粪肠球菌BN6株的体外益生特性评价

Evaluation of probiotic characteristics of Enterococcus faecalis BN6 isolate in vitro

为了评价粪肠球菌BN6株的益生潜能,本试验测定了BN6株在低pH值和高胆盐环境的耐受性,对抗生素敏感性以及抑菌、细菌的疏水率、自凝集率和抗氧化性能等特性。结果表明,BN6株在pH=2.5的PBS中耐受3 h的存活率达到97.45%,并且能够耐受0.3%的胆盐环境;BN6株对氨苄西林、万古霉素、红霉素、阿莫西林和氯霉素敏感;BN6株培养上清对大肠埃希氏杆菌、小肠结肠炎耶尔森菌和普通变形杆菌等肠道致病菌具有良好的抑菌作用;以二甲苯和三氯甲烷为有机相,疏水率分别为47.8%和55.19%,自凝集率为21.57%;BN6株无细胞提取物和菌体DPPH清除率分别为26.83%±4.93%和22.13%±9.43%,无细胞提取物抗脂质过氧化率35.55%±3.28%。结论,粪肠球菌BN6株具有良好的益生特性,可作为候选益生菌进行深入研究。

In order to evaluate the probiotic characteristics of Enterococcus faecalis BN6 isolate in vitro,the experiment was conducted to determine characteristics on the tolerance to acid and bile,antibiotic sensitivity,antibacterial activity,hydrophobic and auto-agglutination rate,and antioxidant property of E.faecalis BN6 isolate in vitro.The results showed that E.faecalis BN6 isolate had97.45%of survival rate at p H=2.5 after incubation 3 hours and it could tolerate 0.3%bile salt;the culture supernatant of BN6 isolate showed a good antibacterial effect on intestinal pathogenic bacteria such as Escherichia coli,Yersinia enterocolitica and Proteus vulgaris;BN6 isolate was sensitive to ampicillin,vancomycin,erythromycin,amoxicillin and chloramphenicol;the hydrophobic rates of BN6 isolate were 47.8%in organic phase dimethylbenzene and 55.19%in organic phase trichloromethane,respectively,and the auto-aggregation rate of BN6 isolate was 21.57%;DPPH radical scavenging rates of intact-cell and cell-free extracts of BN6 isolate were 26.83%±4.39%and 22.13%±9.43%,respectively;the radical clearance rate of anti-lipid peroxidation of cell-free extracts of BN6 isolate was 35.55%±3.28%.In conclusion,E.faecalis BN6 isolate has some good probiotic properties and can be used as a candidate for further study.