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1.
Nat Commun ; 10(1): 4055, 2019 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-31492836

RESUMO

Long-chain polyunsaturated fatty acids (LC-PUFAs), particularly the omega-3 LC-PUFAs eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA), have been associated with beneficial health effects. Consequently, sustainable sources have to be developed to meet the increasing demand for these PUFAs. Here, we demonstrate the design and construction of artificial PUFA biosynthetic gene clusters (BGCs) encoding polyketide synthase-like PUFA synthases from myxobacteria adapted for the oleaginous yeast Yarrowia lipolytica. Genomic integration and heterologous expression of unmodified or hybrid PUFA BGCs yielded different yeast strains with specific LC-PUFA production profiles at promising yield and thus valuable for the biotechnological production of distinct PUFAs. Nutrient screening revealed a strong enhancement of PUFA production, when cells were phosphate limited. This represents, to the best of our knowledge, highest concentration of DHA (16.8 %) in total fatty acids among all published PUFA-producing Y. lipolytica strains.


Assuntos
Proteínas de Bactérias/metabolismo , Ácido Graxo Sintases/metabolismo , Ácidos Graxos Insaturados/biossíntese , Myxococcales/enzimologia , Yarrowia/metabolismo , Proteínas de Bactérias/genética , Biotecnologia/métodos , Ácidos Docosa-Hexaenoicos/metabolismo , Ácido Graxo Sintases/genética , Ácidos Graxos Ômega-3/metabolismo , Ácidos Graxos Insaturados/metabolismo , Engenharia Metabólica/métodos , Myxococcales/genética , Reprodutibilidade dos Testes
2.
Bioprocess Biosyst Eng ; 42(10): 1561-1571, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31187270

RESUMO

In this study, the microalga Chlorella saccharophila was subjected to ultraviolet (UV) mutagenesis, and mutant screening was conducted based on acidity tolerance to generate mutants with increased triacylglycerol (TAG) and polyunsaturated fatty acid (PUFA) contents. Two improved mutant strains (M1 and M5) were generated. M1 and M5 accumulated 27.2% and 27.4% more TAG, respectively, and showed stronger fluorescence intensity than the wild-type (WT) strain when the cells of these mutants were stained with the lipophilic Nile Red stain. In the M1 mutant, 50.5% of the fatty acid methyl esters (FAMEs) were saturated (C16:0 and C18:0) and 25.27% were monounsaturated (C18:1) fatty acids which are suitable for biofuels production. In the M5 mutant, 65.19% of the total FAMEs were nutritional PUFAs (C16:2, C18:2, and C18:3), while these FAMEs were not detected in the WT. These results demonstrated that UV mutagenesis coupled to an acid pH screening strategy represents a valuable and fast platform to generate mutants of C. saccharophila with improved TAG and PUFA contents for biofuels and nutraceutical applications, respectively.


Assuntos
Chlorella , Ácidos Graxos Insaturados , Microalgas , Mutação , Triglicerídeos , Chlorella/genética , Chlorella/metabolismo , Ácidos Graxos Insaturados/biossíntese , Ácidos Graxos Insaturados/genética , Microalgas/genética , Microalgas/metabolismo , Triglicerídeos/biossíntese , Triglicerídeos/genética
3.
Appl Biochem Biotechnol ; 189(4): 1127-1140, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31168708

RESUMO

Cyanobacteria have immense prospective as a platform for renewable energy; however, a major barrier in achieving optimal productivity is the low lipid yield. Fremyella diplosiphon, a model cyanobacterium, is an ideal biofuel agent due to its desirable fatty acid methyl esters (FAMEs). To enhance lipid content, we overexpressed the sterol desaturase (SD) gene in F. diplosiphon B481 wild type by genetic transformation. This effort resulted in a transformant (B481-SD) with a 64-fold increase in the SD gene at the mRNA transcript level, with no loss in growth and pigmentation. The transformant was persistently grown for over 32 generations indicating long-term stability and vitality. We observed 27.3% and 23% increases in total lipid content and unsaturated FAMEs respectively in B481-SD transesterified lipids with methyl octadecadienoate as the most abundant unsaturated component. In addition, we detected an 81% increase in FAME composition in the transformant compared with the wild type. Theoretical physical and chemical properties confirmed a FAME profile with very high cetane number (65.972-67.494) and oxidative stability (50.493-18.66 h) in the engineered strain. Results of the study offer a promising approach to augment F. diplosiphon total lipid content and unsaturated FAMEs, thus paving the way to enhance biofuel capacity of the organism.


Assuntos
Biocombustíveis , Cianobactérias , Ácidos Graxos Insaturados , Engenharia Metabólica , Cianobactérias/genética , Cianobactérias/metabolismo , Ésteres/metabolismo , Ácidos Graxos Insaturados/biossíntese , Ácidos Graxos Insaturados/genética
4.
Medicina (Kaunas) ; 55(6)2019 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-31216723

RESUMO

Asthma is one of the most important medical and social problems of our time due to the prevalence and the complexity of its treatment. Chronic inflammation that is characteristic of asthma is accompanied by bronchial obstruction, which involves various lipid mediators produced from n-6 and n-3 polyunsaturated fatty acids (PUFAs). The review is devoted to modern ideas about the PUFA metabolites-eicosanoids (leukotrienes, prostaglandins, thromboxanes) and specialized pro-resolving lipid mediators (SPMs) maresins, lipoxins, resolvins, protectins. The latest advances in clinical lipidomics for identifying and disclosing the mechanism of synthesis and the biological action of SPMs have been given. The current views on the peculiarities of the inflammatory reaction in asthma and the role of highly specialized metabolites of arachidonic, eicosapentaenoic and docosahexaenoic acids in this process have been described. The possibility of using SPMs as therapeutic agents aimed at controlling the resolution of inflammation in asthma is discussed.


Assuntos
Asma/fisiopatologia , Ácidos Graxos Insaturados/farmacologia , Asma/tratamento farmacológico , Eicosanoides/biossíntese , Eicosanoides/farmacologia , Eicosanoides/uso terapêutico , Ácidos Graxos Insaturados/biossíntese , Ácidos Graxos Insaturados/uso terapêutico , Humanos , Inflamação/fisiopatologia
5.
Bioprocess Biosyst Eng ; 42(9): 1517-1526, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31111212

RESUMO

In this study, Pavlova lutheri, Chlorella vulgaris, and Porphyridium cruentum were cultured using modified F/2 media in a 1 L flask culture. Various nitrate concentrations were tested to determine an optimal nitrate concentration for algal growth. Subsequently, the effect of light emitted at a specific wavelength on biomass and lipid production by three microalgae was evaluated using various wavelengths of light-emitting diodes (LED). Biomass production by P. lutheri, C. vulgaris, and P. cruentum were the highest with blue, red, and green LED wavelength with 1.09 g dcw/L, 1.23 g dcw/L, and 1.28 g dcw/L on day 14, respectively. Biomass production was highest at the complementary LED wavelength to the color of microalgae. Lipid production by P. lutheri, C. vulgaris, and P. cruentum were the highest with yellow, green, and red LEDs' wavelength, respectively. Eicosapentaenoic acid production by P. lutheri, C. vulgaris, and P. cruentum was 10.35%, 10.14%, and 14.61%, and those of docosahexaenoic acid were 6.09%, 8.95%, and 11.29%, respectively.


Assuntos
Chlorella vulgaris/crescimento & desenvolvimento , Ácidos Graxos Insaturados/biossíntese , Haptófitas/crescimento & desenvolvimento , Luz , Iluminação , Microalgas/crescimento & desenvolvimento , Porphyridium/crescimento & desenvolvimento , Técnicas de Cultura de Células
6.
PLoS One ; 14(5): e0216939, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31141543

RESUMO

In the present two-year study, an attempt was made to estimate the grain yield, grain nutrient uptake, and oil quality of three commonly grown maize (Zea mays L.) hybrids fertilized with varied levels of nitrogen (N), phosphorus (P) and potassium (K). Results obtained from both the experimental years indicated that application of 125% of recommended dose of fertilizer (RDF) recorded maximum grain yield (10.37 t ha-1; 124% higher than control). When compared with 100% RDF, grain yield reduction with nutrient omission was 44% for N omission, 17% for P omission, and 27% for K omission. Nitrogen uptake was increased with increasing NPK levels up to 150% RDF that was statistically at par (p ≥ 0.01) with 125% RDF. Increasing trend in P and K uptake was observed with successive increase in NPK levels up to 125% RDF, above which it declined. The protein content was significantly higher in grains of var. P 3396 with 125% RDF. Nutrient management has significant (p ≤ 0.01) role in the grain oil content. Saturated fatty acids (palmitic, stearic and arachidic acid) content decreased, and unsaturated fatty acid (oleic, linoleic and linolenic acid) increased with increasing NPK levels. The average oleic acid desaturation and linoleic acid desaturation ratios were increased with increasing NPK levels up to 100 and 125% RDF, respectively. However, average monounsaturated fatty acids (MUFA): poly-unsaturated fatty acids (PUFA), saturated: unsaturated as well as linoleic: linolenic acid ratios were increased on receiving 75% RDF, and beyond that it showed decreasing trend. The omission of K had the highest inhibitory effect on corn oil quality followed by N and P omission.


Assuntos
Óleo de Milho/química , Grão Comestível/efeitos dos fármacos , Nitrogênio/farmacologia , Fósforo/farmacologia , Potássio/farmacologia , Zea mays/efeitos dos fármacos , Quimera/crescimento & desenvolvimento , Quimera/metabolismo , Óleo de Milho/metabolismo , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/metabolismo , Ácidos Graxos/biossíntese , Ácidos Graxos/classificação , Ácidos Graxos/isolamento & purificação , Ácidos Graxos Insaturados/biossíntese , Ácidos Graxos Insaturados/classificação , Ácidos Graxos Insaturados/isolamento & purificação , Fertilizantes/análise , Humanos , Nitrogênio/metabolismo , Nutrientes/metabolismo , Nutrientes/farmacologia , Fósforo/metabolismo , Proteínas de Plantas/biossíntese , Proteínas de Plantas/isolamento & purificação , Potássio/metabolismo , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
7.
Biochim Biophys Acta Mol Cell Biol Lipids ; 1864(8): 1134-1144, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31048041

RESUMO

The interest in understanding the capacity of aquatic invertebrates to biosynthesise omega-3 (ω3) long-chain (≥C20) polyunsaturated fatty acids (LC-PUFA) has increased in recent years. Using the common octopus Octopus vulgaris as a model species, we previously characterised a ∆5 desaturase and two elongases (i.e. Elovl2/5 and Elovl4) involved in the biosynthesis of LC-PUFA in molluscs. The aim of this study was to characterise both molecularly and functionally, two methyl-end (or ωx) desaturases that have been long regarded to be absent in most animals. O. vulgaris possess two ωx desaturase genes encoding enzymes with ∆12 and ω3 regioselectivities enabling the de novo biosynthesis of the C18 PUFA 18:2ω6 (LA, linoleic acid) and 18:3ω3 (ALA, α-linolenic acid), generally regarded as dietary essential for animals. The O. vulgaris ∆12 desaturase ("ωx2") mediates the conversion of 18:1ω9 (oleic acid) into LA, and subsequently, the ω3 desaturase ("ωx1") catalyses the ∆15 desaturation from LA to ALA. Additionally, the O. vulgaris ω3 desaturase has ∆17 capacity towards a variety of C20 ω6 PUFA that are converted to their ω3 PUFA products. Particularly relevant was the affinity of the ω3 desaturase towards 20:4ω6 (ARA, arachidonic acid) to produce 20:5ω3 (EPA, eicosapentaenoic acid), as supported by yeast heterologous expression, and enzymatic activity exhibited in vivo when paralarvae were incubated in the presence of [1-14C]20:4ω6. These results confirmed that several routes enabling EPA biosynthesis are operative in O. vulgaris whereas ARA and docosahexaenoic acid (DHA, 22:6ω3) should be considered essential fatty acids since endogenous production appears to be limited.


Assuntos
Ácidos Graxos Dessaturases/metabolismo , Ácidos Graxos Insaturados/biossíntese , Octopodiformes/metabolismo , Animais , Ácido Araquidônico/biossíntese , Ácido Araquidônico/metabolismo , Ácidos Docosa-Hexaenoicos/biossíntese , Ácidos Docosa-Hexaenoicos/metabolismo , Ácido Eicosapentaenoico/biossíntese , Ácidos Graxos Dessaturases/genética , Ácido Linoleico/biossíntese , Octopodiformes/enzimologia , Ácido alfa-Linoleico/biossíntese
8.
Mar Biotechnol (NY) ; 21(4): 475-487, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31020472

RESUMO

Post-transcriptional regulatory mechanisms play important roles in the regulation of LC-PUFA biosynthesis. Our previous study revealed that miR-33 could increase the expression of fatty acyl desaturases (fads2) in the rabbitfish Siganus canaliculatus, but the specific mechanism is unknown. Here, we confirmed that miR-33 could target the 3'UTR of insulin-induced gene 1 (insig1), resulting in downregulation of its protein level in the rabbitfish hepatocyte line (SCHL). In vitro overexpression of miR-33 inhibited the mRNA level of insig1 and increased the mRNA levels of Δ6Δ5 fads2 and elovl5, as well as srebp1. In SCHL cells, proteolytic activation of sterol-regulatory-element-binding protein-1 (Srebp1) was blocked by Insig1, with overexpression of insig1 decreasing mature Srebp1 level, while inhibition of insig1 led to the opposite effect. Srebp1 could enhance the promoter activity of Δ6Δ5 fads2 and elovl5, whose expression levels decreased with knockdown of srebp1 in SCHL. Overexpression of miR-33 also resulted in a higher conversion of 18:3n-3 to 18:4n-3 and 20:5n-3 to 22:5n-3, linked to desaturation and elongation via Δ6Δ5 Fads2 and Elovl5, respectively. The results suggested that the mechanism by which miR-33 regulates LC-PUFA biosynthesis in rabbitfish is through enhancing the expression of srebp1 by targeting insig1. The findings here provide more insight to the mechanism of miRNAs involvement in the regulation of LC-PUFA biosynthesis in teleosts.


Assuntos
Ácidos Graxos Dessaturases/genética , Ácidos Graxos Insaturados/biossíntese , Proteínas de Peixes/genética , MicroRNAs/genética , Perciformes/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Regiões 3' não Traduzidas , Animais , Linhagem Celular , Clonagem Molecular , Ácidos Graxos Dessaturases/metabolismo , Proteínas de Peixes/metabolismo , Expressão Gênica , Regulação da Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Células HEK293 , Hepatócitos/citologia , Hepatócitos/metabolismo , Humanos , Metabolismo dos Lipídeos/genética , MicroRNAs/metabolismo , Perciformes/metabolismo , Regiões Promotoras Genéticas , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transdução de Sinais , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo
9.
J Agric Food Chem ; 67(16): 4700-4708, 2019 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-30929441

RESUMO

Fat-related traits have great influences on pork quality. As different fat tissues have different biochemical profiles depending on their location, intramuscular fat contributes to gustatory qualities, while subcutaneous fat is considered as a negative factor associated with growth performance. In this study, both primary intramuscular and subcutaneous vascular stem cells (IVSCs and SVSCs) could be differentiated into mature adipocytes, though the IVSC differentiation efficiency was lower. By comparative analysis of transcriptomes, 2524 differentially expressed genes (DEGs) were found between two VSCs before differentiation, while only 551 DEGs were found and enriched in two pathways including biosynthesis of unsaturated fatty acids after differentiation. This result indicated that differentiated VSCs were more similar. During differentiation, more DEGs existed in IVSCs than that in SVSCs, suggesting that adipogenesis of IVSCs might be more complex. Additionally, the expression level of DEGs involved in the adipogenic process helps to explain the difference of differentiation efficiency between IVSCs and SVSCs.


Assuntos
Adipócitos/citologia , Adipogenia , Células-Tronco/citologia , Gordura Subcutânea/citologia , Adipócitos/metabolismo , Animais , Ácidos Graxos Insaturados/biossíntese , Perfilação da Expressão Gênica , Carne Vermelha/análise , Células-Tronco/metabolismo , Gordura Subcutânea/irrigação sanguínea , Gordura Subcutânea/metabolismo , Suínos , Transcriptoma
10.
Biochim Biophys Acta Mol Cell Biol Lipids ; 1864(8): 1083-1090, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31002943

RESUMO

As an unusual economically important aquaculture species, Sinonovacula constricta possesses high levels of long-chain polyunsaturated fatty acids (LC-PUFA). Previously, our group identified fatty acyl desaturases (Fad) with Δ5 and Δ6 activities in S. constricta, which was the first report of Δ6 Fad in a marine mollusc. Here, we further successfully characterize elongases of very long-chain fatty acids (Elovl) in this important bivalve species, including one Elovl2/5, two Elovl4 isoforms (a and b) and a novel Elovl (c) with Elovl4 activity. In addition, we also determined the desaturation activity of S. constricta Δ6 Fad toward 24:5n-3 to give 24:6n-3, a key intermediate in docosahexaenoic acid (DHA) biosynthesis. Therefore, S. constricta is the first marine mollusc reported to possess all Fad and Elovl activities required for LC-PUFA biosynthesis via the 'Sprecher pathway'. This finding greatly increases our understanding of LC-PUFA biosynthesis in marine molluscs. Phylogenetic analysis by interrogating six marine molluscan genomes, and previously functionally characterized Elovl and Fad from marine molluscs, suggested that DHA biosynthetic ability was limited to a few species, due to the general lack of Δ4 or Δ6 Fad in most molluscs.


Assuntos
Bivalves/metabolismo , Ácidos Graxos Dessaturases/metabolismo , Ácidos Graxos Insaturados/biossíntese , Animais , Bivalves/enzimologia , Ácidos Docosa-Hexaenoicos/biossíntese , Genoma , Moluscos/genética , Filogenia
11.
Genes Genomics ; 41(5): 583-597, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30830682

RESUMO

BACKGROUND: Strongylocentrotus nudus is an important cultured sea urchin species in north China, because its gonad is rich in unsaturated fatty acids, particularly long polyunsaturated fatty acids (LC-PUFAs). These PUFAs play pleiotropic and crucial roles in a wide range of biological process. OBJECTIVE: However, the genes contributing to biosynthesis PUFAs have not been elucidated yet, and the molecular mechanism relative to the difference in PUFA composition between male and female gonad as been revealed but the corresponding has not been understood. METHODS: In this paper, solexa sequencing based transcriptomic approach was used to identify and characterize the key genes relative to PUFA synthesis and further conducted different expressed genes between male and female gonad. RESULTS: A total of 130,124 transcripts and 189330 unigenes were de novo assembled from 64.32 Gb data. Next, these unigenes were subjected to functional annotation by mapping to six public databases, and this process revealed a lot of genes involving in lipid metabolism. In addition, three types of fatty acids front-end desaturase and three species of very long fatty acids elongase were identified and the pathway for PUFA biosynthesis was hypothesized. Last, comparative analysis revealed the higher expression level of Δ5 desaturase, Δ6 desaturase, ELOVL-4, -6 and -7 in male gonad compared with female. CONCLUSION: This results could plausible explain the differ in composition of PUFAs between male and female gonad of sea urchin.


Assuntos
Ácidos Graxos Insaturados/biossíntese , Perfilação da Expressão Gênica/métodos , Strongylocentrotus/genética , Animais , China , Ácidos Graxos , Ácidos Graxos Insaturados/genética , Feminino , Estudos de Associação Genética , Gônadas/metabolismo , Metabolismo dos Lipídeos/genética , Masculino , Strongylocentrotus/metabolismo , Transcriptoma/genética
12.
Artigo em Inglês | MEDLINE | ID: mdl-30831207

RESUMO

The capacity of crustaceans to biosynthesise long-chain polyunsaturated fatty acids has yet to be fully defined, due to the lack of evidence on the functional activities of enzymes involved in desaturation or elongation of fatty acid substrates. We report here the cloning and in vitro functional analysis of an elongase from the orange mud crab, Scylla olivacea. Sequence and phylogenetic analysis placed the elovl close to the vertebrate Elovl1 and Elovl7 clade, which is distinct from the other remaining five Elovl families. The elongase was also clustered together with several elongases from crustaceans and insects. This elongase showed activities towards 16:1n-7, and at lower rate, linoleic acid (18:2n-6) and linolenic acid (18:3n-3). To our knowledge this is the first description of a functional enzyme involved in biosynthesis of long-chained polyunsaturated fatty acids in a crustacean species. Expression of the S. olivacea elovl7-like mRNA was prominent in stomach, intestine and gill tissues, due to the need to regulate the permeability of epithelial tissue through modification of fatty acid compositions. The implication of our findings, in terms of ability of Crustacea phylum to biosynthesise polyunsaturated fatty acids is discussed.


Assuntos
Acetiltransferases , Proteínas de Artrópodes , Braquiúros , Ácidos Graxos Insaturados , Regulação Enzimológica da Expressão Gênica/fisiologia , Filogenia , Acetiltransferases/biossíntese , Acetiltransferases/química , Acetiltransferases/genética , Animais , Proteínas de Artrópodes/biossíntese , Proteínas de Artrópodes/química , Proteínas de Artrópodes/genética , Braquiúros/enzimologia , Braquiúros/genética , Clonagem Molecular , Ácidos Graxos Insaturados/biossíntese , Ácidos Graxos Insaturados/genética , Especificidade de Órgãos/fisiologia
13.
Artigo em Inglês | MEDLINE | ID: mdl-30904725

RESUMO

Optimizing physiological functions at different temperatures includes shifts in the lipid composition of ectothermic animals. These shifts may be associated with changes in lipid peroxidation in response to oxidative stress, because lipids differ in their susceptibility to oxidative damage. Polyunsaturated fatty acids (PUFA) are particular prone to peroxidation. Here, we analyzed changes in the fatty acid composition, cholesterol content and the level of oxidative damage as thiobarbituric reactive substances (TBARS) in Daphnia magna as a function of acclimation temperature. The total fatty acid content was highest in cold-acclimated animals. The relative share of most PUFA decreased with increasing acclimation temperature. In contrast, the contribution of saturated and monounsaturated fatty acids (SFA and MUFA) increased with acclimation temperature, although the latter to a lower extent. Cholesterol content remained unchanged. The level of oxidative damage was lowest in animals reared at warm temperatures, most likely reflecting their lowest content of PUFA. Heat exposure (1 h at 33 °C) caused the highest increase in lipid peroxidation in cold-acclimated animals, containing more PUFA. Our data suggest that cold-induced adjustments in the body lipid composition increase the vulnerability of zooplankton to heat-induced oxidative stress. In particular, animals performing diel vertical migration may be highly susceptible to temperature-induced lipid damage.


Assuntos
Aclimatação , Daphnia/metabolismo , Ácidos Graxos Insaturados/biossíntese , Temperatura Alta , Peroxidação de Lipídeos , Estresse Oxidativo , Animais
14.
Mar Drugs ; 17(3)2019 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-30836652

RESUMO

Microalgae are the primary producers of carbon in marine ecosystems, fixing carbon and subsequently generating various biomolecules such as carbohydrates, proteins and lipids. Most importantly, microalgae are the generators and main suppliers of ω3 polyunsaturated fatty acids (ω3PUFA) in the marine ecosystem, which have a fundamental importance for the functioning and quality of the whole marine food web. A meta-analysis of over 160 fatty acid profiles of 7 marine phytoplankton phyla reveals not only a phyla-specific, but also a highly class-specific PUFA production of marine phytoplankton. The highest EPA (Eicosapentaenoic acid; 20:5ω3) production per total fatty acids was found in 2 classes of Haptophyta and in Ochrophyta, while Dinophyta and the Haptophyte Emiliana huxleyi show the highest production of DHA (Docosahexaenoic acid; 22:6ω3). An important precursor for EPA, Stearidonic acid (SDA, 18:4ω3) is found in high proportions in Cryptophyta and the Chlorophta class Pyramimonadophyceae. Per unit of carbon, Chlorophyta and Cyanobacteria were the poorest producers of highly unsaturated fatty acids (HUFA). The remaining phyla had a similar HUFA contribution per unit of carbon but with different compositions. The nutritional and environmental effects on the phytoplankton PUFA production is summarized and shows a lowering of the PUFA content under stressful environmental conditions.


Assuntos
Ácidos Graxos Insaturados/biossíntese , Cadeia Alimentar , Microalgas/metabolismo , Zooplâncton/fisiologia , Animais , Vias Biossintéticas , Ácidos Graxos Insaturados/análise , Microalgas/química , Oceanos e Mares
15.
Mar Drugs ; 17(2)2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30781416

RESUMO

Polyunsaturated fatty acids (PUFAs) are essential for human function, however they have to be provided through the diet. As their production from fish oil is environmentally unsustainable, there is demand for new sources of PUFAs. The aim of the present work was to establish the microalgal platform to produce nutraceutical-value PUFAs from forest biomass. To this end, the growth of Phaeodactylum tricornutum on birch and spruce hydrolysates was compared to autotrophic cultivation and glucose synthetic media. Total lipid generated by P. tricornutum grown mixotrophically on glucose, birch, and spruce hydrolysates was 1.21, 1.26, and 1.29 g/L, respectively. The highest eicosapentaenoic acid (EPA) production (256 mg/L) and productivity (19.69 mg/L/d) were observed on spruce hydrolysates. These values were considerably higher than those obtained from the cultivation without glucose (79.80 mg/L and 6.14 mg/L/d, respectively) and also from the photoautotrophic cultivation (26.86 mg/L and 2.44 mg/L/d, respectively). To the best of our knowledge, this is the first report describing the use of forest biomass as raw material for EPA and docosapentaenoic acid (DHA) production.


Assuntos
Betula/química , Biomassa , Suplementos Nutricionais/análise , Ácidos Graxos Insaturados/biossíntese , Microalgas/metabolismo , Picea/química , Meios de Cultura , Ácido Eicosapentaenoico/análise , Ácido Eicosapentaenoico/biossíntese , Ácidos Graxos Insaturados/análise , Glucose/metabolismo , Madeira
16.
Bioresour Technol ; 281: 118-125, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30811998

RESUMO

Algal growth limitation in large-scale cultivation mostly results from high level synthesis of photosynthetic pigments, owing to self-shading effects and attenuation of light distribution. To overcome this problem, here we investigated the influence of nitrogen modulation on changes in antenna pigments as well as biomass and lipid production by Chlorella vulgaris under a chemostat continuous cultivation mode. The production of algal antenna pigments, including chlorophylls and carotenoids, was promoted in a total nitrogen (TN) concentration-dependent manner. Maximum algal biomass and lipid production were obtained from 70 mg/L of TN concentration along with a significant increase in light transmittance and reduction in antenna pigments. Furthermore, the composition of polyunsaturated fatty acids remarkably augmented at low TN concentrations. These results suggest that the reduction in algal antenna pigment synthesis via modulation of nitrogen concentration may serve as an effective strategy to enhance algal biomass and lipid production.


Assuntos
Biomassa , Carotenoides/metabolismo , Chlorella vulgaris/metabolismo , Clorofila/metabolismo , Lipídeos/biossíntese , Nitrogênio/metabolismo , Ácidos Graxos Insaturados/biossíntese , Fotossíntese
17.
J Microbiol Methods ; 158: 80-85, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30708087

RESUMO

Screening oleaginous microorganisms capable of accumulating considerable lipids is essential for industrial lipid production. Here we demonstrated forty-seven filamentous fungal isolates were obtained from eight soil samples using a new screening strategy with both triphenyltetrazolium chloride (TTC), a redox indicator used for testing oil presence, and cerulenin, an inhibitor of fatty acid synthase (FAS), supplemented in screening medium. Among these fungal isolates, nineteen have high lipid content (>20% dry biomass weight) and were affiliated with the genus Mortierella by morphology identification and phylogenetic analysis based on ITS gene sequences. Notably, one strain designated as SL-4 reached 32% of its biomass weight as lipid, displaying the highest potential. Two candidates with high lipid content as well as biomass production were selected for exploring the effect of different carbon and nitrogen sources on morphology, biomass and lipid accumulation.


Assuntos
Ácidos Graxos Insaturados/biossíntese , Fungos/isolamento & purificação , Fungos/metabolismo , Metabolismo dos Lipídeos , Microbiologia do Solo , Biomassa , Cerulenina/química , Fermentação , Ensaios de Triagem em Larga Escala , Mortierella/metabolismo , Sais de Tetrazólio/química
18.
BMC Genomics ; 20(1): 68, 2019 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-30665360

RESUMO

BACKGROUND: The nutritional value of soybean oil is largely influenced by the proportions of unsaturated fatty acids (FAs), including oleic acid (OA, 18:1), linoleic acid (LLA, 18:2), and linolenic acid (LNA, 18:3). Genome-wide association (GWAS) studies along with gene expression studies in soybean [Glycine max (L.) Merr.] were leveraged to dissect the genetics of unsaturated FAs. RESULTS: A association panel of 194 diverse soybean accessions were phenotyped in 2013, 2014 and 2015 to identify Single Nucleotide Polymorphisms (SNPs) associated with OA, LLA, and LNA content, and determine putative candidate genes responsible for regulating unsaturated FAs composition. 149 SNPs that represented 73 genomic regions were found to be associated with the unsaturated FA contents in soybean seeds according to the results of GWAS. Twelve novel genes were predicted to be involved in unsaturated FA synthesis in soybean. The relationship between expression pattern of the candidate genes and the accumulation of unsaturated FAs revealed that multiple genes might be involved in unsaturated FAs regulation simultaneously but work in very different ways: Glyma.07G046200 and Glyma.20G245500 promote the OA accumulation in soybean seed in all the tested accessions; Glyma.13G68600 and Glyma.16G200200 promote the OA accumulation only in high OA germplasms; Glyma.07G151300 promotes OA accumulation in higher OA germplasms and suppresses that in lower OA germplasms; Glyma.16G003500 has the effect of increasing LLA accumulation in higher LA germplasms; Glyma.07G254500 suppresses the accumulation of LNA in lower OA germplasms; Glyma.14G194300 might be involved in the accumulation of LNA content in lower LNA germplasms. CONCLUSIONS: The beneficial alleles and candidate genes identified might be valuable for improving marker-assisted breeding efficiency and exploring the molecular mechanisms underlying unsaturated fatty acid of soybean.


Assuntos
Ácidos Graxos Insaturados/biossíntese , Soja/genética , Genes de Plantas , Estudo de Associação Genômica Ampla , Desequilíbrio de Ligação , Polimorfismo de Nucleotídeo Único , Sementes/metabolismo , Soja/metabolismo , Transcrição Genética
19.
Cell Mol Life Sci ; 76(9): 1795-1806, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30694347

RESUMO

Saturated fatty acids, such as palmitate, lead to circadian disruption in cell culture. Moreover, information regarding the effects of unsaturated fatty acids on circadian parameters is scarce. We aimed at studying the effects of low doses of saturated as well as unsaturated fatty acids on circadian metabolism in vivo and at deciphering the mechanism by which fatty acids convey their effect. Mice were fed non-obesogenic doses of palm or olive oil and hepatocytes were treated with palmitate and oleate. Mice fed non-obesogenic doses of palm oil showed increased signaling towards fatty acid synthesis, while olive oil increased signaling towards fatty acid oxidation. Low doses of palmitate and oleate were sufficient to alter circadian rhythms, due to changes in the expression and/or activity of key metabolic proteins. Palmitate, but not oleate, counteracted the reduction in lipid accumulation and BMAL1-induced expression of mitochondrial genes involved in fatty acid oxidation. Palmitate was also found to interfere with the transcriptional activity of CLOCK:BMAL1 by preventing BMAL1 deacetylation and activation. In addition, palmitate, but not oleate, reduced PER2-mediated transcriptional activation and increased REV-ERBα-mediated transcriptional inhibition of Bmal1. The inhibition of PER2-mediated transcriptional activation by palmitate was achieved by interfering with PER2 nuclear translocation. Indeed, PER2 reduced fat accumulation in hepatocytes and this reduction was prevented by palmitate. Herein, we show that the detrimental metabolic alteration seen with high doses of palmitate manifests itself early on even with non-obesogenic levels. This is achieved by modulating BMAL1 at several levels abrogating its activity and expression.


Assuntos
Relógios Circadianos/fisiologia , Ritmo Circadiano/efeitos dos fármacos , Ácidos Graxos Insaturados/farmacologia , Ácido Oleico/farmacologia , Azeite de Oliva/farmacologia , Óleo de Palmeira/farmacologia , Palmitatos/farmacologia , Fatores de Transcrição ARNTL/metabolismo , Animais , Proteínas CLOCK/metabolismo , Linhagem Celular , Ácidos Graxos Insaturados/biossíntese , Fígado/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Oxirredução/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos
20.
Br J Nutr ; 121(4): 374-383, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30621805

RESUMO

To compare the growth and biosynthetic ability of long-chain PUFA (LC-PUFA) of the genetically improved farmed tilapia (GIFT) (Oreochromis niloticus) in different water salinities, an 8-week feeding trial was conducted on the GIFT juveniles at 0, 12 and 24 ‰ (parts per thousand; ppt), respectively, with three isonitrogenous (32 %) and isolipidic (8 %) diets (D1-D3). Diet D1 with fish oils (rich in LC-PUFA) as lipid source was used as the control, while D2 and D3 with vegetable oil (free LC-PUFA) blends as lipid source contained different ratios of linoleic acid (LA, 18 : 2n-6) and α-linolenic acid (ALA, 18 : 3n-3) at 4·04 (D2) and 0·54 (D3), respectively. At the end of feeding trial, the growth performance of D2 and D3 groups under all salinity treatments was as good as that of D1 group, which indicates that the GIFT juveniles may convert dietary LA and ALA into LC-PUFA to meet the requirement of essential fatty acids for normal growth and physiology. When fed the same diets, GIFT at 12 ppt had a better growth performance coupled with a higher liver and muscle arachidonic acid content than those in freshwater. Furthermore, brackish water (24 ppt) significantly promoted the mRNA levels of elongase 5 of very long-chain fatty acids (elovl5) and peroxisome proliferator-activated receptor α (pparα) in liver, when compared with freshwater. These results suggest that the GIFT may display better growth performance together with a relatively higher endogenous LC-PUFA biosynthetic ability under brackish water (12 and 24 ppt), probably through improving the expression of elovl5 and pparα in liver.


Assuntos
Aquicultura/métodos , Dieta/métodos , Ácidos Graxos Insaturados/biossíntese , Salinidade , Tilápia/crescimento & desenvolvimento , Ração Animal/análise , Animais , Animais Geneticamente Modificados , Óleos de Peixe/administração & dosagem , Fígado/metabolismo , PPAR alfa/metabolismo , Óleos Vegetais/administração & dosagem , Tilápia/genética
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