5-hydroxyvaleric acid (5-HV) is a versatile C5 intermediate of bio-based high-value chemical synthesis pathways. However, 5-HV production faces a few shortcomings involving the supply of cofactors, especially α-ketoglutaric acid (α-KG). Herein, we established a two-cell biotransformation system by introducing glutamate oxidase (GOX) to regenerate α-KG. Additionally, the catalase KatE was adapted to inhibit α-KG degradation by the HO produced during GOX reaction. We searched for the best combination of genes and vectors and optimized the biotransformation conditions to maximize GOX effectiveness. Under the optimized conditions, 5-HV pathway with GOX showed 1.60-fold higher productivity than that of without GOX, showing 11.3 g/L titer. Further, the two-cell system with GOX and KatE was expanded to produce poly(5-hydroxyvaleric acid) (P(5HV)), and it reached at 412 mg/L of P(5HV) production and 20.5% PHA contents when using the biotransformation supernatant. Thus, the two-cell biotransformation system with GOX can potentially give the practical and economic alternative of 5-HV production using bio-based methods. We also propose direct utilization of 5-HV from bioconversion for P(5HV) production.

中文翻译：

---

α-酮戊二酸再生高效5-羟基戊酸生产体系的建立及其在聚5-羟基戊酸生产中的应用

5-羟基戊酸 (5-HV) 是一种生物基高价值化学合成途径的多功能 C5 中间体。然而，5-HV 的生产面临一些涉及辅因子供应的缺点，尤其是 α-酮戊二酸 (α-KG)。在此，我们通过引入谷氨酸氧化酶（GOX）来再生α-KG，建立了双细胞生物转化系统。此外，过氧化氢酶 KatE 适合抑制 GOX 反应过程中产生的 H2O 降解 α-KG。我们寻找基因和载体的最佳组合，并优化生物转化条件，以最大限度地提高 GOX 的有效性。在优化条件下，含有GOX的5-HV途径的生产率比不含GOX的5-HV途径高1.6倍，效价为11.3 g/L。此外，GOX和KatE的双细胞系统被扩展以生产聚(5-羟基戊酸)(P(5HV))，并且使用时P(5HV)产量达到412 mg/L，PHA含量达到20.5%生物转化上清液。因此，具有 GOX 的双细胞生物转化系统有可能为使用生物方法生产 5-HV 提供实用且经济的替代方案。我们还建议直接利用生物转化产生的 5-HV 来生产 P(5HV)。