Biosynthesis of polyhydroxyalkanoates containing 2-hydroxybutyrate from unrelated carbon source by metabolically engineered Escherichia coli SCIE SCOPUS

Cited 65 time in WEB OF SCIENCE Cited 73 time in Scopus
Title
Biosynthesis of polyhydroxyalkanoates containing 2-hydroxybutyrate from unrelated carbon source by metabolically engineered Escherichia coli
Author(s)
Park, Si Jae; Lee, Tae Woo; Lim, Sung-Chul; Kim, Tae Wan; Lee, Hyuk; Kim, Min Kyung; Lee, Seung Hwan; Song, Bong Keun; Lee, Sang Yup
Publication Year
2012-01
Abstract
We have previously reported in vivo biosynthesis of polylactic acid (PLA) and poly(3-hydroxybutyrate-co-lactate) [P(3HB-co-LA)] employing metabolically engineered Escherichia coli strains by the introduction of evolved Clostridium propionicum propionyl-CoA transferase (Pct (Cp) ) and Pseudomonas sp. MBEL 6-19 polyhydroxyalkanoate (PHA) synthase 1 (PhaC1 (Ps6-19)). Using this in vivo PLA biosynthesis system, we presently report the biosynthesis of PHAs containing 2-hydroxybutyrate (2HB) monomer by direct fermentation of a metabolically engineered E. coli strain. The recombinant E. coli ldhA mutant XLdh strain expressing PhaC1 (Ps6-19) and Pct (Cp) was developed and cultured in a chemically defined medium containing 20 g/L of glucose and varying concentrations of 2HB and 3HB. PHAs consisting of 2HB, 3HB, and a small fraction of lactate were synthesized. Their monomer compositions were dependent on the concentrations of 2HB and 3HB added to the culture medium. Even though the ldhA gene was completely deleted in the chromosome of E. coli, up to 6 mol% of lactate was found to be incorporated into the polymer depending on the culture condition. In order to synthesize PHAs containing 2HB monomer without feeding 2HB into the culture medium, a heterologous metabolic pathway for the generation of 2HB from glucose was constructed via the citramalate pathway, in which 2-ketobutyrate is synthesized directly from pyruvate and acetyl-CoA. Introduction of the Lactococcus lactis subsp. lactis Il1403 2HB dehydrogenase gene (panE) into E. coli allowed in vivo conversion of 2-ketobutyrate to 2HB. The metabolically engineered E. coli XLdh strain expressing the phaC1437, pct540, cimA3.7, and leuBCD genes together with the L. lactis Il1403 panE gene successfully produced PHAs consisting of 2HB, 3HB, and a small fraction of lactate by varying the 3HB concentration in the culture medium. As the 3HB concentration in the medium increased the 3HB monomer fraction in the polymer, the polymer content increased. When Ralstonia eutropha phaAB genes were additionally expressed in this recombinant E. coli XLdh strain, P(2HB-co-3HB-co-LA) having small amounts of 2HB and LA monomers could also be produced from glucose as a sole carbon source. The metabolic engineering strategy reported here should be useful for the production of PHAs containing 2HB monomer.
ISSN
0175-7598
URI
https://sciwatch.kiost.ac.kr/handle/2020.kiost/3724
DOI
10.1007/s00253-011-3530-x
Bibliographic Citation
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY, v.93, no.1, pp.273 - 283, 2012
Publisher
SPRINGER
Subject
MICROBIAL-PRODUCTION; POLYLACTIC ACID; ENZYME; SYNTHASE; DEHYDROGENASE; POLYESTERS; COPOLYMERS; BIOFUELS; PATHWAY; CLONING
Keywords
Polyhydroxyalkanoate (PHA); 2-hydroxybutyrate (2HB); PHA synthase; Recombinant E. coli
Type
Article
Language
English
Document Type
Article
Publisher
SPRINGER
Files in This Item:
There are no files associated with this item.

qrcode

Items in ScienceWatch@KIOST are protected by copyright, with all rights reserved, unless otherwise indicated.

Browse