Establishment of a yeast platform strain for production of p-coumaric acid through metabolic engineering of aromatic amino acid biosynthesis

摘要

Aromatic amino acids are precursors of numerous plant secondary metabolites with diverse biological functions. Many of these secondary metabolites are already being used as active pharmaceutical or nutraceutical ingredients, and there are numerous exploratory studies of other compounds with promising applications. -Coumaric acid is derived from aromatic amino acids and, besides being a valuable chemical building block, it serves as precursor for biosynthesis of many secondary metabolites, such as polyphenols, flavonoids, and some polyketides. Here we developed a-coumaric acid-overproducing platform strain. First, we reduced by-product formation by knocking out phenylpyruvate decarboxylase and pyruvate decarboxylase . Second, different versions of feedback-resistant DAHP synthase and chorismate mutase were overexpressed. Finally, we identified shikimate kinase as another important flux-controlling step in the aromatic amino acid pathway by overexpressing enzymes from , homologous to the pentafunctional enzyme Aro1p and to the bifunctional chorismate synthase-flavin reductase Aro2p. The highest titer of -coumaric acid of 1.93±0.26 g L was obtained, when overexpressing tyrosine ammonia-lyase from , DAHP synthase , chorismate mutase and shikimate kinase II () in strain background. To our knowledge this is the highest reported titer of an aromatic compound produced by yeast. The developedstrain represents an attractive platform host for production of -coumaric-acid derived secondary metabolites, such as flavonoids, polyphenols, and polyketides.