枯草芽孢杆菌体外益生效果评估

Evaluation of probiotic effect of Bacillus subtilis in vitro

试验旨在评估枯草芽孢杆菌的体外益生效果。以存活率为指标,考察枯草芽孢杆菌对高温、酸、碱、胃液、肠液、胆盐的耐受性,应用牛津杯法研究枯草芽孢杆菌对致病菌的抑制作用。结果显示,随处理温度的升高和处理时间的延长,所有枯草芽孢杆菌的活菌数均呈下降趋势。同种枯草芽孢杆菌的耐碱性优于耐酸性。所有枯草芽孢杆菌对鼠伤寒沙门氏菌均无抑制作用。体外评估结果显示,BS-5对高温、不同pH值、胃液、肠液的耐受性最好,存活率在72.75%~95.83%;BS-3对胆盐的耐受性最好,存活率为68.84%,BS-1体外抑菌效果最好,对大肠埃希氏菌、产气荚膜梭菌的体外抑菌直径分别为10.47、13.45 mm。研究表明,不同枯草芽孢杆菌的体外抗逆性和抑菌性不同。

The experiment was designed to evaluate the probiotic effect of Bacillus subtilis in vitro. Taking survival rate as index, the tolerance of Bacillus subtilis to high temperature, acid, alkali, gastric juice, intestinal juice and bile salt was investigated. The inhibition effect of Bacillus subtilis on pathogenic bacteria was studied by Oxford cup method. The results showed that with the increase of treatment temperature and treatment time, the viable count of Bacillus subtilis showed a decreasing trend. The alkali tolerance of Bacillus subtilis is better than acid tolerance. All Bacillus subtilis had no inhibitory effect on Salmonella typhimurium. In vitro evaluation results showed that BS-5 had the best tolerance to high temperature, different pH values, gastric and intestinal fluids, the survival rate was 72.75%~95.83%. BS-3 had the best tolerance to bile salt, and the survival rate was 68.84%. BS-1 had the best antibacterial effect in vitro, with antibacterial diameters of 10.47, 13.45 mm against Escherichia coli and Clostridium perfringens, respectively. The experiment indicates that the stress resistance and bacteriostasis of different Bacillus subtilis are different in vitro.