分枝杆菌转化甾醇产9α-羟基雄甾烯酮促进剂的筛选

Screening of An Accelerant for the Transformation of Sterol to Androstenone by Mycobacteria

以甾醇为原料、利用分枝杆菌等微生物转化生产甾体医药中间体9α-羟基雄甾烯酮,是当下甾体医药工业体系的一条重要工艺路线。甾醇作为一种非极性化合物,在水中的溶解度极低,传质效率低,其生物可利用度不高,这严重制约了分枝杆菌对甾醇底物的摄取利用效率。就PEG200、PPG2000和多种硅油对分枝杆菌转化甾醇产9α-羟基雄甾烯酮的促进效果进行了比较分析。结果表明:PEG200、PPG2000和聚醚改性硅油的添加均能有效改善菌体的甾醇转化能力,产物的积累量大幅提高,升幅分别约为50%、85%和300%。随后,重点考察了多种硅油对甾醇转化的影响,从中筛选出效果最好的甾醇转化促进剂并就添加量和添加方式进行了优化,结果显示,最佳甾醇转化促进剂是聚醚改性硅油,其最佳添加方式是在发酵起始时与甾醇同时添加、10g·L-1甾醇投料量下的最佳添加量为15%。

The transformation of sterol to androstenone（9α-OHAD） by microorganisms,such as Mycobacteria,is one of the important technological route to produce steroidal medicines in the pharmaceutical industry.The sterol of non-polar compound has very low solubility in water,which severely restricts strains from uptaking of the sterol substrates.Promotion effects of PEG200,PPG2000 and a variety of silicone oils on the transformation of sterol to 9α-OHAD were investigated.The experimental results showed that：the transformation ability of strains could be effectively improved by the addition of PEG200,PPG2000 or polyether-modified silicone oil,with which the accumulated amount of end-product could be increased by about 50 ％,85 ％ and 300 ％,respectively.Subsequently,the transformation enhancement effects of severalsilicone oils were analyzed,the high-efficient sterol transformation accelerator was screened,and its addition amount and addition method were optimized.The results showed that polyether-modified silicone oil was the optimal sterol transformation accelerator and 15％ polyether-modified silicone oil was the optimal concentration for the transformation of 10 g ·L-1 sterol,and thebest adding method was at the beginning of fermentation while added sterol.