Complex Toxin Profile of French Mediterranean Ostreopsis cf. ovata Strains, Seafood Accumulation and Ovatoxins Prepurification
|Author(s)||Brissard Charline1, Herrenknecht Christine2, Sechet Veronique1, Herve Fabienne1, Pisapia Francesco1, Harcouet Jocelyn1, Lemee Rodolphe3, 4, Chomerat Nicolas5, Hess Philipp1, Amzil Zouher1|
|Affiliation(s)||1 : IFREMER, Phycotoxins Lab, F-44311 Nantes, France.
2 : Univ Nantes, Univ Nantes Angers Le Mans LUNAM, Fac Pharm, F-44035 Nantes, France.
3 : Univ Paris 06, Sorbonne Univ, UMR 7093, LOV,Observ Oceanol, F-06230 Villefranche Sur Mer, France.
4 : CNRS, UMR 7093, LOV, Grp Biodivers & Biogeochim,Observ Oceanol, F-06230 Villefranche Sur Mer, France.
5 : IFREMER, LER BO, Marine Biol Stn, F-29185 Concarneau, France.
|Source||Marine Drugs (1660-3397) (Mdpi Ag), 2014-05 , Vol. 12 , N. 5 , P. 2851-2876|
|WOS© Times Cited||56|
|Keyword(s)||Ostreopsis cf. ovata, palytoxin & ovatoxins, culture, seafood contamination, LC-MS/MS, hemolysis assay, Mediterranean Sea|
|Abstract||Ostreopsis cf. ovata produces palytoxin analogues including ovatoxins (OVTXs) and a putative palytoxin (p-PLTX), which can accumulate in marine organisms and may possibly lead to food intoxication. However, purified ovatoxins are not widely available and their toxicities are still unknown. The aim of this study was to improve understanding of the ecophysiology of Ostreopsis cf. ovata and its toxin production as well as to optimize the purification process for ovatoxin. During Ostreopsis blooms in 2011 and 2012 in Villefranche-sur-Mer (France, NW Mediterranean Sea), microalgae epiphytic cells and marine organisms were collected and analyzed both by LC-MS/MS and hemolysis assay. Results obtained with these two methods were comparable, suggesting ovatoxins have hemolytic properties. An average of 223 mu g.kg(-1) of palytoxin equivalent of whole flesh was found, thus exceeding the threshold of 30 mu g.kg(-1) in shellfish recommended by the European Food Safety Authority (EFSA). Ostreopsis cells showed the same toxin profile both in situ and in laboratory culture, with ovatoxin-a (OVTX-a) being the most abundant analogue (similar to 50%), followed by OVTX-b (similar to 15%), p-PLTX (12%), OVTX-d (8%), OVTX-c (5%) and OVTX-e (4%). Ostreopsis cf. ovata produced up to 2 g of biomass per L of culture, with a maximum concentration of 300 pg PLTX equivalent cell(-1). Thus, an approximate amount of 10 mg of PLTX-group toxins may be produced with 10 L of this strain. Toxin extracts obtained from collected biomass were purified using different techniques such as liquid-liquid partition or size exclusion. Among these methods, open-column chromatography with Sephadex LH20 phase yielded the best results with a cleanup efficiency of 93% and recovery of about 85%, representing an increase of toxin percentage by 13 fold. Hence, this purification step should be incorporated into future isolation exercises.|