响应面法优化短短芽孢杆菌S1039发酵培养基的研究

Study on optimization of fermentation medium for Brevibacillus brevis S1039 by response surface methodology

近年来,传统抗生素的过量使用导致动植物病害耐药性增强,这不仅使得抗生素的作用越来越小,而且严重威胁着人类的健康.因此寻找高产细菌素或类细菌素的微生物菌株成为研究的热点.本研究为了提高短短芽孢杆菌(Brevibacillus brevis S1039)类细菌素的抑菌活性,对其发酵培养基进行了响应面优化.通过单因素试验筛选出了适合短短芽孢杆菌产抗菌物质的最佳碳源、氮源分别是马铃薯淀粉和蛋白胨,并发现适量的CaCl_2和Tween-20能够有效的促进类细菌素的产生.利用Box-Behnken实验设计及响应面分析确定了培养基四个因子的最佳浓度分别为:马铃薯淀粉12.9g/L、蛋白胨27.6g/L、CaCl_21.2g/L、Tween-20 1.05%.采用优化后的培养基发酵,类细菌素抑菌圈直径达到25.4mm,比优化前提高了56.8%,说明响应面法优化短短芽孢杆菌发酵培养基能够明显的提高类细菌素的抑菌活性,为该菌株规模化生产类细菌素提供了基础应用参考.

In recent years,excessive use of traditional antibiotics has led to increased resistance of animal and plant diseases,which not only makes antibiotics less and less efficient,but also seriously threatens human health.Therefore,to screen microbial strains of high-yield bacteriocin or bacteriocin-like substance(BLS)becomes a research hotspots.In order to improve the antibacterial activity of bacteriocin-like substance that produced from Brevibacillus brevis S1039,the fermentation medium was optimized by response surface methodology.The optimum carbon sources and nitrogen sources suitable for the production of bacteriocin-like substance were potato starch and peptone,respecively,it was also effectively promoted via addtion of CaCl 2 and tween-20,and four factors were screened by Box-Behnken experimental design and response surface analysis.The optimized concentrations of four factors were as follows:12.9 g/L potato starch,27.6 g/L peptone,1.2 g/L CaCl 2,1.05%Tween-20.The inhibition zone diameter of antimicrobial substance was 25.4 mm when used the optimized medium for fermentation,which is 56.8%higher than before.The results showed that the optimized fermentation medium of B.brevis could effectively improve the activity of the antimicrobial substance,which provides a basic application reference for the production of bacteriocin-like substance.