Ruiz Lorena, Sánchez Borja, Ruas-Madiedo Patricia, de Los Reyes-Gavilán Clara G, Margolles Abelardo
Departamento de Microbiología y Bioquímica de Productos Lácteos, Consejo Superior de Investigaciones Científicas, Villaviciosa, Asturias, Spain.
FEMS Microbiol Lett. 2007 Sep;274(2):316-22. doi: 10.1111/j.1574-6968.2007.00854.x. Epub 2007 Jul 25.
Bifidobacterium animalis ssp. lactis is a probiotic frequently used as adjunct culture in fermented dairy products. In order to ensure its proper function at the intestinal level, this bacterium has to be tolerant to physiological concentrations of bile. This study examined the influence of bile on the fatty acid composition and the membrane characteristics of B. animalis IPLA 4549 and its mutant with acquired resistance to bile, B. animalis 4549dOx. Bile adaptation triggers in B. animalis 4549dOx a decrease in membrane fluidity and in the protein : phospholipid ratio, as well as a shift in the fatty acid composition of the cell. Remarkably, the presence of bile in the growth medium induced similar changes in both B. animalis cells. Furthermore, transmission electron microscopy analysis showed that bile promotes a severe distortion of the cell surface. This study provides new insights of the action of bile on the cell envelope of bifidobacteria.
动物双歧杆菌乳酸亚种是一种常用于发酵乳制品的益生菌。为了确保其在肠道水平的正常功能，这种细菌必须耐受生理浓度的胆汁。本研究考察了胆汁对动物双歧杆菌IPLA 4549及其获得性胆汁抗性突变体动物双歧杆菌4549dOx的脂肪酸组成和膜特性的影响。胆汁适应导致动物双歧杆菌4549dOx的膜流动性和蛋白质:磷脂比率降低，以及细胞脂肪酸组成的变化。值得注意的是，生长培养基中胆汁的存在在两种动物双歧杆菌细胞中诱导了类似的变化。此外，透射电子显微镜分析表明，胆汁会导致细胞表面严重变形。本研究为胆汁对双歧杆菌细胞壁的作用提供了新的见解。
