Metabolic engineering of Escherichia coli for enhanced biosynthesis of polydatin

Polydatin is a bioactive stilbene with pharmaceutical potential, but its limited availability from natural sources poses a challenge for large-scale production. Here, we constructed an Escherichia coli strain capable of de novo biosynthesis of polydatin. A key bottleneck identified was the poor expression level of stilbene synthase (STS), which was addressed by screening heat shock proteins and promoter engineering, achieving a 50-fold increase in conversion capacity. Further optimization through chromosomal integration of glucosyltransferase led to an initial polydatin titer of 205.9 ± 4.9 mg/L. Enhancements in precursor supply, inactivation of competing pathways, and manipulation of the shikimate pathway improved polydatin titer to 3.8 ± 0.1 g/L. Finally, scale-up production in a 3-L fermentor coupled with optimization of key enzymes, malonyl-CoA availability and culture conditions, achieved a final titer of 14.9 ± 0.3 g/L. These results provide a robust framework for the efficient biosynthesis of high-value bioactive compounds in microbial cell factories.