This study reports on the improving of muconic acid (MA) production by using metabolically engineered Escherichia coli. Three MA synthesis pathways separately were introduced into E. coli. After 72 h of cultivation, two of the three strains, i.e., one carrying the Pathway 1 (1.00 g/L) and the other carrying the Pathway 3 (1.34 g/L) produced MA. To increase MA production, the enzymes of the shikimate pathway (AroC and AroD) were overexpressed in these strains. Although the overexpression of AroC increased the MA production (1.59 g/L) by the Pathway 1, AroD overexpression decreased it by the Pathway 3. The metabolic channeling using gene-level fusion proteins additionally increased the MA production. In the pathway 1 and pH-controlled cultures, the overexpression of a fusion protein (AroC and MenF) increased the MA production from 20 g/L glucose to >3 and 4.45 g/L, respectively. These results suggest that the metabolic channeling approach is a promising strategy to increase the yield of the target compound.

中文翻译：

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利用基因水平融合蛋白在大肠杆菌中生产粘康酸

这项研究报告了通过使用代谢工程大肠杆菌改善粘康酸（MA）的生产。三种MA合成途径分别引入大肠杆菌。培养72小时后，三个菌株中的两个，即，其中一种携带途径1（1.00 g / L），另一种携带途径3（1.34 g / L）产生MA。为了增加MA的产生，在这些菌株中过表达the草酸途径的酶（AroC和AroD）。尽管通过途径1的AroC过表达增加了MA的产量（1.59 g / L），但是通过途径3的AroD过度表达降低了它的水平。使用基因水平融合蛋白进行的代谢通道额外增加了MA的产量。在途径1和pH受控的培养物中，融合蛋白（AroC和MenF）的过表达将MA的产生分别从20 g / L葡萄糖增加到> 3和4.45 g / L。这些结果表明，代谢通道方法是增加目标化合物产率的有前途的策略。