Kakuda H, Shiroishi K, Hosono K, Ichihara S
Laboratory of Microbiology, School of Agriculture, Nagoya University, Japan.
Biosci Biotechnol Biochem. 1994 Dec;58(12):2232-5. doi: 10.1271/bbb.58.2232.
Escherichia coli grown in a rich medium excreted acetate and reused the acetate. Using cloned genes and a plasmid with a temperature-sensitive replication origin, three kinds of Pta-Ack pathway deletion mutants were constructed. Acetate production and reuse by wild-type cells grown in the rich medium was confirmed to largely occur through the Pta-Ack pathway. The deletion mutants of the gene encoding phosphotransacetylase secreted pyruvate before the secretion of acetate into the medium. A deletion mutant of the gene encoding acetate kinase grew at a slow rate, but its secretion and use of acetate were rapid. These results indicated that a pathway(s), other than the Pta-Ack pathway, functions in the control of excess carbon flow in the mutants.
在丰富培养基中生长的大肠杆菌会分泌乙酸盐并重新利用乙酸盐。利用克隆基因和带有温度敏感型复制起点的质粒，构建了三种磷酸转乙酰酶-乙酸激酶（Pta-Ack）途径缺失突变体。在丰富培养基中生长的野生型细胞产生和重新利用乙酸盐的过程被证实主要通过Pta-Ack途径发生。编码磷酸转乙酰酶的基因缺失突变体在乙酸盐分泌到培养基之前先分泌丙酮酸。编码乙酸激酶的基因缺失突变体生长缓慢，但其乙酸盐的分泌和利用速度很快。这些结果表明，除Pta-Ack途径外，还有其他途径在控制突变体中过量碳流方面发挥作用。
