Immobilization of Bovine Trypsin onto Controlled Pore Glass

Abstract

Bovine trypsin was immobilized onto controlled pore glass (CPG) beads by covalent binding using glutaraldehyde as a cross-linking reagent. Increasing the concentration of the enzyme solution resulted in an increase in the amount of enzyme protein bound to the support material. The effects of pH and incubation time on immobilization were studied as well. For the pH range (pH 3.0 to pH 11.0), the stability of the immobilized enzyme was shifted to a relatively higher pH value (pH 9) compared with the free soluble form of the enzyme (pH 3 and 5). The immobilized enzyme was evaluated for its capacity to extract carotenoproteins from shrimp shell. After 11 reuses, the immobilized enzyme retained about 77% of its initial activity, and the total yield of the product from the same immobilized trypsin of 11 reuses was 4.3 times higher than a single use of the same amount of the free enzyme. Practical Applications Enzyme immobilization technology provides a means for recovering and reusing enzymes to reduce food processing cost for the food industry. Trypsins and other proteases have received a lot of attention by the food industry because they are used extensively in food processing. For example, approximately 50% of the enzymes used as processing aids in food industry are protein hydrolases. The study reported here is intended to serve as a model for use to study fish trypsin immobilization.