中国生物工程杂志

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.