响应面法优化土芽孢杆菌XS2产生物乳化剂的研究

Study on the Optimization of Bio-emulsifier Production by Geobacillus sp.XS2 by Means of Response Surface Methodology

[目的]采用响应面法对土芽孢杆菌XS2产生物乳化剂的发酵培养基进行优化研究。[方法]利用单因素试验确定影响土芽孢杆菌XS2产生物乳化剂的主要培养基成分,再采用响应面分析法和Design-Expert 7.0软件建立响应曲面模型,来优化土芽孢杆菌XS2产生物乳化剂的发酵培养基。[结果]葡萄糖、磷酸氢二钾、磷酸二氢钾为影响土芽孢杆菌XS2产生物乳化剂的主要因素,土芽孢杆菌XS2产生物乳化剂的最佳发酵培养基为:葡萄糖68 g/L,硝酸钠2 g/L,磷酸二氢钾5.03 g/L,磷酸氢二钾1.36 g/L,硫酸镁结晶0.2 g/L,硫酸亚铁0.02 g/L,氯化钙0.01 g/L,微量元素液2 ml。在此条件下,生物乳化剂乳化活性的实测值(67.0%)与预测值(66.7%)较为接近,比优化前提高了27%。[结论]响应面法适用于土芽孢杆菌XS2产生物乳化剂发酵培养基的优化,优化结果与实际情况吻合较好。

[Objective] The aim was to study the optimization of fermentation medium for bio-emulsifier production by Geobacillus sp.XS2 by means of response surface methodology.[Method] Firstly,single-factor experiment was conducted to determine the main medium components influencing bio-emulsifier production by Geobacillus sp.XS2,and then response surface model was established by using response surface methodology and Design-Expert 7.0.2,so as to optimize the fermentation medium for bio-emulsifier production by Geobacillus sp.XS2.[Result] Glucose,KH2PO4 and K2HPO4 were the main factors influencing bio-emulsifier production by Geobacillus sp.XS2,and its optimal fermentation medium was as follows： glucose 68 g/L,NaNO3 2 g/L,KH2PO4 5.03 g/L,K2HPO4 1.36 g/L,MgSO4·7H2O 0.2 g/L,FeSO4·7H2O 0.02 g/L,CaCl2·2H2O 0.01 g/L,element solution 2 ml.Under the optimal condition,the measured value（67.0%） of bio-emulsifier of emulsifying activity was close to predictive value（66.7%） and increased by 27% compared with previous value before optimization.[Conclusion] Response surface methodology was applicable to the optimization of fermentation medium for bio-emulsifier production by Geobacillus sp.XS2 and its optimal result was consistent with actual result.