(R)-3-Hydroxybutyric acid (R-3HB) is an important chiral chemical with extensive applications in the agricultural, food, and chemical industries. The synthesis of R-3HB by microbial fermentation is of interest due to its remarkable stereoselectivity and economy. However, the low production of R-3HB failed to meet the needs of large-scale industrial production. In this study, an engineered strain for the efficient biosynthesis of R-3HB was constructed through a three-pronged approach encompassing biosynthetic pathway optimization, engineering of NADPH regenerators, and central metabolism regulation. The engineered strain Q5081 produced 75.7 g/L R-3HB, with a productivity of 1.26 g/L/h and a yield of 0.34 g/g glucose in fed-batch fermentation, showing the highest reported titer and productivity of R-3HB to date. We also performed transcriptome sequencing and annotation to illustrate the mechanism underlying the enhanced R-3HB production. The systematic metabolic engineering by a three-pronged approach demonstrated the feasibility of improving the biosynthesis, and the engineered strain Q5081 has the potential for widespread applications in the industrial production of R-3HB.

中文翻译：

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通过三管齐下的方法进行大肠杆菌代谢工程生物生产 (R)-3-羟基丁酸


(R)-3-羟基丁酸(R-3HB)是一种重要的手性化学品，在农业、食品和化学工业中有着广泛的应用。通过微生物发酵合成R-3HB因其显着的立体选择性和经济性而引起人们的兴趣。但R-3HB产量较低，无法满足大规模工业化生产的需要。在本研究中，通过生物合成途径优化、NADPH再生器工程和中枢代谢调节三管齐下的方法构建了用于高效生物合成R-3HB的工程菌株。工程菌株 Q5081 在补料分批发酵中产生 75.7 g/L R-3HB，生产率为 1.26 g/L/h，葡萄糖产量为 0.34 g/g，显示了迄今为止报道的最高 R-3HB 滴度和生产率。日期。我们还进行了转录组测序和注释，以说明 R-3HB 产量增强的机制。三管齐下的系统代谢工程证明了改善生物合成的可行性，工程菌株Q5081在R-3HB的工业生产中具有广泛应用的潜力。