Rapid Biotic and Abiotic Transformation of Toxins produced by <i>Ostreopsis.</i> cf. <i>ovata</i>

The dinoflagellate <i>Ostreopsis</i> cf. <i>ovata</i> produces several families of toxic polyketides. Despite only a few field measurements of these phycotoxins in seawater and aerosols, they are believed to be responsible for dermatitis and the toxic inhalations reported dur...

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Main Authors: Eva Ternon, Olivier P. Thomas, Rodolphe Lemée, William H. Gerwick
Format: Article
Language:English
Published: MDPI AG 2022-11-01
Series:Marine Drugs
Subjects:
Online Access:https://www.mdpi.com/1660-3397/20/12/748
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author Eva Ternon
Olivier P. Thomas
Rodolphe Lemée
William H. Gerwick
author_facet Eva Ternon
Olivier P. Thomas
Rodolphe Lemée
William H. Gerwick
author_sort Eva Ternon
collection DOAJ
description The dinoflagellate <i>Ostreopsis</i> cf. <i>ovata</i> produces several families of toxic polyketides. Despite only a few field measurements of these phycotoxins in seawater and aerosols, they are believed to be responsible for dermatitis and the toxic inhalations reported during blooms of this species. Therefore, the stability of these compounds in seawater is essential to understanding the causes of these symptoms, however, this has never been assessed. In the current study, the optimization of a solid phase extraction (SPE) procedure was first performed to ensure the most efficient extraction of all phycotoxins known to be produced by this strain, including the recently described liguriatoxins. The SPE cartridge SDBL<sup>®</sup> under non acidified conditions offered the best option. The stability of the ovatoxins and the liguriatoxins under biotic and abiotic stress was assessed by exposing the spent medium of a culture of <i>Ostreopsis</i> cf. <i>ovata</i> to its bacterial consortium and natural sunlight. A rapid biotic transformation was detected for both families of compounds. When exposed to bacteria, the half-lives of the ovatoxins were reached before 10 h and at 36 h, 97% of these toxins had been transformed. The half-lives of the liguriatoxins were 10 h under these conditions. Photolysis (abiotic degradation) of the ovatoxins (T<sub>1/2</sub> < 36 h) was faster than for the liguriatoxins (T<sub>1/2</sub> > 62 h). Although none of the catabolites of these phycotoxins were thoroughly identified, an untargeted metabolomics approach combined with molecular networking highlighted the presence of several compounds exhibiting structural similarities with the ovatoxins. Additional work should confirm the preliminary findings on these potential ovatoxins’ catabolites and their biological properties. The rapid transformation of <i>O</i>. cf. <i>ovata</i>’s phycotoxins introduces questions concerning their presence in seawater and their dispersion in the sea spray aerosols. The compounds involved in the toxic inhalations and dermatitis often experienced by beachgoers may stem from the catabolites of these toxins or even unrelated and as yet unidentified compounds.
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spelling doaj.art-3af883f5e1a545b5b53dc7334a3cff6a2023-11-24T16:19:31ZengMDPI AGMarine Drugs1660-33972022-11-01201274810.3390/md20120748Rapid Biotic and Abiotic Transformation of Toxins produced by <i>Ostreopsis.</i> cf. <i>ovata</i>Eva Ternon0Olivier P. Thomas1Rodolphe Lemée2William H. Gerwick3Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, La Jolla, CA 92037, USASchool of Biological and Chemical Sciences, Ryan Institute, University of Galway, University Road, H91TK33 Galway, IrelandLaboratoire d’Océanographie de Villefranche (UMR 7093), Sorbonne Université, CNRS, 06230 Villefranche-Sur-Mer, FranceCenter for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, La Jolla, CA 92037, USAThe dinoflagellate <i>Ostreopsis</i> cf. <i>ovata</i> produces several families of toxic polyketides. Despite only a few field measurements of these phycotoxins in seawater and aerosols, they are believed to be responsible for dermatitis and the toxic inhalations reported during blooms of this species. Therefore, the stability of these compounds in seawater is essential to understanding the causes of these symptoms, however, this has never been assessed. In the current study, the optimization of a solid phase extraction (SPE) procedure was first performed to ensure the most efficient extraction of all phycotoxins known to be produced by this strain, including the recently described liguriatoxins. The SPE cartridge SDBL<sup>®</sup> under non acidified conditions offered the best option. The stability of the ovatoxins and the liguriatoxins under biotic and abiotic stress was assessed by exposing the spent medium of a culture of <i>Ostreopsis</i> cf. <i>ovata</i> to its bacterial consortium and natural sunlight. A rapid biotic transformation was detected for both families of compounds. When exposed to bacteria, the half-lives of the ovatoxins were reached before 10 h and at 36 h, 97% of these toxins had been transformed. The half-lives of the liguriatoxins were 10 h under these conditions. Photolysis (abiotic degradation) of the ovatoxins (T<sub>1/2</sub> < 36 h) was faster than for the liguriatoxins (T<sub>1/2</sub> > 62 h). Although none of the catabolites of these phycotoxins were thoroughly identified, an untargeted metabolomics approach combined with molecular networking highlighted the presence of several compounds exhibiting structural similarities with the ovatoxins. Additional work should confirm the preliminary findings on these potential ovatoxins’ catabolites and their biological properties. The rapid transformation of <i>O</i>. cf. <i>ovata</i>’s phycotoxins introduces questions concerning their presence in seawater and their dispersion in the sea spray aerosols. The compounds involved in the toxic inhalations and dermatitis often experienced by beachgoers may stem from the catabolites of these toxins or even unrelated and as yet unidentified compounds.https://www.mdpi.com/1660-3397/20/12/748ova- and liguriatoxinscatabolitesmetabolomics<i>Ostreopsis</i> cf. <i>ovata</i>
spellingShingle Eva Ternon
Olivier P. Thomas
Rodolphe Lemée
William H. Gerwick
Rapid Biotic and Abiotic Transformation of Toxins produced by <i>Ostreopsis.</i> cf. <i>ovata</i>
Marine Drugs
ova- and liguriatoxins
catabolites
metabolomics
<i>Ostreopsis</i> cf. <i>ovata</i>
title Rapid Biotic and Abiotic Transformation of Toxins produced by <i>Ostreopsis.</i> cf. <i>ovata</i>
title_full Rapid Biotic and Abiotic Transformation of Toxins produced by <i>Ostreopsis.</i> cf. <i>ovata</i>
title_fullStr Rapid Biotic and Abiotic Transformation of Toxins produced by <i>Ostreopsis.</i> cf. <i>ovata</i>
title_full_unstemmed Rapid Biotic and Abiotic Transformation of Toxins produced by <i>Ostreopsis.</i> cf. <i>ovata</i>
title_short Rapid Biotic and Abiotic Transformation of Toxins produced by <i>Ostreopsis.</i> cf. <i>ovata</i>
title_sort rapid biotic and abiotic transformation of toxins produced by i ostreopsis i cf i ovata i
topic ova- and liguriatoxins
catabolites
metabolomics
<i>Ostreopsis</i> cf. <i>ovata</i>
url https://www.mdpi.com/1660-3397/20/12/748
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