading time was 6 h. The catalytic properties increased after immobilization and the immobilized catalase achieved optimum activity at a temperature range of 30-50 °C that was compared to the optimum activity of free catalase which occurred at 40 °C. Higher catalytic activity of immobilized catalase occurred at alkaline pHs than the free one which achieved optimum catalytic activity at neutral pH. A comparison between the kinetic parameters of immobilized and free catalase showed variation. The K _M and Vmax of the immobilized catalase were 2.4 fold and six times higher than those of free catalase. The results of the study indicate that the formulated matrix can be used as a good matrix for catalase enzyme in various industrial applications.

Keywords: Biopolymers; Biotechnology; Enzymes; Immobilized catalase and grafted gel beads.

Fig. 1

Effect of bead composition and hardening solution ratio on catalase loading capacity

Fig. 2

Effect of catalase concentration on loading capacity

Fig. 3

Effect of time on loading capacity of immobilized catalase

Fig. 4

Effect of temperature on catalytic activity of immobilized catalase

Fig. 5

Effect of pH on catalytic activity of immobilized catalase

Fig. 6

Kinetic parameters of free and immobilized catalase

Fig. 7

Reusability study of immobilized catalase beads