scholarly journals Transcriptomics and Metabolomics Analyses Provide Novel Insights into Glucose-Induced Trophic Transition of the Marine Diatom Nitzschia laevis

Marine Drugs ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. 426
Author(s):  
Xuemei Mao ◽  
Mengdie Ge ◽  
Xia Wang ◽  
Jianfeng Yu ◽  
Xiaojie Li ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Carotenoid Biosynthesis ◽  
Marine Diatom ◽  
Physiological Data ◽  
Biomass Density ◽  
Nitzschia Laevis ◽  
Transcriptome Resource ◽  
Rate Limiting ◽  
Molecular Framework ◽  
Glucose Supplementation

Diatoms have important ecological roles and are natural sources of bioactive compounds. Nitzschia laevis is a member of marine diatoms that accumulates high-value products including fucoxanthin and eicosapentaenoic acid (EPA). In this study, physiological data showed that comparing to autotrophic growth, mixotrophic cultivation with glucose supplementation led to a decrease of chlorophyll and fucoxanthin content in N. laevis, and an increase of biomass density and EPA yield. To further examine the metabolic barriers for fucoxanthin and EPA biosynthesis, comparative transcriptomic and metabolome analyses were conducted, with a focus on the genes related to carotenoids biosynthesis and fatty acid metabolism. The results indicated that phytoene desaturase (PDS) and zeta-carotene isomerase (ZISO) could be the rate-limiting enzymes in carotenoid biosynthesis. The transcription regulation of 3-ketoacyl-CoA synthase (KCS) and elongation of very long chain fatty acids protein (EVOVL) are important contributors associated with polyunsaturated fatty acids (PUFAs) accumulation. Furthermore, we also investigated the glucose-associated regulatory genes using weighted gene co-expression network analysis, and identified potential hub genes linked with cell cycle, carbohydrate metabolism, purine biosynthesis, and lipid metabolism. This study offers a high-quality transcriptome resource for N. laevis and provides a molecular framework for further metabolic engineering studies on fucoxanthin and EPA production.

Design of the oxygen and substrate pathways. V. Structural basis of vascular substrate supply to muscle cells.

1996 ◽  
Vol 199 (8) ◽  
pp. 1675-1688 ◽  
Author(s):  
R Vock ◽  
E R Weibel ◽  
H Hoppeler ◽  
G Ordway ◽  
J M Weber ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Surface Area ◽  
Oxygen Demand ◽  
Intercellular Junctions ◽  
Muscle Cells ◽  
Structural Basis ◽  
Physiological Data ◽  
Capillary Surface ◽  
Substrate Supply ◽  
Structural Capacity

This paper quantifies the structural capacity of the transport steps for oxygen, glucose and fatty acids from the blood in capillaries to the cytosol of muscle cells and compares it with maximal rates of oxygen and substrate transport measured in the same animals and reported in the preceding papers of this series. Dogs have relatively more muscle per unit body mass than goats (37 versus 26%), but the maximal rate of oxidation per gram of muscle is still larger in the dog by a factor of 1.55. The maximal rates of substrate supply from the circulation are similar in both species. We predict that these differences in physiological parameters should be matched by proportional differences in structural capacity. We find that capillary volume and surface area are matched to maximal oxygen demand. The rate of vascular substrate supply is proportional neither to the capillary surface area nor to the length of intercellular junctions. The sarcolemmal surface area per gram of muscle is the same in both species. Using the physiological data presented in the companion papers of this series, we have calculated the maximal flux densities of circulatory glucose and fatty acids across the capillary wall and the sarcolemma. We find, for both substrates, that the flux densities across the sarcolemma reach a maximum at nearly the same level and at low exercise intensities in both species. In contrast, the flux densities across the capillary surface and the endothelial junctions are higher in goats than in dogs. We conclude that the capillaries are designed for O2 supply up to maximal rates of oxidation but not for the supply of the substrates (glucose and fatty acids) at the rates required at high exercise intensities. These are limited by the transport capacities of the sarcolemma.

Impact of UV-B Radiation on the Lipid and Fatty Acid Composition of Synchronized Ditylum brightwellii (West) Grunow

1994 ◽  
Vol 49 (9-10) ◽  
pp. 607-614 ◽  
Author(s):  
Günter Döhler ◽  
Thomas Biermann
Keyword(s):  
Cell Cycle ◽  
Fatty Acids ◽  
Dark Period ◽  
Inhibitory Effect ◽  
Light Period ◽  
Marine Diatom ◽  
Lag Phase ◽  
Ditylum Brightwellii ◽  
Acyl Lipids ◽  
The Impact

Abstract The marine diatom Ditylum brightwellii (West) Grunow isolated from the Baltic Sea could be synchronized by a light/dark rhythm of 6.5:17.5 h (white light intensity 8 W m-2) at 18 °C and 0.035 vol.% CO2. Content of protein, DNA and RNA increased linearly up to the end of the cell cycle. Pigments (chlorophyll a, chlorophyll c1 + c2, carotenoids) and galactolipids were synthesized in the light period only. A lag phase of 2 h was observed in the biosynthesis of sulphoquinovosyl diacylglycerol and phosphatidylglycerol. Formation of phosphatidylglycerol and phosphatidylcholin continued in the dark period (30% and 28%, respectively). The pattern of major fatty acids (C14:0, C16:1, C16:0, C18:1 and C20:5) varied during the cell cycle of Ditylum.Biosynthesis of acyl lipids was reduced in dependence on the UV-B dose. The most sensitive lipid was digalactosyl diacylglycerol (total inhibition at 585 J m-2), whereas phosphatidylcholin was less affected (20% reduction). UV-B radiation during the dark period had no effect on the lipid and pigment content. Strongest inhibitory effect of UV-B on cell division, synthesis of protein, pigments, sulphoquinovosyl diacylglycerol and phosphatidylglycerol was found after UV-B radiation at the beginning of the cell cycle (0.-2. h). An exposure time at the end of the light period (4.-6. h) led to a marked damage on the synthesis of monogalactosyl diacylglycerol and phosphatidylglycerol. These findings indicate a stage-dependent response of Ditylum to UV-B irradiance. The impact of UV-B resulted in an increase of unsaturated long chained fatty acids (C18, C20) and in a diminution of short chained fatty acids (C14, C16). Content of ATP was not affected by UV-B radiation under the used conditions. The inhibitory effect of UV-B on synthesis of DNA, RNA, protein and acyl lipids was mainly reversible. Results were discussed with reference to UV-B damage on the enzymes involved in the biosynthesis of acyl lipids and by a reduction of available metabolites.

scholarly journals Potential of the marine diatom Halamphora coffeaeformis to simultaneously produce omega-3 fatty acids, chrysolaminarin and fucoxanthin in a raceway pond

2020 ◽  
Vol 51 ◽  
pp. 102030 ◽  
Author(s):  
Cecilia A. Popovich ◽  
María B. Faraoni ◽  
Alejandra Sequeira ◽  
Yasmín Daglio ◽  
Lucas A. Martín ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Marine Diatom ◽  
Omega 3 Fatty Acids ◽  
Omega 3 ◽  
Raceway Pond

scholarly journals Phenomics reveals a novel putative chloroplast fatty acid transporter in the marine diatom Skeletonema marinoi involved in temperature acclimation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Oskar N. Johansson ◽  
Mats Töpel ◽  
Jenny Egardt ◽  
Matthew I. M. Pinder ◽  
Mats X. Andersson ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Temperature Acclimation ◽  
Marine Diatom ◽  
Specific Gene ◽  
Hypothetical Proteins ◽  
Omega 3 ◽  
Fatty Acid Transporter ◽  
Future Value ◽  
Acid Transporter

Abstract Diatoms are the dominant phytoplankton in temperate oceans and coastal regions and yet little is known about the genetic basis underpinning their global success. Here, we address this challenge by developing the first phenomic approach for a diatom, screening a collection of randomly mutagenized but identifiably tagged transformants. Based upon their tolerance to temperature extremes, several compromised mutants were identified revealing genes either stress related or encoding hypothetical proteins of unknown function. We reveal one of these hypothetical proteins is a novel putative chloroplast fatty acid transporter whose loss affects several fatty acids including the two omega-3, long-chain polyunsaturated fatty acids - eicosapentaenoic and docosahexaenoic acid, both of which have medical importance as dietary supplements and industrial significance in aquaculture and biofuels. This mutant phenotype not only provides new insights into the fatty acid biosynthetic pathways in diatoms but also highlights the future value of phenomics for revealing specific gene functions in these ecologically important phytoplankton.

scholarly journals Fatty Acids Regulate Porcine Reproductive and Respiratory Syndrome Virus Infection via the AMPK-ACC1 Signaling Pathway

Viruses ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1145 ◽  
Author(s):  
Siwen Long ◽  
Yanrong Zhou ◽  
Dongcheng Bai ◽  
Wanjun Hao ◽  
Bohan Zheng ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Adenosine Monophosphate ◽  
Respiratory Syndrome Virus ◽  
Biosynthesis Pathway ◽  
Acetyl Coa Carboxylase ◽  
Inactive Form ◽  
Antiviral Targets ◽  
Amp Activated Protein Kinase ◽  
New Evidence ◽  
Rate Limiting

Lipids play a crucial role in the replication of porcine reproductive and respiratory syndrome virus (PRRSV), a porcine virus that is endemic throughout the world. However, little is known about the effect of fatty acids (FAs), a type of vital lipid, on PRRSV infection. In this study, we found that treatment with a FA biosynthetic inhibitor significantly inhibited PRRSV propagation, indicating the necessity of FAs for optimal replication of PRRSV. Further study revealed that 5′-adenosine monophosphate (AMP)-activated protein kinase (AMPK), a key kinase antagonizing FA biosynthesis, was strongly activated by PRRSV and the pharmacological activator of AMPK exhibited anti-PRRSV activity. Additionally, we found that acetyl-CoA carboxylase 1 (ACC1), the first rate-limiting enzyme in the FA biosynthesis pathway, was phosphorylated (inactive form) by PRRSV-activated AMPK, and active ACC1 was required for PRRSV proliferation, suggesting that the PRRSV infection induced the activation of the AMPK–ACC1 pathway, which was not conducive to PRRSV replication. This work provides new evidence about the mechanisms involved in host lipid metabolism during PRRSV infection and identifies novel potential antiviral targets for PRRSV.

Regulation of ethanolamine and choline phosphatide biosynthesis in isolated rat intestinal villus cells

1980 ◽  
Vol 58 (7) ◽  
pp. 527-533 ◽  
Author(s):  
P. J. A. O'Doherty
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Lauric Acid ◽  
Unsaturated Fatty Acids ◽  
Phospholipid Synthesis ◽  
Intestinal Villus ◽  
Maximal Stimulation ◽  
Rate Limiting ◽  
Isolated Rat

The effects of ethanolamine, choline, and different fatty acids on phospholipid synthesis via the CDP-ester pathways were studied in isolated rat intestinal villus cells. The incorporation of [14C]glucose into phosphatidylethanolamine was stimulated severalfold by the addition of ethanolamine and long-chained unsaturated fatty acids, while the addition of lauric acid inhibited the incorporation of radioactivity into phosphatidylethanolamine. At concentrations of ethanolamine higher than 0.2 mM, phosphoethanolamine accumulated, but the concentration of CDP-ethanolamine and the incorporation of radioactivity into phosphatidylethanolamine did not increase further. The incorporation of [14C]glucose into phosphatidylcholine responded in a way similar to that of phosphatidylethanolamine, except that a 10-fold higher concentration of choline was required for maximal stimulation. CCC inhibited the incorporation of choline into phosphatidylcholine. In contrast with hepatocytes, villus cells did not form phosphatidylcholine via phospholipid N-methylation. The data indicate that, in intestinal villus cells, the cytidylyltransferase reactions are rate limiting in the synthesis of phosphatidylethanolamine and probably also of phosphatidylcholine. The availability of diacylglycerol and its fatty acid composition may also significantly affect the rate of phospholipid synthesis.

scholarly journals The ANGPTL3-4-8 model, a molecular mechanism for triglyceride trafficking

Open Biology ◽  
2016 ◽  
Vol 6 (4) ◽  
pp. 150272 ◽  
Author(s):  
Ren Zhang
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acids ◽  
Adipose Tissue ◽  
Free Fatty Acids ◽  
White Adipose Tissue ◽  
Skeletal Muscles ◽  
General Framework ◽  
Peripheral Tissues ◽  
Specific Regulation ◽  
Rate Limiting

Lipoprotein lipase (LPL) is a rate-limiting enzyme for hydrolysing circulating triglycerides (TG) into free fatty acids that are taken up by peripheral tissues. Postprandial LPL activity rises in white adipose tissue (WAT), but declines in the heart and skeletal muscle, thereby directing circulating TG to WAT for storage; the reverse is true during fasting. However, the mechanism for the tissue-specific regulation of LPL activity during the fed–fast cycle has been elusive. Recent identification of lipasin/angiopoietin-like 8 (Angptl8), a feeding-induced hepatokine, together with Angptl3 and Angptl4, provides intriguing, yet puzzling, insights, because all the three Angptl members are LPL inhibitors, and the deficiency (overexpression) of any one causes hypotriglyceridaemia (hypertriglyceridaemia). Then, why does nature need all of the three? Our recent data that Angptl8 negatively regulates LPL activity specifically in cardiac and skeletal muscles suggest an Angptl3-4-8 model: feeding induces Angptl8, activating the Angptl8–Angptl3 pathway, which inhibits LPL in cardiac and skeletal muscles, thereby making circulating TG available for uptake by WAT, in which LPL activity is elevated owing to diminished Angptl4; the reverse is true during fasting, which suppresses Angptl8 but induces Angptl4, thereby directing TG to muscles. The model suggests a general framework for how TG trafficking is regulated.

Sterols and fatty acids of the marine diatom biddulphia sinensis

1980 ◽  
Vol 19 (8) ◽  
pp. 1809-1813 ◽  
Author(s):  
John K. Volkman ◽  
Geoffrey Eglinton ◽  
Eric D.S. Corner
Keyword(s):  
Fatty Acids ◽  
Marine Diatom
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