分枝杆菌LY-1转化植物甾醇产9α羟基雄烯二酮的发酵工艺优化

摘要

9α-Hydroxy-4-androstene-3, 17-dione (9α-OH-AD) is an important precursor to produce glucocorticoid drugs. To improve the yield of 9α-OH-AD, Mycobacterium sp. LY-1 was used as the wild strain. To study the effects of different carbon sources, nitrogen source, phosphate and inorganic salts on the concentration of 9α-OH-AD, we optimized the medium by orthogonal experiments.The optimized medium was composed as (g/L):corn steep liquor 30, KNO3 4.0, NaH2PO4 1.2, FeSO4 0.075, and CaCl2 0.10. Under this condition, the yield of 9α-OH-AD reached 43.9％-44.9％ when the concentration of phytosterol was 15 g/L. Then, the conditions of culture were optimized through single factors experiments. The suitable culture conditions were determined as:pH 8.0, 2％ inoculum concentration and 30 ℃. Under these conditions, the yield of 9α-OH-AD reached 46.2％-47.0％, increased by 22.1％ compared with the control, and the concentration of 9α-OH-AD was 5.21 g/L. It has a potential industrial application.%9α-羟基雄甾-4-烯-3, 17-二酮 (9α-OH-AD) 是一种重要的甾体药物中间体, 可用于糖皮质激素类药物的生产.为了提高目的产物的产量, 以分枝杆菌 (Mycobacterium sp.) LY-1作为出发菌株, 研究不同碳源、氮源、磷酸盐和金属离子等培养基组分对菌株LY-1转化植物甾醇生产9α-OH-AD的影响, 结合正交试验优化, 确定最适培养基组分为玉米浆30 g/L、KNO3 4.0 g/L、NaH2PO4 1.2 g/L、FeSO4 0.075 g/L及CaCl2 0.10 g/L.在此条件下, 当植物甾醇投料质量浓度为15 g/L时, 产物得率达到43.9％～44.9％.通过单因素实验优化培养条件, 得到最适培养条件为pH 8.0、接种量2％、温度30℃时, 9α-OH-AD的得率可达46.2％～47.0％, 比优化前提高了22.1％, 产量达到5.21 g/L, 具有潜在的工业应用价值.