Zhang Yuanyuan, Zhao Mengdi, Li Yueyao, Liang Shuang, Li Xinkang, Wu Yi, Li Guangyu
College of Animal Science and Technology, Qingdao Agricultural University, Qingdao 266109, China.
College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China.
Microorganisms. 2024 Sep 2;12(9):1811. doi: 10.3390/microorganisms12091811.
This study aimed to isolate and screen canine-derived probiotics with excellent probiotic properties. Strain characterization was conducted using a combination of in vitro and in vivo probiotic characterization and safety assessments, as well as complete genome analysis. The results showed that LRA7 exhibited excellent bacteriostatic and antioxidant activities. The survival rate at pH 2.5 was 79.98%, and the viable counts after exposure to gastrointestinal fluid and 0.5% bile salts were 7.77 log CFU/mL and 5.29 log CFU/mL, respectively. The bacterium also exhibited high hydrophobicity, self-coagulation, and high temperature tolerance, was negative for hemolysis, and was sensitive to clindamycin. In vivo studies in mice showed that the serum superoxide dismutase activity level was 53.69 U/mL higher in the MR group of mice compared to that of the control group, the malondialdehyde content was 0.53 nmol/mL lower in the HR group, and the highest jejunal V/C value was 4.11 ± 1.05 in the HR group ( < 0.05). The LRA7 gene is 2.021 megabases in size, contains one chromosome and one plasmid, and is annotated with 1978 functional genes. In conclusion, LRA7 has good probiotic potential and is safe. It can be used as an ideal probiotic candidate strain of canine origin.
本研究旨在分离和筛选具有优良益生菌特性的犬源益生菌。采用体外和体内益生菌特性及安全性评估相结合的方法进行菌株鉴定，并进行全基因组分析。结果表明，LRA7表现出优异的抑菌和抗氧化活性。在pH 2.5时的存活率为79.98%，暴露于胃肠液和0.5%胆盐后的活菌数分别为7.77 log CFU/mL和5.29 log CFU/mL。该菌还表现出高疏水性、自凝性和耐高温性，溶血试验为阴性，对克林霉素敏感。在小鼠体内的研究表明，与对照组相比，MR组小鼠血清超氧化物歧化酶活性水平高53.69 U/mL，HR组丙二醛含量低0.53 nmol/mL，HR组空肠V/C值最高，为4.11±1.05（P<0.05）。LRA7基因大小为2.021兆碱基，包含一条染色体和一个质粒，注释有1978个功能基因。综上所述，LRA7具有良好的益生菌潜力且安全。它可作为一种理想的犬源益生菌候选菌株。
