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Characterization of H+ and Cd2+ binding properties of the bacterial exopolysaccharides.
Journal article

Characterization of H+ and Cd2+ binding properties of the bacterial exopolysaccharides.

  • Lamelas C Environmental Biophysical Chemistry, Environmental Science and Technology Institute, School of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
  • Benedetti M
  • Wilkinson KJ
  • Slaveykova VI
  • 2006-06-07
Published in:
  • Chemosphere. - 2006
Cadmium
Cell Proliferation
Hydrogen-Ion Concentration
Oceans and Seas
Polysaccharides, Bacterial
Protons
Sinorhizobium meliloti
Soil Pollutants
Static Electricity
Titrimetry
Water
English The proton and Cd binding capacities of microbially produced exopolysaccharides, EPS, were quantified by the determination of stability constants and the concentration of complexing sites using H(+) or Cd(2+) selective electrodes in dynamic titrations. The influence of ionic strength, pH and the Cd to EPS ratio was evaluated over large concentration ranges. The applicability of the non-ideal competitive adsorption isotherm combined with a Donnan electrostatics approach was tested with respect to the EPS. Proton and cadmium binding data were compared with literature data examining other ubiquitous environmental ligands including humic substances, alginate, bacteria, etc. Subsequent modelling of Cd speciation in aquatic (fresh and marine waters) and soil systems suggested that the exopolysaccharides would play non-negligible role, under most conditions. The quantitative information provided in this paper thus represents an important advance in our understanding of Cd transport, bioavailability and impact in aquatic and terrestrial systems.
Language
  • English
Open access status
closed
Identifiers
Persistent URL
https://sonar.ch/global/documents/96732
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