产enterocin E5细菌素粪肠球菌发酵条件的优化

Study on the Optimum enterocin E5 Production Condition of Enterococcus faecalis E5

采用琼脂扩散法测定粪肠球菌发酵上清液对大肠埃希菌K88的抑菌活性,从而确定产enterocin E5细菌素粪肠球菌的发酵条件。结果表明,粪肠球菌E5产细菌素的发酵培养基为MRS培养基,最适温度为37℃,最适起始pH值6.5,最佳接种量2%,种龄14 h,发酵时间16 h,最佳培养基组分氮源为1%胰蛋白胨、0.5%酵母浸粉,最佳碳源为1%葡萄糖、0.5%蔗糖,0.1%Tween-80有利于enterocin E5的产生。这是分离自北京优良商品猪黑六产enterocin E5粪肠球菌的首次报道。

To investigate the fermentation conditions for growth and antibacterial substance production by Enterococcus faecalis E5,the antibacterial activity of the supernatant against Escherichia coli K88 was tested with agar well diffusion method.The results showed that the optimum fermentation conditions for Enterococcus faecalis E5 to produce enterocin E5 ran as follows：tryptone 1%,yeast extract powder 0.5%,glucose 1%,sucrose 0.5% and Tween-80 0.1%.This formula of modified MRS could stimulate the generation of enterocin E5.The optimum initial pH value was 6.5,while the best temperature was 37℃ with the inoculation amount of 2%（V/V）,the seed age of 14 h and the fermentation period of 16 h.This was the first report on enterocin E5 produced by Enterococcus faecalis E5 isolated from Beijing black six swine.