*4.7. In vivo Bioconversion of 3-(2,4-Dihydroxyphenyl)-propionic Acid*

*E. coli* BL21 (DE3) bacteria, containing p4pmPmo and pTHPPDO plasmids, were grown in 200 mL of BHI medium at 30 ◦C and 180 rpm overnight. High density bacterial culture was centrifuged and resuspended in 200 mL of minimal C-750501 medium, in which synthesis of proteins was induced with 1 mM of IPTG at 20 ◦C and 180 rpm [65]. After 24 h of induction 3-(2,4-dihydroxyphenyl)-propionic acid was added to the final concentration of 4 mM. Bioconversion mixture was incubated for another 3 days at 30 ◦C with shaking. Cells were removed by centrifugation for 30 min at 3220× *g* and the supernatants were kept at 4 ◦C.
