吸附交联法固定化黑曲霉β-葡萄糖苷酶

Immobilization of β-glucosidase from Aspergillus niger by adsorption and crosslinking method

以壳聚糖为载体,戊二醛为交联剂,采用吸附交联法对黑曲霉(Aspergillus niger)β-葡萄糖苷酶进行了固定化。考察了固定化pH、戊二醛含量、吸附时间、交联时间和壳聚糖微球加入量等对固定化酶活力回收率的影响,在单因素试验的基础上,采用正交试验设计确定最佳固定化条件为固定化pH 5.0、戊二醛含量3.0%、吸附时间12 h、交联时间2 h、壳聚糖微球加入量0.91 g/IU,此时固定化酶活力回收率达到87.0%。固定化和游离β-葡萄糖苷酶的最适p H值均为4.2,最适温度分别为65℃和60℃,固定化酶具有更高的耐酸碱性和热稳定性。

Using the chitosan as cartier, glutaraldehyde as cross-linking agent, β-glucosidase from Aspergillus niger was immobilized by adsorption and crosslinking method. The effects of immobilization pH, glutaraldehyde content, adsorption time, crosslinking time and chitosan microspheres addtion on the recovery rate of immobilized enzyme activity were investigated. On the basis of single factor experiments, by orthogonal experiments, the optimum immobilization conditions was determined as immobilization pH 5.0, glutaraldehyde content 3.0%, adsorption time 12 h, crosslinking time 2 h and chitosan microspheres addition 0.91 g/IU. Under the conditions, the recovery rate of immobilized enzyme activity was up to 87.0%. The optimum pH of immobilized and free β-glucosidase was 4.2, and the optimum temperature was 65 ℃ and 60℃, respectively. Immobilized enzyme had higher acid-base resistance property and thermostability.