De novo biosynthesis of vanillin in engineered Saccharomyces cerevisiae

Abstract

Vanillin, an important aldehyde compound, is widely used in food and medicine industries. Natural and chemical-synthesized vanillin are facing significant challenge for the sustainabledevelopment.Here, de novo biosynthesis of vanillin inS. cerevisiaewas thus designed. Through integrating sam8, CYP199A2, comt, fcs and echinto the genome of S. cerevisiae, vanillin was successfully biosynthesized with a titer of 26.3 μg/L. Preferred sam5efficiently enriched caffeic acid pool, improving vanillin production to 50.2 μg/L in haploid engineered yeast. Expressing the mutants of ARO4 K229L and ARO7 G141S had reduced the negative feedback of tyrosine, increased the vanillin titer to 700 μg/L. Finally, the titer of vanillin was increased to 8545 μg/L through supplying 400 mg/L ferulic acid. The strategies of metabolic engineering and fermentation optimization achieved de novo biosynthesis of vanillin inS. cerevisiae, showing the feasibility of vanillin production by microbial technology.