High-level production of trans -cinnamic acid by fed-batch cultivation of Escherichia coli

•Trans-cinnamic acid has been widely used with various applications.•Trans-cinnamic acid pathway was reconstructed by optimization of PAL gene expression in E. coli.•With the engineered strain, 650 mg/L trans-cinnamic acid was produced in flask cultivation.•By the optimization of feeding solution, trans-cinnamic acid could be produced as high as 6.9 g/L in fed-batch cultivation.