1. Biosynthesis of novel lactate-based polymers containing medium-chain-length 3-hydroxyalkanoates by recombinant Escherichia coli strains from glucose
- Author
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Hideki Abe, Hiromi Matsusaki, Ken'ichiro Matsumoto, Hideki Shiratsuchi, Ayaka Hokamura, Kenji Tanaka, Saki Goto, and Seiichi Taguchi
- Subjects
0106 biological sciences ,0301 basic medicine ,Polymers ,Stereochemistry ,DNA, Recombinant ,Bioengineering ,medicine.disease_cause ,01 natural sciences ,Applied Microbiology and Biotechnology ,Polyhydroxyalkanoates ,03 medical and health sciences ,chemistry.chemical_compound ,Biosynthesis ,Thioesterase ,Pseudomonas ,010608 biotechnology ,Lactate dehydrogenase ,Escherichia coli ,medicine ,Transferase ,Lactic Acid ,Chemistry ,Lactic acid ,Alcohol Oxidoreductases ,Glucose ,030104 developmental biology ,D-lactate dehydrogenase ,Acyltransferases ,Biotechnology - Abstract
Novel lactate (LA)-based polymers containing medium-chain-length 3-hydroxyalkanoates (MCL-3HA) were produced in fadR-deficient Escherichia coli strains from glucose as the sole carbon source. The genes encoding LA and 3-hydroxybutyrate (3HB) monomers supplying enzymes [propionyl-CoA transferase (PCT), d -lactate dehydrogenase (D-LDH), β-ketothiolase (PhaA), and NADPH-dependent acetoacetyl-CoA reductase (PhaB)], MCL-3HA monomers supplying enzymes [(R)-3-hydroxyacyl-ACP thioesterase (PhaG) and (R)-3-hydroxyacyl (3HA)-CoA ligase] via fatty acid biosynthesis pathway, and modified polyhydroxyalkanoate (PHA) synthase [PhaC1(STQK)] of Pseudomonas sp. 61-3 were introduced into E. coli LS5218. This resulted in the synthesis of a novel LA-based copolymer, P(LA-co-3HB-co-3HA). 1H-nuclear magnetic resonance (NMR) analysis revealed the composition of P(LA-co-3HB-co-3HA) to be 19.7 mol% LA (C3), 74.9 mol% 3HB (C4), and 5.4 mol% MCL-3HA units of C8 and C10. Furthermore, the recombinant E. coli CAG18497 strain carrying these genes, excluding the phaAB genes, accumulated P(92.0% LA-co-3HA) with a novel monomer composition containing C3, C8, C10, and C12. 13C-NMR analysis showed the existence of LA-3HA sequence in the polymer. The solvent cast film of P(92.0% LA-co-3HA) exhibited transparency similar to poly(lactic acid).
- Published
- 2019
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