Abstract:   The fermentation medium of daptomycin，produced by Streptomyces roseosporus，was optimized by response surface methodology. It was found that initial pH，glucose，L-Asp and K₂SO₄ affected the daptomycin production significantly in Plackett–Burman experiment，but the affection of initial pH was predominant （p<0.01）. The initial pH was optimized by one-factor-at-a-time experiment and the optimal pH obtained was 8.6. Then through the steepest ascent method and central composite design（CCD），the optimal fementation medium obtained were：13.0 g/L glucose，2.6 g/L L-Asp and 4.1 g/L K₂SO₄，and the daptomycin production reached 373.98 mg/L，which was in agreement with predicted value（365.76 mg/L）and 2.25 folds higher than that under the initial culture conditions.

Key words: streptomyces roseosporus, daptomycin, response surface methodology, optimization,  ,

摘要： 采用响应面法对玫瑰孢链霉菌发酵产达托霉素的培养基进行了优化。首先通过Placket-Burman设计法筛选出影响达托霉素产量的4个重要因素：初始pH值、葡萄糖、L-天冬氨酸（L-Asp）、硫酸钾。其中初始pH值的影响极为显著（p<0.01），因此，对初始pH值进行了单因素试验，得到最优初始pH值为8.6。在此基础上对其余3个因素用最陡爬坡路径逼近最大响应区域后，利用响应面中心组合设计对显著因素进行优化，得到最适培养基组成为：葡萄糖13.0 g/L、L-Asp 2.6 g/L、硫酸钾4.1 g/L。在此优化条件下，达托霉素产量达373.98 mg/L，与预测值（365.76 mg/L）非常接近，比优化前产量提高了2.25倍。

关键词: 玫瑰孢链霉菌, 达托霉素, 响应面法, 优化,  ,