海洋红球菌SY095产生物表面活性剂发酵培养基的优化

Optimization fermentation medium for production of biosurfactant by Rhodococcus SY095

为提高海洋红球菌SY095发酵产生物表面活性剂的能力,研究发酵培养基中碳源及氮源的影响,并通过响应面分析法优化培养基各组分的含量。首先通过单因素实验,确定培养基最佳碳源、氮源分别为大豆油和尿素,在此基础上,利用Plackett-Burman实验设计筛选出2个对表面活性剂产量有显著影响的因子为尿素和K2HPO_4,通过最陡爬坡实验和响应面分析法对显著影响因子进行优化,获得海洋红球菌产表面活性剂的最佳培养基配方为:大豆油2%(体积分数),尿素2.35 g·L^(-1),K_2HPO_40.69 g·L^(-1),KH_2PO_41.0 g·L^(-1),Mg SO_40.5 g·L^(-1)。使用该优化培养基配方,海洋红球菌发酵液的表面张力为29.254 m N·m^(-1),与预测值接近,表面张力活性比优化前提高了12.9%。

To improve biosurfactant production,fermentation conditions of Rhodococcus SY095 were studied by optimization experiments. Based on the single factor experiment,soybean oil and urea were selected as the best carbon and nitrogen source,respectively. The Plackett-Burman design was used to evaluate the influence of related factors,and two significant factors,urea and monopotassium phosphate were selected. The path of steepest ascent and response surface methodology were used to explore optimal levels of significant factors. The optimal medium composition for biosurfactant production by Rhodococcus SY095 was determined as follows： soybean oil of2%,urea of 2. 35 g·L-1,monopotassium phosphate of 0. 69 g·L-1,dipotassium hydrogen phosphate of 1 g·L-1,and magnesium sulfate 0. 5 g·L-1. With this optimum medium,the surface tension of the culture could reach 29. 054 m N·m-1,which was 12. 9% higher than that using the original medium.