Abstract
Formate is a promising environmentally friendly and sustainable feedstock synthesized from syngas or carbon dioxide. Methylorubrum extorquens is a type II methylotroph that can use formate as a carbon source. It accumulates polyhydroxyalkanoates (PHAs) inside the cell, mainly producing poly-3-hydroxybutyrate (PHB), a degradable biopolymer. Owing to its high melting point and stiff nature, however, mechanical property improvement is warranted in the form of copolymerization. To produce the PHA copolymer, poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), the endogenous gene phaC was deleted and the pathway genes bktB, phaJ1, and phaC2, with broader substrate specificities, were heterologously expressed. To improve the incorporation of 3-hydroxyvalerate (3HV), the expression level of bktB was improved by untranslated region (UTR) engineering, and the endogenous gene phaA was deleted. The engineered M. extorquens produced PHBV with 8.9% 3HV using formate as the sole carbon source. In addition, when propionate and butyrate were supplemented, PHBVs with 3HV portions of up to 70.6% were produced. This study shows that a PHBV copolymer with a high proportion of 3HV can be synthesized using formate, a C1 carbon source, through metabolic engineering and supplementation with short-chain fatty acids.
Original language | English |
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Pages (from-to) | 284-293 |
Number of pages | 10 |
Journal | International Journal of Biological Macromolecules |
Volume | 177 |
DOIs | |
Publication status | Published - 2021 Apr 30 |
Bibliographical note
Funding Information:This research was supported by the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT, South Korea ( 2015M3D3A1A01064919 and 2012M1A2A2026560 ).
Publisher Copyright:
© 2021 Elsevier B.V.
Keywords
- Formate
- Metabolic engineering
- Methylorubrum extorquens AM1
- PHBV copolymer
- SCFAs
ASJC Scopus subject areas
- Structural Biology
- Biochemistry
- Molecular Biology
- Economics and Econometrics
- General Energy