具有潜在抑制肠道致病菌能力的乳酸菌的筛选

目的]从实验室保藏的乳酸菌中筛选出耐酸耐胆盐能力较强的乳酸菌,并研究其对肠上皮细胞的黏附能力及对肠道病原菌的抑制能力。方法]通过模拟人工胃肠液及体外与IEC-6细胞共培养来分别研究乳酸菌的耐酸耐胆盐能力及对细胞的黏附能力,并利用单层琼脂平板扩散法测定其抑菌效果。结果]试验的27株乳酸菌中,10株乳酸菌在p H 3.0的人工模拟胃液中培养3 h的存活率均大于44.00%,在p H 8.0的人工模拟肠液中培养4 h的存活率均大于51.56%,在含0.30%胆盐的培养基中培养24 h的存活率均大20.00%;其中菌株C13、A03、A17及A90对IEC-6细胞的黏附个数均大于8个/cell;菌株C13、A03对艰难梭菌、沙门氏菌和大肠杆菌的抑制能力较强,抑菌圈直径均大于22 mm。经16S rRNA测序将C13和A03分别鉴定为鼠李糖乳杆菌(Lactobacillus rhamnosu)和植物乳杆菌(Lactobacillus plantarum)。结论]L.rhamnosu C13、L.plantarum A03的耐酸耐胆盐能力及对上皮细胞的黏附能力较强,对肠道病原菌有较好的抑制作用,可作为良好的抑制肠道病原菌的候选益生菌株。

Screening of Lactic Acid Bacteria with the Ability of Inhibiting Enteropathogenic Bacteria in Potential

Objective] Lactic acid bacteria (LAB) with strong resistance of acid and bile salt were screened from laboratory,and their adhesion ability of intestinal epithelial cells and inhibition ability to intestinal pathogens were studied.Method]The resistance of acid and bile salt and the adhesion ability of IEC-6 cells were studied by artificial gastrointestinal fluid and co-cultured with IEC-6 cells,respectively,and the bacteriostatic effect was deter mined by single agar plate diffusion method.Result]The survival rate of 10 strains were cultured 3 h in pH 3.0 artificial gastric juice was greater than 44.00％,and cultured 4h in pH 8.0 artificial intestinal juice was greater than 51.56％,and cultured 24 h in medium containing 0.30％ bile salts was greater than 20.00％;the adhesion number of C13,A03,A17 and A90 on IEC-6 cells was greater than 8 cells;the inhibiting capacity of C13,A03 on Clostridium difficile,Salmonella and Escherichia coli was stronger than others,the antibacterial circle diameter was greater than 22 mm.C13 and A03 were identified as Lactobacillus rhanmosu and Lactobacillus plantarum by 16S rRNA sequencing,respectively.Conclusion] L.rhamnosu C13,L.plantarum A03 with the strong ability of acid and bile salt resistance and adhesion to epithelial cells,which have good inhibitory effect on pathogenic bacteria,and can be used as a fit probiotic candidate strain.