Fig. 2

Design and build a minimal aromatic aldehyde reduction (MARE) yeast platform. a Schematic diagram showing different sets of oxidoreductases for deletion to reduce vanillin conversion to vanillyl alcohol. b The vanillin stability test using engineered S. cerevisiae. JS-MARE1 involves the knockout of group 1 oxidoreductases together with ∆hfd1:ubiC. JS-MARE2 is a JS-MARE1 derivative with the knockout of group 2 oxidoreductases. JS-MARE3 is a JS-MARE2 derivative by further deleting group 3 oxidoreductases. Cells were harvested after 24 h cultivation in SC media. Equal amounts of cells were resuspended into potassium-phosphate buffer (pH 8.0) with 2% glucose + 5 mM of vanillin to a final OD600 of 10. Samples were monitored at regular intervals (4, 8, 24, 48 h) using gas chromatography. c The deletion of oxidoreductases did not compromise the growth of engineered yeasts. Control, the parental strain of JS-CR (2 M)