scholarly journals GFP Scaffold-Based Engineering for the Production of Unbranched Very Long Chain Fatty Acids in Escherichia coli With Oleic Acid and Cerulenin Supplementation

Author(s):  
Elias Kassab ◽  
Norbert Mehlmer ◽  
Thomas Brueck
2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Elias Kassab ◽  
Monika Fuchs ◽  
Martina Haack ◽  
Norbert Mehlmer ◽  
Thomas B. Brueck

Abstract Background Sustainable production of microbial fatty acids derivatives has the potential to replace petroleum based equivalents in the chemical, cosmetic and pharmaceutical industry. Most fatty acid sources for production oleochemicals are currently plant derived. However, utilization of these crops are associated with land use change and food competition. Microbial oils could be an alternative source of fatty acids, which circumvents the issue with agricultural competition. Results In this study, we generated a chimeric microbial production system that features aspects of both prokaryotic and eukaryotic fatty acid biosynthetic pathways targeted towards the generation of long chain fatty acids. We redirected the type-II fatty acid biosynthetic pathway of Escherichia coli BL21 (DE3) strain by incorporating two homologues of the beta-ketoacyl-[acyl carrier protein] synthase I and II from the chloroplastic fatty acid biosynthetic pathway of Arabidopsis thaliana. The microbial clones harboring the heterologous pathway yielded 292 mg/g and 220 mg/g DCW for KAS I and KAS II harboring plasmids respectively. Surprisingly, beta-ketoacyl synthases KASI/II isolated from A. thaliana showed compatibility with the FAB pathway in E. coli. Conclusion The efficiency of the heterologous plant enzymes supersedes the overexpression of the native enzyme in the E. coli production system, which leads to cell death in fabF overexpression and fabB deletion mutants. The utilization of our plasmid based system would allow generation of plant like fatty acids in E. coli and their subsequent chemical or enzymatic conversion to high end oleochemical products.


1998 ◽  
Vol 53 (11-12) ◽  
pp. 995-1003 ◽  

Abstract Herbicidal chloroacetamides cause a very sensitive inhibition of fatty acid incorporation into an insoluble cell wall fraction of Scenedesmus acutus. The molecular basis was investigated in more detail. After incubation of the algae with [14C]oleic acid and saponification, the remaining pellet was solubilized and fractionated consecutively with chloroform / methanol, phosphate buffer, amylase, pronase, and finally with dioxane/HCl. By acid hydrolysis in dioxane a part of the cell wall residue was solubilized showing inhibition of exogenously applied oleic acid and other labelled precursors such as stearic acid, palmitic acid, and acetate. After extraction of this dioxane-soluble subfraction with hexane, HPLC could separate labelled metabolites less polar than oleic acid. T heir formation was completely inhibited by chloroacetam ides, e.g. 1 μᴍ metazachlor. This effect was also observed with the herbicidally active 5-enantiomer of metolachlor while the inactive R-enantiomer had no influence. These strongly inhibited metabolites could be characterized by radio-HPLC /MS as very long chain fatty acids (VLCFAs) with a carbon chain between 20 and 26. Incubating am etazachlor-resistant cell line of S. acutus (Mz-1) with [14C]oleic acid, V LCFA s could not be detected in the dioxane/ HCl-subfraction. Furthermore, comparing the presence of endogenous fatty acids in wildtype and mutant Mz-1 the VLCFA content of the mutant is very low, while the content of long chain fatty acids (C16 -18) is increased, particularly oleic acid. Obviously, the phytotoxicity of chloroacetam ides in S. acutus is due to inhibition of VLCFA synthesis. The resistance of the mutant to metazachlor has a bearing on the higher amount of long chain fatty acids replacing the missing VLCFAs in essential membranes or cell wall components.


1965 ◽  
Vol 43 (1) ◽  
pp. 49-62 ◽  
Author(s):  
D. T. Canvin

Acetate-1-C14 and acetate-2-C14 were supplied to slices of developing castor bean endosperm. The molecules were extensively incorporated into long-chain fatty acids, water-soluble compounds, and protein. Oleic acid was the fatty acid initially labelled from acetate and it was the precursor of ricinoleic acid. Aerobic conditions were required for the formation of oleic acid and for the conversion of oleic acid to ricinoleic acid. Under anaerobic conditions the incorporation of acetate carbon into fatty acids was inhibited more than 90% and almost all of the C14 was found in stearic and palmitic acids. Stearic acid appeared to be formed first and palmitic acid appeared to be derived from it through a shortening of the chain. The position of linoleic acid in the fatty acid interconversions was not clear except that it was not a free intermediate in the conversion of oleic acid to ricinoleic acid.Malonate-C14 was only absorbed slightly by the tissue and although absorption could be increased by the use of diethyl malonate the metabolism of the compound was not facilitated. Because of its poor utilization by the tissue the role of malonate in long-chain fatty acid synthesis in this tissue could not be ascertained.


1973 ◽  
Vol 81 (1) ◽  
pp. 107-112 ◽  
Author(s):  
C. Henderson

SummaryThe effects of fatty acids, at low concentrations (0–005-O5 g/1), on the growth of seven species of rumen bacteria were examined.Anaerovibrio lipolytica(strain 5 S),Peptostreptococcus elsdenii(type 2),Bacteroides ruminicola46/52 andSelenomonas ruminantium(strain 17) were unaffected by addition of oleic acid to the medium. Growth ofButyrivibrioB 835 was stimulated by low concentrations of oleic (< 0–01 g/1), lauric (< 0–1 g/1) or capric (< 0–1 g/1) acids while higher concentrations of these acids were inhibitory. Myristic, palmitic and stearic acids were inhibitory at all concentrations tested.Ruminococcus4263/1 was inhibited at all concentrations of the six acids. Production of methane by pure cultures ofMethanobacterium ruminantiumwas also inhibited by the additions of long-chain fatty acids. Oleic acid was the most inhibitory of the series of acids. These results are consistent with the reported effects of lipids on rumen function.


1995 ◽  
Vol 73 (5-6) ◽  
pp. 223-234 ◽  
Author(s):  
Dev Mangroo ◽  
Bernardo L. Trigatti ◽  
Gerhard E. Gerber

Long chain fatty acids are important substrates for energy production and lipid synthesis in prokaryotes and eukaryotes. Their cellular uptake represents an important first step leading to metabolism. This step is induced in Escherichia coli by growth in medium containing long chain fatty acids and in murine 3T3-L1 cells during differentiation to adipocytes. Consequently, these have been used extensively as model systems to study the cellular uptake of long chain fatty acids. Here, we present an overview of our current understanding of long chain fatty acid uptake in these cells. It consists of several distinct steps, mediated by a combination of biochemical and physico-chemical processes, and is driven by conversion of long chain fatty acids to acyl-CoA by acyl-CoA synthetase. An understanding of long chain fatty acid uptake may provide valuable insights into the roles of fatty acids in the regulation of cell signalling cascades, in the regulation of a variety of metabolic and transport processes, and in a variety of mammalian pathogenic conditions such as obesity and diabetes.Key words: acyl-CoA synthetase, adipocyte, Escherichia coli, fatty acid, transport, uptake.


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