纤维素酶固定化工艺条件优化及在甘蔗渣酶解中的应用

Optimization of Cellulase Immobilization Process Conditions and Its Application in Sugarcane Bagasse Enzymatic Hydrolysis

针对纤维素酶利用率低、成本高的问题,本研究采用复合载体材料进行纤维素酶固定化,并优化固定化工艺条件,以提高纤维素酶的利用率和降低成本。本研究采用海藻酸钠和戊二醛交联包埋法进行纤维素酶固定化,并通过单因素和正交实验优化固定化条件,包括固定化酶量、海藻酸钠浓度和戊二醛浓度。随后,将固定化酶应用于甘蔗渣酶解,并与游离纤维素酶进行对比,评估固定化酶的效果。优化后的固定化条件为:固定化纤维素酶量7mL,海藻酸钠浓度4.5%,戊二醛浓度1.25%,p H值5.0,在65℃下固定化2h,纤维素酶活力回收率可达86.24%。与游离纤维素酶相比,固定化酶在甘蔗渣酶解中表现出更高的还原糖含量,循环使用4次后,还原糖含量提高了约29.67%。固定化纤维素酶可反复循环利用,提高酶解效率,降低纤维素酶成本,在甘蔗渣等生物质原料水解中具有广阔的应用前景。

To address the problems of low utilization and high cost of cellulase,this study used composite carrier materials for cellulase immobilization and optimized the immobilization process conditions in order to improve the utilization of cellulase and reduce the cost.In this study,cellulase immobilization was carried out by crosslinking and embedding sodium alginate and glutaraldehyde,and the immobilization conditions,including the amount of immobilized enzyme,the concentration of sodium alginate,and the concentration of glutaraldehyde,were optimized by single-factor and orthogonal experiments.Subsequently,the immobilized enzyme was applied to the enzymatic hydrolysis of sugarcane bagasse and compared with free cellulase to evaluate the effect of immobilized enzyme.The optimized immobilization conditions were as follows:immobilized cellulase volume of 7 mL,sodium alginate concentration of 4.5%,glutaraldehyde concentration of 1.25%,pH 5.0,and immobilization at 65℃for 2 h.The cellulase viability recovery could reach 86.24%.Compared with free cellulase,the immobilized enzyme exhibited higher reducing sugar content in the enzymatic digestion of sugarcane bagasse,and the reducing sugar content increased by about 29.67%after recycling for four times.The immobilized cellulase can be recycled repeatedly to improve the enzymatic efficiency and reduce the cost of cellulase,which has a broad application prospect in the hydrolysis of biomass raw materials such as sugarcane bagasse.