壳聚糖小球共价固定化α-淀粉酶的研究

Covalent Immobilization of α-amylase on Chitosan Beads

以壳聚糖小球为载体,采用戊二醛交联共价固定α-淀粉酶。试验结果表明,以1 g壳聚糖小球为载体,经5m L 2%戊二醛处理后,加入24 mgα-淀粉酶,30℃,在p H 6的磷酸缓冲液中固定化2 h,制备的固定化α-淀粉酶活力达1 407.6 U/g。固定化酶最适p H向酸性方向偏移,最适反应温度不变,固定化α-淀粉酶的酸碱稳定性和热稳定性均优于游离酶。

α-amylase was immobilized on chitosan beads with glutaraldehyde by cross-linking reaction, the immobilization conditions and characterization of the immobilized a-amylase were studied. The optimal conditions for immobilization were as followings： 1 g chitosan beads were treated with 5 mL 2% glutaraldehyde, and then 24 nag a-amylase was immobilized on to the carrier. When the temperature, crosslinking time and pH for the immobilized enzyme were 30 %, 2 h and 6 respectively, the activity of the wet immobilized α-amylase was 1 407.6 U/g. The optimum pH of the immobilized enzyme was 5, which was 1 lower than the nature one＇s. The temperature and pH stability of the immobilized enzyme was better than free enzyme.