State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, People's Republic China.
Appl Biochem Biotechnol. 2013 Jan;169(2):612-23. doi: 10.1007/s12010-012-0028-7. Epub 2012 Dec 27.
An organic solvent-tolerant lipase from Serratia marcescens ECU1010 (rSML) was overproduced in Escherichia coli in an insoluble form. High concentrations of both biomass (50 g cell wet weight/L culture broth) and inclusion bodies (10.5 g/L) were obtained by applying a high-cell-density cultivation procedure. Activity assays indicated that the enzymatic activity of rSML reached 600 U/L. After treatment with isopropyl ether for 12 h, the maximum lipase activity reached 6,000 U/L. Scanning electron microscopy and Fourier transform infrared microspectroscopy revealed the activation mechanism of rSML in the presence of organic solvents. rSML was stable in broad ranges of temperatures and pH values, as well as in a series of organic solvents. Besides, rSML showed the best enantioselectivity for the kinetic resolution of (±)-trans-3-(4-methoxyphenyl)glycidic acid methyl ester. These features render the S. marcescens ECU1010 lipase attractive for biotechnological applications in the field of organic synthesis and pharmaceutical industry.
一株耐有机溶剂的地衣芽孢杆菌脂肪酶(rSML)在大肠杆菌中以不溶形式过表达。通过采用高密度细胞培养方法,获得了高浓度的生物质(50 g 细胞湿重/培养物)和包涵体(10.5 g/L)。活性测定表明 rSML 的酶活性达到 600 U/L。经异丙醚处理 12 h 后,最大脂肪酶活性达到 6,000 U/L。扫描电子显微镜和傅里叶变换红外微光谱揭示了 rSML 在有机溶剂存在下的激活机制。rSML 在较宽的温度和 pH 值范围以及一系列有机溶剂中均稳定。此外,rSML 对(±)-反式-3-(4-甲氧基苯基)缩水甘油酸甲酯的动力学拆分表现出最佳的对映选择性。这些特性使得地衣芽孢杆菌 ECU1010 脂肪酶在有机合成和制药工业领域的生物技术应用中具有吸引力。