Figure 5
Production of phenolic acids by engineered tyrosine overproducing E. coli ΔCOS1 with engineered expression vectors. A HPLC profile of the standard 4-coumaric acid (a), caffeic acid (b), and ferulic acid (c); the culture broth of tyrosine overproducing E. coli ΔCOS1 harboring pET-opTAL (d); pET-opT5 (e); pET-opT5 M (f). The absorbance was monitored at 300 nm. Peak 1 4-coumaric acid, peak 2 caffeic acid, peak 3 ferulic acid. B The production of 4-coumaric acid (diagonal blue), caffeic acid (diagonal red), ferulic acid (diagonal green) with pET-opTAL, pET-opT5 and pET-opT5 M in mutant ΔCOS1 strain. Error bars indicate standard errors of the means (n = 3). The production of 4-coumaric acid, caffeic acid and ferulic acid in ΔCOS1 were compared with single-factor ANOVA (P < 0.05) using Microsoft Excel. A different letter code (double asterisk) indicates significant difference (P = 2.25E−08).