Binding of Cu(II) to the Surface and Exudates of the Alga Dunaliella tertiolecta in Seawater

González‐Dávila, Melchor; Santana-Casiano, J. Magdalena; Pérez‐Peña, J.; Millero, Frank J.

doi:10.1021/es00002a004

Cited by 130 publications

(72 citation statements)

References 32 publications

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“…of 1.5 pM, suggesting that the production was produced in response to or stimulated by the copper addition. Such a response has been observed before for cultures of Dunaliella tertiolecta (Gonzalez-Davila et al 1995) and cyanobacteria (Moffett and Brand 1996), suggesting that the release of ligands may be a general mechanism of resistance to excessive metal levels.…”

Section: Resultssupporting

confidence: 70%

“…The copper associated with the algae may have been either taken up or adsorbed on the cell walls, which could act as ligand (Gonzalez-Davila et al 1995) (adsorption on the cell walls is unlikely in view of the strong complexation necessary to compete against the dissolved ligands). The adsorbed fraction was estimated by washing the cells on the filter (10 min) with 3 ϫ 10 Ϫ3 M EDTA (Knauer et al 1997) at various copper concentrations; only a small fraction of the algalbound copper was released, indicating that most (86-96%) was intracellular.…”

Section: Resultsmentioning

confidence: 99%

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Copper‐induced release of complexing ligands similar to thiols by Emiliania huxleyi inseawater cultures

Leal

Vasconcelos

Berg

1999

Limnology & Oceanography

177

121

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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 2ϩ ] 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.Culture experiments have shown that marine and freshwater phytoplankton release complexing ligands into culture medium (e.g., van den Berg et al. 1979;Imber and Robinson 1983), which may be important because the availability of metals to algae is known to depend on their chemical composition (e.g., Brand et al. 1983). Therefore, the interaction of phytoplankton with trace metals is reciprocal: the biota affect the trace metal chemistry and the trace metals affect the biota.Using marine algal cultures where the metal chemistry was controlled by a synthetic chelator (usually ethylenediaminetetraacetic acid [EDTA]), the biological uptake of copper has been shown to be related to the cupric ion concentration, [Cu 2ϩ ] (e.g., Brand et al. 1986); toxicity occurs at pM levels of Cu 2ϩ . The concentration of Cu 2ϩ is typically lowered by by 2-3 orders of magnitude by organic complexation in seawater to a [Cu 2ϩ ] of 0.03-0.3 pM, which is thought to be sufficiently high to meet algal nutritional requirements but is below copper toxicity levels (Sunda 1995).

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Section: Resultssupporting

confidence: 70%

Section: Resultsmentioning

confidence: 99%

Copper‐induced release of complexing ligands similar to thiols by Emiliania huxleyi inseawater cultures

Leal

Vasconcelos

Berg

1999

Limnology & Oceanography

177

121

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“…Its capability to produce phenolic compounds as a cellular response in the uptake mechanisms against stress conditions has been studied. Microorganisms are able to act under the presence of high metal concentration and produce organic exudates to ameliorate harmful effects of these metals (Jones 1998;González et al 2010), which affect bioavailability, bioaccumulation, nd not detected a attomol of phenolic compound exuded per cell±standard deviation of two measurements b nmol of phenolic compound per litre of seawater±standard deviation of two measurements a Radical scavenging activities expressed as inhibition percentage±standard deviation of three measurements toxicity and transport (González-Dávila et al 1995;Croot et al 2000). Microorganisms will only grow under optimal conditions; therefore, they excrete organic ligands capable of binding metals to reduce the free metal concentration in solution.…”

Section: Discussionmentioning

confidence: 99%

Phenolic profile of Dunaliella tertiolecta growing under high levels of copper and iron

López

Rico

Santana-Casiano

et al. 2015

Environ Sci Pollut Res

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The present study investigates the phenolic profile of exudates and extracts of the green algae Dunaliella tertiolecta, harvested in natural seawater in the absence (control) and in the presence of Cu(II) (315 and 790 nmol L(-1)) and Fe(III) (900 nmol L(-1)) in order to identify and quantify the phenolic compounds produced under metallic stress conditions. The presence of metal ions modifies the growth of cells and changes cell metabolism by producing phenolic compounds adapted to the solution. The use of reversed-phase high-performance liquid chromatography (RP-HPLC) permitted the identification of 14 phenolic constituents. The concentration and type of polyphenols detected in cell extracts and in solution are directly related with the metal and its concentration during growth cultures, achieving 1.4 times higher levels of polyphenols under 790 nmol Cu(II) L(-1) with respect to the control experiments. Microalga excretes polyphenols to be adapted to the environmental conditions. Gentisic acid, (+) catechin and (-) epicatechin, the most prominent phenolic compounds detected in the algae extracts, showed high antioxidant activity in inhibiting 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. This potent activity may be related to its presence in cells and exudates in high concentrations.

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“…It is in a complex relation to both season (factor 1) and re-suspension (factor 3) but appears in a separate factor. Beside complexation of major and trace elements by inorganic and organic ligands [30], biota plays an important role in trace element complexation and transport [31,32]. On the one hand, with the phytoplankton development, the consumption of SRP and the detachment or incorporation of dissolved heavy metals is expected.…”

Section: Complexation (Factor 5)mentioning

confidence: 99%

Assessment of Water Quality in the Elbe River at Low Water Conditions Based on Factor Analysis

Baborowski

Büttner

Einax

2011

CLEAN Soil Air Water

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An assessment of water quality measurements during a long-lasting low water period in the Elbe River is presented. Weekly samples were taken from May to December 2003 at a sampling site in the middle part of the Elbe River. For multivariate data analysis, 34 parameters of 46 samplings were considered. As a result of this analysis, 78% of the variance of the data set is explained by five factors. They can be assigned to the following latent variables: season (37.5%) > tributaries (12.7%) > re-suspension (10.4%) > discharge (9.4%) > complexation (8.5%). For the investigated sampling site, two key processes were identified as dominating factors on the water quality during low water conditions. First, seasonal phytoplankton development caused changes in redox conditions with consequences for re-solution of pollutants from sediments. Second, tributaries have a higher impact on the main stream, due to changes in mixing processes. Therefore, in addition to flood investigations, monitoring strategies, and management plans should be developed in order to survey changes in water quality during low water conditions.

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Binding of Cu(II) to the Surface and Exudates of the Alga Dunaliella tertiolecta in Seawater

Cited by 130 publications

References 32 publications

Copper‐induced release of complexing ligands similar to thiols by Emiliania huxleyi inseawater cultures

Copper‐induced release of complexing ligands similar to thiols by Emiliania huxleyi inseawater cultures

Phenolic profile of Dunaliella tertiolecta growing under high levels of copper and iron

Assessment of Water Quality in the Elbe River at Low Water Conditions Based on Factor Analysis

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