Production of Carminic Acid by Metabolically Engineered <i>Escherichia coli</i>

Carminic acid is an aromatic polyketide found in scale insects (i.e., Dactylopius coccus) and a widely used natural red colorant. It has long been produced by the cumbersome farming of followed multistep purification processes. Thus, there much interest producing carminic fermentation engineered bacteria. Here we report complete biosynthesis from glucose Escherichia coli. We first optimized type II synthase machinery Photorhabdus luminescens, enabling high-level production flavokermesic upon coexpression cyclases ZhuI ZhuJ Streptomyces sp. R1128. To discover enzymes responsible for remaining two reactions (hydroxylation C-glucosylation), biochemical reaction analyses were performed testing enzyme candidates reported to perform similar reactions. The identified enzymes, aklavinone 12-hydroxylase (DnrF) peucetius C-glucosyltransferase (GtCGT) Gentiana triflora, could successfully hydroxylation C-glucosylation acid, respectively. Then, homology modeling docking simulations enhance activities these leading generation beneficial mutants with 2-5-fold enhanced conversion efficiencies. In addition, GtCGT mutant was be generally applicable E. coli, as showcased successful aloesin Aloe vera. Simple metabolic engineering fed-batch resulted 0.63 ± 0.02 mg/L glucose. strategies described here will useful design construction biosynthetic pathways involving unknown consequently diverse industrially important products.