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Feixue Fu - One of the best experts on this subject based on the ideXlab platform.
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CO_2 and vitamin B_12 interactions determine bioactive trace metal requirements of a subarctic Pacific diatom
The ISME Journal, 2011Co-Authors: Andrew L King, Sergio A Sañudo-wilhelmy, Karine Leblanc, David A Hutchins, Feixue FuAbstract:Phytoplankton growth can be limited by numerous inorganic nutrients and organic growth factors. Using the subarctic diatom Attheya sp. in culture studies, we examined how the availability of vitamin B_12 and carbon dioxide partial pressure (pCO_2) influences growth rate, primary productivity, cellular iron (Fe), cobalt (Co), zinc (Zn) and cadmium (Cd) quotas, and the net use efficiencies (NUEs) of these bioactive trace metals (mol C fixed per mol cellular trace metal per day). Under B_12-replete conditions, cells grown at high pCO_2 had lower Fe, Zn and Cd quotas, and used those trace metals more efficiently in comparison with cells grown at low pCO_2. At high pCO_2, B_12-limited cells had ∼50% lower specific growth and carbon fixation rates, and used Fe ∼15-fold less efficiently, and Zn and Cd ∼3-fold less efficiently, in comparison with B_12-replete cells. The observed higher Fe, Zn and Cd NUE under high pCO_2/B_12-replete conditions are consistent with predicted downregulation of carbon-concentrating mechanisms. Co quotas of B_12-replete cells were ∼5- to 14-fold higher in comparison with B_12-limited cells, suggesting that >80% of cellular Co of B_12-limited cells was likely from B_12. Our results demonstrate that CO_2 and vitamin B_12 interactively influence growth, carbon fixation, trace metal requirements and trace metal NUE of this diatom. This suggests the need to consider complex feedback interactions between multiple environmental factors for this biogeochemically critical group of phytoplankton in the last glacial maximum as well as the current and future changing ocean.
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CO2 and vitamin B12 interactions determine bioactive trace metal requirements of a subarctic Pacific diatom
The ISME Journal, 2011Co-Authors: Andrew L King, Sergio A Sañudo-wilhelmy, Karine Leblanc, David A Hutchins, Feixue FuAbstract:Phytoplankton growth can be limited by numerous inorganic nutrients and organic growth factors. Using the subarctic diatom Attheya sp. in culture studies, we examined how the availability of vitamin B-12 and carbon dioxide partial pressure (pCO(2)) influences growth rate, primary productivity, cellular iron (Fe), cobalt (Co), zinc (Zn) and cadmium (Cd) quotas, and the net use efficiencies (NUEs) of these bioactive trace metals (mol C fixed per mol cellular trace metal per day). Under B-12-replete conditions, cells grown at high pCO(2) had lower Fe, Zn and Cd quotas, and used those trace metals more efficiently in comparison with cells grown at low pCO(2). At high pCO(2), B-12-limited cells had similar to 50% lower specific growth and carbon fixation rates, and used Fe similar to 15-fold less efficiently, and Zn and Cd similar to 3-fold less efficiently, in comparison with B-12-replete cells. The observed higher Fe, Zn and Cd NUE under high pCO(2)/B-12-replete conditions are consistent with predicted downregulation of carbon-concentrating mechanisms. Co quotas of B-12-replete cells were similar to 5- to 14-fold higher in comparison with B-12-limited cells, suggesting that >80% of cellular Co of B-12-limited cells was likely from B-12. Our results demonstrate that CO2 and vitamin B-12 interactively influence growth, carbon fixation, trace metal requirements and trace metal NUE of this diatom. This suggests the need to consider complex feedback interactions between multiple environmental factors for this biogeochemically critical group of phytoplankton in the last glacial maximum as well as the current and future changing ocean. The ISME Journal (2011) 5, 1388-1396; doi: 10.1038/ismej.2010.211; published online 20 January 2011
I V Stonik - One of the best experts on this subject based on the ideXlab platform.
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Sterols and Fatty Acids from Attheya Planktonic Diatoms
Chemistry of Natural Compounds, 2017Co-Authors: I V Stonik, N. A. Aizdaicher, I. I. Kapustina, V. I. SvetashevAbstract:Sterols and fatty-acids isolated from laboratory cultures of the diatoms Attheya decora, A. arenicola, and A. longicornis were studied. The studied cultures of these species were substantially different with respect to the quantitative contents of polyunsaturated fatty acids and sterols. Rare sterols were found in several strains. It was shown that A. arenicola contained primarily 24-ethylcholesterol; A. longicornis and A. decora, 24-ethylcholesterol, 24-methylcholesterol, fucosterol, and 24-methylenecholesterol. Such differences indicate that the genus comprises various groups of species, the phylogenetic positions of which need to be defined.
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The species composition, morphology, and seasonal distribution of diatoms of the genus Attheya West, 1860 from the Sea of Japan
Russian Journal of Marine Biology, 2016Co-Authors: I V Stonik, N. A. AizdaicherAbstract:Six species that belong to the diatom genus Attheya were found in the Russian waters of the Sea of Japan. A. cf. flexuosa is a new record for the seas of Russia. A. decora is recorded for the first time for the Sea of Japan. The peculiarities of the morphology of A. decora and A . cf. flexuosa are described and illustrated. The study of the seasonal distribution, abundance, and ecology of Attheya species in the northwestern Sea of Japan showed that A. longicornis and A. ussurensis were the most numerous and widespread species, reaching maximum densities (up to 1.5 × 10^6 and 1.8 × 10^4 cells/liter, respectively) in the spring, summer, and fall. A . cf. flexuosa and A. septentrionalis were rare and were found in low numbers in the winter and early spring. Based on the ultrastructure of the girdle bands, the form and number of chloroplasts, the presence/absence of rimoportula on the valve, and habitat features, we distinguished two groups of species of the genus Attheya from the Sea of Japan. The first group includes psammophytes A. decora, A. arenicola , and A. ussurensis ; the second one comprises A. longicornis and A . cf. flexuosa epiphytic on other diatoms, as well as A. septentrionalis , which is found in the under-ice plankton and is able to attach to the underside of ice.
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The morphology, development, and state of the photosynthetic apparatus of the diatom Attheya ussurensis Stonik, Orlova et Crawford, 2006 (Bacillariophyta) in long-term culture
Russian Journal of Marine Biology, 2011Co-Authors: T. Yu. Orlova, I V Stonik, N. A. Aizdaicher, O. G. Schevchenko, S. I. PogosyanAbstract:The development of the marine benthic diatom Attheya ussurensis (Bacillariophyta) isolated from Ussuriisky Bay (Sea of Japan) was examined in laboratory culture. It was found that the development of A. ussurensis was characterized by a short lag phase or its absence and high growth rates (about 1.7 divisions per day) during the exponential phase. Resting cells were formed during the stationary growth phase. Morphological and ultrastructural changes in the cells of A. ussurensis during its life cycle are described based on light and electron microscopic observations. Resting cells retained their photosynthetic activity when stored in the dark for a long period of time (up to 1 year) at a temperature of 4–6°C. After 30, 60, 90, 120, 150, and 180 days of storage under such conditions, the culture of A. ussurensis was capable of regeneration due to the existence of the resting cell stage in the life cycle of the microalga.
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Diatoms of the genus Attheya west, 1860 from the Sea of Japan
Russian Journal of Marine Biology, 2006Co-Authors: I V Stonik, T. Yu. Orlova, N. A. AizdaicherAbstract:This paper documents the species diversity of the diatom genus Attheya from the Sea of Japan. Two species ( A. arenicola and A. longicornis ) were studied in field samples and in culture. Their morphology is described using light and electron microscopy; the ecology and the distribution data are provided. A. arenicola is a new record for the seas of Russia.
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Attheya ussurensis sp nov bacillariophyta a new marine diatom from the coastal waters of the sea of japan and a reappraisal of the genus
Phycologia, 2006Co-Authors: I V Stonik, Tatiana Yu Orlova, Richard M CrawfordAbstract:Abstract A new species of the mainly sand-dwelling marine diatom genus Attheya is described from the Sea of Japan. Of the seven species of the genus, Attheya ussurensis most closely resembles Attheya decora in its valve and girdle structure and in its plastid form and number, but it also possesses features found in one or other of the remaining species (presence of a rimoportula, pores in the girdle bands and horn morphology). Keys are provided to aid ide.gification of all known Attheya species.
N. A. Aizdaicher - One of the best experts on this subject based on the ideXlab platform.
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Sterols and Fatty Acids from Attheya Planktonic Diatoms
Chemistry of Natural Compounds, 2017Co-Authors: I V Stonik, N. A. Aizdaicher, I. I. Kapustina, V. I. SvetashevAbstract:Sterols and fatty-acids isolated from laboratory cultures of the diatoms Attheya decora, A. arenicola, and A. longicornis were studied. The studied cultures of these species were substantially different with respect to the quantitative contents of polyunsaturated fatty acids and sterols. Rare sterols were found in several strains. It was shown that A. arenicola contained primarily 24-ethylcholesterol; A. longicornis and A. decora, 24-ethylcholesterol, 24-methylcholesterol, fucosterol, and 24-methylenecholesterol. Such differences indicate that the genus comprises various groups of species, the phylogenetic positions of which need to be defined.
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The species composition, morphology, and seasonal distribution of diatoms of the genus Attheya West, 1860 from the Sea of Japan
Russian Journal of Marine Biology, 2016Co-Authors: I V Stonik, N. A. AizdaicherAbstract:Six species that belong to the diatom genus Attheya were found in the Russian waters of the Sea of Japan. A. cf. flexuosa is a new record for the seas of Russia. A. decora is recorded for the first time for the Sea of Japan. The peculiarities of the morphology of A. decora and A . cf. flexuosa are described and illustrated. The study of the seasonal distribution, abundance, and ecology of Attheya species in the northwestern Sea of Japan showed that A. longicornis and A. ussurensis were the most numerous and widespread species, reaching maximum densities (up to 1.5 × 10^6 and 1.8 × 10^4 cells/liter, respectively) in the spring, summer, and fall. A . cf. flexuosa and A. septentrionalis were rare and were found in low numbers in the winter and early spring. Based on the ultrastructure of the girdle bands, the form and number of chloroplasts, the presence/absence of rimoportula on the valve, and habitat features, we distinguished two groups of species of the genus Attheya from the Sea of Japan. The first group includes psammophytes A. decora, A. arenicola , and A. ussurensis ; the second one comprises A. longicornis and A . cf. flexuosa epiphytic on other diatoms, as well as A. septentrionalis , which is found in the under-ice plankton and is able to attach to the underside of ice.
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The morphology, development, and state of the photosynthetic apparatus of the diatom Attheya ussurensis Stonik, Orlova et Crawford, 2006 (Bacillariophyta) in long-term culture
Russian Journal of Marine Biology, 2011Co-Authors: T. Yu. Orlova, I V Stonik, N. A. Aizdaicher, O. G. Schevchenko, S. I. PogosyanAbstract:The development of the marine benthic diatom Attheya ussurensis (Bacillariophyta) isolated from Ussuriisky Bay (Sea of Japan) was examined in laboratory culture. It was found that the development of A. ussurensis was characterized by a short lag phase or its absence and high growth rates (about 1.7 divisions per day) during the exponential phase. Resting cells were formed during the stationary growth phase. Morphological and ultrastructural changes in the cells of A. ussurensis during its life cycle are described based on light and electron microscopic observations. Resting cells retained their photosynthetic activity when stored in the dark for a long period of time (up to 1 year) at a temperature of 4–6°C. After 30, 60, 90, 120, 150, and 180 days of storage under such conditions, the culture of A. ussurensis was capable of regeneration due to the existence of the resting cell stage in the life cycle of the microalga.
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Influence of changes in sea water salinity on the growth, photosynthetic pigment content, and cell size of the benthic alga Attheya ussurensis Stonik, Orlova et Crawford, 2006 (Bacillariophyta)
Russian Journal of Marine Biology, 2011Co-Authors: N. A. Aizdaicher, Zh. V. MarkinaAbstract:The study deals with the effect of changes in salinity from 32 to 4‰ (at an interval of 4‰) on the growth, chlorophyll a and carotenoid contents, and cell size of the benthic alga Attheya ussurensis (Bacillariophyta). A. ussurensis showed high tolerance to reduced salinity and ability to adapt to salinity changes from 16 to 12‰. In this salinity range, the cells restored their shapes, sizes, and physiological functions. The number of cells and photosynthetic pigment content were highest at a salinity reduction to 24‰. At 8‰, algal cells remained alive, but the process of cell division was inhibited; as a result, the number of cells was significantly lower than in the control, the cells did not restore their sizes and shapes and remained deformed until the end of the experiment. A drop in salinity to 4‰ caused a complete loss of cell viability of A. ussurensis within a day of exposure to this factor.
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The influence of hexavalent chromium salt on the population growth, cell morphology, and physiological parameters of the benthic microalga Attheya ussurensis Stonik, Orlova, Crawford, 2006 (BACILLARIOPHYTA) in culture
Russian Journal of Marine Biology, 2011Co-Authors: N. A. Aizdaicher, Zh. V. MarkinaAbstract:The presence of hexavalent chromium salt in culture medium negatively affected the growth dynamics and physiological parameters of the benthic microalga Attheya ussurensis . After 1 day of exposure to toxicant at concentrations of 2, 4, 7, and 10 mg/l, the cell counts were 10, 7.9, 5.6, and 4.3 × 10^3 cells/ml, respectively (versus 13 × 10^3 cells/ml in the control). A tendency towards a decrease in cell number remained until the end of the experiments; after 7 days of exposure the cell counts were 133, 102, 11, and 7.5 × 10^3 cells/ml (versus 204 × 10^3 cells/ml in the control). With increase in potassium bichromate concentration in the culture medium, there was an increase in the ratio of cell height to width and a change in the form of the cell to horseshoe shaped. The contents of chlorophyll a in microalgal cells after 1 day of exposure to 2, 4, 7, and 10 mg/l were 40, 37, 34, and 30 μg/l, respectively (45 μg/l in the control). After 7 days, at chromium salt concentrations of 2 and 4 mg/l, the chlorophyll a content was higher (670 and 647 μg/l) than in the control (605 μg/l); at 7 and 10 mg/l, it significantly decreased to 87 and 65 μg/l, respectively. The contents of carotinoids in microalgal cells after 7 days of exposure to 2 and 4 mg/l were comparable to the control values, while at 7 and 10 mg/l they decreased sharply. The amount of phaeophytin (as a percentage of total chlorophyll a content) increased with increasing potassium bichromate concentration.
Richard M Crawford - One of the best experts on this subject based on the ideXlab platform.
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Attheya ussurensis sp nov bacillariophyta a new marine diatom from the coastal waters of the sea of japan and a reappraisal of the genus
Phycologia, 2006Co-Authors: I V Stonik, Tatiana Yu Orlova, Richard M CrawfordAbstract:Abstract A new species of the mainly sand-dwelling marine diatom genus Attheya is described from the Sea of Japan. Of the seven species of the genus, Attheya ussurensis most closely resembles Attheya decora in its valve and girdle structure and in its plastid form and number, but it also possesses features found in one or other of the remaining species (presence of a rimoportula, pores in the girdle bands and horn morphology). Keys are provided to aid ide.gification of all known Attheya species.
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the combination of chaetoceros gaussii bacillariophyta with Attheya
Phycologia, 2000Co-Authors: Richard M Crawford, Friedel Hinz, Peter KoschinskiAbstract:Abstract The extremely rare, single-celled diatom Chaeloceros gausii is reported from a polynya in the southern Weddell Sea. Comparison of this material with preparations made by Heiden from the German South Pole expedition of 1901–1903 and with cultured cells has revealed affinities with the genus Attheya of benthic habitats and the combination Attheya gaussii (Heiden in Heiden & Kolbe) Crawford is proposed. Although found in the open water, we suspect that the diatom grows attached to sea ice in a similar situation to that shown by Attheya septentrionalis, which is its larger counterpart in the Arctic. An epitype is selected to support the lectotype illustrated by Simonsen in 1992.
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the genus Attheya i a description of four new taxa and the transfer of gonioceros septentrionalis and g armatas
Diatom Research, 1994Co-Authors: Richard M Crawford, Claire Gardner, Linda K MedlinAbstract:Four new taxa belonging to the genus Attheya West are described from the west coast of Britain and from the North Sea. Attheya arenicola sp. nov. was found on sandy beaches in southwest Wales, Cornwall and the west coast of Scotland in the U.K., and on the edge of the North Sea at Renesse, Netherlands. A. flexuosa var. flexuosa sp. nov. and A. flexuosa var. enodulifer sp. nov. have been found in a similar habitat attached to cells of Hantzschia Grunow and Bacillaria Gmelin spp. A. longicorrus sp. nov. attaches to other diatoms in the plankton. Using light and electron microscopy, they are compared with A. decora West, the type species of Attheya, and with Chaetoceros sessilis Grontved, Gonioceros armatus (T. West) H. & M. Peragallo and Gonioceros septentrionalis (Ostrup) Round, Crawford & Mann. It is suggested that all taxa should be placed within Attheya because of similarity of horn structure and habitat preferences.
Hans Christian Eilertsen - One of the best experts on this subject based on the ideXlab platform.
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lipid content and fatty acid composition of porosira glacialis and Attheya longicornis in response to carbon dioxide co2 aeration
PLOS ONE, 2017Co-Authors: Elena Artamonova, Terje Vasskog, Hans Christian EilertsenAbstract:In the current study two novel psychrophilic diatoms Porosira glacialis and Attheya longicornis were tested for suitability to CO2 mitigation coupled with production of the physiologically requisite omega- 3 fatty acids. This study is in line with the worldwide conducted research aimed at applying biorefinery concept to heavy polluting industries. Since the production of algal high value compounds, i.e. essential fatty acids, relies on utilization of residual CO2 emissions coming from industry, the costs of such production maybe substantially reduced. Besides, the ecological benefits of the biorefinery concept being implemented are obvious, since CO2 is one of the major greenhouse gases. The current research has shown that one of the tested microalgal species, the diatom P. glacialis showed good tolerance to high (20-25%) levels of CO2 and maintained growth rates comparable to controls. The total lipid content in the CO2 aerated culture increased from 8.91 to 10.57% in cell dry mass. Additionally, the content of docosahexaenoic acid (DHA) increased from 3.90 to 5.75%, while the concentration of eicosapentaenoic acid (EPA) decreased from 26.59 to 23.66%. In contrast, A. longicornis did not demonstrate any significant increase in total lipid content. Besides, its growth was hampered by high levels of CO2 aeration.
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Light and temperature effects on bioactivity in diatoms
Journal of Applied Phycology, 2016Co-Authors: Richard A. Ingebrigtsen, Espen Hansen, Jeanette Hammer Andersen, Hans Christian EilertsenAbstract:Isolates of five pelagic North Atlantic marine diatoms (Bacillariophyceae): Attheya longicornis , Chaetoceros socialis , Chaetoceros furcellatus , Skeletonema marinoi and Porosira glacialis were cultivated in large photobioreactors at two light and two temperature regimes to test if this affected bioactivity. We screened for bioactivity in assays representing five different therapeutic areas: diabetes II (PTP1b), cancer (melanoma cells, A2058), anti-oxidants (FRAP), immunomodulation (TNFa) and anti-infection (MRSA, Enterococcus faecalis , Staphylococcus aureus , Escherichia coli and Pseudomonas aeruginosa ). All the diatom strains showed activity in two or more assays. We detected differences in bioactivity both between species and within species cultivated with different light and temperature regimes. Our results demonstrate the potential for a more exhaustive exploitation of diatom metabolites that can be obtained by manipulation of the cultivation conditions.
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In vivo exposure to northern diatoms arrests sea urchin embryonic development
Toxicon, 2015Co-Authors: Elena Gudimova, Hans Christian Eilertsen, Trond Ø. Jørgensen, Espen HansenAbstract:There are numerous reports indicating that marine diatoms may act harmful to early developmental stages of invertebrates. It is believed that the compounds responsible for these detrimental effects are oxylipins resulting from oxidized polyunsaturated fatty acids, and that they may function as grazing deterrents. Most studies reporting these effects have exposed test organisms to diatom extracts or purified toxins, but data from in vivo exposure to intact diatoms are scarce. We have conducted sea urchin egg incubation and plutei feeding experiments to test if intact diatom cells affected sea urchin embryo development and survival. This was done by exposing the common northern sea urchins Strongylocentrotus droebachiensis and Echinus acutus to northern strains of the diatoms Chaetoceros socialis, Skeletonema marinoi, Chaetoceros furcellatus, Attheya longicornis, Thalassiosira gravida and Porosira glacialis. The intact diatom cell suspensions were found to inhibit sea urchin egg hatching and embryogenesis. S. marinoi was the most potent one as it caused acute mortality in S. droebachiensis eggs after only four hours exposure to high (50 μg/L Chla) diatom concentrations, as well as 24 h exposure to normal (20 μg/L Chla) and high diatom concentrations. The second most potent species was T. gravida that caused acute mortality after 24 h exposure to both diatom concentrations. A. longicornis was the least harmful of the diatom species in terms of embryo development arrestment, and it was the species that was most actively ingested by S. droebachiensis plutei.
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Chemical diversity as a function of temperature in six northern diatom species.
Marine Drugs, 2013Co-Authors: Siv Huseby, Hans Christian Eilertsen, Maria Degerlund, Gunilla Kristina Eriksen, Richard Andre Ingebrigtsen, Espen HansenAbstract:In this study, we investigate how metabolic fingerprints are related to temperature. Six common northern temperate diatoms (Attheya longicornis, Chaetoceros socialis, Chaetoceros furcellatus, Porosira glacialis, Skeletonema marinoi, and Thalassiosira gravida) were cultivated at two different temperatures, 0.5 and 8.5 °C. To exclude metabolic variations due to differences in growth rates, the growth rates were kept similar by performing the experiments under light limited conditions but in exponential growth phase. Growth rates and maximum quantum yield of photosynthesis were measured and interpreted as physiological variables, and metabolic fingerprints were acquired by high-resolution mass spectrometry. The chemical diversity varied substantially between the two temperatures for the tested species, ranging from 31% similarity for C. furcellatus and P. glacialis to 81% similarity for A. longicornis. The chemical diversity was generally highest at the lowest temperature.
