饲用地衣芽孢杆菌抗逆性与益生性的体外评价

In-vitro evaluation of stress resistance and probiotic characteristics of Bacillus licheniformis for feed

为了探讨地衣芽孢杆菌的抗逆性与益生性,研究通过5个试验评定地衣芽孢杆菌的耐高温、耐酸性、耐胆盐、抑菌性和黏附性,于85℃水浴分别处理地衣芽孢杆菌2.5 min、5 min、7.5 min模拟制粒条件;利用pH值分别为2,3,4的人工胃液模拟胃液环境;用0.3%的胆盐模拟肠液环境;抑菌试验测定地衣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地衣芽孢杆菌的黏附能力。结果表明:85℃处理地衣芽孢杆菌2.5 min后活菌数最高,与对照组相比提高了2.25%(P>0.05);用pH值为2,3,4的胃液分别处理,与对照组相比活菌数分别提高0.77%(P>0.05)、1.54%(P>0.05)、1.34%(P>0.05);地衣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和16.16 mm;在黏附性试验中,每100个蛋鸡肠道黏膜上皮细胞上平均可以黏附27个地衣芽孢杆菌。说明制粒过程、人工胃液、人工肠液不影响地衣芽孢杆菌的活菌数,地衣芽孢杆菌对金黄色葡萄球菌有显著抑制作用,使金黄色葡萄球菌基本不能在蛋鸡消化道内定植。

To investigate the stress resistance and probiotic characteristics of Bacillus licheniformis,five trials were conducted to evaluate the thermostability,acid and bile tolerance,antibacterial activity and adhesion property of Bacillus licheniformis.The pelletizing processes were simulated that the Bacillus licheniformis was heat-treated in the waterbath for 2.5 min,5 min and 7.5 min at 85 degrees C respectively.The pH values of simulated stomach juice were 2,3,and 4 respectively,and simulated small intestinal juices was mixed 0.3% bile salts.Through the inhibiting bacteria test,the antibacterial properties of Bacillus licheniformis were determined.Adhere ability of Bacillus licheniformis to layer intestinal tract epithelium were studied in adhesiveness trial.The results showed that the viable count in high-temperature treatment group for 2.5 min is 2.25% higher than that of the control group（P〉0.05）.In acid tolerance trial,the viable counts were raised by 0.77%（P〉0.05）,1.54%（P〉0.05）,1.34%（P〉0.05） in pH 2,3 and 4 gastric fluid treatment group compared with the control group respectively.In bile salt treatment,the viable count of Bacillus licheniformis was 2.06%（P〈0.05） less than that of the control（P〉0.05）.The bacteriostatic circles of Bacillus licheniformis culture to Bacillus coli and Staphylococcus Aureus were 0 and 16.16 mm respectively.In the adhesive trial,the number of adhesive Bacillus licheniformis to the intestinal epithelia was 27 cfu/100 cells.The results indicated that the pelletizing process,artificial stomach juice and simulated small intestinal juices had no effect on the viable counts of Bacillus licheniformis.The Bacillus licheniformis has strong inhibitting capability to Staphylococcus Aureu,it can not plant in layer digestive tract permanently.