Synthesis of poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) by recombinant Escherichia coli

✍ Scribed by Kang Sub Yim; Sang Yup Lee; Ho Nam Chang

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 819 KB
• Volume: 49
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/(sici)1097-0290(19960305)49:5<495::aid-bit2>3.0.co;2-e

✦ Synopsis

Several recombinant Escherichia coli strains, including XLI-Blue, JM109, HB101, and DH5a harboring a stable high-copynumber plasmid pSYL105 containing the Alcaligenes eutrophus polyhydroxyal ka noate (PHA) biosynt hesis genes were constructed. These recombinant strains were examined for their ability to synthesize and accumulate poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)I copolymer from glucose and either propionate or valerate. All recombinant €. coli strains could synthesize the P(3HB-co-3HV) copolymer in the medium containing glucose and propionate. However, only the homopolymer poly-(3-hydroxybutyrate) [P(3HB)I was synthesized from glucose and valerate. The PHA concentration and the 3HV fraction could be increased by inducing with acetate and/or oleate. When supplemented with oleate, the 3HV fraction increased by fourfold compared with that obtained without induction. Induction with propionate resulted in lower PHA concentration due to the inhibitory effect, but an 3HV fraction of as high as 33.0% could be obtained. These results suggest that P(3HB-co-3HV) can be efficiently produced from propionate by recombinant €. coli by inducing with acetate, propionate, or oleate. 0