Efficient <i>De Novo</i> Biosynthesis of Curcumin in <i>Escherichia coli</i> by Optimizing Pathway Modules and Increasing the Malonyl-CoA Supply
Jianbin Chen, Weigao Wang, Lian Wang, Huijing Wang, Minglong Hu, Jingwen Zhou, Guocheng Du, Weizhu Zeng
Abstract
Curcumin is a natural phenylpropanoid compound with various biological activities and is widely used in food and pharmaceuticals. A de novo curcumin biosynthetic pathway was constructed in Escherichia coli BL21(DE3). Optimization of the curcumin biosynthesis module achieved a curcumin titer of 26.8 ± 0.6 mg/L. Regulating the metabolic fluxes of the β-oxidation pathway and fatty acid elongation cycle and blocking the endogenous malonyl-CoA consumption pathway increased the titer to 113.6 ± 7.1 mg/L. Knockout of endogenous curcumin reductase ( curA ) and intermediate product detoxification by heterologous expression of the solvent-resistant pump ( srpB ) increased the titer to 137.5 ± 3.0 mg/L. A 5 L pilot-scale fermentation, using a three-stage pH alternation strategy, increased the titer to 696.2 ± 20.9 mg/L, 178.5-fold higher than the highest curcumin titer from de novo biosynthesis previously reported, thereby laying the foundation for efficient biosynthesis of curcumin and its derivatives.