Construction of Artificial Micro-Aerobic Metabolism for Energy- And Carbon-Efficient Synthesis of Medium Chain Fatty Acids in Escherichia Coli
TL;DR: An artificial micro-aerobic metabolism for energy and carbon-efficient conversion of glycerol to MCFAs was constructed to enable the cost-effective, large-scale production of fatty acids and other value-added reduced chemicals.
About: This article is published in Metabolic Engineering.The article was published on 2019-05-01. It has received 36 citations till now. The article focuses on the topics: Metabolic engineering & Fermentation.
Citations
More filters
TL;DR: This review focuses on the production of SCFA and MCFA from CO2, synthetic substrates and waste materials and introduces the metabolic engineering of Escherichia coli and Saccharomyces cerevisiae for SCFAs/MCFAs production.
42 citations
TL;DR: In this paper , an extensive review demonstrated that anaerobic fermentation has great potential in achieving economical and sustainable medium chain carboxylates production from complex organic substrates, including organic waste streams, which would significantly broaden the application of MCCs, especially in the renewable energy field.
41 citations
TL;DR: The results indicate that the combination of Enterobacter and Comamonas strains with the production of H2S and biofilm are important effectors for the highly efficient immobilization of Cd.
Abstract: Enterobacter sp. A11 and Comamonas sp. A23 were isolated and identified. Coculturing these two strains with Cd(II) led to the production of biofilm, H2S, and succinic acid (SA), and Cd(II) was adsorbed by cells and formed CdS precipitates. After centrifugation, 97% Cd(II) was removed from the coculture. Proteomic and metabolomic analyses of the cocultured bacteria revealed that H2S and SA production pathways, metal transportation, and TCA cycle were active under Cd(II) stress. In vitro addition of SA enhanced the production of H2S and biofilm formation and Cd(II) adsorption. Two-season greenhouse pot experiments with Brassica rapa L. were performed with and without the coculture bacteria. Compared with the control, the average Cd amounts of the two-season pot experiments of the aboveground plants were decreased by 71.3%, 62.8%, and 38.6%, and the nonbioavailable and immobilized Cd in the soils were increased by 211.8%, 213.4%, and 116.7%, for low-, medium-, and high- Cd-spiked soils, respectively. The two strains survived well in soil during plant growth using plate counting, quantitative real-time PCR, and metagenomics analysis. Our results indicate that the combination of Enterobacter and Comamonas strains with the production of H2S and biofilm are important effectors for the highly efficient immobilization of Cd.
37 citations
TL;DR: A range of fuels and chemicals that can be produced from renewable resources by engineered E. coli are reviewed to help the readers better understand the current progress in this field and provide insights for further metabolic engineering efforts in E. Escherichia coli.
34 citations
TL;DR: Shaping the substrate binding pocket of a bacterial thioesterase enzyme by manipulating the hydrophobicity of multiple residues altered the substrate selectivity and therefore fatty acid product distributions in cells is shown to be relevant for increasing titers of industrially attractive MCFAs as fermentation products.
31 citations
References
More filters
TL;DR: This assay is very reproducible and rapid with the dye binding process virtually complete in approximately 2 min with good color stability for 1 hr with little or no interference from cations such as sodium or potassium nor from carbohydrates such as sucrose.
225,085 citations
TL;DR: A new minimal medium for enterobacteria is developed that supports growth of Escherichia coli and Salmonella typhimurium at rates comparable to those of any of the traditional media that have high phosphate concentrations, but each of the macronutrients is present at a sufficiently low level to permit isotopic labeling.
Abstract: A new minimal medium for enterobacteria has been developed. It supports growth of Escherichia coli and Salmonella typhimurium at rates comparable to those of any of the traditional media that have high phosphate concentrations, but each of the macronutrients (phosphate, sulfate, and nitrogen) is present at a sufficiently low level to permit isotopic labeling. Buffering capacity is provided by an organic dipolar ion, morpholinopropane sulfonate, which has a desirable pK (7.2) and no apparent inhibitory effect on growth. The medium has been developed with the objectives of (i) providing reproducibility of chemical composition, (ii) meeting the experimentally determined nutritional needs of the cell, (iii) avoiding an unnecessary excess of the major ionic species, (iv) facilitating the adjustment of the levels of individual ionic species, both for isotopic labeling and for nutritional studies, (v) supplying a complete array of micronutrients, (vi) setting a particular ion as the crop-limiting factor when the carbon and energy source is in excess, and (vii) providing maximal convenience in the manufacture and storage of the medium.
2,930 citations
TL;DR: The anaerobic fermentation of Glycerol in microbes and the harnessing of this metabolic process to convert abundant and low-priced glycerol streams into higher value products, thus creating a path to viability for the biofuels industry are reviewed.
977 citations
TL;DR: The reversal of the β-oxidation cycle was engineered in Escherichia coli and used in combination with endogenous dehydrogenases and thioesterases to synthesize n-alcohols, fatty acids and 3-hydroxy-, 3-keto- and trans-Δ2-carboxylic acids.
Abstract: Biosynthetic pathways that mediate the formation of amino acids, fatty acids and secondary metabolites can be re-engineered to produce complex compounds that show promise as potential biofuels. Dellomonaco et al. show that reversing the direction of the endogenous β-oxidation cycle of fatty acids in Escherichia coli can be used to efficiently synthesize alcohols and carboxylic acids — both potential biofuels — with various chain lengths and functionalities. The β-oxidation cycle is ubiquitous in microbes, so it should be possible to engineer the combinatorial synthesis of non-native products in industrial organisms without recruiting foreign genes. Advanced (long-chain) fuels and chemicals are generated from short-chain metabolic intermediates through pathways that require carbon-chain elongation. The condensation reactions mediating this carbon–carbon bond formation can be catalysed by enzymes from the thiolase superfamily, including β-ketoacyl-acyl-carrier protein (ACP) synthases, polyketide synthases, 3-hydroxy-3-methylglutaryl-CoA synthases, and biosynthetic thiolases1. Pathways involving these enzymes have been exploited for fuel and chemical production, with fatty-acid biosynthesis (β-ketoacyl-ACP synthases) attracting the most attention in recent years2,3,4. Degradative thiolases, which are part of the thiolase superfamily and naturally function in the β-oxidation of fatty acids5,6, can also operate in the synthetic direction and thus enable carbon-chain elongation. Here we demonstrate that a functional reversal of the β-oxidation cycle can be used as a metabolic platform for the synthesis of alcohols and carboxylic acids with various chain lengths and functionalities. This pathway operates with coenzyme A (CoA) thioester intermediates and directly uses acetyl-CoA for acyl-chain elongation (rather than first requiring ATP-dependent activation to malonyl-CoA), characteristics that enable product synthesis at maximum carbon and energy efficiency. The reversal of the β-oxidation cycle was engineered in Escherichia coli and used in combination with endogenous dehydrogenases and thioesterases to synthesize n-alcohols, fatty acids and 3-hydroxy-, 3-keto- and trans-Δ2-carboxylic acids. The superior nature of the engineered pathway was demonstrated by producing higher-chain linear n-alcohols (C ≥ 4) and extracellular long-chain fatty acids (C > 10) at higher efficiency than previously reported2,4,7,8,9. The ubiquitous nature of β-oxidation, aldehyde/alcohol dehydrogenase and thioesterase enzymes has the potential to enable the efficient synthesis of these products in other industrial organisms.
580 citations
TL;DR: A thorough genotypic and phenotypic optimization of an oleaginous organism to create a strain with significant lipogenesis capability is reported, which advances fundamental understanding of lipogenesis, and non-canonical environmental and intracellular stimuli are demonstrated and uncouple lipogenesis from nitrogen starvation.
Abstract: Bio-based production of oils and lipids could potentially provide a sustainable fuel alternative to petroleum. Here, the authors show that Yarrowia lipolytica’s metabolism can be rewired to saturate cells with upwards of 90% lipid content and significantly increase lipid production.
480 citations