Paralytic shellfish toxins or spirolides? The role of environmental and genetic factors in toxin production of the Alexandrium ostenfeldii complex

摘要: Abstract Dinoflagellates of the Alexandrium ostenfeldii complex (A. ostenfeldii, A. peruvianum) are capable producing different types neurotoxins: paralytic shellfish toxins (PSTs), spirolides and gymnodimines, depending on strain its geographic origin. While Atlantic Mediterranean strains have been reported to produce spirolides, originating from brackish Baltic Sea PSTs. Some North Sea, USA New Zealand contain both toxins. Causes for such intraspecific variability in toxin production unknown. We investigated whether salinity affects growth rate 5 ostenfeldii/peruvianum with water (Baltic Sea) or oceanic (NE Atlantic) The were grown until stationary phase at 7 salinities (6–35), their was monitored. Presence saxitoxin (STX) genes (sxtA1 sxtA4 motifs) each also analyzed. Salinity significantly affected toxicity individual but did not change major profile. two exhibited 6–25 consistently produced gonyautoxin (GTX) 2, GTX3 STX. grew 20–35 mainly 20-methyl spirolide G (20mG), whereas northern coast Ireland able grow 15–35, only 13-desmethyl C (13dmC). effects total cellular concentration distribution analogs strain-specific. Both gene motifs present strains, 2 lacked sxtA4, Irish motifs. Thus seems be specific PST strains. results show that profiles predetermined either PSTs cannot induced by changes. However, changes may lead changed rates, concentrations as well relative analogs, thus affecting actual populations.