Lg Chem, Ltd

Korea Advanced Institute of Science and Technology

Hye Ok Kang

Sang Yup Lee

Tae Wan Kim

Sang Hyun Lee

Si Jae Park

Taek Ho Yang

Eun Jung Lee

Jung Yun Choi

Chul Woong Kim

Donggyun Kang

In Young Huh

Eun Jeong Lee

Jae Hyung Kim

Younghyun Cho

Yu Kyung Jung

The present invention relates to a novel 3-hydroxypropionate-lactate block copolymer [P(3HP-b-LA)], and a method for preparing same, and more specifically, provides a method for preparing a 3-hydroxypropionate-lactate block copolymer, and a 3-hydroxypropionate-lactate block copolymer produced thereby, the method comprising: a first culture step in which, by using recombinantimproved so as to be incapable of biosynthesizing lactic acid, P(3HP) is biosynthesized at the early stage of culturing by having glycerol as a carbon source and through 3-hydroxypropionate-generating genes and an enhanced PHA synthase; and a second culture step in which P(3HP) production is inhibited by using a carbon catabolic repression system for selectively introducing only glucose intowhen glycerol and glucose are supplied together as carbon sources, and in which polylactate is biosynthesized to an interrupted P(3HP) terminus by the enabling of the expression of a lactate synthase and a lactyl-CoA converting enzyme through an IPTG induction system.

Poly(3-hydroxypropionate-b-lactate) block copolymer using microorganisms

Provided is a lactic acid-based block copolymer which is biodegradable while having excellent mechanical properties.

Block copolymer

Provided are a novel 3-hydroxypropionate-lactate block copolymer [P(3HP-b-LA)], and a method for preparing same, comprising: a) transforming a recombinant microorganism modified to be incapable of biosynthesizing lactic acid with a vector including a 3-hydroxypropionyl-CoA biosynthesis gene and a polyhydroxyalkanoate (PHA) synthetase gene, and a vector including a lactate biosynthesis gene and a gene of an enzyme that converts lactate to lactyl-CoA; (b) synthesizing poly(3-hydroxypropionate) (P(3HP)) by culturing the recombinant microorganism using a glycerol as a carbon source; and (c) inhibiting P(3HP) production by adding IPTG and glucose, and biosynthesizing polylactate (PLA) at the end of P(3HP) synthesized in step (b) by enabling the expression of a lactate biosynthesis enzyme and an enzyme that converts lactate to lactyl-CoA. Also provided is a recombinant microorganism produced in step a).

Provided is a mutant of propionyl-CoA transferase fromthat 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, when a mutant of propiony-CoA transferase fromis introduced into recombinant, lactyl-CoA can be supplied very smoothly, thereby enabling highly efficient preparation of polylactate (PLA) and PLA copolymer.

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Provided are a recombinantcapable of producing polylactate or a hydroxyalkanoate-lactate copolymer, and a method of preparing polylactate or a hydroxyalkanoate-lactate copolymer using the same. The recombinant, which is prepared by introducing a gene of an enzyme converting lactate into lactyl-CoA and a gene of a polyhydroxyalkanoate (PHA) synthase using lactyl-CoA as a substrate thereto, may be cultured, thereby efficiently preparing a lactate polymer and a lactate copolymer.

Provided is a mutant of propionyl-CoA transferase fromthat 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, when a mutant of propionyl-CoA transferase fromis introduced into recombinant, lactyl-CoA can be supplied very smoothly, thereby enabling highly efficient preparation of polylactate (PLA) and PLA copolymer.

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Daejeon, South Korea

Hye Ok Kang