脂肪酶中具有壳聚糖降解活力酶组分的性质研究

目的]为酶法降解壳聚糖提供科学依据。方法]从脂肪酶中分离具壳聚糖降解活力的电泳纯酶,研究pH值、温度和金属离子对壳聚糖酶活力的影响,并分析了该酶的pH值稳定性、热稳定性和底物特异性。结果]该酶降解壳聚糖的最适pH值为4.5,最适温度为60℃。Ni2+、Co2+和Mn2+对酶活具有明显的激活作用,而Fe3+、Pb2+和Hg2+则强烈抑制酶的活力。该酶对脱乙酰度为73%~82%的壳聚糖具有较高的水解活性,而对脱乙酰度为64%和90%的壳聚糖水解活力较低。结论]该酶在pH值为5~9范围内和60℃以下都具有较好的稳定性。

Characteristics of Enzyme Components with the Degradation Activity to Chitosan in Lipase

Objective] The aim of the research was to provide scientific basis for enzymatic degradation of chitosan.Method] The purified enzyme by electrophoresis with the degradation activity to chitosan was separated from lipase to study the effects of pH value,temperature and metal ions on the activity of chitosanase.And pH value stability,the thermal stability and substrate specificity of this enzyme were analyzed.Result] The optimum pH value for degrading chitosan by this enzyme was 4.5 and the optimum temperature was 60 ℃.Ni2+,Co2+ and Mn2+ had obvious activation to the enzyme activity,while Fe3+,Pb2+ and Hg2+ inhibited the enzyme activity strongly.The enzyme had higher hydrolytic activity to chitosan with the deacetylation degree of 73%～82% and had lower hydrolytic activity to chitosan with the deacetylation degree of 64% and 90%.Conclusion] This enzyme was stable in the pH value range of 5～9 and at the temperatures of lower than 60 ℃.