【摘要】 大肠杆菌野生型菌株MC4100A经低能氮离子注入处理后,根据细胞排列方式定向筛选到了一株突变菌株ZSY。ZSY与MC4100A相比有很大的差异,细胞呈链状排列,丧失了细胞分裂后分离的能力;2%SDS对ZSY有一定的杀伤性;在厌氧状态下,失去了以甘油为碳源和TMAO为电子受体的生长能力。结果表明:突变株ZSY具有的一系列性状同编码双精氨酸转运系统受阻的菌株相同,因而ZSY的突变很可能发生在与细菌蛋白质Tat转运系统相关的基因上。特别有意义的是突变菌株在37℃下生长缓慢,难以形成菌落,而在4℃放置3天,可形成直径为0.5mm的菌落。更多还原

【Abstract】 Characteristics of Mutant Defective in the Twin-Arginine Translocation Pathway Characteristics of mutant ZSY have been investigated. After the strain of wild type MC4100 of Escheriochia coli was treated by low energy nitrogen ion beam implantation, mutant ZSY was obtained by the array of cells. Significant differences exist between ZSY and MC4100A. First, ZSY cells formed chains, which indicates a division defect in cells. Second, ZSY was also sensitive to SDS when the strain was streaked in the LB medium containing 2% SDS, showing the membrane of cell was not complete. More importantly, the mutant could not grow anaerobically with trimethylamine-N-oxide as sole terminal electron acceptor, indicting the failure to translocate the trimethylamine N-oxide (TMAO) reductase. The above results indicate that the properties of mutant ZSY are the same as those of tat mutant strains. Specifically, the mutant ZSY showed discernible growth phenotype. It grew very slowly at the temperature of 37℃ and was difficult to form colony. On the other hand, it formed colony with a diameter of 0.5mm after being placed at 4℃ for 3 days.更多还原