Sterols and Fatty Acids Isolated from Laboratory Culture of the Toxic Marine Diatom Pseudo-nitzschia pungens

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.

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

Algal Research ◽

10.1016/j.algal.2020.102030 ◽

2020 ◽

Vol 51 ◽

pp. 102030 ◽

Cited By ~ 1

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

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

Scientific Reports ◽

10.1038/s41598-019-51683-y ◽

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.

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Heterotrophic Production of Omega-3 Long-Chain Polyunsaturated Fatty Acids by Trophically Converted Marine Diatom Phaeodactylum tricornutum

Marine Drugs ◽

10.3390/md14030053 ◽

2016 ◽

Vol 14 (3) ◽

pp. 53 ◽

Cited By ~ 40

Author(s):

Mary Hamilton ◽

Stephen Powers ◽

Johnathan Napier ◽

Olga Sayanova

Keyword(s):

Fatty Acids ◽

Polyunsaturated Fatty Acids ◽

Phaeodactylum Tricornutum ◽

Marine Diatom ◽

Omega 3 ◽

Long Chain ◽

Heterotrophic Production

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Sterols and fatty acids of the marine diatom biddulphia sinensis

Phytochemistry ◽

10.1016/s0031-9422(00)83818-2 ◽

1980 ◽

Vol 19 (8) ◽

pp. 1809-1813 ◽

Cited By ~ 98

Author(s):

John K. Volkman ◽

Geoffrey Eglinton ◽

Eric D.S. Corner

Keyword(s):

Fatty Acids ◽

Marine Diatom

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The effect of salinity on growth and amino acid composition in the marine diatom Nitzschia pungens

Canadian Journal of Botany ◽

10.1139/b92-272 ◽

1992 ◽

Vol 70 (11) ◽

pp. 2198-2201 ◽

Cited By ~ 44

Author(s):

Anne E. Jackson ◽

Stephen W. Ayer ◽

Maurice V. Laycock

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Osmotic Pressure ◽

Marine Diatom ◽

Salinity Range ◽

Optimal Salinity ◽

Maritime Canada ◽

Total Amino Acids ◽

Positive Compound ◽

Nitzschia Pungens

Nitzschia pungens f. multiseries and N. pungens f. pungens, isolated from two estuaries in Maritime Canada, were grown at various salinities (6–48‰) and their growth rates and free amino acid compositions were determined. The optimal salinity range for growth of f. multiseries was 30–45‰, whereas that of f. pungens was 15–30‰. At higher salinities there was increased production of a ninhydrin-positive compound, which was identified as the amino acid taurine. When f. multiseries was grown at a salinity of 48‰ and rapidly exposed to 15‰, the concentration of taurine decreased markedly (from 61 to 7% of the total amino acids). The evidence indicates that taurine may serve to regulate the osmotic pressure of N. pungens f. multiseries, a role not previously assigned to taurine in a marine diatom. Key words: Nitzschia pungens, salinity, osmotic pressure, amino acids, taurine.

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Studies on the production of useful chemicals, especially fatty acids in the marine diatom Nitzschia conspicua Grunow

Hydrobiologia ◽

10.1007/bf00005651 ◽

1994 ◽

Vol 285 (1-3) ◽

pp. 33-40 ◽

Cited By ~ 8

Author(s):

Wan-Loy Chu ◽

Siew-Moi Phang ◽

Swee-Hock Goh

Keyword(s):

Fatty Acids ◽

Marine Diatom

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Stability of lipids during wet storage of the marine diatom Porosira glacialis under semi-preserved conditions at 4 and 20 °C

Journal of Applied Phycology ◽

10.1007/s10811-020-02292-0 ◽

2020 ◽

Author(s):

Lars Dalheim ◽

Jon B. Svenning ◽

Hans C. Eilertsen ◽

Terje Vasskog ◽

Ragnar L. Olsen

Keyword(s):

Heat Treatment ◽

Fatty Acids ◽

Fatty Acid Composition ◽

Fatty Acid ◽

Benzoic Acid ◽

Formic Acid ◽

Storage Conditions ◽

Marine Diatom ◽

Lipid Quality ◽

Heat Treated

Abstract Cultivation of diatoms may help alleviate the pressure on wild fish stocks for marine nutrient availability in aquaculture feed and for human consumption. However, the lipids in microalgae biomass are easily deteriorated, both trough lipolysis and degradation of polyunsaturated fatty acids (PUFA). Proper storage conditions are therefore necessary to maintain the lipid quality. Additionally, the storage conditions must have a low cost and facilitate further processing of the biomass. In this study, we investigated the formation of free fatty acids, changes in lipid classes, and fatty acid composition of the psychrophilic marine diatom Porosira glacialis under storage. The wet biomass was stored for 14 days at 4 and 20 °C with either heat treatment, formic acid, or benzoic acid addition, and a control sample. Heat-treated and formic acid samples had the lowest rate of free fatty acid formation during storage. Mainly, polar lipids were hydrolyzed to free fatty acids and this occurred fastest at 20 °C. The fatty acid composition remained stable in heat-treated samples during storage, whereas a loss of PUFA was observed in the other treatments. The lack of effect from benzoic acid indicates that the loss of lipid quality stems from endogenous enzymes rather than exogenous organisms. Heat treatment and formic acid appeared to effectively reduce lipase activity, and potentially lipoxygenase and similar enzymes that affect the fatty acids. The low pH of the formic acid samples seems to have a negative effect on the PUFA content, in particular at 20 °C.

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