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Increased fatty acid unsaturation and production of arachidonic acid by homologous over-expression of the mitochondrial malic enzyme in Mortierella alpina.

ABSTRACT: Malic enzyme (ME) catalyses the oxidative decarboxylation of L-malate to pyruvate and provides NADPH for intracellular metabolism, such as fatty acid synthesis. Here, the mitochondrial ME (mME) gene from Mortierella alpina was homologously over-expressed. Compared with controls, fungal arachidonic acid (ARA; 20:4 n-6) content increased by 60 % without affecting the total fatty acid content. Our results suggest that enhancing mME activity may be an effective mean to increase industrial production of ARA in M. alpina.

SUBMITTER: Hao G

PROVIDER: S-EPMC4386067 | biostudies-literature | 2014 Sep

REPOSITORIES: biostudies-literature

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Increased fatty acid unsaturation and production of arachidonic acid by homologous over-expression of the mitochondrial malic enzyme in Mortierella alpina.

Hao Guangfei G Chen Haiqin H Du Kai K Huang Xiaoyun X Song Yuanda Y Gu Zhennan Z Wang Lei L Zhang Hao H Chen Wei W Chen Yong Q YQ

Biotechnology letters 20140527 9

Malic enzyme (ME) catalyses the oxidative decarboxylation of L-malate to pyruvate and provides NADPH for intracellular metabolism, such as fatty acid synthesis. Here, the mitochondrial ME (mME) gene from Mortierella alpina was homologously over-expressed. Compared with controls, fungal arachidonic acid (ARA; 20:4 n-6) content increased by 60 % without affecting the total fatty acid content. Our results suggest that enhancing mME activity may be an effective mean to increase industrial production ...[more]

PMID: 24863290

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Role of malic enzyme during fatty acid synthesis in the oleaginous fungus Mortierella alpina.

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Expression of Vitreoscilla hemoglobin enhances production of arachidonic acid and lipids in Mortierella alpina.

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An Online Respiratory Quotient-Feedback Strategy of Feeding Yeast Extract for Efficient Arachidonic Acid Production by Mortierella alpina.

Project description:Mortierella alpina (M. alpina) is well known for arachidonic acid (ARA) production. However, low efficiency and unstableness are long existed problems for industrial production of ARA by M. alpina due to the lack of online regulations. The aim of the present work is to develop an online-regulation strategy for efficient and stable ARA production in industry. The strategy was developed in 50 L fermenters and then applied in a 200 m3 fermenter. Results indicated that yeast extract (YE) highly increased cell growth in shake flask, it was then used in bioreactor fermentation by various feeding strategies. Feeding YE to control respiratory quotient (RQ) at 1.1 during 0-48 h and at 1.5 during 48-160 h, dry cell weight, and ARA titer reached 53.1 and 11.49 g/L in 50 L fermenter, which were increased by 79.4 and 36.9% as compared to that without YE feeding, respectively. Then, the online RQ-feedback strategy was applied in 200 m3 bioreactor fermentation and an average ARA titer of 16.82 g/L was obtained from 12 batches, which was 41.0% higher than the control batches. This is the first report on successful application of online RQ-feedback control of YE in ARA production, especially in an industrial scale of 200 m3 fermentation. It could be applied to other industrial production of microbial oil by oleaginous microorganisms.

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Biosynthesis of uniformly labeled 13C- and 14C-arachidonic acid in Mortierella alpina.

Project description:Arachidonic acid (ARA) is one of the most abundant polyunsaturated fatty acids (PUFAs) in the mammalian brain. Many enzymatically- and nonenzymatically-produced metabolic products have important and potent pharmacological properties. However, uniformly isotope labeled forms of ARA are not commercially available for studying the metabolic fates of ARA. This study describes a simple and efficient protocol for the biosynthesis of U-13C-ARA from U-13C-glucose, and U-14C-ARA from U-14C-glucose by Mortierella alpina. The protocols yield approximately 100nmol quantities of U-13C-ARA with an isotopic purity of 95% from a 500μl batch volume, and approximately 2μCi quantities of U-14C-ARA with an apparent specific activity in excess of 1200Ci/mol from a 250μl batch volume.

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Production and enhancement of omega-3 fatty acid from Mortierella alpina CFR-GV15: its food and therapeutic application.

Project description:Mortierella sp. has been known to produce polyunsaturated fatty acids (PUFAs) such as GLA and AA under normal growth medium conditions. Similarly, under the stress condition, this fungus produces EPA and DHA in their mycelial biomass. Among the 67 soil samples screened from the Western Ghats of India, 11 Mortierella isolates showed the presence of omega-6 and omega-3 fatty acid, mainly GLA, AA, EPA, and DHA in starch, yeast-extract medium. Nile red and TTC strains were used for screening their qualitative oleaginesity. Among the representative isolates, when Mortierella sp. is grown in a fat-producing basal medium, a maximum lipid content of 42.0 ± 1.32% in its mycelia, 6.72 ± 0.5% EPA, and 4.09 ± 0.1% DHA was obtained. To understand the Mortierella sp. CFR-GV15, to the species level, its morphology was seen under the light microscope and scanning electron microscope, respectively. These microscopic observations showed that isolate Mortierella sp. CFR-GV15 produced coenocytic hyphae. Later on, its 18S rRNA and the internal transcribed spacer (ITS) sequences were cloned, sequenced, and analyzed phylogenetically to 18S rRNA and ITS1 and ITS4 sequences of related fungi. This newly isolated Mortierella alpina CFR-GV15 was found to be promising culture for the development of an economical method for commercial production of omega-3 fatty acid for food and therapeutical application.

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NADPH-Cytochrome P450 Reductase Mediates the Fatty Acid Desaturation of ω3 and ω6 Desaturases from Mortierella alpina.

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| S-EPMC9164069 | biostudies-literature

Influence of Supplementation of Vegetable Oil Blends on Omega-3 Fatty Acid Production in Mortierella alpina CFR-GV15.

Project description:Objectives of this study were designed for improved production of mycelial omega-3 fatty acids with particular reference to EPA and DHA from the oleaginous fungus Mortierella alpina CFR-GV15 under submerged low temperatures fermentation supplemented with linseed oil and garden cress oil as an additional energy source. The fungus was grown at 20°C temperature for four days initially followed by 12°C temperature for next five days. The basal medium contained starch, yeast extract, and a blend of linseed oil (LSO) and garden cress oil (GCO) in the ratio 1 : 1. Results of the study revealed that, after nine days of total incubation period, the enhancement of biomass was up to 16.7 g/L dry weight with a total lipid content of 55.4% (v/w). Enrichment of omega-3 fatty acids indicated a significant increase in fatty acid bioconversion (ALA 32.2 ± 0.42%, EPA 7.9 ± 0.1%, and DHA 4.09 ± 0.2%) by 2.5-fold. The two-stage temperature cultivation alters the fatty acid profile due to activation of the desaturase enzyme in the cellular levels due to which arachidonic acid (AA) content reduced significantly. It can be concluded that Mortierella alpina CFR-GV15 is a fungal culture suitable for commercial production of PUFAs with enriched EPA and DHA.

| S-EPMC5390627 | biostudies-literature

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