两性霉素B补料分批发酵工艺优化

Optimization in Synthesis of Amphotericin B by Fed-Batch Fermentation

为大幅提高产两性霉素B菌株的发酵产抗水平,对外源性短链脂肪酸类前体物质及其添加时机、添加量进行优化,得到了两性霉素B补料分批发酵工艺,即在产两性霉素B菌株发酵培养24~56 h左右,一次性补入2~4 g·L^-1(以发酵液总量计)的丙酸钠。该工艺解决了两性霉素B生物合成途径中内酯环形成的关键性因素,大幅提高了产两性霉素B菌株的发酵产抗水平。经15 t生产罐验证,最终实现了连续3批平均放罐效价达10977μg·mL^-1的发酵产抗水平,与采用原发酵工艺的生产罐批相比,放罐效价提高了39.4%。

In order to improve the levels of fermentation and antibiotic-production of Amphotericin B-producing strain,we optimized the exogenous short-chain fatty acids precursor and its adding time and adding amount,and obtained the fed-batch fermentation process of Amphotericin B as follows:adding 2~4 g·L^-1(calculated by the total amount of fermentation liquid)sodium propionate in a once-through operation when the Amphotericin B-producing strain is cultured for 24~56 h.The process solves the key factors of lactone-ring synthesis in the Amphotericin B biosynthetic pathway,and greatly improves the antibiotic-production level of the Amphotericin B-producing strain.The verification in 50 t production tank indicates that the average draw-off titer of three batches is up to 10977μg·mL^-1,which increases by 39.4%compared with that of the original batch.