De Novo Biosynthesis of Sakuranetin from Glucose by Engineered
Sakuranetin is a plant-natural product, which has increasingly been
utilized in cosmetic and pharmaceutical industries for its extensive
anti-inflammatory, anti-tumor, and immunomodulatory effects. Sakuranetin
was mostly produced via extraction technology from plants, which is
limited to natural conditions and biomass supply. In this study, a novel
strategy to produce sakuranetin via de novo synthesis from
glucose by engineering S. cerevisiae was introduced .
After a series of heterogenous genes integration, a biosynthetic pathway
of sakuranetin from glucose was successfully constructed in S.
cerevisiae which sakuranetin yield reached only 4.28 mg/L. Then, a
multi-module metabolic engineering strategy was applied for improving
sakuranetin yield in S. cerevisiae: (1) adjusting the copy number
of sakuranetin synthesis genes; (2) removing the rate-limiting factor of
aromatic amino pathway and optimizing the synthetic pathway of aromatic
amino acids to enhance the supply of carbon flux for sakuranetin; (3)
introducing acetyl-CoA carboxylase mutants
ACC1S659A, S1157A, and knocking-out
YPL062W to strengthen the supply of malonyl-CoA which is another
synthetic precursor of sakuranetin. The resultant mutant S.
cerevisiae exhibited a more than 10-fold increase of sakuranetin titer
(50.62 mg/L) in shaking flasks. Furthermore, the sakuranetin titer
increased to 158.65 mg/L in a 1-L bioreactor, which is the highest
sakuranetin titer among all publications reported yield of the
engineered microbial cell.