Abstract
Medium chain hydroxy fatty acids (HFAs) at ω-1, 2, or 3 positions (ω-1/2/3) are rare in nature but are attractive due to their potential applications in industry. They can be metabolically engineered in Escherichia coli, however, the current yield is low. In this study, metabolic engineering with P450BM3 monooxygenase was applied to regulate both the chain length and sub-terminal position of HFA products in E. coli, leading to increased yield. Five acyl-acyl carrier protein thioesterases from plants and bacteria were first evaluated for regulating the chain length of fatty acids. Co-expression of the selected thioesterase gene CcFatB1 with a fatty acid metabolism regulator fadR and monooxygenase P450BM3 boosted the production of HFAs especially ω-3-OH-C14:1, in both the wild type and fadD deficient strain. Supplementing renewable glycerol to reduce the usage of glucose as a carbon source further increased the HFAs production to 144 mg/L, representing the highest titer of such HFAs obtained in E. coli under the comparable conditions. This study illustrated an improved metabolic strategy for medium chain ω-1/2/3 HFAs production in E. coli. In addition, the produced HFAs were mostly secreted into culture media, which eased its recovery.
Highlights
Hydroxy fatty acids (HFAs) are widely found in plants, animals, and microorganisms, rare in medium-chain length (C8-C14)
For selective production of medium chain ω-1/2/3 HFAs, several steps involved in the biosynthesis pathway were tested in this study (Figure 1)
Expressing Acyl-ACP thioesterase (TE) increased the cellular Free fatty acid (FFA) amount, there was no significant effect on the biomass and total fatty acid (TFA) amounts (Table 1)
Summary
Hydroxy fatty acids (HFAs) are widely found in plants, animals, and microorganisms, rare in medium-chain length (C8-C14). Their physiological roles, including anti-biotic, antiinflammatory, and anti-diabetic effects, have been uncovered recently. The position of hydroxyl groups in the fatty acyl chain shows a key effect on the activity against certain plant pathogenic fungi. The hydroxylation at different positions of the fatty acid chain is needed for different chemical industries. Ω-HFAs can be used as renewable starting materials for the synthesis of Production of Medium-Chain Omega HFA in E. coli polymers, with high resistance to heat or chemicals, flexibility, biocompatibility, and non-toxicity (Seo et al, 2015; Bowen et al, 2016). The geometry of sub-terminal ω-1/2/3 HFA combined with different chain length provides diversity of characteristics for polymer synthesis from HFA, generating potential for wide range of commercial use
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
