Abstract: Provided is a mutant of propionyl-CoA transferase from Clostridium propionicum that can convert lactate into lactyl-CoA with high efficiency in a method of preparing a polylactate (PLA) or PLA copolymer using microorganisms. Unlike conventional propionyl-CoA transferase which is weakly expressed in E. coli, when a mutant of propiony-CoA transferase from Clostridium propionicum is introduced into recombinant E. coli, lactyl-CoA can be supplied very smoothly, thereby enabling highly efficient preparation of polylactate (PLA) and PLA copolymer.

Abstract: The present invention relates to a copolymer comprising 3-hydroxyalkanoate monomer unit and lactate monomer unit, or their preparing method. More specifically, the present invention relates to a method for preparing a copolymer comprising lactate monomer and 3-hydroxyalkanoate monomer, wherein the method comprises culturing a cell or plant comprising the gene of enzyme converting lactate and 3-hydroxyalkanoate into lactyl-CoA and 3-hydroxyalkanoyl-CoA, respectively, and polyhydroxyalkanoate synthase gene together, and the copolymer made by the method. The copolymer of the present invention is a biodegradable polymer being able to be usefully used instead of conventional synthetic plastic, and the copolymer can be used also for medical use.

Abstract: Provided are a microorganism capable of producing a polylactate (PLA) or PLA copolymer from sucrose and a method of producing the PLA or PLA copolymer from sucrose using the same. A gene of an enzyme converting lactate into lactyl-CoA and a gene of a polyhydroxyalkanoate (PHA) synthase using lactyl-CoA as a substrate are introduced into a microorganism capable of using sucrose as a substrate, and the microorganism is cultured using sucrose as the substrate, thereby allowing efficient production of a PLA or PLA copolymer.

Abstract: The present invention relates to a copolymer comprising 4-hydroxybutyrate monomer unit and lactate monomer unit, a copolymer 4-hydroxybutyrate monomer unit, lactate monomer unit and 3-hydroxyalkanoate, or their preparing method. More specifically, the present invention relates to a method for preparing a copolymer comprising lactate monomer; 4-hydroxybutyrate monomer; and optionally 3-hydroxyalkanoate, wherein the method comprises culturing a cell or plant comprising the gene of enzyme converting lactate and 3-hydroxyalkanoate into lactyl-CoA and 3-hydroxyalkanoyl-CoA, respectively, phosphotransbutylase gene, butyrate kinase gene and polyhydroxyalkanoate synthase gene together, and the copolymer made by the method. The copolymer of the present invention is a biodegradable polymer being able to be usefully used instead of conventional synthetic plastic, and the copolymer can be used for medical use.

Abstract: Provided are a recombinant microorganism capable of producing polylactate (PLA) or hydroxyalkanoate-lactate copolymers and a method of preparing PLA or hydroxyalkanoate-lactate copolymers using the same. The recombinant microorganism has both a gene encoding a propionyl-CoA transferase from Megasphaera elsdenii and a gene encoding a polyhydroxyalkanoate (PHA) synthase using lactyl-CoA as a substrate. A propionyl-CoA transferase from Megasphaera elsdenii is introduced into the recombinant microorganism to effectively provide lactyl-CoA, thereby enabling efficient preparation of PLA or PLA copolymers.

Abstract: The present invention relates to polyhydroxyalkanoate synthase (PHA synthase) mutant originated from Pseudomonas sp. 6-19 (KCTC 11027BP) which can prepare lactate polymer and/or copolymer by using lactyl-CoA as a substrate. The present invention relates to a method for preparing lactate polymer and/or copolymer with the synthase mutant. The polyhydroxyalkanoate synthase mutants of the present invention originated from Pseudomonas sp. 6-19 can efficiently prepare lactate polymer and/or copolymer by using as a substrate lactyl-CoA which is difficult to be used as a substrate by conventional polyhydroxyalkanoate synthase.