Effect of a short-term salinity stress on the growth, biovolume, toxins, osmolytes and metabolite profiles on three strains of the Dinophysis acuminata-complex (Dinophysis cf. sacculus)

Dinophysis is the main dinoflagellate genus responsible for diarrheic shellfish poisoning (DSP) in human consumers of filter feeding bivalves contaminated with lipophilic toxins. Species this have a worldwide distribution driven by environmental conditions (temperature, irradiance, salinity, nutrients etc.), and these factors are sensitive to climate change. The D. acuminata-complex may contain several species, including sacculus. latter has been found estuaries semi-enclosed areas, water bodies subjected quick salinity variations its natural repartition suggests some tolerance changes. However, response strains (D. cf. sacculus) stress underlying mechanisms never studied laboratory. Here, 24 h hypoosmotic (25) hyperosmotic (42) was performed vitro metabolomic study carried out three cultivated sacculus isolated from French Atlantic Mediterranean coasts. Growth rate, biovolume osmolyte (proline, glycine betaine dimethylsulfoniopropionate (DMSP)) toxin contents were measured. Osmolyte higher at highest but only significant increase observed between control (35) treatment. Metabolomics revealed strain-dependent differences metabolite profiles different salinities. These results, as well absence effects on growth biovolume, okadaic acid (OA) pectenotoxin (PTXs) cellular contents, suggest that highly tolerant variations.