scholarly journals The role of fluconazole in the regulation of fatty acid and unsaponifiable matter biosynthesis in Schizochytrium sp. MYA 1381

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Jun Li ◽  
Hao Zhou ◽  
Xueshan Pan ◽  
Zhipeng Li ◽  
Yinghua Lu ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Cell Growth ◽  
Unsaponifiable Matter ◽  
Fatty Acid Biosynthesis ◽  
Mevalonate Pathway ◽  
Reducing Power ◽  
Fatty Acid Production ◽  
Membrane Function ◽  
Β Carotene

Abstract Background Schizochytrium has been widely used in industry for synthesizing polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid (DHA). However, unclear biosynthesis pathway of PUFAs inhibits further production of the Schizochytrium. Unsaponifiable matter (UM) from mevalonate pathway is crucial to cell growth and intracellular metabolism in all higher eukaryotes and microalgae. Therefore, regulation of UM biosynthesis in Schizochytrium may have important effects on fatty acids synthesis. Moreover, it is well known that UMs, such as squalene and β-carotene, are of great commercial value. Thus, regulating UM biosynthesis may also allow for an increased valuation of Schizochytrium. Results To investigate the correlation of UM biosynthesis with fatty acids accumulation in Schizochytrium, fluconazole was used to block the sterols pathway. The addition of 60 mg/L fluconazole at 48 h increased the total lipids (TLs) at 96 h by 16% without affecting cell growth, which was accompanied by remarkable changes in UMs and NADPH. Cholesterol content was reduced by 8%, and the squalene content improved by 45% at 72 h, which demonstrated fluconazole’s role in inhibiting squalene flow to cholesterol. As another typical UM with antioxidant capacity, the β-carotene production was increased by 53% at 96 h. The increase of squalene and β-carotene could boost intracellular oxidation resistance to protect fatty acids from oxidation. The NADPH was found to be 33% higher than that of the control at 96 h, which meant that the cells had more reducing power for fatty acid synthesis. Metabolic analysis further confirmed that regulation of sterols was closely related to glucose absorption, pigment biosynthesis and fatty acid production in Schizochytrium. Conclusion This work first reported the effect of UM biosynthesis on fatty acid accumulation in Schizochytrium. The UM was found to affect fatty acid biosynthesis by changing cell membrane function, intracellular antioxidation and reducing power. We believe that this work provides valuable insights in improving PUFA and other valuable matters in microalgae.

scholarly journals Understanding and exploiting the fatty acid desaturation system in Rhodotorula toruloides

2020 ◽  
Author(s):  
Yanbin Liu ◽  
Chong Mei John Koh ◽  
Sihui Amy Yap ◽  
Lin Cai ◽  
Lianghui Ji
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Linolenic Acid ◽  
Stress Resistance ◽  
Metabolic Flux ◽  
Unsaturated Fatty Acids ◽  
Fatty Acid Biosynthesis ◽  
Cell Mass ◽  
Fatty Acid Desaturase ◽  
Fatty Acid Production

Abstract Background Rhodotorula toruloides is a robust producer of triacylglycerol owing to its fast growth rate and strong metabolic flux under conditions of high cell density fermentation. However, the molecular basis of fatty acid biosynthesis, desaturation and regulation remain elusive.Results We present the molecular characterization of four fatty acid desaturase (FAD) genes in R. toruloides. Biosynthesis of oleic acid (OA) and palmitoleic acid (POA) was conferred by a single-copy ∆9 Fad (Ole1) as targeted deletion of which abolished the biosynthesis of all unsaturated fatty acids. Conversion of OA to linoleic acid (LA) and α-linolenic acid (ALA) was predominantly catalyzed by the bifunctional ∆12/∆15 Fad2. FAD4 was found to encode a trifunctional ∆9/∆12/∆15 FAD, playing important roles in lipid and biomass production as well as stress resistance. Furthermore, an abundantly transcribed OLE1-related gene, OLE2 encoding a 149-aa protein, was shown to regulate Ole1 regioselectivity. Like other fungi, the transcription of FAD genes was controlled by nitrogen levels and fatty acids in the medium. A conserved DNA motif, (T/C)(G/A)TTGCAGA(T/C)CCCAG, was demonstrated to mediate the transcription of OLE1 by POA/OA. The applications of these FAD genes were illustrated by engineering high level production of OA and g-linolenic acid (GLA). Conclusion Our work has gained novel insights on the transcriptional regulation of FAD genes, evolution of FAD enzymes and their roles in UFA biosynthesis, membrane stress resistance and, cell mass and total fatty acid production. Our findings should illuminate fatty acid metabolic engineering in R. toruloides and beyond.

scholarly journals Understanding and exploiting the fatty acid desaturation system in Rhodotorula toruloides

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yanbin Liu ◽  
Chong Mei John Koh ◽  
Sihui Amy Yap ◽  
Lin Cai ◽  
Lianghui Ji
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Linolenic Acid ◽  
Stress Resistance ◽  
Metabolic Flux ◽  
Unsaturated Fatty Acids ◽  
Fatty Acid Biosynthesis ◽  
Cell Mass ◽  
Fatty Acid Desaturase ◽  
Fatty Acid Production

Abstract Background Rhodotorula toruloides is a robust producer of triacylglycerol owing to its fast growth rate and strong metabolic flux under conditions of high cell density fermentation. However, the molecular basis of fatty acid biosynthesis, desaturation and regulation remains elusive. Results We present the molecular characterization of four fatty acid desaturase (FAD) genes in R. toruloides. Biosynthesis of oleic acid (OA) and palmitoleic acid (POA) was conferred by a single-copy ∆9 Fad (Ole1) as targeted deletion of which abolished the biosynthesis of all unsaturated fatty acids. Conversion of OA to linoleic acid (LA) and α-linolenic acid (ALA) was predominantly catalyzed by the bifunctional ∆12/∆15 Fad2. FAD4 was found to encode a trifunctional ∆9/∆12/∆15 FAD, playing important roles in lipid and biomass production as well as stress resistance. Furthermore, an abundantly transcribed OLE1-related gene, OLE2 encoding a 149-aa protein, was shown to regulate Ole1 regioselectivity. Like other fungi, the transcription of FAD genes was controlled by nitrogen levels and fatty acids in the medium. A conserved DNA motif, (T/C)(G/A)TTGCAGA(T/C)CCCAG, was demonstrated to mediate the transcription of OLE1 by POA/OA. The applications of these FAD genes were illustrated by engineering high-level production of OA and γ-linolenic acid (GLA). Conclusion Our work has gained novel insights on the transcriptional regulation of FAD genes, evolution of FAD enzymes and their roles in UFA biosynthesis, membrane stress resistance and, cell mass and total fatty acid production. Our findings should illuminate fatty acid metabolic engineering in R. toruloides and beyond.

scholarly journals Quantitative in vivo evaluation of the reverse β-oxidation pathway for fatty acid production in Saccharomyces cerevisiae

2017 ◽  
Author(s):  
Paulo Gonçalves Teixeira ◽  
Verena Siewers ◽  
Jens Nielsen
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Acid Production ◽  
Production Efficiency ◽  
Fatty Acid Biosynthesis ◽  
Alternative Pathway ◽  
In Vivo Evaluation ◽  
Fatty Acid Production ◽  
Oxidation Pathway

AbstractProduction of fatty acids using engineered Saccharomyces cerevisiae cells is a challenging task in part due to low efficiency of the native fatty acid biosynthesis pathway. One option for improving production efficiency relies on exploring alternative fatty acid production pathways with either improved kinetics, thermodynamics or yield properties.In this work, we explored the reverse β-oxidation pathway as an alternative pathway for free fatty acid production. Different gene combinations and analysis methods were tested for assessing pathway efficiency when expressed in the yeast Saccharomyces cerevisiae. Even though different alternatives were tested, quantitative analysis showed no improvement or major change in fatty acid production of the tested strains in our conditions. This lack of improvement suggests that the tested pathway designs and constructs are either nonfunctional in the tested conditions or the resulting strains lack a metabolic driving force that is needed for a functional pathway.We conclude that expression of the reverse β-oxidation pathway in S. cerevisiae poses many challenges when compared to expression in bacterial systems. These factors gravely hinder development efforts and success rate for producing fatty acids through this pathway.

scholarly journals Fatty Acid Composition and Antioxidant Activity of Tricholoma Imbricatum and T. Focale

2017 ◽  
Vol 5 (9) ◽  
pp. 1080 ◽  
Author(s):  
Erhan Kaplaner ◽  
Mehmet Hüseyin Singeç ◽  
Mehmet Öztürk
Keyword(s):  
Fatty Acids ◽  
Antioxidant Activity ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Acid Composition ◽  
Antioxidant Properties ◽  
Reducing Power ◽  
Hexane Extract ◽  
Β Carotene

Edible mushrooms are one of the important food source because of their tastes, and having high concentration of fatty acids and the other nutrients. In this study, fatty acid composition and antioxidant properties of Tricholoma imbricatum and T. focale were determined. The fatty acids were analysed by GC, and GC-MS while the antioxidant activity was tested using five complimentary methods; namely, β-carotene-linoleic acid, DPPH scavenging, ABTS scavenging, CUPRAC and metal chelating assays. Eight fatty acids were determined in hexane extract, and oleic acid was the major fatty acid with 46.4% and 35.0%, respectively. Palmitic acid (12.8%, and 5.12%) and lineloic acid (28.2% and 31.0%) were also detected in high amounts. In DPPH.scavenging and ABTS·+ scavenging assays, the methanol extract of T. imbricatum (IC50: 0.12±0.01 mg/mL for both assay) showed better antioxidant activity than those of T. focale (IC50>0.8±0.01, and IC50: 0.21±0.01 mg/mL). All extracts of T. focale exhibited good activity in β-carotene-linoleic acid assay while only the hexane extract of T. imbricatum showed activity. Both mushroom indicated moderate in cupric reducing power. Since the mushrooms are nontoxic and edible, both can be used in food industry as preservatives.

Lipid compositional manipulation in Acholeplasma laidlawii B. Effect of exogenous fatty acids on fatty acid composition and cell growth when endogenous fatty acid production is inhibited

1978 ◽  
Vol 56 (6) ◽  
pp. 462-469 ◽  
Author(s):  
John R. Silvius ◽  
Ronald N. McElhaney
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Cell Growth ◽  
Fatty Acid Biosynthesis ◽  
De Novo ◽  
Chain Elongation ◽  
Endogenous Fatty Acid ◽  
Exogenous Fatty Acid ◽  
De Novo Biosynthesis ◽  
Acholeplasma Laidlawii

A variety of potential inhibitors of de novo fatty acid biosynthesis have been tested for activity in Acholeplasma laidlawii B. Two compounds, avidin and N,N-dimethyi-4-oxo-2-trans-dodecenamide (CM-55), an antimicrobial fatty amide, strongly inhibit de novo biosynthesis without nonspecific toxic effects at moderate dosages. Avidin is the more potent inhibitor, abolishing de novo fatty acid synthesis and greatly reducing the chain elongation of exogenous fatty acids at levels of 25 U/ℓ. CM-55 gives complete inhibition of de novo biosynthesis only at low temperatures and inhibits exogenous fatty acid elongation to a variable extent. However, CM-55 is still a more potent antilipogenic agent in this organism than is the fungal antibiotic cerulenin. Cells cultured with avidin grow only when one or more exogenous medium- or long-chain fatty acids are added to the growth medium. The extent of cell growth under these conditions depends primarily on the physical properties of the exogenous fatty acid(s). In general, fatty acids giving diacylglycerolipids of very high or very low fluidity are unsuitable growth substrates, while those whose diacylglycerol derivatives are of intermediate fluidity support fair to good cell growth.

scholarly journals Bicarbonate for microalgae cultivation: a case study in a chlorophyte, Tetradesmus wisconsinensis isolated from a Norwegian lake

2021 ◽  
Author(s):  
Ikumi Umetani ◽  
Eshetu Janka ◽  
Michal Sposób ◽  
Chris J. Hulatt ◽  
Synne Kleiven ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Lipid Production ◽  
Cetane Number ◽  
Fluorescence Analysis ◽  
Dry Weight ◽  
Maximum Growth ◽  
Biodiesel Fuel ◽  
Fatty Acid Production ◽  
Total Fatty Acids

AbstractBicarbonate was evaluated as an alternative carbon source for a green microalga, Tetradesmus wisconsinensis, isolated from Lake Norsjø in Norway. Photosynthesis, growth, and lipid production were studied using four inorganic carbon regimes: (1) aeration only, (2) 20 mM NaHCO3, (3) 5% (v/v) CO2 gas, and (4) combination of 20 mM NaHCO3 and 5% CO2. Variable chlorophyll a fluorescence analysis revealed that the bicarbonate treatment supported effective photosynthesis, while the CO2 treatment led to inefficient photosynthetic activity with a PSII maximum quantum yield as low as 0.31. Conversely, bicarbonate and CO2 treatments gave similar biomass and fatty acid production. The maximum growth rate, the final cell dry weight, and total fatty acids under the bicarbonate-only treatment were 0.33 (± 0.06) day−1, 673 (± 124) mg L−1 and 75 (± 5) mg g−1 dry biomass, respectively. The most abundant fatty acid components were α-linolenic acid and polyunsaturated fatty acids constituting 69% of the total fatty acids. The fatty acid profile eventuated in unsuitable biodiesel fuel properties such as high degree of unsaturation and low cetane number; however, it would be relevant for food and feed applications. We concluded that bicarbonate could give healthy growth and comparative product yields as CO2.

A multigene approach secures hydroxy fatty acid production in Arabidopsis

2021 ◽  
Author(s):  
Daniel Lunn ◽  
James G Wallis ◽  
John Browse
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Lipid Metabolism ◽  
Transgenic Plants ◽  
Oil Content ◽  
Ricinus Communis ◽  
Seed Vigor ◽  
Fatty Acid Production ◽  
Regulatory Processes ◽  
Castor Seeds

Abstract A central goal of green chemistry is to produce industrially useful fatty acids in oilseed crops. Although genes encoding suitable fatty acid-modifying enzymes are available from more than a dozen wild species, progress has been limited because expression of these enzymes in transgenic plants produces only low yields of the desired products. For example, fatty acid hydroxylase 12 (FAH12) from castor (Ricinus communis) produces only 17% hydroxy fatty acids (HFAs) when expressed in Arabidopsis (Arabidopsis thaliana), compared to 90% HFA in castor seeds. The transgenic plants also have reduced oil content and seed vigor. Here, we review experiments that have provided for steady increases HFA accumulation and oil content. This research has led to exciting new discoveries of enzymes and regulatory processes in the pathways of both seed oil synthesis and lipid metabolism in other parts of the plant. Recent investigations have revealed that HFA-accumulating seeds are unable to rapidly mobilize HFA- containing triacylglycerol (TAG) storage lipid after germination to provide carbon and energy for seedling development, resulting in reduced seedling establishment. These findings present a new opportunity to investigate a different, key area of lipid metabolism - the pathways of TAG lipolysis and β-oxidation in germinating seedlings.

scholarly journals The same rat Δ6-desaturase not only acts on 18- but also on 24-carbon fatty acids in very-long-chain polyunsaturated fatty acid biosynthesis

2002 ◽  
Vol 364 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Sabine D'ANDREA ◽  
Hervé GUILLOU ◽  
Sophie JAN ◽  
Daniel CATHELINE ◽  
Jean-Noël THIBAULT ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acid ◽  
Unsaturated Fatty Acids ◽  
Fatty Acid Biosynthesis ◽  
Chain Polyunsaturated Fatty Acid ◽  
Acid Biosynthesis ◽  
Highly Unsaturated Fatty Acids ◽  
Long Chain ◽  
Δ6 Desaturase

The recently cloned Δ6-desaturase is known to catalyse the first step in very-long-chain polyunsaturated fatty acid biosynthesis, i.e. the desaturation of linoleic and α-linolenic acids. The hypothesis that this enzyme could also catalyse the terminal desaturation step, i.e. the desaturation of 24-carbon highly unsaturated fatty acids, has never been elucidated. To test this hypothesis, the activity of rat Δ6-desaturase expressed in COS-7 cells was investigated. Recombinant Δ6-desaturase expression was analysed by Western blot, revealing a single band at 45kDa. The putative involvement of this enzyme in the Δ6-desaturation of C24:5n-3 to C24:6n-3 was measured by incubating transfected cells with C22:5n-3. Whereas both transfected and non-transfected COS-7 cells were able to synthesize C24:5n-3 by elongation of C22:5n-3, only cells expressing Δ6-desaturase were also able to produce C24:6n-3. In addition, Δ6-desaturation of [1-14C]C24:5n-3 was assayed invitro in homogenates from COS-7 cells expressing Δ6-desaturase or not, showing that Δ6-desaturase catalyses the conversion of C24:5n-3 to C24:6n-3. Evidence is therefore presented that the same rat Δ6-desaturase catalyses not only the conversion of C18:3n-3 to C18:4n-3, but also the conversion of C24:5n-3 to C24:6n-3. A similar mechanism in the n-6 series is strongly suggested.

scholarly journals DETERMINATION OF CHEMICAL PROPERTIES, COMPOSITION OF FATTY ACID, CAROTENOIDS AND TOCOPHEROLS OF DEGUMMED AND NEUTRALIZED RED FRUIT (Pandanus conoideus) OIL

2020 ◽  
Vol 82 (6) ◽  
pp. 71-78
Author(s):  
Zita Letviany Sarungallo ◽  
Budi Santoso ◽  
Risma Uli Situngkir ◽  
Mathelda Kurniaty Roreng ◽  
Meike Meilan Lisangan
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Water Content ◽  
Acid Composition ◽  
Unsaturated Fatty Acids ◽  
Chemical Properties ◽  
Carotenoid Content ◽  
Fruit Oil ◽  
Β Carotene

Refining of crude red fruit oil (CRFO) through the degumming and neutralization steps intended to produce oil free of impurities (non triglycerides) such as phospholipids, proteins, residues and carbohydrates, and also reducing the amount of free fatty acids (FFA). This study aims to determine the effect of red fruit oil purification through degumming and neutralization stages on chemical properties, fatty acid composition, carotenoid content and tocopherol of red fruit oil (RFO). The results showed that degumming of CRFO did not affect the decrease in water content, FFA levels, peroxide numbers, iodine values, carotenoids and tocopherols content; but decrease in levels of phosphorus, β-carotene and α-tocopherol. Neutralization of degummed-RFO (DRFO) did not affect the decrease in water content, iodine value, carotenoid, tocopherol and α-tocopherol; but the FFA levels, peroxide number, phosphorus and β-carotene levels decreased significantly. The fatty acid composition of RFO was dominated by unsaturated fatty acids (± 75%), which increases through degumming and neutralization stages. β-carotene is more sensitive than α-tocopherol during refining process of crude oil, but in general, this process can improve the RFO quality.

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