REGULATION OF SUGAR TRANSPORT AND METABOLISM IN LACTIC ACID BACTERIA

从细胞中发现、分离和纯化了两种新的氨基酸 乳酸链球菌：N（5）-（1-羧乙基）鸟氨酸和 N（6）-（1-羧乙基）赖氨酸。 已获得结构确认 通过1-H和13-C核磁共振光谱（NMR），质量 光谱学和化学合成。 可能的体内途径 合成了两个新的化合物，已通过放射性示踪剂进行了鉴定。 方法和薄层荧光法。 第一次详细的研究 口腔厌氧微生物消化链球菌的糖转运 厌氧杆菌（革兰氏阳性）和具核梭杆菌（革兰氏阴性） 进行了。 这些细菌的葡萄糖转运依赖于 细胞外环境中存在特定氨基酸。 的 这种独特的氨基酸依赖性的生化基础，以及 能量与糖积累的耦合已经建立。 的 葡萄糖载体的特异性。nucleatum已被确定， 结构葡萄糖类似物的使用和糖原已被发现代表 细胞摄取葡萄糖的主要产物。 这些发现， 通过使用[14-C]葡萄糖和化学分析， 通过超微结构和形态学研究证实， 和相差显微镜。

Two new amino acids have been discovered, isolated and purified from cells of Streptococcus lactis: N(5)-(1-carboxyethyl)ornithine and N(6)-(1-carboxyethyl) lysine. Confirmation of structure has been obtained by 1-H and 13-C nuclear magnetic resonance spectroscopy (NMR), mass spectroscopy and by chemical synthesis. Probable routes of in vivo synthesis of the two novel compounds, have been elucidated by radiotracer procedures and by thin-layer fluorography. The first detailed studies of sugar transport by the oral anaerobic microorganisms Peptostreptococcus anaerobius (Gram-positive) and Fusobacterium nucleatum (Gram-negative) have been conducted. Glucose transport by these bacteria is dependent upon the presence of specific amino acids in the extracellular environment. The biochemical basis for this unique amino acid dependency, and the modes of energy coupling to sugar accumulation have been established. The specificity of the glucose carrier in F. nucleatum has been determined by use of structural glucose analogs, and glycogen has been found to represent the major product of glucose uptake by the cell. These findings, obtained by use of [14-C]glucose and chemical analysis, have been elegantly confirmed by ultrastructural and morphological studies involving electron- and phase-contrast microscopy.