Efficient production hyperoside from quercetin in Escherichia coli through increasing UDP‑galactose supply and recycling of resting cell

In this study, a recombinant strain was reconstructed by introducing an efficient UDP-galactose biosynthesis pathway and E. coli UDP-galactose/4-epimerase (GalE) to produce hyperoside from quercetin. Recycling of resting cell fermentation was used to improve hyperoside production. Finally, maximal hyperoside production reached equivalent to 18,000 mg/L by recycling 7 times of resting cell in 168 h, which was 393% of that in the batch fermentation and the first to reach 10 g per liter scale in E. coli.

本研究通过引入高效UDP-半乳糖生物合成途径（UDP-galactose biosynthesis pathway）与大肠杆菌UDP-半乳糖/4-差向异构酶（GalE），构建重组菌株以利用槲皮素（quercetin）生产金丝桃苷（hyperoside）。为提升金丝桃苷产量，本研究采用静止细胞发酵循环工艺。最终，在168小时内将静止细胞循环使用7次后，金丝桃苷最高产量可达18000 mg/L，为分批发酵产量的393%，且是大肠杆菌表达体系中首次达到10 g/L级别的产量。