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

Fermentation process of Mycobacterium sp. LY-1 for the transformation of phytosterol to 9α-hydroxy-4-androstenedione

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、KNO_3 4.0 g/L、NaH_2PO_4 1.2 g/L、FeSO_4 0.075 g/L及CaCl_2 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。

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.