Centro de Referencia para Lactobacilos (CERELA-CONICET), Chacabuco 145, San Miguel de Tucumán, Argentina.
Biotechnol Lett. 2011 Jul;33(7):1389-94. doi: 10.1007/s10529-011-0564-1. Epub 2011 Mar 2.
To apply a fluorescent dye as an alternative technique to evaluate the survival of potentially probiotic lactobacilli to bile acids (BA) as first step in the design of probiotic functional foods. The use of lactic acid bacteria (LAB) in the functional food design depends on their ability to survive in the gastrointestinal tract where bile is an important natural barrier. Bile is mainly constituted by conjugated BA, which can be hydrolyzed to free BA and taurine or glycine. Changes in the transmembrane electrical potential (ΔΨ) of probiotic LAB strains due to the effect of conjugated and free BA were measured and showed that the majority of the tested LAB strains had greater sensibility to free BA than to their respective conjugated acids. Variations in the ΔΨ of the microorganism correlated well with bacterial viability determined by standard plate count method. We therefore propose the DiSC(3)-based fluorescent technique as a rapid and effective method to evaluate the resistance of probiotic lactobacilli to bile as first step for strain selection to be included in functional foods.
为了将荧光染料作为替代技术应用于评估潜在益生菌乳杆菌对胆汁酸（BA）的生存能力，作为益生菌功能性食品设计的第一步。在功能性食品设计中使用乳酸菌（LAB）取决于其在胃肠道中生存的能力，而胆汁是一个重要的天然屏障。胆汁主要由结合型 BA 组成，可被水解为游离 BA 和牛磺酸或甘氨酸。通过测量益生菌 LAB 菌株的跨膜电势能（ΔΨ）变化，发现大多数测试的 LAB 菌株对游离 BA 的敏感性大于各自的结合酸。微生物 ΔΨ 的变化与标准平板计数法确定的细菌活力相关性良好。因此，我们提出基于 DiSC(3)的荧光技术作为一种快速有效的方法来评估益生菌乳杆菌对胆汁的抗性，作为选择用于功能性食品的菌株的第一步。
