Zhongguo youzhi (Apr 2022)
固定化米黑根毛霉脂肪酶的制备工艺优化 及其酶学性质 Optimization of preparation process of immobilized Rhizomucor miehei lipase and its enzymatic properties
Abstract
以海藻酸钠-羧甲基纤维素钠（CMC）为复合载体，戊二醛为交联剂，探究了包埋-交联法制备固定化米黑根毛霉脂肪酶的最佳工艺条件，并对固定化米黑根毛霉脂肪酶的酶学性质进行分析。结果表明，制备固定化米黑根毛霉脂肪酶的最佳工艺条件为海藻酸钠质量分数2.5%、CMC质量分数1.5%、脂肪酶液浓度800 U/mL、CaCl2质量分数5%、戊二醛质量分数0.03%、交联固定化时间30 min，在此条件下固定化米黑根毛霉脂肪酶的酶活力为245.58 U/g，与游离脂肪酶相比，固定化脂肪酶热稳定性和pH稳定性均有所提高。交联剂戊二醛的添加可以提高固定化脂肪酶的操作稳定性和储存稳定性，在重复使用7次后相对酶活力保持在57.39%，在4 ℃下存放7周后相对酶活力为61.89%。包埋-交联法制备的固定化米黑根毛霉脂肪酶具有更好的稳定性和适应性，为实现植物油酶法酯化脱酸工业化生产提供参考。With sodium alginate and sodium carboxymethyl cellulose(CMC) as the compound carrier, glutaraldehyde as the crosslinking agent, the process conditions of preparing immobilized Rhizomucor miehei lipase(RML) by embedding- crosslinking method was optimized, and its enzymatic properties were analyzed. The results showed that the optimal process conditions of preparing immobilized RML were obtained as follows: sodium alginate mass fraction 2.5%, CMC mass fraction 1.5%, enzyme concentration 800 U/mL, CaCl2 mass fraction 5%, glutaraldehyde mass fraction 0.03% and crosslinking immobilization time 30 min. Under these conditions, the enzyme activity of immobilized RML was 245.58 U/g. Moreover, the immobilized enzyme was performed better in pH stability and thermal stability than free lipase. The addition of crosslinking agent glutaraldehyde could improve the operation stability and storage stability of immobilized lipase, and after recycling 7 times and storing at 4 ℃ for 7 weeks, the relative activity of immobilized RML still kept at 57.39% and 61.89%, respectively. Thus, the immobilized RML prepared by embedding-crosslinking method had better stability and adaptability and laid the foundation for industrial production of enzymatic esterification deacidification.
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