摘要
分别以海藻酸钠、聚乙烯醇(PVA)及聚乙烯醇(PVA)-海藻酸钠复合凝胶为载体,对植酸酶进行固定化研究。结果表明,由于PVA复合凝胶的多孔性网状结构,有利于物质传递。海藻酸钠有助于阻止酶活力的漏失,包埋效果优于其他两种方法。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45和60℃。固定化酶的Km(20 mg/mL)大于自由酶的Km(14 mg/mL)。植酸酶经固定化,提高了酶的操作、温度和贮藏稳定性。
The phytase produced by Aspergillu niger CN-50 were immobilized by compound gels of sodium alginate, polyvinyl alcohol （PVA） and PVA-cryogel. The results showed that gel network is favour to mass transfer due to PVA composite porous structure. Alginate could prevent enzyme leakage. The embedding method was more effective than the other two methods. The mechanical properties and chemical stability of phytase have been improved after immobilization. In addition, it can be repeated for several times for hydrolysising sodium phytate. The enzymatic characteristics were further investigated. The results showed that the optimum pH of free and immobilized phytase were 5.5 and 7.0, respective. Their optimum reaction temperature were 45 and 60℃, respective. The Km of immobilized enzyme （20 mg / ml） is greater than that of free enzyme （14 mg / ml）. In addition, the operation of the enzyme, temperature and storage stability were improved by immobilized phytase.
出处
《中国酿造》
CAS
北大核心
2009年第11期112-115,共4页
China Brewing
关键词
植酸酶
聚乙烯醇
海藻酸钠
固定化
phytase
polyvinyl alcohol
sodium alginate
immobilization
