利用响应面法优化Bacillus natto TK-1产脂肽发酵培养基

用响应面法对Bacillus natto TK-1发酵产脂肽的培养基进行了优化。首先用Plackett-Burman法筛选出三个影响较大的重要因素，分别为：蛋白胨、酵母粉、CaCl2 ，然后进行最陡爬坡实验逼近最佳响应面区域，最后通过Box-Behnken设计，利用SAS软件进行回归分析，得到各因素的最佳浓度。在优化培养基条件下，发酵液的溶血圈直径较初始培养基提高了29.3 %，脂肽的产量提高了约30%。

Medium Optimization for Lipopeptide Produced by Bacillus natto TK-1 Using Response Surface Methodology

Response surface methodology was implied to optimize the culture components for lipopeptide production of Bacillus natto TK-1. In the first step, two level factorial design of Plackett-Burman was used to evaluate the influence of related factors. It showed that there were three factors play the important role in the medium, they were peptone, yeast extract powder, CaCl2. The path of steepest ascent was used to approach the optimal region of the fermentation conditions subsequently. In the third step, the concentrations of these three main factors were further optimized using Box-Behnken and response surface analysis. Under the optimized fermentation conditions, the diameter of haemolysis of fermentation culture increased 29.3 % than before. HPLC analysis was also used to estimated the precise production of lipopeptide. By using the optimal culture, its production was 30.2% higher than preliminary culture. It showed that the HPLC method was in accordance with the blood plate method. Furthermore, at three batches cultivation, the experiment value under the optimal conditions agreed with the predictive value. It showed that Response Surface Methodology was proper and a good choice for optimization.