Fig. 4.
Using the bifunctional E. coli enzyme PheAfbr for mandelic acid production in an aro7Δ S. cerevisiae strain. A) Growth test with MRY36 (CEN.PK2-1C TRP1 Shik↑ aro10Δ aro8Δ pdc5Δ aro7Δ) cells harboring different plasmid combinations on SMD with and without supplementation of aromatic amino acids. Cell dilutions of OD600 1, 10−1, 10−2 and 10−3 (from left to right, respectively) were used. The picture was taken after 3d at 30 °C. EV, empty vector. B), C) and D) Production of mandelic acid (MA, B), hydroxymandelic acid (HMA, C) and phenylacetic acid + phenylethanol (PAA+PET, D) by the aro7Δ strain MRY36 expressing either pheAfbr and hmaS (red) or ARO7fbr, PHA2 and hmaS (blue). E) Fermentation with the aro7Δ strain MRY36 harboring the hmaS-pheAfbr plasmid MRV144. MA, glucose and ethanol titers and OD600 in SMD without supplementation of aromatic amino acids. The fermentations were performed in SMD (20 g/L glucose) without supplementation aromatic amino acids and with a starting OD600 of 5. Error bars indicate standard deviation of biological duplicates (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article).