棘白霉素B脱酰基酶产生菌转化条件的优化研究

摘要

To enhance the efficiency of the conversion,the echinocandin B deacylase-producing original strain was treated by UV,followed by resistance selection with heavy metal Cu2+ and the conversion condition was op-timized by uniform design method.A stable mutant strain 132# was obtained and its conversion efficiency was 22.6% higher than that of the original strain.The optimum conversion conditions were determined as follows:echinocandin B concentration was 2 400μg·mL-1 ,the conversion time was 56 h,the conversion temperature was 30 ℃ and the pH value of the fermentation medium was 6.0.Under the optimum conditions,the conversion efficiency of strain 1 3 2# was 5 7.3% higher than that of the original strain under the initial conversion condi-tions.The optimum conversion condition was more suitable for the high-yield strain,for it could improve the conversion efficiency remarkably,which established the foundation for the conversion on industrial scale.%为提高棘白霉素B脱酰基酶产生菌的转化率，通过紫外诱变复合Cu2＋抗性处理筛选转化高产菌种，利用均匀设计方法优化菌种的转化工艺。结果表明，筛选得到的突变株132＃的棘白霉素 B转化率比出发菌株提高了22.6％，优化后的转化条件为：底物浓度2400μg·mL-1，转化时间56 h，转化温度30℃，发酵培养基 pH 值6.0。132＃菌株在优化转化条件下的转化率较出发菌株在原始转化条件下提高了57.3％。优化的转化条件更有利于高产菌株的转化，转化率得到大幅提高，也为其工业化应用打下基础。