Gamma-Aminobutyric acid (GABA) is a derivative of L-glutamate, also a precursor for the synthesis of 2-pyrrolidone, which is a monomer of nylon-4. This study achieved a one-step biosynthesis of GABA and 2-pyrrolidone by Halomonas bluephagenesis overexpressing key genes involved in GABA and 2-pyrrolidone synthesis and deleting GABA degradation genes combined with reducing the degradation of 2-pyrrolidone precursor. The resulting H. bluephagenesis strain WLp07 was employed in whole-cell catalysis, producing 357 g/L of GABA and 72 wt% of PHA. Furthermore, a self-flocculating H. bluephagenesis allowed rapid, convenient recycling of the cells, achieving 880 g/L of GABA over three cycles. Shake flask studies showed that engineered H. bluephagenesis harboring β-alanine CoA transferase was able to synthesized 2-pyrrolidone from GABA. H. bluephagenesis as a chassis of next generation industrial biotechnology (NGIB), demonstrated its diverse ability to produce GABA and 2-pyrrolidone in addition to intracellular PHA.

中文翻译：

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用于生产 γ-氨基丁酸和 2-吡咯烷酮的工程盐单胞菌


γ-氨基丁酸 （GABA） 是 L-谷氨酸的衍生物，也是合成 2-吡咯烷酮的前体，2-吡咯烷酮是尼龙-4 的单体。本研究通过卤单胞菌蓝噬作用实现了 GABA 和 2-吡咯烷酮的一步生物合成，过表达参与 GABA 和 2-吡咯烷酮合成的关键基因，并删除 GABA 降解基因，同时减少 2-吡咯烷酮前体的降解。所得的 H. bluephagenesis 菌株 WLp07 用于全细胞催化，产生 357 g/L 的 GABA 和 72 wt% 的 PHA。此外，自絮凝 H. bluephagenic 允许快速、方便地回收细胞，在三个循环中达到 880 g/L 的 GABA。摇瓶研究表明，含有 β-丙氨酸辅酶 A 转移酶的工程化蓝噬菌生成能够从 GABA 合成 2-吡咯烷酮。H. bluephagenesis 作为下一代工业生物技术 （NGIB） 的底盘，证明了其除细胞内 PHA 外产生 GABA 和 2-吡咯烷酮的多种能力。