Copper-induced release of complexing ligands similar to thiols by Emiliania huxleyi in seawater cultures
| Autor: | Constant M.G. van den Berg, M. Fernanda C. Leal, M. Teresa S. D. Vasconcelos |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
chemistry.chemical_classification
biology Ligand Inorganic chemistry Copper toxicity chemistry.chemical_element Aquatic Science Oceanography biology.organism_classification medicine.disease Copper Salicylaldoxime Metal chemistry.chemical_compound chemistry visual_art Cathodic stripping voltammetry medicine Thiol visual_art.visual_art_medium Emiliania huxleyi |
| Zdroj: | Limnology and Oceanography. 44:1750-1762 |
| ISSN: | 0024-3590 |
| DOI: | 10.4319/lo.1999.44.7.1750 |
| Popis: | Marine microalgae (Emiliania huxleyi) were grown in seawater enriched only with nitrogen and phosphorus, without control of free metal concentrations using synthetic chelators. Complexing ligands and thiol compounds were determined by cathodic stripping volt-ammetry. Copper was added to these cultures, and ligands were produced in response to the copper addition. Parallel measurements of thiols showed that glutathione and other unidentified thiols (electrochemically similar to thioacetamide) were produced by the algae at rates and concentrations similar to those of the complexing ligands. Smaller amounts of thiols were produced when ligands including thiols were added to the culture. The results indicate that thiols can account for a major part or most of the copper-complexing ligands produced by these algae. Furthermore, a feedback mechanism exists in which the production of thiol-type complexing ligands is controlled by the free copper concentration, production already being stimulated by an increase of [Cu 21 ] from 0.4 to 1.5 pM. Incubations with added exudates, thiols, and salicylaldoxime (SA) showed much reduced copper toxicity even though copper uptake was increased by the exudates and the SA. |
| Databáze: | OpenAIRE |
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