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| Kerbrat, Anne Sophie; Amzil, Zouher; Pawlowiez, Ralph; Golubic, Stjepko; Sibat, Manoella; Darius, Helene Taiana; Chinain, Mireille; Laurent, Dominique. |
| Marine pelagic diazotrophic cyanobacteria of the genus Trichodesmium (Oscillatoriales) are widespread throughout the tropics and subtropics, and are particularly common in the waters of New Caledonia. Blooms of Trichodesmium are suspected to be a potential source of toxins in the ciguatera food chain and were previously reported to contain several types of paralyzing toxins. The toxicity of water-soluble extracts of Trichodesmium spp. were analyzed by mouse bioassay and Neuroblastoma assay and their toxic compounds characterized using liquid chromatography coupled with tandem mass spectrometry techniques. Here, we report the first identification of palytoxin and one of its derivatives, 42-hydroxy-palytoxin, in field samples of Trichodesmium collected in... |
| Tipo: Text |
Palavras-chave: Cyanobacteria; Trichodesmium; Palytoxin; 42-hydroxy-palytoxin; Clupeotoxism. |
| Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00040/15143/12576.pdf |
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| Berthelot, H.; Benavides, M.; Moisander, P. H.; Grosso, O.; Bonnet, S.. |
| Dinitrogen (N-2) fixation rates were investigated in the euphotic layer of the Bismarck and Solomon Seas using N-15(2) incubation assays taking into account both the particulate and the dissolved pools. Average depth-integrated particulate N-2 fixation rates were 203 (range 43-399) and 1396 (range 176-3132)mol N m(-2) d(-1) in the Bismarck and Solomon Seas, respectively. In both seas, N-2 fixation measured in the dissolved pool was similar to particulate N-2 fixation, highlighting the potentially substantial underestimation of N-2 fixation in oceanic budgets when only particulate N-2 fixation is considered. Among the diazotroph phylotypes targeted using quantitative polymerase chain reaction amplification of nifH genes, Trichodesmium was the most abundant.... |
| Tipo: Text |
Palavras-chave: Diazotrophy; Trichodesmium; Crocosphaera; Cyanothece; N release. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00404/51512/72629.pdf |
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| Proença,LAO; Tamanaha,MS; Fonseca,RS. |
| Blooms of the cyanobacterium Trichodesmium occur in massive colored patches over large areas of tropical and subtropical oceans. Recently, the interest in such events has increased given their role in major nitrogen and carbon dioxide oceanic fluxes. Trichodesmium occurs all along the Brazilian coast and patches frequently migrate towards the coast. In this paper we screen the toxicity and toxin content of Trichodesmium blooms off the coast of Bahia state. Four samples, collected from February to April 2007, were analyzed. Organisms were identified and assessed for toxicity by means of several methods. Analogues of microcystins, cylindrospermopsins and saxitoxins were analyzed using HPLC. Microcystins were also assayed through ELISA. Results showed... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Saxitoxin; Microcystin; Harmful algae; Trichodesmium; Bloom. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992009000200004 |
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| Santos,Douglas Henrique Cavalcanti dos; Silva-Cunha,Maria da Glória Gonçalves; Santiago,Marilene Felipe; Passavante,José Zanon de Oliveira. |
| The phytoplankton community was studied around two artificial reefs (shipwrecks Servemar-X and Servemar-I), located off the coast of Pernambuco, northeastern Brazil, aiming to identify and thus, better describe these environments. Water samples were collected with Nansen bottle at three depths (surface, mid-column and bottom) for chlorophyll a analysis and salinity; temperature and water transparency were also measured. To collect phytoplankton samples, a diver using SCUBA equipment carried out phytoplankton hauls with a 20 µm net around the shipwrecks, about 1.5 m from the bottom for approximatly 3 minutes. Chlorophyll a concentrations at the bottom varied between 0.61 and 5.97 mg.m-3, with an average that indicates a mesotrophic environment. Temperature... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chlorophyll a; Artificial reef; Trichodesmium; Diving. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062010000400007 |
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