Figure 6

Production of hydroxystyrene derivatives by engineered tyrosine overproducing E. coli ΔCOS1 with engineered expression vectors. A HPLC profiles of standard 4-hydroxystyrene (a); 3,4-dihydroxystyrene (b); 4-hydroxy-3-methoxystyrene (c); the culture broth of tyrosine overproducing E. coli harboring pET-opTD (d); pET-opT5D (e); pET-opT5MD (f). The absorbance was monitored at 259 nm. Peak 5 4-hydroxystyrene, peak 6 3,4-dihydroxystyrene, peak 7 4-hydroxy-3-methoxystyrene. B The productivity of 4-hydroxystyrene (blue bar), 3,4-dihydroxystyrene (red bar), and 4-hydroxy-3-methoxystyrene (green bar) with pET-opTD, pET-opT5D, and pET-opT5MD in ΔCOS1 strain. Error bars indicate standard errors of the means (n = 3). The production of 4-hydroxystyrene, 3,4-dihydroxystyrene, 4-hydroxy-3-methoxystyrene in ΔCOS1 were compared with single-factor ANOVA (P < 0.05) using Microsoft Excel. A different letter code (triple asterisk) indicates significant difference (P = 5.66E−11).