短短芽胞杆菌产抗菌物质——羟苯乙酯发酵培养基的优化

Medium Optimization for the Production of Antimicrobial Ethylparaben from Brevibacillus brevis FJAT-0809-GLX using Response Surface Methodology

羟苯乙酯是短短芽胞杆菌FJAT-0809-GLX的主要抑菌活性物质,为提高该菌株发酵液中羟苯乙酯的产量,本研究采用响应面法对其发酵培养基成分进行优化。首先通过单因素试验,对发酵培养基中的碳源、氮源和无机盐进行了优化,进一步通过Plackett-Burman设计对培养基的影响因素进行筛选,最后采用最陡爬坡路径逼近最大响应区域,通过Box-Behnken设计,结合响应面分析,获得短短芽胞杆菌FJAT-0809-GLX发酵产生羟苯乙酯的最佳培养基配方。结果表明,培养基最佳碳源、氮源和无机盐分别为DL-苹果酸、蛋白胨和NaCl。影响显著的3个因素分别为DL-苹果酸、豆饼粉和NaCl。最佳培养基配方为可溶性淀粉8 g/L、DL-苹果酸29.68 g/L、豆饼粉25.18 g/L、蛋白胨2 g/L、NaCl 13.18 g/L,pH 7.0~7.2。采用此培养基配方进行短短芽胞杆菌FJAT-0809-GLX发酵,羟苯乙酯平均产量为8.15μg/mL,较基础发酵培养基提高了286.26%。

Ethylparaben is the main antimicrobial substance of Brevibacillus brevis FJAT-0809-GLX.To improve the yield of ethylparaben,the fermentation medium components were optimized using response surface method.The carbon sources,nitrogen sources and inorganic salts in the fermentation medium were optimized by single factor experiment.Plackett-Burman design was undertaken to evaluate the influence factors of the culture medium.The path of steepest ascent was adopted to approach the optimal region of the three significant factors,and then Box-Behnken design and response surface methodology were applied to determine the optimal levels of the main factors.The results showed that the best carbon source,nitrogen source and inorganic salt were DL-malic acid,peptone and NaCl,respectively;DL-malic acid,soybean cake powder and NaCl were the main factors of the culture medium;The best fermentation medium for ethylparaben production of this strain contained soluble starch 8 g/L,DL-malic acid 29.68 g/L,bean powder 25.18 g/L,peptone 2 g/L,NaCl 13.18 g/L and pH 7.0—7.2.Using this fermentation medium,the average yield of ethylparaben was increased by 286.26%compared the basal fermentation medium and reached up to 8.15μg/mL.