One-step fermentative production of aromatic polyesters from glucose by metabolically engineered Escherichia coli strains

Aromatic polyesters are widely used plastics currently produced from petroleum. Here we engineer Escherichia coli strains for the production of aromatic polyesters from glucose by one-step fermentation. When the Clostridium difficile isocaprenoyl-CoA:2-hydroxyisocaproate CoA-Transferase (HadA) and evolved polyhydroxyalkanoate (PHA) synthase genes are overexpressed in a d-phenyllactate-producing strain, poly(52.3 mol% 3-hydroxybutyrate (3HB)-co-47.7 mol% d-phenyllactate) can be produced from glucose and sodium 3HB. Also, various poly(3HB-co-d-phenyllactate) polymers having 11.0, 15.8, 20.0, 70.8, and 84.5 mol% of d-phenyllactate are produced from glucose as a sole carbon source by additional expression of Ralstonia eutropha β-ketothiolase (phaA) and reductase (phaB) genes. Fed-batch culture of this engineered strain produces 13.9 g l^-1 of poly(61.9 mol% 3HB-co-38.1 mol% d-phenyllactate). Furthermore, different aromatic polyesters containing d-mandelate and d-3-hydroxy-3-phenylpropionate are produced from glucose when feeding the corresponding monomers. The engineered bacterial system will be useful for one-step fermentative production of aromatic polyesters from renewable resources.