多粘芽孢杆菌抗逆性与益生性的体外评价

Study on stress resistance and probiotic characteristics of Bacillus polymyxas in vitro

为了探讨多粘芽孢杆菌的抗逆性与益生特性,通过5个试验评定多粘芽孢杆菌的抗热、抗酸、耐胆盐、抑菌性能和粘附性。85℃水浴对多粘芽孢杆菌分别处理2.5,5.0,7.5 min模拟制粒条件;利用pH分别为2、3、4的人工胃液模拟胃液环境;0.3%胆盐模拟肠液环境;抑菌试验测定多粘芽孢杆菌发酵液对大肠杆菌、金黄色葡萄球菌的抑制能力;以蛋鸡肠道上皮细胞为模型测定多粘芽孢杆菌的粘附能力。结果表明:多粘芽孢杆菌高温处理7.5min活菌数较对照组减少1.17%(P>0.05)。在耐酸性试验中,pH3的试验组较对照组活菌数降低0.37%(P>0.05)。在耐胆盐试验中,试验组活菌数较对照组降低了0.74%(P>0.05)。多粘芽孢杆菌发酵液对大肠杆菌、金黄色葡萄球菌的抑菌环直径分别为0,17.46 mm。粘附性试验结果显示,在每100个蛋鸡肠道黏膜上皮细胞上可以粘附30个多粘芽孢杆菌。因此,制粒温度、人工胃液、人工肠液不影响多粘芽孢杆菌活菌数;多粘芽孢杆菌对金黄色葡萄球菌有显著的抑制能力,基本不能在蛋鸡消化道内定植。

This study aims to explore the stress resistance and characteristics of B. polymyxas. Five trials were conducted to evaluate the thermostability, acid and bile tolerance, antibacterial activity and adhesion property of B. polymyxas. Pelleting process was simulated by B. polymyxas water bath at 85 ℃ for 2.5, 5.0 and 7.5 min respectively. Simulated stomach juice pH at 2, 3, and 4, and simulated small intestinal juices with 0. 3% bile salts. Through the test of inhibiting bacteria, the antibacterial properties of B. polymyxas fermentation liquor were de- termined. Adherence ability of B. polymyxas to layer intestinal tract epithelium was also studied in adhesiveness trial. The trial results were： Viable count in high-temperature treatment group for 7.5 min is 1.17% lower than the control＇s （P〉0.05）. In acid tolerance trial, viable count in treatment group decreased 0.37% （P〉0.05） in pH3.0 gastric fluid treatment group compared with that of the control. In bile salt treatment, B. polymyxas viable count was 0.74% less than that of conrol（P〉0.05）. The bacteriostasis circle of B. polymyxas culture to Bacillus coli,and Staphylococcus aureus was 0, 17.46 mm respectively. In the adhesive trial, the number of adhesive B. polymyxas to the intestinal epithelia was 30 cfu/100 cell. These results indicated that the pelleting temperature, artificial stomach juice and simulated small intestinal juices have no effect on B. polymyxas viable counts. The B. polymyxas have strong inhibition capability to Staphylococcus aureu. The B. polymyxas can not plant in layer digestive tract permanently.