响应面法优化枯草芽孢杆菌表面活性素的发酵工艺

Optimization of Fermentation Conditions of Surfactin from Bacillus subtilis by Response Surface Methodology

为提高枯草芽孢杆菌FHYB201030的表面活性素生产能力,本文以枯草芽孢杆菌FHYB201030为试验菌株,CPC-BTB(氯化十六烷基吡啶-溴百里酚蓝)值为考核指标,利用单因素实验、Plackett-Burman试验、最陡爬坡试验和响应面试验进行优化,筛选出产表面活性素的最优发酵条件。Plackett-Burman试验筛选出对表面活性素产量影响显著的因素为温度、乳糖、谷氨酸(Glu),采用最陡爬坡设计和Box-Behnken中心组合设计三因素三水平试验,计算得到表面活性素产量最高的培养基成分为乳糖25 g/L、酪蛋白10 g/L、牛肉膏3 g/L、蛋白胨10 g/L、NaCl 5 g/L、Mn;0.5 mmol/L、Glu 2.5 g/L;最佳培养条件为温度40℃、转速200 r/min、装液量30%(体积比)。在上述发酵条件下,枯草芽孢杆菌FHYB201030表面活性素的产量为0.48 mg/mL,较优化前的0.35 mg/mL提高34.56%。研究结果为提高表面活性素生产水平奠定良好的基础。

In order to improve the surfactin production capacity of Bacillus subtilis FHYB201030, taking Bacillus subtilis FHYB201030 as the experimental strain, and CPC-BTB(cetylpyridyl chloride-bromothymol blue) value was used as the evaluation index. Single factor tests, Plackett-Burman test, steepest climbing test and response surface test were used to optimize the optimal fermentation conditions for surfactin production. Plackett-Burman test showed that temperature,lactose and glutamic acid(Glu) had significant effects on surfactin yield. The steepest climbing design and the Box-Behnken central combination design three-factor three-level test were used to calculate the culture medium composition with the highest surfactin yield: 25 g/L of lactose, 10 g/L of casein, 3 g/L of beef extract, 10 g/L of peptone, 5 g/L of NaCl,0.5 mmol/L of Mn;, 2.5 g/L of Glu. The optimum cultivation conditions were temperature of 40 ℃, rotation speed of 200 r/min, filling volume of 30%. Under the fermentation condition, the amount of surfactant produced by Bacillus subtilis FHYB201030 was 0.48 mg/mL, which was 34.56% higher than the 0.35 mg/mL before optimization. This result would lay a good foundation for improving the production level of surfactin.