THE RELEASE OF COPPER‐COMPLEXING LIGANDS BY THE BROWN ALGA <i>FUCUS VESICULOSUS</i> (PHAEOPHYCEAE) IN RESPONSE TO INCREASING TOTAL COPPER LEVELS

Gledhill, Martha; Nimmo, Malcolm; Hill, Steve J.; Brown, Murray T.

doi:10.1046/j.1529-8817.1999.3530501.x

Cited by 71 publications

(48 citation statements)

References 37 publications

(74 reference statements)

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“…For example, Cu toxicity may also be reduced due to detoxification pathway of Cu by the algal cell. Certain algal species, including Scenedesmus acutiformis , Chlorella fusca and Fucus vesiculosis , have been shown to release strong ligands that reduce the bioavailability of Cu in aqueous phase if they are released in sufficient amounts (Robinson, 1989;Gledhill et al, 1999;Rijstenbil and Gerringa, 2002). Cell wall exclusion of Cu and intracellular detoxification by binding to phytochelatins or polyphosphate have also been demonstrated in a variety of freshwater algal species in response to elevated Cu concentrations (Twiss et al, 1993;Knauer et al, 1997).…”

Section: Resultsmentioning

confidence: 99%

Accumulation, assimilation and growth inhibition of copper on freshwater alga (Scenedesmus subspicatus 86.81 SAG) in the presence of EDTA and fulvic acid

et al. 2003

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Accumulation and growth inhibition of Cu to fresh water alga (Scenedesmus subspicatus 86.81 SAG) and the influences of ethylenediaminetetraacetic acid (EDTA) and fulvic acid (FA) were examined. These results demonstrated that both EDTA and FA could reduce toxicity of Cu to alga by the way of preventing Cu from being adsorbed by cell wall of alga. When dissolved Cu (Cu dissolved ), extracellular Cu (Cu extracellular ), and intracellular Cu (Cu intracellular ) were differentiated, our results showed that the concentration level of extracellular Cu ([Cu extracellular ]) was a good indicator for measuring the toxic effects of Cu on alga growth in complex matrix. Either in the absence or in the presence of EDTA and FA, the concentration of intracellular Cu increased to 0.6 Á/1.5 )/10 (8 mM per cell when the growth inhibition reached to about 50%. We found that the acute toxicity of copper on unicellular alga could be interpreted by its accumulation at a discrete site or biotic ligand at alga cell wall and critical accumulation of Cu associated with EC 50 was determined to be 1 )/10 (8 mM per cell. Therefore, the Biotic Ligand Model (BML) could be extended to predict the influence of copper on growth inhibition of alga. #

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Section: Resultsmentioning

confidence: 99%

Accumulation, assimilation and growth inhibition of copper on freshwater alga (Scenedesmus subspicatus 86.81 SAG) in the presence of EDTA and fulvic acid

et al. 2003

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“…Eukaryotic phytoplankton (Zhou and Wangersky 1989;Lage et al 1994;Leal et al 1999;Croot et al 2000) and macroalgae (Gledhill et al 1999) have been found to produce extracellular Cu complexing ligands in response to Cu stress. In general, it appears that the organisms producing the strongest chelators are the most sensitive to Cu f .…”

Section: Possible Sources and Sinks Of Cu Complexing Ligands-inmentioning

confidence: 99%

Seasonal cycle of copper speciation in Gullmar Fjord, Sweden

Croot

2003

Limnology & Oceanography

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The chemical speciation of dissolved Cu was investigated by voltammetric methods in Gullmar Fjord, Sweden, over the course of a year from September 1996 until August 1997. Sampling was carried out on a roughly monthly basis, with an intensive survey carried out in May 1997. Surface water temperatures ranged from Ϫ1 to 22ЊC, whereas bottom waters in the fjord were approximately 6ЊC throughout. Macronutrient concentrations in the fjord during the period of the survey were investigated independently by the Göteborgs och Bohus läns Vattenvårdsför-bund (Water Quality Association of Göteborg and Bohus). Surface phosphate concentrations were highest in early spring with low levels (Ͻ0.1 mol kg Ϫ1 ) over the late spring and summer. Nitrate and silicate showed a similar pattern to phosphate with the exception of high concentrations encountered in surface waters when low salinity plumes caused by runoff were encountered. A period of calm, sunny weather in January 1997 saw the initiation of the spring bloom some 2 months earlier than usual. Dissolved Cu speciation was dominated by organic complexation (over 99.8%) throughout this study. Strong Cu binding ligands (log K Ͼ 12.5) were not detected during the winter or early spring and could be related to the temperature-related seasonal appearance of the cyanobacterium Synechoccocus in these waters. The appearance of the strong Cu ligands led to a decrease in the concentration of free copper, resulting in a seasonal cycle for free copper in the fjord. This is the first study to examine Cu speciation over an annual cycle in a coastal environment.The distribution and chemical speciation of trace metals in the upper water column plays an important role in the community structure and physiology of phytoplankton (Sunda 1994). Speciation is important because only particular chemical forms of a given metal may be biologically available. In the upper water column, the speciation of many biologically active trace metals is controlled by complexation with strong organic ligands (Bruland et al. 1991). In general, when a metal is complexed by an organic ligand, the metal becomes less biologically available because the free metal ions are the most labile to the biota (Sunda 1994;Campbell 1995). Organic complexation also can play an important role in the biogeochemical cycling of these elements in the upper ocean. For most elements, organic ligand concentrations are highest in the euphotic zone (Bruland et al. 1991), which suggests a recent biological source.

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“…To identify possible reasons, the mechanism(s) of resistance in G. longissima need to be elucidated, which are likely to involve a combination of exclusion and tolerance of the metal, as found in several other seaweed species (e.g. Gledhill et al 1999;Garcia-Ríos et al 2007; Contents at the start of the transplantation experiment are also shown.…”

Section: Discussionmentioning

confidence: 99%

Inter-population comparisons of copper resistance and accumulation in the red seaweed, Gracilariopsis longissima

Brown

Newman²,

Han

2011

Ecotoxicology

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Copper (Cu) resistance and accumulation of five populations of the red seaweed Gracilariopsis longissima collected from sites in south west England (Fal Estuary, Helford Estuary and Chesil Fleet) that differ in their degree of Cu contamination was assessed under controlled laboratory conditions, on two separate occasions (April and October). The effects of a range of Cu concentrations (0-250 μg l(-1)) on relative growth rates was the same for all populations with reductions observable at concentrations as low as 12 μg l(-1) and cessation of growth at 250 μg l(-1). There was no significant difference in the calculated EC(50) values for the April and October samples, with means of 31.1 and 25.8 μg l(-1), respectively. Over the range of concentrations used in this study, copper content increased linearly and the pattern of accumulation was the same for all populations at both time periods. From the linear regressions of the pooled data a concentration factor of 2.25 × 10(3) was calculated. These results imply that G. longissima has an innate tolerance to Cu and that populations have not evolved copper-tolerant ecotypes. In laboratory studies, accumulated Cu was released when transferred to 'clean' seawater with approximately 80% being lost after 8 days, with no significant difference between populations in their response. The results from a 30 days in situ transplantation experiment using two populations from the Fal Estuary provided further evidence for dynamic changes in Cu content in response to changes in Cu bioavailability. The findings in this study are discussed in the context of implications for seaweed biomonitoring.

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THE RELEASE OF COPPER‐COMPLEXING LIGANDS BY THE BROWN ALGA FUCUS VESICULOSUS (PHAEOPHYCEAE) IN RESPONSE TO INCREASING TOTAL COPPER LEVELS

Cited by 71 publications

References 37 publications

Accumulation, assimilation and growth inhibition of copper on freshwater alga (Scenedesmus subspicatus 86.81 SAG) in the presence of EDTA and fulvic acid

Accumulation, assimilation and growth inhibition of copper on freshwater alga (Scenedesmus subspicatus 86.81 SAG) in the presence of EDTA and fulvic acid

Seasonal cycle of copper speciation in Gullmar Fjord, Sweden

Inter-population comparisons of copper resistance and accumulation in the red seaweed, Gracilariopsis longissima

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