Culture of Gambierdiscus strains for the evaluation of extraction efficiency and inter-and intra-specific variability of growth as function of nutrition

• Main Authors: Pisapia, Francesco, Séchet, Véronique, Sibat, Manoëlla, Raimbault, Virginie, Herrenknecht, Christine, Amzil, Zouher, Hess, Philipp
• Format: Conference Object
• Language: English
• Published: Zenodo 2015
• Subjects: North East Atlantic
• Online Access: https://doi.org/10.5281/zenodo.7813021

Ciguatera fish poisoning (CFP) is a food-borne illness caused by consumption of fishes contaminated with polyether toxins known as ciguatoxins (CTXs). Originally known as a tropical disease, CFP is being increasingly reported from areas previously not considered endemic. The benthic dinoflagellate Gambierdiscus is considered to be the primary producer of CTXs. This genus has recently been shown to have an increasing number of species, also discovered in areas where it had not been observed before.This genus also produces other types of potent toxins, such as maitotoxins and others. CTXs are bio-accumulated and transformed in herbivorous and carnivorous fish along the marine trophic chain. The study presented here is part of a PhD aiming at the elucidation of hitherto unidentified Ciguatoxins in recently discovered species from the Caribbean and North East Atlantic seas. Cultures have been obtained from culture collections and from international collaborators for evaluation of growth characteristics and toxin production. To date, a total of 19 strains are currently maintained in our laboratory, belonging to eleven different species from the Pacific, Caribbean and North East Atlantic areas. Extraction techniques were evaluated using an ultrasonic probe and a bead-mill. As the toxins of most of the strains are not yet known, extraction efficiency was evaluated using algal metabolites of similar nominal mass and chromatographic retention times as CTXs. These initial trials suggest that both techniques have very similar extraction efficiency. These trials also suggest that duplicate extraction of pellets is sufficient for retrieval of more than 95% of the metabolites in the molecular size range of CTXs. Different culture media (L1, L1+ soil extract, K2, K2 + soil extract, Kmodified and IMK2) were evaluated for their influence on growth of one species (CCMP 1653, a Hawaiian species). For this particular species, no significant major differences were detected in cell volumes; however, some differences were observed in ...