2-Pyrone-4,6-dicarboxylic acid (PDC), a chemically stable pseudo-aromatic dicarboxylic acid, is a promising building block compound for manufacturing biodegradable polyesters. This study aimed to construct high-performance cell factories enabling the efficient production of PDC from glucose. Firstly, the effective enzymes of the PDC biosynthetic pathway were overexpressed on the chromosome of the 3-dehydroshikimate overproducing strain. Consequently, the one-step biosynthesis of PDC from glucose was achieved. Further, the PDC production was enhanced by multi-copy integration of the key gene PsligC encoding 4-carboxy-2-hydroxymuconate-6-semialdehyde dehydrogenase and co-expression of Vitreoscilla hemoglobin. Subsequently, the PDC production was substantially improved by redistributing the metabolic flux for cell growth and PDC biosynthesis based on dynamically downregulating the expression of pyruvate kinase. The resultant strain PDC50 produced 129.37 g/L PDC from glucose within 78 h under fed-batch fermentation conditions, with a yield of 0.528 mol/mol and an average productivity of 1.65 g/L/h. The findings of this study lay the foundation for the potential industrial production of PDC.

中文翻译：

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大肠杆菌的代谢工程，用于可生物降解聚酯单体 2-吡喃酮-4,6-二羧酸的高效生产


2-吡喃酮-4,6-二羧酸 （PDC） 是一种化学性质稳定的伪芳香族二羧酸，是一种很有前途的合成砌块化合物，可用于制造可生物降解聚酯。本研究旨在构建高性能细胞工厂，能够从葡萄糖中高效生产 PDC。首先，PDC 生物合成途径的有效酶在 3-脱氢莽草酸盐过生产菌株的染色体上过表达。因此，实现了从葡萄糖中一步生物合成 PDC。此外，编码 4-羧基-2-羟基粘康酸-6-半醛脱氢酶的关键基因 PsligC 的多拷贝整合和玻璃体血红蛋白的共表达增强了 PDC 的产生。随后，通过动态下调丙酮酸激酶的表达，重新分配细胞生长和 PDC 生物合成的代谢通量，PDC 产生得到显着改善。所得菌株 PDC50 在补料分批发酵条件下，在 78 h 内从葡萄糖中生产 129.37 g/L PDC，产量为 0.528 mol/mol，平均生产率为 1.65 g/L/h。这项研究的结果为 PDC 的潜在工业生产奠定了基础。