添加保护剂促进碱性果胶酶的工业保藏稳定性

Addition of protective agents for enhancing storage stabilization of alkaline polygalacturonate lyase

保藏稳定性对于商品酶具有重要的实际意义。通过对碱性果胶酶的保护剂进行研究,最终筛选得到最优复合保护剂配方为:Tween 20 1 mL/L,六偏磷酸钠1.5 g/L,明胶5g/L,甘油5%(v/v),CaCl_2 2g/L;热稳定性提高18倍。此外在常温保藏时,在酶液中添加0.3‰山梨酸钾和0.3‰苯甲酸钠,能有效提高保藏效果,减少酶液染菌、混浊和发臭,最终常温保藏90 d后酶活保留率为84.5%,达到工业化保藏的要求。

Preserving stability is significant important to the industrial enzyme. The protective agents for the alkaline polygalacturonate lyase （PGL） were investigated and the optimal composite protective agents were as follows： Tween 20 1 mL/L, sodium hexametaphosphate 1.5 g/L, gelatin 5 g/L, glycerol 5% v/v, CAC122 g/L. The results indicated that the thermostability of PGL was enhanced by 18 folds, compared with that of the control. Besides, when the enzyme was stored at room temperature, the addition of 0.3 potassium sorbate and 0.3 sodium benzoate could improve the preserva- tion effect, reducing bacterial contamination, turbidity and smdl. The residual activity maintained 84.5 % after stored for 90 days at room temperature, meeting the requirements of industrialization.