Effect of Pseudokirchneriella subcapitata (Chlorophyceae) exudates on metal toxicity and colloid aggregation

Koukal, Brahim; Rossé, Patrick; Reinhardt, Alain; Ferrari, B.; Wilkinson, Kevin J.; Loizeau, Jean‐Luc; Dominik, Janusz

doi:10.1016/j.watres.2006.09.014

Cited by 68 publications

(42 citation statements)

References 40 publications

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“…Another question is how we take into account the kinetic nature of the test system including the fact that test organisms themselves influence the nanoparticle behavior. Algae exudates have been found to increase aggregation of colloidal particles (Koukal et al 2007), but as we have shown increased aggregation/ agglomeration may also be due to modifications, such as new coatings or the disappearance of the coating during the course of the test. For poorly soluble substances, such as metals and inorganic metal compounds, it has been suggested by OECD (2000) and OECD (2001) that information on stability, transformation and changes in concentration should be obtained.…”

Section: Pigment Extractionmentioning

confidence: 68%

“…The particle transformations are thought to be caused by degradation of the starch coating. Also algal exudates are known to increase aggregation (Koukal et al 2007). However, disappearance of Au particles <2 mm at 48 h was also observed for samples without algal cells.…”

Section: Pigment Extractionmentioning

confidence: 99%

“…This includes the dynamic nature of the nanoparticles in aqueous media resulting from e.g., aggregation/agglomeration and sedimentation (Keller et al 2010). This may be increased due to algal exudates (Koukal et al 2007), and biomodifications of nanoparticle properties (Roberts et al 2007) as illustrated in Figure 1 -all of which impairs the quantification and controlling of actual exposure conditions. Hence, a number of environmental factors are known to influence nanoparticle behavior including pH, ionic strength and particle concentration (e.g., Bai et al 2010;von der Kammer et al 2010;Tiede et al 2009).…”

Section: Introductionmentioning

confidence: 99%

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The challenges of testing metal and metal oxide nanoparticles in algal bioassays: titanium dioxide and gold nanoparticles as case studies

et al. 2012

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Section: Pigment Extractionmentioning

confidence: 68%

Section: Pigment Extractionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The challenges of testing metal and metal oxide nanoparticles in algal bioassays: titanium dioxide and gold nanoparticles as case studies

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“…10,25,[29][30][31][32] These mechanisms may be extracellular processes, such as physical exclusion due to reduced membrane permeability 31 or extracellular binding of metal ions to cell exudates or ligands. 31,33,34 Intracellular mechanisms may include the immobilisation of metals through the high affinity binding of Cu to sulfate in granules, polyphosphate bodies or calcium calcretions, or in non-metabolically active areas of the cell, e.g. the cell wall or vacuoles.…”

Section: Discussionmentioning

confidence: 99%

Copper Uptake, Intracellular Localization, and Speciation in Marine Microalgae Measured by Synchrotron Radiation X-ray Fluorescence and Absorption Microspectroscopy

Adams

Dillon

Vogt

et al. 2016

Environ. Sci. Technol.

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Metal toxicity to aquatic organisms depends on the speciation of the metal and its binding to the critical receptor site(s) (biotic ligand) of the organism. The intracellular nature of the biotic ligand for Cu in microalgal cells was investigated using the high elemental sensitivity of microprobe synchrotron radiation X-ray fluorescence (SR-XRF) and X-ray absorption near-edge spectroscopy (XANES). The marine microalgae, Ceratoneis closterium, Phaeodactylum tricornutum, and Tetraselmis sp. were selected based on their varying sensitivities to Cu (72-h 50% population growth inhibitions of 8–47 μg Cu/L). Intracellular Cu in control cells was similar for all three species (2.5–3.2 × 10–15 g Cu/cell) and increased 4-fold in C. closterium and Tetraselmis sp. when exposed to copper, but was unchanged in P. tricornutum (72-h exposure to 19, 40, and 40 μg Cu/L, respectively). Whole cell microprobe SR-XRF identified endogenous Cu in the central compartment (cytoplasm) of control (unexposed) cells. After Cu exposure, Cu was colocated with organelles/granules dense in P, S, Ca, and Si and this was clearly evident in thin sections of Tetraselmis sp. XANES indicated coexistence of Cu(I) and Cu(II) in control and Cu-exposed cells, with the Cu ligand (e.g., phytochelatin) in P. tricornutum different from that in C. closterium and Tetraselmis sp. This study supports the hypothesis that Cu(II) is reduced to Cu(I) and that polyphosphate bodies and phytochelatins play a significant role in the internalization and detoxification of Cu in marine microalgae.

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“…[19] Moreover, a protective effect of exudates against Cd, Cu, Pb and Zn toxicity on Pseudokirchneriella subcapitata has recently been observed. [20] Nonetheless, it is currently unclear whether the non-humic components of DOM play an important role in metal uptake when humic substances are also present.…”

Section: Introductionmentioning

confidence: 99%

Pb uptake by the freshwater alga Chlorella kesslerii in the presence of dissolved organic matter of variable composition

Lamelas¹

2008

Environ. Chem.

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Environmental context. Dissolved organic matter (DOM) is of utmost importance for a toxic metal's fate and ecotoxicity in the aquatic system, but the complex nature and variable composition of DOM makes the quantitative understanding of DOM's role in the environment very difficult. We have demonstrated that the assumption that the properties of a DOM mixture are the sum of the properties of its individual fractions can capture the main trends characterising the role of DOM in lead speciation and adsorption by freshwater microalgae. This was done by mixing the isolated, well-characterised fractions of DOM and measuring levels of free lead ion and Pb adsorbed and internalised by algae.Abstract. Dissolved organic matter (DOM) is a complex mixture of ill-defined components, which makes the quantitative understanding of DOM functions in aquatic systems a challenging task. The traditional approach for studying such complex mixtures involves their separation into groups of different components, while assuming minimal or no alteration of their properties. By mixing the pre-isolated and well-characterised individual fractions of the DOM, including humic, fulvic and alginic acids, we have demonstrated that the free Pb ion concentrations and the adsorbed Pb plus Pb internalised by the alga Chlorella kesslerii in the presence of DOM samples of different compositions can be predicted on the basis of the experiments performed in the presence of the individual DOM fractions. An additivity model assuming that the properties of the mixture can be considered as the sum of the properties of the individual components captured the Pb speciation and adsorption behaviour in the presence of DOM of variable compositions. Similarly to the results with the individual DOM fractions, internalised Pb concentrations in the presence of the reconstituted DOM were greater than that predicted by the corresponding free lead ion concentration. An improved fit between experimental observations and the model predictions of adsorbed plus internalised Pb in the presence of DOM of different compositions was observed by assuming that each individual component adsorbed by the algae gave access to additional binding sites for Pb. Furthermore, the contribution of the Pb-DOM complex to total cellular Pb was dominated by the humic and fulvic acids, whereas the contribution of alginate was minimal.

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Effect of Pseudokirchneriella subcapitata (Chlorophyceae) exudates on metal toxicity and colloid aggregation

Cited by 68 publications

References 40 publications

The challenges of testing metal and metal oxide nanoparticles in algal bioassays: titanium dioxide and gold nanoparticles as case studies

The challenges of testing metal and metal oxide nanoparticles in algal bioassays: titanium dioxide and gold nanoparticles as case studies

Copper Uptake, Intracellular Localization, and Speciation in Marine Microalgae Measured by Synchrotron Radiation X-ray Fluorescence and Absorption Microspectroscopy

Pb uptake by the freshwater alga Chlorella kesslerii in the presence of dissolved organic matter of variable composition

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