重组脂肪酶X12-5的大规模发酵及其酶学性质研究

Research of large-scale fermentation of Recombinant Lipase X12-5 and its characterization

实验室保藏的一株产脂肪酶基因工程菌X12-5,经过摇瓶发酵,测得酶活力为65U/mL。为进一步提高酶活力,应用于工业生产,将其进行上罐(180L)发酵。大规模发酵后,酶活高达220000U/g,实现了脂肪酶的高效表达。对其酶学性质研究表明,最适温度和pH分别为45℃和7.0;pH在4.0～7.0,温度在50℃以下酶活相对稳定;Mg2+、Mn2+、Ca2+对酶活有明显促进作用。由该脂肪酶的酶学性质初步判断其在制革工业上具有潜在的应用价值。

Though shaking fermentation,the enzyme activity of a laboratory preserved genetic engineered strain X12-5 which could produce lipase had reached up to 65U/mL. For the purpose of enhancing the enzyme activity which could help a lot in industrial production,the tank （180L） fermentation had been used. After the tank （180L） fermentation, mass fermentation,the enzyme activity of genetic engineering bacteria X12-5 had reached to 220000U/g which achieved efficient expression of lipase. From the study of its enzymatic characteristics,the lipase exhibited maximum activity at 45℃ and pH7.0,and it was stable below 50℃ while the pH was ranging from 4.0 to 7.0. The lipase＇s activity could be activated by Ca2＋,Mn2＋ and Mg2＋. From preliminary judgment to the enzymatic characteristics,the conclusion we got is that the Iipase has a potential value in applications of the leather industry.