响应面法优化可得然胶发酵培养基

Optimization of fermentation medium for curdlan by response surface methodology

可得然胶是细菌在氮源限制条件下生成的水不溶性胞外多糖。发酵培养基的各组分配比对可得然胶的产量有极大的影响。因此,优化发酵培养基对提高可得然胶产量有重要意义。本文采用响应面分析法对可得然胶的发酵培养基进行优化设计。通过Plackett-Burman实验进行重要因素筛选,得出影响可得然胶产量的主要因素为:蔗糖、(NH4)2HPO4、MgSO4和玉米浆。利用最陡爬坡实验逼近响应区域,应用Box-Behnken实验设计和响应面法分析优化得到最佳的发酵培养基为:蔗糖61g/L、MgSO41g/L、玉米浆2.5mL/L、(NH4)2HPO42.4g/L、KH2PO41.4g/L、CaCO31.4g/L。发酵结果(47.73g/L)与优化之前(35.2g/L)的可得然胶产量进行比较,优化后的产量提高了35.6%。

Curdlan is a water insoluble exopolysaceharide produced by bacteria under nitrogen-limiting conditions. Curdlan production is great impacted by distribution ratio for each group of fermentation medium wall. Thus optimization of fermentation medium is important to curdlan production. The fermentation medium of curdlan were optimized by the response surface methodology. First,Plackett-Burman design was adopted to screen out the important factors affecting the output of curdlan sucrose, （NH4）2HPO4,MgSO4 and corn syrup. Then the path of the steepest ascent was utilized to approach the optimal region. At last,the optimized medium was obtained by Box-Behnken design and response surface methodology. Under the condition（sucrose 61g/L, MgSO4 1g/L,corn syrup 2.5mL/L, （NH4）2HPO4 2.4g/L, KH2PO4 1.4g/L,CaCO3 1.4g/L）,the result of fermentation （47.73g/L） was increased by about 35.6% compared with the previous condition（35.2g/L）.