Abstract Cadaverine is a five-carbon diamine which serves as an important biochemical for the synthesis of bio-based nylon. It can be produced by the bioconversion of l -lysine with lysine decarboxylase (CadA; EC 4.1.1.18) and relies on cofactor pyridoxal 5′-phosphate (PLP), thus to recycle PLP from the super-salvage pathway by the genes of pdxH, pdxY, and pdxK in Escherichia coli is crucial and urgent. In this study, the optimal PLP production per gram dry cell weight (i.e., 7008 nmol/g-DCW) increased 30-fold in E. coli BL21 by overexpressing pdxY. Cadaverine production reached 34.7 g/L or 41.2 g/L by in vivo CadA co-expression with plasmids of pJY or pPK. The better conversion was obtained in APK strain (co-expressing CadA and pPK) via whole cell biotransformation, resulting in 97 % and 68 % conversion of 0.4 M and 1.2 M L -lysine to 39.6 g/L and 83.2 g/L cadaverine, respectively. Finally, cold shock treatment of whole-cell biocatalyst showed a significant increasing and achieved the highest cadaverine productivity of 121 g/L/h compared to the previous reports.

中文翻译：

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通过冷休克处理增强大肠杆菌中吡哆醛 5'-磷酸依赖性蛋白，将 l-赖氨酸有效生物转化为尸胺

摘要 尸胺是一种五碳二胺，是合成生物基尼龙的重要生化物质。它可以通过 l-赖氨酸与赖氨酸脱羧酶 (CadA; EC 4.1.1.18) 的生物转化产生，并依赖辅因子吡哆醛 5'-磷酸 (PLP)，从而通过 pdxH 基因从超补救途径中回收 PLP 、 pdxY 和 pdxK 在大肠杆菌中至关重要且紧迫。在这项研究中，通过过表达 pdxY，大肠杆菌 BL21 中每克干细胞重量的最佳 PLP 产量（即 7008 nmol/g-DCW）增加了 30 倍。通过体内 CadA 与 pJY 或 pPK 质粒的共表达，尸胺产量达到 34.7 g/L 或 41.2 g/L。通过全细胞生物转化在 APK 菌株（共表达 CadA 和 pPK）中获得了更好的转化，导致 97% 和 68% 的 0.4 M 和 1.2 ML 赖氨酸转化为 39。分别为 6 g/L 和 83.2 g/L 尸胺。最后，与之前的报道相比，全细胞生物催化剂的冷休克处理显示出显着增加并实现了最高的尸胺生产率 121 g/L/h。