Lipid and Fatty-acid Composition of Diatoms

Opute, F. I.

doi:10.1093/jxb/25.4.823

Cited by 99 publications

(28 citation statements)

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“…The overall lipid class compositon in diatoms resembles closely that of green algae and higher plants with the main components TAG, FFA, MGDG, DGDG, SQDG, PG, PI, PC and PE (Kates and Volcani 1966;Opute 1974a;Darley 1977). Additionally, diatoms possess according to Kates and Volcani (1966) diphosphatidylglycerol and phosphatidic acid, two minor unidentified sulfur-containing lipids (less polar than SQDG) which are more produced in the dark (Kates and Volcani 1966;Opute 1974b) and an unidentified spingolipide, which could be cerebroside (Kates and Volcani 1966).…”

Section: Lipid Class Compositionmentioning

confidence: 86%

Effects of prolonged darkness and temperature on the lipid metabolism in the benthic diatom Navicula perminuta from the Arctic Adventfjorden, Svalbard

et al. 2017

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which could consequently lead to a depletion of this energy reserves before the end of the polar night. On the other hand, the membrane building phospho-and glycolipids remained unchanged during the 8 weeks darkness, indicating still intact thylakoid membranes. These results explain the shorter survival times of polar diatoms with increasing water temperatures during prolonged dark periods. Abstract The Arctic represents an extreme habitat for phototrophic algae due to long periods of darkness caused by the polar night (~4 months darkness). Benthic diatoms, which dominate microphytobenthic communities in shallow water regions, can survive this dark period, but the underlying physiological and biochemical mechanisms are not well understood. One of the potential mechanisms for long-term dark survival is the utilisation of stored energy products in combination with a reduced basic metabolism. In recent years, water temperatures in the Arctic increased due to an ongoing global warming. Higher temperatures could enhance the cellular energy requirements for the maintenance metabolism during darkness and, therefore, accelerate the consumption of lipid reserves. In this study, we investigated the macromolecular ratios and the lipid content and composition of Navicula cf. perminuta Grunow, an Arctic benthic diatom isolated from the microphytobenthos of Adventfjorden (Svalbard, Norway), over a dark period of 8 weeks at two different temperatures (0 and 7 °C). The results demonstrate that N. perminuta uses the stored lipid compound triacylglycerol (TAG) during prolonged dark periods, but also the pool of free fatty acids (FFA). Under the enhanced temperature of 7 °C, the lipid resources were used significantly faster than at 0 °C, Keywords

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Section: Lipid Class Compositionmentioning

confidence: 86%

Effects of prolonged darkness and temperature on the lipid metabolism in the benthic diatom Navicula perminuta from the Arctic Adventfjorden, Svalbard

et al. 2017

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“…The most common fatty acids are myristic acid (14:0), palmitic acid (C16:0), palmitoleic acid (C16:1n-7), DHA, and EPA (Opute, 1974;Jiang et al, 2016). The number of double bonds in fatty acid chains is usually two or three, and rarely more than six.…”

Section: Fatty Acidsmentioning

confidence: 99%

“…The number of double bonds in fatty acid chains is usually two or three, and rarely more than six. Many known microalgal species have similar fatty acid profile, but fatty acid content in each species varies and it mainly depends on the strains and culture conditions (Opute, 1974;Stonik and Stonik, 2015;Jiang et al, 2016). EPA was one of the most characterized fatty acids in diatom lipids (Stonik and Stonik, 2015), while small portion of rare C24-C28 polyunsaturated fatty acids (PUFAs) were also found in diatoms and other microalgae (Mansour et al, 2005).…”

Section: Fatty Acidsmentioning

confidence: 99%

Exploring Valuable Lipids in Diatoms

et al. 2017

Front. Mar. Sci.

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Diatoms are one major group of algae in oceans that accounts almost half of marine primary food production and have also been identified as a promising candidate for biofuel production for their high level accumulation of lipids. They have gained increasingly attention for their potential applications in pharmaceuticals, cosmetics, nutrient supplements, and biofuels. This review aims to summarize the recent advances in diatom lipid study. Chemical structures and bioactivities of different lipid classes are discussed with a focus on valuable lipids such as fatty acids, polar lipids, steroids, and oxylipins from various diatoms species. Further, current extraction and fractionation approaches are compared and recent analytical techniques and methods are also reviewed with an emphasis on lipid class composition and fatty acid profiling. Biosynthetic pathways and key catalyzing enzymes are illustrated for a better understanding of fatty acid metabolism. Past engineering attempts toward generating appropriate diatom strains for lipid production are discussed with examples using mutagenesis, environmental stimulants, and genetic modification methods. Some possible future directions and applications of diatom-derived lipids are also proposed.

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“…opute (100) found that the diatom Nitzschia palea changed its unsaturated to saturated fatty acid ratio from 2 to 1.3 between roughly 2% to 0.2% sunlight intensity. He also found that in low light very little triglycerides were formed and attributed this to the preferential synthesis of the necessary structural lipids in an energy limited environment.…”

Section: Factors Affecting the Lipid Content Of Microalgaementioning

confidence: 99%

Effects of Fluctuating Environments on the Selection of High Yielding Microalgae

Benemann¹,

Tillett²

1987

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Microalgae have the potential of producing biomass with a high content of lipids at high productivities using seawater or saline ground water resources. Microalgal lipids are similar to vegetable oils and suitable for processing to liquid fuels. Engineering Icost analysis studies have concluded that, at a favorable site, microalgae cultivation for fuel production could be economically viable. The major uncertainties involve the microalgae themselves: biomass and lipid productivity and culture stability.The mass culture of microalgae for low cost lipids production requires a detailed understanding of both the physiology of lipid biosynthesis by the selected algal strains and of the factors making these strains competitive in outdoor ponds. Mass culture systems will, because of climatic variability, the day-night cycle, and inherent design factors, exhibit fluctuations in key parameters affecting algal growth, productivity and competitiveness: temperature, pH, po?, pC02' light, and nutrient availability. This project has for ~ts overall objective to quantitate the effects of such fluctuations on culture productivity and species competitiveness. A second objective has been the development of basic information on algal physiology as it relates to lipid productivity.Species competition experiments with several strains of algae isolated by the SERI/DOE Aquatic Species Program, some of which were previously used in outdoor mass cultures, were carried out. In these experiments certain parameters proved to be more important then others in determining species succession: fluctuating p02 was more important than fluctuating temperature, which was more important than fluctuating pH. These results must be extended to other species and conditions to determine how far these findings can be generalized. Future work will concentrate on comparing unialgal to mixed culture experiments and on elucidating the specific environmental factors that impact on species productivity and competitiveness.To help guide this work, a computer model was developed capable of predicting the amplitude and frequency of the environmental parameters (p02' pH, PC02, temperature, and light intensity) over the diurnal cycle throughout the year at any location for which climatic data is available. This model must still be validated with data collected from operating ponds.Using one algal strain, "Nanno Q" (Nannochloropsis sp.), as a test organism we also have investigated strategies for maximizing lipid productivity. Our data suggest a two stage process: the first stage is operated at the highest density permitting maximal productivity and the second stage at a higher light input (lower standing biomass or cell density) and under conditions of nitrogen starvation. Such a two stage system is more productive than a continuous nitrogen limited culture process. Future work in this area should utilize algal strains that have previously been selected for their competitiveness under outdoor conditions.

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Lipid and Fatty-acid Composition of Diatoms

Cited by 99 publications

References 0 publications

Effects of prolonged darkness and temperature on the lipid metabolism in the benthic diatom Navicula perminuta from the Arctic Adventfjorden, Svalbard

Effects of prolonged darkness and temperature on the lipid metabolism in the benthic diatom Navicula perminuta from the Arctic Adventfjorden, Svalbard

Exploring Valuable Lipids in Diatoms

Effects of Fluctuating Environments on the Selection of High Yielding Microalgae

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