Monster Seminar JAM - The dinoflagellate genus Azadinium identified as the planktonic producer of azaspiracid toxins
Dr. Urban Tillman, Senior Scientist, Alfred Wegener Institute
AbstractAzaspiracids (AZAs) are the most recently discovered group of lipophilic marine biotoxins of microalgal origin associated with human incidents of shellfish poisoning. The first azaspiracid poisoning (AZP) event was recorded after eight people in the Netherlands became ill in November 1995 after consumption of mussels from the Irish west coast. The causative toxin was later isolated and structurally characterized as a nitrogen-containing polyether with a unique spiral ring assembly, a cyclic amine, and a carboxylic acid. Although knowledge of the toxins involved has been continually increasing, the biological source remained elusive. For a time the heterotrophic dinoflagellate Protoperidinium crassipes has been proposed as the causative organism, however the culprit for AZA production was recently unambiguously identified and described as a novel species within a newly created genus Azadinium Elbrächter et Tillmann. The toxigenic type species, a small photosynthetic dinoflagellate, was described as Azadinium spinosum Elbrächter & Tillmann. Stimulated by this finding, further isolation of Azadinium-like species was performed so that currently seven strains of Azadinium are available, belonging to three different species: A. spinosum (3 strains), A. obesum Tillmann & Elbrächter (1 strain), and three strains of A. poporum Tillmann & Elbrächter. Among these strains and species, only A. spinosum, available as isolates from Scotland, Denmark and Ireland, turned out to produce Azaspiracids, the two other species are non-toxic. In addition, there is continuously increasing evidence for a world-wide distribution of the genus with probably many more species than currently described. We will present an update on the current status of knowledge on the genus Azadinium including various aspects of morphology, phylogeny, molecular detection methods, and toxin profile, content and trophic transfer.
Date and Time:
April 21, 2011,
11:00 am - 12:00 pm