earticle

영어

Flavonoids are plant secondary metabolites with pharmacological and nutraceutical properties. To expand the applicability of Streptomyces venezuelae as a heterologous host to plant polyketide production, flavonoid biosynthetic genes were expressed in an engineered strain of S. venezuelae DHS2001 bearing a deletion of native pikromycin polyketide synthase gene. A plasmid expressing the 4-coumarate/cinnamate:coenzyme A ligase from Streptomyces coelicolor (ScCCL) and the chalcone synthase from Arabidopsis thaliana (atCHS) under the control of a single ermE*promoter was constructed and introduced into S. venezuelae DHS2001. The resulting strain produced racemic naringenin and pinocembrin from 4-coumaric acid and cinnamic acid. Placement of an additional ermE* promoter upstream of the codon-optimized atCHS (atCHSop) gene increased the yield of naringenin and pinocembrin. Expression of codonoptimized chalcone isomerase gene from Medicago sativa, together with ScCCL and atCHSop genes led to production of (2S)-flavanones, but the yield was reduced. This is the first report on the heterologous expression of plant phenylpropanoid biosynthetic pathways in Streptomyces genus.