Yuki N, Watanabe K, Mike A, Tagami Y, Tanaka R, Ohwaki M, Morotomi M
Yakult Central Institute for Microbiological Research, Tokyo, Japan.
Int J Food Microbiol. 1999 Apr 1;48(1):51-7. doi: 10.1016/s0168-1605(99)00029-x.
Lactobacillus casei strain Shirota (LCS) is a probiotic bacterium used in the production of fermented milk products and lactic acid bacteria preparations. To investigate the survival of LCS in the gastrointestinal tract, we have developed a selective medium and specific monoclonal antibodies to isolate and identify this strain. Selective LLV agar medium was prepared by modifying LBS medium, a selective medium for lactobacilli, through the replacement of glucose with lactitol as a carbon source and vancomycin as a selective antibiotic. Culture in LLV agar medium followed by ELISA using monoclonal antibodies specific for LCS was able to detect the organism in faeces. Using this method, we studied the faecal recovery of LCS in individuals who drank 125 ml of fermented milk which contained 10(10) live LCS for 3 days. The mean recovery was about 10(7) live bacteria per gram of faeces, indicating that LCS survived transit through the gastrointestinal tract after ingestion of the fermented milk.
干酪乳杆菌代田株（LCS）是一种用于生产发酵乳制品和乳酸菌制剂的益生菌。为了研究LCS在胃肠道中的存活情况，我们开发了一种选择性培养基和特异性单克隆抗体，用于分离和鉴定该菌株。选择性LLV琼脂培养基是通过对乳酸菌选择性培养基LBS培养基进行改良制备而成，用乳糖醇替代葡萄糖作为碳源，并使用万古霉素作为选择性抗生素。在LLV琼脂培养基中培养，然后使用针对LCS的特异性单克隆抗体进行酶联免疫吸附测定（ELISA），能够检测出粪便中的该微生物。使用这种方法，我们研究了饮用125毫升含有10¹⁰个活LCS的发酵乳3天的个体粪便中LCS的回收率。平均回收率约为每克粪便10⁷个活细菌，这表明摄入发酵乳后，LCS在通过胃肠道的过程中能够存活。
