Hydroxytyrosol Biosynthesis in E. coli

DNA polymerase mix kits were purchased from Takara Bio, Inc. (Dalian, China) and YEASEN Biotechnology Co., Ltd. (Shanghai, China). Gibson assembly kit was purchased from GeneralBio Co., Ltd. (Anhui, China). Tyrosine, 4-hydroxyphenylpyruvate, 4-hydroxyphenylacetaldehyde, tyrosol, hydroxytyrosol, and L-dopa were all purchased from Sigma-Aldrich Co., Ltd. (St. Louis, MO, USA). E. coli BL21 (DE3) and W3110 were used for cloning and hydroxytyrosol biosynthesis, respectively. All E. coli strains were grown at 37 °C in yeast extract M9Y medium (M9 minimal salts (Becton, Dickinson and Company), 1% (w/v) glucose, 5 mM MgSO₄, 0.1 mM CaCl₂ supplemented with 0.025% (w/v) of yeast extract) [35 (link)]. Ampicillin (100 μg mL⁻¹) and kanamycin (50 μg/mL) were used when necessary.