费氏丙酸杆菌生物学特性及与5株益生菌拮抗性试验研究

为了评价费氏丙酸杆菌的益生特性，费氏丙酸杆菌活化后，划线和镜检观察其形态特征，然后利用体外共培养法测定费氏丙酸杆菌对3种致病菌的抑制效果，同时利用平板计数法研究费氏丙酸杆菌的耐酸性、耐胆盐和耐高温等生物学特性，以及5株益生菌拮抗性试验。结果表明，费氏丙酸杆菌对大肠杆菌和沙门氏菌没有显著的抑制作用，而对金黄色葡萄球菌的抑制效果明显（P＜0.01）；其在pH值为2.0条件下维持3 h，活菌数降低一个数量级；在胆盐含量为0.30%条件下维持6 h，存活率为18.67%；在60 ℃下处理20 min，存活率为12%，因此费氏丙酸杆菌具有一定的耐酸、耐高温能力以及很强的耐胆盐活性。除枯草芽孢杆菌与丁酸梭菌有拮抗作用外，其余菌株间均没有拮抗作用。

Biological characteristics of Propionibacterium freudenreichii and antagonism tests of five probiotics

To evaluate the probiotic properties of Propionibacterium freudenreichii, the inhibitory effect of P. freudenreichii on three pathogens was determined by in vitro co-culture method, and the biological characteristics were measured by plate count method, including acid tolerance characteristic, bile salts tolerance characteristic, high-temperature tolerance characteristic, as well as five probiotics antagonistic characteristics. The results showed that P. freudenreichii had no obvious antibacterial effect on Escherichia coli and Salmonella, but a powerful antibacterial effect on Staphylococcus aureus (P＜0.01). When P. freudenreich was maintained at pH 2.0 for 3 h, the viable count decreased by one order of magnitude, and when it was maintained in the bile salt concentration of 0.30% for 6 h, the survival rate was 18.67%. After treated at 60 ℃ for 20 min, the survival rate was 12%. Therefore, P. freudenreichii had certain tolerance to acid, high temperature and strong tolerance to bile salts. There was no antagonism among probiotics except for Bacillus subtilis and Clostridium butyricum.