Development of metabolic engineering strategies for the enhanced production of lycopene

Abstract

Lycopene is red-colored open-chain unsaturated carotenoid, which is an intermediate compound for many isoprenoid derivatives. Lycopene biosynthesis genes (crtE, crtB and crtI) of Erwinia uredovora was introduced into Escherichia coli for the efficient production of lycopene. In addition, the dxs gene involving in the biosynthesis of lycopene precursor (IPP) was co-overexpressed with lycopene biosynthesis genes. While 226.38 mg/L of lycopene was obtained by DO-stat fermentation of metabolically engineered E. coli, lycopene content was still low (4.83 mg/g DCW). It might be due to insufficient supply of lycopene precursors such as G3P and pyruvate. Therefore, amplification of glycolytic flux and Entner-Doudoroff pathway flux through overexpression of related enzymes fba and tpiA for glycolysis, eda for ED pathway was examined. As a result, 13.25 mg/L of lycopene was produced with 9.84 mg/g of lycopene content when eda was co-overexpressed with dxs in E. coli. These results showed that the amplification of ED pathway is a good strategy for the efficient production of isoprenoids by allowing the increase of precursor supply.