Li Jinhui, Xing Yi, Wang Xin, Zhu Tong, Fan Feiyu, Xu Hongtao, Han Peipei, Cai Jun, Zhu Xinna, Zhang Xueli
College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China.
Haihe Laboratory of Synthetic Biology, Tianjin, China.
Biotechnol Bioeng. 2025 Oct;122(10):2850-2861. doi: 10.1002/bit.70018. Epub 2025 Jul 10.
Butyric acid is a four-carbon fatty acid with a range of applications in chemical, food and pharmaceutical industries. In this study, a heterologous butyrate biosynthetic pathway was engineered in Escherichia coli, which was afflicted by low titer and low yield. To address these issues, two key strategies for metabolic engineering of E. coli were implemented by enhancing coenzyme A (CoA) biosynthesis and optimizing butyrate transport. First, the CoA biosynthesis pathway was engineered through alleviating CoA-mediated inhibition, and enhancing the supply of pantothenate and cysteine precursors. Second, a TolC-associated MdtEF efflux pumps was identified and optimized to mitigate butyrate reuptake. The combined implementation in strain JH016 led to 11.1-fold and 86% increase of butyrate titer and yield, resulting in production of 21.12 g/L butyrate with a yield of 0.95 mol/mol. Our results suggested that CoA engineering and butyrate transporter optimization had a synergistic effect on butyrate production. Furthermore, these strategies could be broadly utilized for the production of various other useful chemicals in the fields of metabolic engineering and synthetic biology.
丁酸是一种四碳脂肪酸，在化学、食品和制药行业有一系列应用。在本研究中，在产量低、产率低的大肠杆菌中构建了一条异源丁酸生物合成途径。为了解决这些问题，通过增强辅酶A（CoA）生物合成和优化丁酸转运，实施了大肠杆菌代谢工程的两个关键策略。首先，通过减轻CoA介导的抑制作用，并增加泛酸和半胱氨酸前体的供应，对CoA生物合成途径进行了改造。其次，鉴定并优化了一种与TolC相关的MdtEF外排泵，以减少丁酸的再摄取。在菌株JH016中的联合实施使丁酸滴度和产率分别提高了11.1倍和86%，产生了21.12 g/L的丁酸，产率为0.95 mol/mol。我们的结果表明，CoA工程和丁酸转运体优化对丁酸生产具有协同作用。此外，这些策略可广泛用于代谢工程和合成生物学领域中各种其他有用化学品的生产。
