罗伊氏乳杆菌ZL2a株体外益生潜能的评价

In vitro evaluation of probiotic potential of Lactobacillus reuteri ZL2a

为了评价新分离猪源罗伊氏乳杆菌ZL2a株的益生潜能,通过测定其生长曲线、产酸能力、对低pH和高胆盐环境的耐受性、在体外模拟胃肠道溶液中的存活能力、抑菌能力、抗生素抗性及对Caco-2细胞的黏附能力评价了该菌株的益生特性。结果表明,菌株ZL2a产酸能力较强且能迅速进入对数生长期;在pH为2.5的MRS培养基中耐受4 h时活菌数目基本不变,在胆盐浓度为3 g/L的条件下至少可耐受4 h,在人工模拟胃液和肠液中耐受8 h时存活率高于70%;对大肠杆菌、溶血性葡萄球菌、普通变形杆菌等致病菌具有广谱的抑菌效果;对Caco-2细胞的黏附能力为621±30.4 CFU/30 cells。这些特性表明,新分离的罗伊氏乳杆菌ZL2a株具有优良的体外益生性能,可作为潜在饲用益生菌进一步研究。

In order to evaluate the probiotic potential of Lactobacillus reuteri ZL2a,a new isolate from pig faeces,the probiotic characteristics of this strain were evaluated by measuring its growth curve,acid production capacity,tolerance to low pH and high concentration of bile salt,viability in vitro simulated gastrointestinal solution,antibacterial capacity,antibiotic resistance and adhesion to Caco-2 cells.The results showed that ZL2a strain had strong acid-producing ability and was able to enter logarithmic growth phase rapidly.ZL2a strain,which viable numbers remained unchanged in MRS broth(pH 2.5)in 4 hours of tolerance,was tolerant to 3 g/L bile salt at least 4 hours.Simultaneously,70%bacteria were survived in simulated gastric and intestinal juices in 8 hours.The antimicrobial effect of ZL2a strain on pathogens such as Escherichia coli,Staphylococcus haemolyticus and Proteus vulgaris was broad.Moreover,the adhesion ability of this strain to Caco-2 cells was(621±30.4)CFU/30 cells.All of these probiotic properties indicated that the newly isolated L.reuteri ZL2a had good beneficial effects in vitro and could be further studied as candidate probiotics for feeding.