犬源芽孢杆菌分离鉴定及其耐受性的研究

Study on Isolation, Identification and Tolerance of Bacillus of Canine

芽孢杆菌作为益生菌的一种,具备维持动物肠道菌群平衡、增强动物机体免疫力、提高动物生产性能等功能。本试验应用肉汤琼脂从正常比格犬的粪便中分离纯化出菌株,进行了染色镜检、生化试验、PCR测序及耐受性试验。结果表明:革兰氏染色阳性,镜检芽孢显著,生化试验及PCR测序的结果表明此菌株为芽孢杆菌;耐热性试验结果表明,在80℃条件下芽孢杆菌仍可以生长,有很高的热稳定性;耐酸试验结果表明其对酸的耐性较强,适宜的p H值应在3~5之间;在模拟胃液和肠液中,芽孢杆菌在1.5 h后的存活率均为80%左右。综合而言,分离的犬源芽孢杆菌具备耐胃液、耐高温、耐胆盐等理化特征,该试验结果为犬源微生态制剂的研制奠定了基础。

Bacillus was a kind of probiotics, and has the functions of maintaining the balance of intestinal flora of animals, enhancing the immunity of animals, and improving animal production performance. In this experiment, broth agar was used to separate and purified the strains from the feces of normal beagle dogs, and staining microscopy, biochemical tests, PCR sequencing, and tolerance tests were performed. The identification results showed that Gram stain was positive, spore staining microscopic examination was clear, biochemical tests and PCR sequencing results proved that this strain was Bacillus. The heat resistance test results showed that Bacillus could grow at 80 °C and had high thermal stability. Acid resistance test results showed that it was suitable for acid resistance, and the suitable p H should be between 3 and 5. In simulated gastric fluid and intestinal fluid, the viability of Bacillus was approximately 80%after 1.5 h. The Bacillus separate from the experiment had resistance to gastric juice, high temperature, and bile salts, providing the foundation for the development of canine-derived microecological preparations.