One-step fermentative production of polylactic acid

In 2004, LG Chem and KAIST, Daejeon, Korea, initiated a joint project L-Project to develop a process to make polylactic acid (PLA) via metabolically engineered bacteria. In the new one-step process lactic acid is used immediately by a strain of E. Coli that has been engineered to efficiently synthesize PLA and its copolymers form glucose and accumulate these polymers as distinct granules in the cytoplasm. Early staged of the L-Project investigated the ability of several PHA syntheses to incorporate various PHA monomers into the PLA backbone polymer to create novel PLA copolymers with better material properties. After the synthetic PLA biosynthesis pathway was established in E. Coli, the metabolic fluxes were optimized to supply enough substrates for polymer biosynthesis. In these engineered E. Coli strains, the lactyl-CoA biosynthesis pathway was strengthened, and metabolic pathways that use acetyl-CoA as a precursor was removed