摘要
分别采用纳米CaCO3吸附法、聚丙烯酰胺(PAG)包埋交联法和DEAE-22纤维素交联法固定化假单胞菌H3壳聚糖酶,结果表明:以DEAE-22纤维素为载体、戊二醛为交联剂的固定化方法较优,酶活保留率达91.4%;此外,还确定了DEAE-22纤维素交联法的固定化条件为:DEAE-22纤维素载体0.5 g,3.5%戊二醛交联剂20 mL,给酶量为15 mg,固定化温度为4℃,固定化时间为12h;壳聚糖酶在经固定化后,最适温度为50℃,最适pH为4.5,并表现出比游离酶更高的热稳定性,固定化酶的米氏常数Km值为14.29 g/L;将该固定化酶重复使用12次,固定化酶的活力降低到75%,具有较好的操作稳定性.
Comparing of three methods about chitosanase immobilization, it found that the method using DEAE-22 cellulose as Carrier and glutaraldehyde as crosslinking agent is thabest qne. The optimal conditions of immobilization was as following-. 0.5 g DEAE-22 cellulose was treated with 20mL 3.5% glutaraldehyde solution, the optimal chitosanase dosage was 15 mg, and the crosslinking temperature was 4℃, the optimal crosslinking time was 12 h. Under this condition , the optimal pH for immobilized enzyme was 4.5, the optimal temperature was 50℃, and Km value was 14.29 g/L. Compared with the free enzyme , its stability and repetition were considerably improved. The enzyme activity retained approximately 75% of its original activity after 12 times batch reaction, the immobilized enzyme showed good stability in operation.
出处
《浙江工业大学学报》
CAS
2007年第2期185-189,共5页
Journal of Zhejiang University of Technology
基金
浙江工业大学科技发展基金资助(X1054024).
