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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2009-11-30
pubmed:abstractText
For the synthesis of polylactic acid (PLA) and its copolymers by one-step fermentation process, heterologous pathways involving Clostridium propionicum propionate CoA transferase (Pct(Cp)) and Pseudomonas sp. MBEL 6-19 polyhydroxyalkanoate (PHA) synthase 1 (PhaC1(Ps6-19)) were introduced into Escherichia coli for the generation of lactyl-CoA endogenously and incorporation of lactyl-CoA into the polymer, respectively. Since the wild-type PhaC1(Ps6-19) did not efficiently accept lactyl-CoA as a substrate, site directed mutagenesis as well as saturation mutagenesis were performed to improve the enzyme. The wild-type Pct(Cp) was not able to efficiently convert lactate to lactyl-CoA and was found to exert inhibitory effect on cell growth, random mutagenesis by error-prone PCR was carried out. By employing engineered PhaC1(Ps6-19) and Pct(Cp), poly(3-hydroxybutyrate-co-lactate), P(3HB-co-LA), containing 20-49 mol% lactate could be produced up to 62 wt% from glucose and 3HB. By controlling the 3HB concentration in the medium, PLA homopolymer and P(3HB-co-LA) containing lactate as a major monomer unit could be synthesized. Also, P(3HB-co-LA) copolymers containing various lactate fractions could be produced from glucose alone by introducing the Cupriavidus necator beta-ketothiolase and acetoacetyl-CoA reductase genes. Fed-batch cultures were performed to produce P(3HB-co-LA) copolymers having 9-64 mol% of lactate, and their molecular weights, thermal properties, and melt flow properties were determined.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1097-0290
pubmed:author
pubmed:issnType
Electronic
pubmed:day
1
pubmed:volume
105
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
150-60
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Biosynthesis of polylactic acid and its copolymers using evolved propionate CoA transferase and PHA synthase.
pubmed:affiliation
Corporate R&D, LG Chem Research Park, 104-1 Moonji-dong, Yuseong-gu, Daejeon 305-380, Republic of Korea.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't