A novel expression system enabling scalable production of glycosylated flavonoids in Escherichia coli W using a plant-derived toxic gene

Abstract

Glycosylated flavonoids are plant-derived compounds of significant interest due to their enhanced solubility, stability, and bioavailability, offering therapeutic potential across pharmaceutical, nutraceutical, and cosmetic sectors. However, their complex biosynthesis in plants hinders scalable production. In this study, we present an innovative microbial platform based on a phosphate-responsive Pliar53 promoter system in non-model chassis Escherichia coli W to enable efficient, regulated heterologous expression of the SbaiC7OGT gene from Scutellaria baicalensis. This platform circumvents common limitations associated with conventional inducible systems that rely on costly or toxic chemical inducers. The engineered E. coli SBG2413 strain demonstrated high titers of naringenin-7-O-glucoside (prunin) and exhibited broad substrate compatibility for the biosynthesis of other flavonoid glycosides. Our findings establish a cost-effective, scalable solution for industrial production of glycosylated flavonoids, with potential applicability to co-culture systems and microbial consortia. Highlights- A phosphate-response gene expression system (Pliar53) enables stable expression of a toxic flavonoid glycosyltransferase. - Translational optimization using the bicistronic BCD2 RBS and high-copy plasmids boosts prunin production from naringenin. - E. coli W SBG2413strain achieves > 9 g/L prunin in fed-batch bioreactor with 70% conversion. - The platform developed allows efficient glycosylation of structurally diverse flavonoids including flavones, flavanones, and isoflavones.