Production of fatty acids in Ralstonia eutropha H16 by engineering β-oxidation and carbon storage
| Autor: | Marika Ziesack, Brendon Dusel, Joseph P. Torella, Brendan Cruz Colon, Jeffrey C. Way, Janice S. Chen |
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| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Mutant
lcsh:Medicine Bioengineering Ralstonia Microbiology Bioplastic General Biochemistry Genetics and Molecular Biology Metabolic engineering Polyhydroxybutyrate oxidation Thioesterase Biofuel Acyl-CoA ligase chemistry.chemical_classification biology General Neuroscience lcsh:R Fatty acid General Medicine biology.organism_classification chemistry Biochemistry Synthetic Biology lipids (amino acids peptides and proteins) General Agricultural and Biological Sciences Bacteria |
| Zdroj: | PeerJ, Vol 3, p e1468 (2015) PeerJ |
| ISSN: | 2167-8359 |
| Popis: | Ralstonia eutrophaH16 is a facultatively autotrophic hydrogen-oxidizing bacterium capable of producing polyhydroxybutyrate (PHB)-based bioplastics. As PHB’s physical properties may be improved by incorporation of medium-chain-length fatty acids (MCFAs), and MCFAs are valuable on their own as fuel and chemical intermediates, we engineeredR. eutrophafor MCFA production. Expression ofUcFatB2, a medium-chain-length-specific acyl-ACP thioesterase, resulted in production of 14 mg/L laurate in wild-typeR. eutropha. Total fatty acid production (22 mg/L) could be increased up to 2.5-fold by knocking out PHB synthesis, a major sink for acetyl-CoA, or by knocking out the acyl-CoA ligasefadD3, an entry point for fatty acids intoβ-oxidation. As ΔfadD3mutants still consumed laurate, and because theR. eutrophagenome is predicted to encode over 50 acyl-CoA ligases, we employed RNA-Seq to identify acyl-CoA ligases upregulated during growth on laurate. Knockouts of the three most highly upregulated acyl-CoA ligases increased fatty acid yield significantly, with one strain (ΔA2794) producing up to 62 mg/L free fatty acid. This study demonstrates that homologousβ-oxidation systems can be rationally engineered to enhance fatty acid production, a strategy that may be employed to increase yield for a range of fuels, chemicals, and PHB derivatives inR. eutropha. |
| Databáze: | OpenAIRE |
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