(280c) Enhancing Flavonoid Production By Metabolically Engineered Microbial Co-Cultures

Flavonoids are a family of secondary plant metabolites with recognized nutraceutical and pharmacological values. Most of the flavonoids are produced mainly by extraction from plants, which suffers from unstable production efficiency and high process cost. In this study, two flavonoids, sakuranetin and pinocembrin, were biosynthesized from simple carbon substrate by rationally designed E. coli-E. coli co-cultures, respectively. The biosynthetic pathways, consisting of E. coli native enzymes several heterologous enzymes, were divided into two distinct modules; each module was accommodated in a metabolically engineered E. coli strain. For biosynthetic pathway balancing, the pathway gene expression levels and co-culture strains inoculation ratios were optimized. The engineered co-culture systems were capable of producing sakuranetin and pinocembrin at concentrations significantly higher than those achieved by the conventional monoculture approach. In addition, sakuranetin biosynthetic pathway was further modularized in the context of three-strain co-cultures. The optimization of cultivation conditions for these co-cultures resulted in elevated production yields, which are the highest for de novo sakuranetin and pinocembrin biosynthesis reported to date. This study demonstrates the strong applicability of co-culture engineering in complex natural product biosynthesis.