Optimization of Fermentation Conditions of Biosurfactant by Response Surface Analysis

The fermentation conditions of biosurfactant production by strain DN4-3 were optimized with the Plackett-Burman design and response surface analysis.Plackett-Burman design was used to evaluate the influence of related factors,as a result,three significant factors,such as the content of glucose,the content of yeast extract power and NaCl content,were selected.The path of steepest ascent and response surface analysis were used to determine the optimal levels of the significant factors.Based on the single factor experiments,the optimal medium composition and fermentation conditions were determined as follows: glucose 27.83 g/L,yeast extract power 2.73 g/L,NaCl 2.37 g/L,KH2PO4 9 g/L,K2HPO4 3 g/L,CaCl2 0.16 g/L,MgSO4· 7H2O 0.5 g/L,inoculation amount 4%,seed age 16 h,medium volume 250 mL/500 mL,temperature 37℃,initial pH 7.0,rotation speed 160 r/min.Under the optimal conditions,1025.98 mg/L biosurfactant was produced by the strain DN4-3,which increased about 35.43% than before.