Suchergebnisse

17 páginas, 8 figuras, 4 tablas ; A single cell of the dinoflagellate genus Fukuyoa was isolated from the island of Formentera (Balearic Islands, west Mediterranean Sea), cultured, and characterized by morphological and molecular methods and toxin analyses. This is the first report of the Gambierdiscus lineage (genera Fukuyoa and Gambierdiscus) from the western Mediterranean Sea, which is cooler than its eastern basin. Molecular analyses revealed that the Mediterranean strain belongs to F. paulensis and that it bears LSU rDNA sequences identical to New Zealand, Australian, and Brazilian strains. It also shared an identical sequence of the more variable ITS-rDNA with the Brazilian strain. Toxin analyses showed the presence of maitotoxin, 54-deoxyCTX1B, and gambieric acid A. This is the first observation of the two latter compounds in a Fukuyoa strain. Therefore, both Gambierdiscus and Fukuyoa should be considered when as contributing to ciguatera fish poisoning. Different strains of Fukuyoa form a complex of morphologically cryptic lineages where F. paulensis stands as the most distantly related nominal species. The comparison of the ITS2 secondary structures revealed the absence of CBCs among strains. The study of the morphological and molecular traits depicted an unresolved taxonomic scenario impacted by the low strains sampling ; Financial support for this research was provided by the Basque Government (project IT699-13). A grant from the University of the Basque Country (UPV/EHU) to H. David also supported this study ; Peer reviewed

8 páginas, 1 tabla, 5 figuras ; Benthic Prorocentrum species can produce toxins that adversely affect animals and human health. They are known to co-occur with other bloom-forming, potentially toxic, benthic dinoflagellates of the genera Ostreopsis, Coolia, and Gambierdiscus. In this study, we report on the presence of P. elegans M.Faust and P. levis M.A.Faust, Kibler, Vandersea, P.A. Tester & Litaker from the southeastern Bay of Biscay. Sampling was carried out in the Summer-Autumn 2010–2012 along the Atlantic coast of the Iberian Peninsula, but these two species were only found in the northeastern part of the Peninsula. Strains were isolated from macroalgae collected from rocky-shore areas bordering accessible beaches. Morphological traits of isolated strains were analyzed by LM and SEM, whereas molecular analyses were performed using the LSU and internal transcribed spacer (ITS)1-5.8S-ITS2 regions of the rDNA. A bioassay with Artemia fransciscana and liquid chromatography–high-resolution mass spectrometry analyses were used to check the toxicity of the species, whose results were negative. The strains mostly corresponded to their species original morphological characterization, which is supported by the phylogenetic analyses in the case of P. levis, whereas for P. elegans, this is the first known molecular characterization. This is also the second known report of P. elegans ; Financial support for this research was provided by the Department for Environment of Bizkaiko Foru Aldundia, the Bilbao-Bizkaia Water Consortium, and the Basque Government (project IT-417-07). A grant from the University of the Basque Country to H. David and a specialization fellowship for PhD researchers awarded by the University of the Basque Country to A. Laza-Martínez also supported this study. And also Project PIE 201270E032. ; Peer reviewed

5 páginas, 4 figuras ; We report the isolation from the green dinoflagellate Lepidodinium chlorophorum and structural characterization of a new carotenoid termed lepidoxanthin 1, determined to be (3S,5R,6S,3´R,6´R)-5,6-epoxy-19-(2-decenoyloxy)-19´-acetoxy-4´,5´- didehydro-5,6,5´,6´-tetrahydro-β,ε-carotene-3,3´-diol. Its until now unidentified 19,19´-diacyloxy substitution constitutes a chemical signature that can aid to unravel the evolutionary course of this unicellular algae based on the proposed biosynthethic pathway from lutein. ; This work was funded by MINECO-Spain (CTM2012-32181) and European Union Seventh Framework Programme [FP7/REGPOT-2012- 2013.1] under Grant Agreement No. 316265, BIOCAPS. A. G.-O. acknowledges financial support from MINECO (doctoral grant BES-2013-065752) ; Peer reviewed

10 páginas, 5 tablas, 3 figuras ; A multitoxin method has been developed for quantification and confirmation of lipophilic marine biotoxins in mussels by liquid chromatography coupled to high resolution mass spectrometry (HRMS), using an Orbitrap-Exactive HCD mass spectrometer. Okadaic acid (OA), yessotoxin, azaspiracid-1, gymnodimine, 13-desmethyl spirolide C, pectenotoxin-2 and Brevetoxin B were analyzed as representative compounds of each lipophilic toxin group. HRMS identification and confirmation criteria were established. Fragment and isotope ions and ion ratios were studied and evaluated for confirmation purpose. In depth characterization of full scan and fragmentation spectrum of the main toxins were carried out. Accuracy (trueness and precision), linearity, calibration curve check, limit of quantification (LOQ) and specificity were the parameters established for the method validation. The validation was performed at 0.5 times the current European Union permitted levels. The method performed very well for the parameters investigated. The trueness, expressed as recovery, ranged from 80% to 94%, the precision, expressed as intralaboratory reproducibility, ranged from 5% to 22% and the LOQs range from 0.9 to 4.8 pg on column. Uncertainty of the method was also estimated for OA, using a certified reference material. A top-down approach considering two main contributions: those arising from the trueness studies and those coming from the precision's determination, was used. An overall expanded uncertainty of 38% was obtained ; Peer reviewed