游离脂肪酶与固定化脂肪酶相比具有成本低、反应速率快等优势,是油脂化工中新的研究方向。前期研究表明,游离脂肪酶NS81006能高效催化多种油脂水解,进一步研究其对含独特羟基的绿色石油材料蓖麻油的水解过程,对于促进游离脂肪酶在新能源领域的应用具有重要意义。本文对影响游离脂肪酶NS81006催化蓖麻油水解过程的主要因素,温度、酶用量、水用量和搅拌速率进行了研究和优化,在优化后的条件下48 h水解率可达94.8%,且发现通过离心分离可有效实现NS81006的重复使用,连续回用5个批次,游离脂肪酶仍能有效催化水解反应。而对比高温高压法水解蓖麻油,发现游离脂肪酶NS81006具有明显优势。
Compared to immobilized lipase, free lipase has the merits of lower cost and faster reaction rate, which is a rising research orientation in oil chemical industry. The previous study showed that free lipase NS81006 is capable of efficiently hydrolyzing oil to fatty acids. Further study on its unique hydrolysis process of castor oil, an environmentally friendly hydroxyl oil, is of great importance for its application in new energy. By means of optimizing the main influence factors of the castor oil hydrolysis catalyzed by NS81006 involving temperature, enzyme dosage, water usage, and stirring speed, 98.4% degree of hydrolysis was achieved under the optimum conditions at 48 h. The free lipase could be reused after centrifugation and maintained high catalytic efficiency in 5 consecutive recovery batches. It was also found that enzyme catalysis has obvious advantage in castor oil hydrolyzation compared with HTHP.