scholarly journals A novel omega3-fatty acid desaturase involved in the biosynthesis of eicosapentaenoic acid

2004 ◽  
Vol 378 (2) ◽  
pp. 665-671 ◽  
Author(s):  
Suzette L. PEREIRA ◽  
Yung-Sheng HUANG ◽  
Emil G. BOBIK ◽  
Anthony J. KINNEY ◽  
Kevin L. STECCA ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Eicosapentaenoic Acid ◽  
Fatty Acid Desaturase ◽  
Pcr Amplification ◽  
Oilseed Crops ◽  
Isolation And Characterization ◽  
Carbon Substrates ◽  
Nutritional Benefits

Long-chain n−3 PUFAs (polyunsaturated fatty acids) such as EPA (eicosapentaenoic acid; 20:5n−3) have important therapeutic and nutritional benefits in humans. In plants, cyanobacteria and nematodes, ω3-desaturases catalyse the formation of these n−3 fatty acids from n−6 fatty acid precursors. Here we describe the isolation and characterization of a gene (sdd17) derived from an EPA-rich fungus, Saprolegnia diclina, that encodes a novel ω3-desaturase. This gene was isolated by PCR amplification of an S. diclina cDNA library using oligonucleotide primers corresponding to conserved regions of known ω3-desaturases. Expression of this gene in Saccharomyces cerevisiae, in the presence of various fatty acid substrates, revealed that the recombinant protein could exclusively desaturate 20-carbon n−6 fatty acid substrates with a distinct preference for ARA (arachidonic acid; 20:4n−6), converting it into EPA. This activity differs from that of the known ω3-desaturases from any organism. Plant and cyanobacterial ω3-desaturases exclusively desaturate 18-carbon n−6 PUFAs, and a Caenorhabditis elegans ω3-desaturase preferentially desaturated 18-carbon PUFAs over 20-carbon substrates, and could not convert ARA into EPA when expressed in yeast. The sdd17-encoded desaturase was also functional in transgenic somatic soya bean embryos, resulting in the production of EPA from exogenously supplied ARA, thus demonstrating its potential for use in the production of EPA in transgenic oilseed crops.

Isolation and characterization of fatty acid desaturase genes from peanut (Arachis hypogaea L.)

2011 ◽  
Vol 30 (8) ◽  
pp. 1393-1404 ◽  
Author(s):  
Xiaoyuan Chi ◽  
Qingli Yang ◽  
Lijuan Pan ◽  
Mingna Chen ◽  
Yanan He ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Arachis Hypogaea ◽  
Fatty Acid Desaturase ◽  
Isolation And Characterization ◽  
Arachis Hypogaea L

Characterization of ω3 fatty acid desaturases from oomycetes and their application toward eicosapentaenoic acid production in Mortierella alpina

2021 ◽  
Author(s):  
Brian K H Mo ◽  
Akinori Ando ◽  
Ryohei Nakatsuji ◽  
Tomoyo Okuda ◽  
Yuki Takemoto ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Arachidonic Acid ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acids ◽  
Eicosapentaenoic Acid ◽  
Polyunsaturated Fatty Acid ◽  
Desaturase Activity ◽  
Mortierella Alpina ◽  
Alternative Sources

Abstract ω3 polyunsaturated fatty acids are currently obtained mainly from fisheries, thus sustainable alternative sources such as oleaginous microorganisms are required. Here we describe the isolation, characterization, and application of three novel ω3 desaturases with ω3 polyunsaturated fatty acid-producing activity at ordinary temperatures (28 °C). First, we selected Pythium sulcatum and Plectospira myriandra after screening for oomycetes with high eicosapentaenoic acid/arachidonic acid ratios and isolated the genes psulω3 and pmd17, respectively, which encode ω3 desaturases. Subsequent characterization showed that PSULω3 exhibited ω3 desaturase activity on both C18 and C20 ω6 polyunsaturated fatty acids while PMD17 exhibited ω3 desaturase activity exclusively on C20 ω6 polyunsaturated fatty acids. Expression of psulω3 and pmd17 in the arachidonic acid-producer Mortierella alpina resulted in transformants that produced eicosapentaenoic acid/total fatty acid values of 38% and 40%, respectively, at ordinary temperatures. These ω3 desaturases should facilitate the construction of sustainable ω3 polyunsaturated fatty acid sources.

scholarly journals Isolation and Characterization of Unsaturated Fatty Acid Auxotrophs of Streptococcus pneumoniae and Streptococcus mutans

2007 ◽  
Vol 189 (22) ◽  
pp. 8139-8144 ◽  
Author(s):  
Silvia Altabe ◽  
Paloma Lopez ◽  
Diego de Mendoza
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Streptococcus Pneumoniae ◽  
Unsaturated Fatty Acid ◽  
Saturated Fatty Acids ◽  
Monounsaturated Fatty Acids ◽  
Chemotherapeutic Agents ◽  
Isolation And Characterization ◽  
Membrane Structure And Function

ABSTRACT Unsaturated fatty acid (UFA) biosynthesis is essential for the maintenance of membrane structure and function in many groups of anaerobic bacteria. Like Escherichia coli, the human pathogen Streptococcus pneumoniae produces straight-chain saturated fatty acids (SFA) and monounsaturated fatty acids. In E. coli UFA synthesis requires the action of two gene products, the essential isomerase/dehydratase encoded by fabA and an elongation condensing enzyme encoded by fabB. S. pneumoniae lacks both genes and instead employs a single enzyme with only an isomerase function encoded by the fabM gene. In this paper we report the construction and characterization of an S. pneumoniae 708 fabM mutant. This mutant failed to grow in complex medium, and the defect was overcome by addition of UFAs to the growth medium. S. pneumoniae fabM mutants did not produce detectable levels of monounsaturated fatty acids as determined by gas chromatography-mass spectrometry and thin-layer chromatography analysis of the radiolabeled phospholipids. We also demonstrate that a fabM null mutant of the cariogenic organism Streptococcus mutants is a UFA auxotroph, indicating that FabM is the only enzyme involved in the control of membrane fluidity in streptococci. Finally we report that the fabN gene of Enterococcus faecalis, coding for a dehydratase/isomerase, complements the growth of S. pneumoniae fabM mutants. Taken together, these results suggest that FabM is a potential target for chemotherapeutic agents against streptococci and that S. pneumoniae UFA auxotrophs could help identify novel genes encoding enzymes involved in UFA biosynthesis.

Isolation and characterization of the omega-6 fatty acid desaturase (FAD2) gene family in the allohexaploid oil seed crop Crambe abyssinica Hochst

2013 ◽  
Vol 32 (3) ◽  
pp. 517-531 ◽  
Author(s):  
Jihua Cheng ◽  
E. M. J. Salentijn ◽  
Bangquan Huang ◽  
F. A. Krens ◽  
A. C. Dechesne ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Gene Family ◽  
Fatty Acid Desaturase ◽  
Crambe Abyssinica ◽  
Seed Crop ◽  
Oil Seed ◽  
Isolation And Characterization ◽  
Omega 6 ◽  
Fad2 Gene

scholarly journals Identification and Characterization of the CYP52 Family of Candida tropicalis ATCC 20336, Important for the Conversion of Fatty Acids and Alkanes to α,ω-Dicarboxylic Acids

2003 ◽  
Vol 69 (10) ◽  
pp. 5983-5991 ◽  
Author(s):  
David L. Craft ◽  
Krishna M. Madduri ◽  
Mark Eshoo ◽  
C. Ron Wilson
Keyword(s):  
Fatty Acids ◽  
Cytochrome P450 ◽  
Fatty Acid ◽  
Candida Tropicalis ◽  
Strain Improvement ◽  
Dicarboxylic Acids ◽  
Fold Increase ◽  
Isolation And Characterization ◽  
Unique Genes

ABSTRACT Candida tropicalis ATCC 20336 excretes α,ω-dicarboxylic acids as a by-product when cultured on n-alkanes or fatty acids as the carbon source. Previously, a β-oxidation-blocked derivative of ATCC 20336 was constructed which showed a dramatic increase in the production of dicarboxylic acids. This paper describes the next steps in strain improvement, which were directed toward the isolation and characterization of genes encoding the ω-hydroxylase enzymes catalyzing the first step in the ω-oxidation pathway. Cytochrome P450 monooxygenase (CYP) and the accompanying NADPH cytochrome P450 reductase (NCP) constitute the hydroxylase complex responsible for the first and rate-limiting step of ω-oxidation of n-alkanes and fatty acids. 10 members of the alkane-inducible P450 gene family (CYP52) of C. tropicalis ATCC20336 as well as the accompanying NCP were cloned and sequenced. The 10 CYP genes represent four unique genes with their putative alleles and two unique genes for which no allelic variant was identified. Of the 10 genes, CYP52A13 and CYP52A14 showed the highest levels of mRNA induction, as determined by quantitative competitive reverse transcription-PCR during fermentation with pure oleic fatty acid (27-fold increase), pure octadecane (32-fold increase), and a mixed fatty acid feed, Emersol 267 (54-fold increase). The allelic pair CYP52A17 and CYP52A18 was also induced under all three conditions but to a lesser extent. Moderate induction of CYP52A12 was observed. These results identify the CYP52 and NCP genes as being involved in α,ω-dicarboxylic acid production by C. tropicalis and provide the foundation for biocatalyst improvement.

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