聚乙烯醇环氧化载体制备及在植酸酶固定化中的应用

Preparation of polyvinyl alcohol epoxidation carrier and its application in immobilization of the phytase

该文以聚乙烯醇为原料,利用戊二醛为交联剂,聚合得到交联球形聚乙烯醇,并将其与环氧氯丙烷反应用以固载环氧基团,得到可用于酶固定化的载体。讨论了交联聚乙烯醇球环氧基的固载条件和酶的固定化条件。植酸酶经过固定化后,机械性能和化学稳定性都得到提高,可以重复多次对植酸钠进行水解反应。同时对该自由酶和固定化酶进行酶学特性研究。发现自由酶和固定化酶的最适pH值分别为5.5和7.0,最适反应温度分别为55℃和70℃。植酸酶经固定化,提高了酶的操作、温度、pH值和贮藏稳定性。

In this study, polyvinyl alcohol （PVA） was used as crosslinking agent with glutaraldehyde, which was polymerized with polyvinyl alcohol and reacted with epichlorohydrin for immobilization of epoxy group. The product can be used as enzyme immobilization carrier. The epoxy immobilization conditions of the cross-linked PVA and enzyme immobilization conditions were investigated. The immobilization can stabilize the enzyme and ensured high mechanical and chemical stability of the biocatalyst, which could be used many times for sodium phytate hydrolysis. Various characteris- tics of immobilized phytase such as optimum thermal storage stability and pH, were evaluated. The optimal pH value of free and immobilized phytase were 5.5 and 7.0, respective, and the optimal thermal free phytase was 55°E, whereas that of immobilized phytase was 70℃. The operational, pH value, and thermal stabilities of the enzyme were increased by immobilization.