Abstract: To improving fermentation production of wuyiencin, the method of one-dimensional search was used to select suitable fermentation medium using the genetic engineering bacterium Streptomyces ahygroscopicus var. wuyiensis W273 as experimental material. Six kinds of nutrients were suitable for fermentation, which was corn starch, glucose, soybean flour, ammonium chloride, calcium carbonate and magnesium chloride, respectively. Plackett-Burman method of statistical anslysis system (SAS) was applied to screen the six factors which affected fermentation production of wuyiencin. By using the Plackett-Burman method, the concentrations of glucose and calcium carbonate were found to significantly influence the production of wuyiencin. Then, these two factors were optimized using central composite design of "response surface methodology". The quadratic regression equation was Y=218.18+270.28X₁+1274.74X₂-3.28X₁²-5.4X₁X₂-200.98X₂²，which was studied on optimal levels of two major factors and their interactions. Finally, the optimized fermentation medium was composed as follows (g/L): corn starch 20, glucose 39, soybean flour 20, smmonium chloride 4, calcium carbonate 2.65 and magnesium chloride 0.4. The verifiable titer was 7215 μg/mL in the medium with shake-flask culture at 28℃ and 220 r/min for 60 h, increased 26.5% over the original medium of wuyiencin.

Key words: wuyiencin, genetically engineered bacteria, fermentation medium, response surface methodology