Laboratorio de Biotecnología Bacteriana, Instituto de Ciencia y Tecnología de Alimentos y Nutrición, CSIC, Madrid, Spain.
Mol Nutr Food Res. 2011 Oct;55(10):1454-65. doi: 10.1002/mnfr.201000621. Epub 2011 Jun 3.
To gain insight on the mechanisms used by intestinal bacteria to adapt and resist the antimicrobial action of dietary tannins and identify targets for tannic acid in Lactobacillus plantarum.
A proteomic analysis of an L. plantarum human isolate exposed to the tannic acid challenge was undertaken. Tannic acid targeted proteins involved in outstanding processes for bacterial stress resistance including cyclopropanation of membrane lipids, stress response at population scale and maintenance of cell shape. To respond to this aggression, tannic acid-misfit cells of L. plantarum challenged with tannic acid reorganized their metabolic capacity to economize energy and express proteins involved in oxidative stress defense and cell wall biogenesis, indicating that the injury incurred by tannic acid was based on oxidative damage and disruption of the cell envelope. The induction of 3-octaprenyl-4-hydroxybenzoate carboxy-lyase, which is sensitive to changes in redox conditions and involved in ubiquinone biosynthesis in other bacteria, suggests for a tannic acid-induced redox imbalance.
The results reveal the adaptation of a gastrointestinal isolate of L. plantarum to tannic acid and identify antibacterial targets for this dietary compound. This provides the basis for the selection of tannin-resistant microorganisms and their use to obtain health benefits from tannin-containing diets.
深入了解肠道细菌适应和抵抗膳食单宁抗菌作用的机制，并确定单宁酸在植物乳杆菌中的作用靶点。
对暴露于单宁酸挑战的植物乳杆菌人源分离株进行蛋白质组学分析。单宁酸靶向的蛋白质涉及细菌应激抗性的突出过程，包括膜脂的环丙烷化、群体水平的应激反应和细胞形状的维持。为了应对这种侵袭，单宁酸不匹配的植物乳杆菌细胞重新组织其代谢能力以节省能量，并表达涉及氧化应激防御和细胞壁生物发生的蛋白质，表明单宁酸造成的损伤基于氧化损伤和细胞 envelope 的破坏。3-辛基-4-羟基苯甲酸羧基-裂解酶的诱导，该酶对氧化还原条件的变化敏感，并且在其他细菌中参与泛醌生物合成，提示单宁酸诱导的氧化还原失衡。
研究结果揭示了植物乳杆菌胃肠道分离株对单宁酸的适应，并确定了这种膳食化合物的抗菌作用靶点。这为选择单宁酸抗性微生物及其用于从含单宁的饮食中获得健康益处提供了基础。
