Study on immobilization of papain by modified cellulose and properties of immobilized enzyme

To immobilize papain with trees cellulose, four kinds of tree cellulose were selected. Then the selected plane trees, mulberry, acacia trees and jujube trees were modified by 2, 4, 6-trichloro-1, 3, 5-triazine. The effect of those factors such as proportion of enzyme, pH value, immobilization time and temperature to papain immubilization were investigated. And the properties of the acid -base stability, the thermodynamic stability, manipulation stability and preservation stability were studied. The results showed that tree cellulose were good carriers for immobilized enzymes, and the best one was plane tree cellulose with loose structure. The optimal immobilization condition were 24h for immobilization time, 16mg/mL for proportion of enzyme, pH7.0, 45℃ temperature. The recovery activity of immobilized papain was 64.3% , and it still remained more than 73% after repeated 6 times. At the same time, its acid-base stability was also strengthened.