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Penicillium sp.ZD-Z1 Chitosanase Immobilized on DEAE Cellulose by Cross-linking Reaction Zheng Lianying, Xiao Yuliang Abstract Chitosanase
obtained from Penicillium sp.ZD-Z1 was
immobilized on DEAE cellulose with glutaraldehyde by cross-linking reaction. The optimal
ratio of immobilization were as following: 0.1g DEAE cellulose was treated with 5mL 5%
glutaraldehyde solution, then 2.3mg chitosanase was immobilized on the carrier. The
optimal temperature and pH was 60°C and 4.0, and the Km
value was 18.87g/L. Under the optimal conditions, the activity of immobilized enzyme is
1.5U/g, and the recovery of enzyme activity is 81.3%. After immobilization, the optimal
temperature and Km value increased
(from 50°C to 60°C, from 2.49g/L to 18.87g/L), whereas the optimal pH reduced (from 5.0 to
4.0). All of these indicated that the effect of intraparticle diffusion resistance for
chitosanase’s kinetic property is greater than that of carrier’s electrical property.
The enzyme activity loss was less than 15% after 10 times batch reaction, the immobilized
enzyme showed good stability in operation 壳聚糖酶的DEAE纤维素固定化与性质研究 郑连英 肖玉良 摘要 以DEAE纤维素为载体、戊二醛为交联剂固定壳聚糖酶，确定了交联剂的最佳用量为100mg DEAE纤维素与5mL 5%戊二醛交联，酶与载体的最佳比例为23mg酶/g DEAE纤维素，固定化酶的最适温度和pH分别为60°C和4.0，其米氏常数为18.87g/L；所得固定化酶活力可达1.5 U/g、酶活回收率可达81.3%。壳聚糖酶在经固定化后，最适温度从50°C升高到60°C、最适pH从5.0下降到4.0、米氏常数从2.49g/L升高到18.87g/L，说明酶经固定化后所产生的空间扩散阻力对壳聚糖酶的动力学性质的影响要比在固定化过程中所用载体所带的电荷的极性对酶的动力学性质的影响大得多。此外将该固定化酶重复使用十次，酶活力损失小于15%，该固定化酶具有较好的操作稳定性。 郑连英 女，56岁，副教授，从事生物工程方向的科研和教学工作。E-mail: zhengly@cmsce.zju.edu.cn |