响应面法优化Paenibacillus sp.JX426产黄原胶降解酶发酵培养基

Optimization of fermentation medium for xanthan gum degrading enzyme produced from Paenibacillus sp.JX426 by response surface methodology

从土壤中分离筛选出1株具有较强黄原胶降解能力的类芽孢杆菌(Paenibacillus sp.)JX426。为了获得高活力的黄原胶降解酶,研究借助Minitab15软件,采用Plackett-Burman试验设计方法、最陡爬坡试验设计方法和响应面分析方法对菌株JX426进行了液体发酵条件的优化。首先通过Plackett-Burman方法对7个相关影响因素的效应进行了评价,并筛选出有显著正效应的黄原胶、CaCl2添加量和有显著负效应的酵母粉添加量等3个因素,然后利用最陡爬坡试验设计方法和响应面分析方法确定了上述3个因素的最佳工艺参数,即黄原胶、CaCl2和酵母粉的添加量分别为0.39%、0.02%和0.042%。试验结果表明,在最佳浓度和组成条件下,黄原胶降解酶的酶活能达到4.20U/mL,较优化前的3.05U/mL提高了37.7%,为黄原胶降解菌的实际应用奠定了基础。

A Paenibacillus sp. JX426 newly isolated from soil samples had high ability of xanthan gum degradation. To improve its activity ofxanthan degrading enzyme, Plackett-Burman experimental design, steepest ascent experimental design and Box-Behnken（BBD）response surface experimental design were applied to optimize the fermentation condition of xanthan gum degrading enzyme by Paenibacillus sp. JX426. Firstly, Plackett-Burman experiment was used to select three significant factors （the content ofxanthan gum, yeast extract and CaC12）. The maximum content of enzyme activity was obtained by experimental design of steepest ascent. Three significant factors were then optimized by Box-Behnken （BBD） response surface. The results showed the optimal content of xanthan gum, yeast extract and CaCl2 were 0.39%, 0.042% and 0.02%, respectively. Under these optimal conditions, the xanthan-degrading enzyme activity was 4.20U/ml, which was increased by 37.7% compared with the value of 3.05U/ml before optimization.