牛源抗腹泻芽孢益生菌的分离与N-4菌株的鉴定

Isolation and Characterization of the Probiotics Strain N-4 Showing Antidysenteriae Effects from Cattle

为了获得对痢疾病原菌有拮抗作用的益生菌株,以0.5%牛胆酸盐为筛选压力,痢疾杆菌菌株作为病原指示菌,从健康青年牛的粪便中,分离对痢疾杆菌具有拮抗作用的产芽孢菌株。通过平板生长对峙法进行初筛,共得到对痢疾杆菌具有拮抗作用的菌株26株,利用发酵液平板打孔法进行复筛,选出1株拮抗活性较高的菌株N-4,抑菌圈直径达到17.6 mm。根据N-4菌株形态和生理生化特征,结合对N-4菌株的16S rDNA序列分析结果,最终鉴定N-4菌株为Bacillus amyloliquefaciens。

To obtain the probiotics strains which show antidysenteriae effects, the probiotics cattle origin Bacillus spp. strains showing antagonistic activities against diarrhea bacilli were isolated from the feces of young cattles using the screening stress of 0. 5% bile salts of cattle. 26 strains were obtained via preliminary screening in growth plate confrontation method and a strain named N- 4 with a relatively higher antagonistic activity was obtained via secondary screening in perforated plate broth method. Then, the N-4 strain was characterized by a series of physiological and biochemical experiment. The 16S rDNA sequence was also analyzed. According to the results, strain N -4 was finally identified as Bacillus amyloliquefaciens.