Gu Rui-Xia, Yang Zhen-Quan, Li Zheng-Hua, Chen Shun-Li, Luo Zhen-Lan
Institute of Dairy Science and Technology of Yangzhou University, 1East Yanfu Road, Yangzhou, Jiangsu 225001, PR China.
Anaerobe. 2008 Dec;14(6):313-7. doi: 10.1016/j.anaerobe.2008.06.001. Epub 2008 Jun 28.
A total of 567 lactic acid bacteria (LAB) strains were isolated from the stool samples of longevous people in regions of Hotan, Xinjiang and Bama, Guangxi, China. In order to reduce the number of strains for further examinations, 36 isolates were screened out for further examination whilst the other strains, which had lower probiotic properties, were not suitable for yogurt production due to the absence of growth in pH 3.5 MRS medium and no curding during fermentation, and so were excluded. The result of identification by API, sequence analysis of 16S rRNA and random amplified polymorphic DNA (RAPD) analysis showed that there were three strains of Lactobacillus acidophilus, 10 strains of Lactobacillus rhamnosus, three strains of Lactobacillus casein, three strains of Lactobacillus brevis, two strains of Enterococcus faecium, two strains of Enterococcus faecalis, four strains of Bifdibacterium infantis, three strains of Bifdibacterium brevise, three strains of Bifdibacterium bifidium, two strains of Bifdibacterium adolecentis and one strain of Bifdibacterium longam among the 36 isolates. These strains were evaluated by in vitro methods including survival upon exposure to pH 2.0, 3.0 and/or 0.3% oxgall and adhesion to the human colon adenocarcinoma cell line Caco-2 as well as antimicrobial activity against potential pathogens. The results presented here show that L. rhamnosus LV108, L. rhamnosus F, B. brevise R39 and B. infantis R42 are acid and bile tolerant, adhere to the cultured human intestinal Caco-2 cell line, antagonistic activity against potential pathogenic bacteria infection in vitro, and so are potential strains for probiotic use.
从中国新疆和田地区和广西巴马地区长寿老人的粪便样本中总共分离出567株乳酸菌（LAB）菌株。为了减少进一步检测的菌株数量，筛选出36株分离株进行进一步检测，而其他益生菌特性较低的菌株，由于在pH 3.5的MRS培养基中不生长且发酵过程中不凝乳，不适合用于酸奶生产，因此被排除。通过API鉴定、16S rRNA序列分析和随机扩增多态性DNA（RAPD）分析结果表明，在这36株分离株中，有嗜酸乳杆菌3株、鼠李糖乳杆菌10株、干酪乳杆菌3株、短乳杆菌3株、粪肠球菌2株、屎肠球菌2株、婴儿双歧杆菌4株、短双歧杆菌3株、两歧双歧杆菌3株、青春双歧杆菌2株和长双歧杆菌1株。通过体外方法对这些菌株进行评估，包括在pH 2.0、3.0和/或0.3%牛胆汁环境下的存活能力、对人结肠腺癌细胞系Caco-2的黏附能力以及对潜在病原体的抗菌活性。此处给出的结果表明，鼠李糖乳杆菌LV108、鼠李糖乳杆菌F、短双歧杆菌R39和婴儿双歧杆菌R42耐酸和耐胆汁，能黏附培养的人肠道Caco-2细胞系，在体外对潜在病原菌感染具有拮抗活性，因此是潜在的益生菌菌株。
