牛源肠道益生菌的筛选与3株芽孢杆菌益生菌株的鉴定

Screening of Probiotics from Bovine Intestine and Identification of Three Probiotics Strains Bacillus

[目的]从健康牛的粪便中筛选出对大肠杆菌(Escherichia coli)有较强抑制作用的芽孢杆菌,并对其进行鉴定。[方法]以大肠杆菌为指示菌进行初筛和复筛,采用SPSS软件对复筛结果进行显著性分析,以选择抑制大肠杆菌活性较强的菌株,经过形态观察、生理生化试验和16S rDNA全序列分析鉴定其种属;采用稀释活菌计数法测绘这些菌株的生长曲线,利用SPSS软件结合修正的Gompertz方程和Logistic方程对生长曲线进行拟合,以获得这些菌株的生长动力学参数。[结果]经过鉴定,筛选得到的对大肠杆菌有较强抑制作用的3株牛源芽孢杆菌均属于解淀粉芽孢杆菌(Bacillus amyloliquefaciens);采用SPSS软件拟合得到的生长曲线的相关系数(R)在0.985以上。[结论]筛选并鉴定了3株牛源肠道益生菌;采用SPSS软件可以较准确地预测这些菌株的生长动力学参数。

[ Objective ] Research was done to screen and identify Basillus which could strongly inhibit Escherichia coli from healthy bovine intestine feces. [ Method ] With Escherichia coli as indicative bacteria, Busillus strains that could strongly inhibit Escherichia coli were prescreened and secondary screened with significance analysis to secondary screening result by SPSS software. Identification of these strains were done through morphological observation, physiological biochemical test and 16S rDNA sequence analysis. Growth curves of these strains were drawn by diluted viable count method. The fitting was done to obtain growth kinetic parameters of these strains with modified Gompertz equation and modified Logistic equation as models by SPSS software. [ Result] 3 strains of Busillus which could strongly inhibit Escherichia coil from healthy bovine intestine feces were obtained and identified to Bacillus amyloliquefaciens. Correlation coefficient of growth curves fitted by SPSS software was all above 0. 985. [ Conclusion ] This study screened and identified 3 strains of Bacillus as probiotics and accurately predicted the growth kinetic parameters of these strains by SPSS software.