多孔壳聚糖固定酵母蛋白酶条件的优化及酶学性质分析

Optimization of immobilized conditions of yeast protease by porous chitosan and analysis of its enzymatic properties

以多孔壳聚糖微球固定酵母蛋白酶,通过对戊二醛含量、吸附时间、固定化温度、p H进行了单因素试验及正交试验,以蛋白酶酶活回收率为评价指标,确定的固定化条件为戊二醛含量1.4%,吸附温度27℃,p H值为10,吸附时间24 h。在此最佳条件下,固定化酵母蛋白酶酶活回收率为68.8%。酶学性质分析结果表明,固定化酶最佳反应温度较游离酶升高10℃,最佳作用p H较游离酶向碱性方向偏移1个p H单位。因此,用多孔壳聚糖对酵母蛋白酶进行包埋可以提高蛋白酶活性。

The yeast protease was immobilized by porous chitosan microspheres. The glutamldehyde content, adsorption time, immobilization temper- ature and pH were determined by single factor and orthogonal experiments. Using the protease activity recovery as evaluation index, the immobilized conditions were as follows： glutaraldehyde content 1.4%, adsorption temperature 27℃, pH 10 and adsorption time 24 h. Under the optimal conditions, the recovery rate of immobilized yeast protease activity was 68.8%. The results of enzymatic properties analysis showed that the optimum reac- tion temperature of immobilized enzyme was 10℃ higher than that of free enzyme, and its optimal pH moved to alkaline direction by 1 pH unit compared with the free enzyme. Therefore, embedding of yeast protease by porous chitosan could improve the protease activity.