絮凝活性菌株培养条件的响应面优化

选取对甘薯淀粉具有明显絮凝效果的活性菌株,利用响应面分析法对其培养条件进行优化。在单因素实验的基础上,采用Box-Behnken中心组合实验设计,以初始pH、接种量、培养温度和培养时间四个因素为响应因子,絮凝率为响应值分析各因子与絮凝率之间的影响关系。最终建立二次回归方程为Y1=-103.602+5.166X1+5.848X2+8.312X3+0.0580X4-1.028X1X1-0.14X1X2+0.263X1X3+0.0185X1X4-0.141X2X2-0.097X2X3-0.003X2X4-0.166X3X3-0.002X3X4-0.0006X4X4,并得到相关系数R2=0.9550,对各因子的显著性及交互作用分析后,确定了最佳培养条件为:初始pH6.0、接种量8%、培养温度27℃、培养时间48h。在此培养条件下絮凝率的理论值为48.72%,重复验证值为48.65%。

Optimization of culture conditions of flocculating activity strains by response surface methodology

Select a strain which has significant flocculation activity towards sweet potato starch,the culture conditions for this flocculation activity strain were optimized by response surface analysis.Based on single-factor experiment,four response factors including initial pH,inoculation,cultivating temperature and cultivating time were selected as response factors and flocculation rate was used as response value,which figured out the relationship between factors and flocculation rates with Box-Behnken central composite experiment.Finally the quadratic regression equation was built:Y1=-103.602+5.166X1+5.848X2+8.312X3+0.0580X4-1.028X1X1-0.14X1X2+0.263X1X3+0.0185X1X4-0.141X2X2-0.097X2X3-0.003X2X4-0.166X3X3-0.002X3X4-0.0006X4X4 and the correlation coefficient was R2=0.9550.By analyzing the significant impact and the interaction of each factor,the optimum culture conditions were determined as follows:initial pH of 6.0,inoculation of 8%,cultivating temperature of 27℃,cultivating time of 48h.Under this culture conditions,the theoretical value of the flocculation rate was 48.72% and the verified value was 48.65%.