Taranto María Pía, Perez-Martinez Gaspar, Font de Valdez Graciela
Centro de Referencia para Lactobacilos (CERELA), CONICET, Chacabuco 145, San Miguel de Tucumán, T4000ILC, Tucumán, Argentina.
Res Microbiol. 2006 Oct;157(8):720-5. doi: 10.1016/j.resmic.2006.04.002. Epub 2006 May 2.
Lactic acid bacteria and other species dwelling in the gut must be tolerant to bile salts. This study sought to determine the effects of the bile salts taurodeoxycholate (TDCA) and deoxycholate (DCA) on Lactobacillus reuteri CRL 1098, a strain of likely probiotic value. When compared to other lactobacilli, L. reuteri showed the highest survival rate but remained sensitive to high (>3 mM) DCA concentrations. DCA produced complete permeabilization of cells, abolished glucose uptake and severely distorted the cell envelope, as shown by electron microscopy. Detailed analytical studies revealed a change in the phospholipid to glycolipid ratio, and also in lipid proportions. The C18:1 W9C form remarkably increased, possibly following a rapid adaptive response during DCA treatment. This study provides the first solid evidence of the mechanism of DCA toxicity in a lactic acid bacterium.
栖居于肠道的乳酸菌及其他菌种必须耐受胆盐。本研究旨在确定牛磺脱氧胆酸盐（TDCA）和脱氧胆酸盐（DCA）这两种胆盐对具有潜在益生菌价值的罗伊氏乳杆菌CRL 1098的影响。与其他乳酸杆菌相比，罗伊氏乳杆菌显示出最高的存活率，但对高浓度（>3 mM）的DCA仍敏感。如电子显微镜所示，DCA导致细胞完全通透化，消除了葡萄糖摄取，并严重扭曲了细胞包膜。详细的分析研究揭示了磷脂与糖脂比例以及脂质比例的变化。C18:1 W9C形式显著增加，这可能是在DCA处理期间快速适应性反应之后出现的。本研究首次提供了DCA对乳酸菌毒性机制的确凿证据。
