Toxin Profile of Two Gymnodinium catenatum Strains from Iberian Coastal Waters

Abstract

Gymnodinium catenatum has been the main species responsible for paralytic shellfish poisoning events along the Portuguese coast (Iberian Peninsula), causing bans on bivalve harvesting that result in huge economic losses. This work presents the characterization of two novel isolates of G. catenatum regarding their growth and toxin profiles. Laboratory growth experiments revealed that, although low growth rates were obtained during cultivation, the cell yields were high compared to those reported in the literature. Evaluation of the toxin profiles, by HPLC-FLD, essentially confirmed the typical composition of toxins of this regional population (Iberian Peninsula), namely, the absence or low representation of the toxins dcNEO, GTX1,4 and NEO and a higher ratio of the toxins C1,2, GTX6 and GTX5. However, the percentage of the identified toxins varied among the strains of this study (under the same isolation, growth, and analysis conditions), and also differed from that of other strains described in the literature. Interestingly, we found a comparatively high abundance of dcSTX in both strains, relative to the other toxins, and an unquantifiable amount of C3,4 toxins. In addition to the geographic relationship between toxin profiles, chemical conversions among toxins may explain some differences encountered in the toxin profiles of G. catenatum strains.

Cation-Exchange Resin Applied to Paralytic Shellfish Toxins Depuration from Bivalves Exposed to Gymnodinium catenatum

“…Gymnodinium catenatum IO13-26-02 was obtained from the ALISU culture collection (Lisbon University) and previously characterized regarding its toxin profile [23]. It was a PST-producing dinoflagellate that was grown under the following culture conditions: 19.0 ± 1.0 • C, under 14 h: 10 h light: dark cycle and 80 µmol m −2 s −1 light intensity.…”

“…For this, PST were extracted from the culture as follows: 3 mL of 1% acetic acid (prepared from glacial acetic acid, HPLC grade ≥ 99.8%, from Carlo Erba reagents S.A.S, Val de Reuil Cedex, France) was added to a falcon tube containing the fibreglass filter with biomass. The filter was crushed with a metal lancet [23] to enhance the extraction yield, and the mixture was stirred using a vortex (±10 s). The tubes containing the samples were placed in the ultrasounds bath (Transsonic 660/H Elma Schmidbauer GmbH, Singen, Germany), with ice, for 10 min.…”

“…After conditioning, 2.5 mL of each sample or blank were added to each cartridge. An amount of 2.0 mL of ultrapure water was added to wash the cartridge, and the final volume was adjusted to 5.0 mL (after pH adjustment to 6.5) [23]. The SPE-COOH procedure was the same as in the official method.…”

“…Instead of the matrix modifier, ultrapure water was used, as suggested by other authors [32]. More details about this procedure and the conditions of preparation of the oxidizing agents may be found in our previous publication [23]. In both procedures, the periodate oxidant was freshly prepared on each day of analysis.…”

Sensor Selection for an Electronic Tongue for the Rapid Detection of Paralytic Shellfish Toxins: A Case Study

“…H Specific toxin profiles observed in bivalves depend primarily on the toxin-producing phytoplankton but also on the bivalve species. The dinoflagellate Gymnodinium catenatum, which is prevalent along the Atlantic coast of Portugal and Spain, the Gulf of Mexico, Venezuela, Chile, and Argentina, produces a toxin profile essentially characterized by N-sulfocarbamoyl group PSTs [21]. In contrast, the dinoflagellate Alexandrium minutum, common in Northern Europe, including the UK, Norway and Iceland, mainly produces carbamoyl PSTs [22].…”