Efficient De Novo Biosynthesis of Curcumin in Escherichia coli by Optimizing Pathway Modules and Increasing the Malonyl-CoA Supply

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 threestage 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.

Improving Production of Coniferyl Alcohol in Escherichia coli by Regulating the Multiple Cofactors and Efflux of Intermediates

“…The final coniferyl alcohol production in the resultant strain was noted to be much higher than the previously reported levels. , Heterologous expression of srpB alleviated the toxicity of ferulic acid and promote the biosynthesis of curcumin in E. coli . It has been reported that a HucR-based dynamic regulation system can be combined to control metabolic flux to reduce excessive accumulation of ferulic acid .…”

“…SrpB was also used to alleviate the effect of ferulic acid on the biosynthesis of curcumin in E. coli, resulting in an increase in curcumin production from 113.6 to 137.5 mg/L . Overexpression of ompF (encoding outer membrane pore protein) has been reported to significantly enhance the biosynthesis of polyphenol resveratrol in E.…”

De Novo Biosynthesis of Curcumin in Saccharomyces cerevisiae

“…Prior to our study, de novo curcumin biosynthesis had only been achieved in genetically modified E. coli. , …”

“…However, curcumin has only been synthesized from simple carbon sources in genetically modified E. coli . 12 , 21 E. coli is not a Generally Regarded As Safe (GRAS) organism, and the expression of the heterologous genes usually relies on the use of plasmids, which require constant selective antibiotic pressure for maintaining, and the supplementation of expensive inductors, which is also not desirable. The yeast S. cerevisiae is a role model microorganism for genetic engineering purposes due to its safety status and clear metabolic pathways.…”