Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China.
Bioresour Technol. 2024 Dec;413:131448. doi: 10.1016/j.biortech.2024.131448. Epub 2024 Sep 5.
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.
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。本研究通过过度表达参与 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，实现了由 Halomonas bluephagenesis 一步生物合成 GABA 和 2-吡咯烷酮。由此产生的 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，自絮凝的 H. bluephagenesis 允许细胞快速、方便地回收，在三个循环中实现了 880 g/L 的 GABA。摇瓶研究表明，携带β-丙氨酸 CoA 转移酶的工程化 H. bluephagenesis 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，除了能够在细胞内产生 PHA 外，还展示了其生产 GABA 和 2-吡咯烷酮的多种能力。
