Seasonal variability in the kinetics of Cu,Pb, Cd and Hg accumulation by macroalgae |
| |
| Institution: | 1. Universidade Tecnológica Federal Paraná, Departamento de Física, 85884-000 Campus Medianeira, Parana, Brazil;2. Universidade Federal do Paraná, Departamento de Física, 81531-980 Curitiba, Parana, Brazil;3. Universidade Federal de São Carlos, Departamento de Física, 13565-905 Sao Carlos, SP, Brazil;1. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA;2. AILES Beamline, Synchrotron SOLEIL, L’Orme des Merisiers Saint-Aubin, 91192 Gif-sur-Yvette Cedex, France;3. Institut des Sciences Moléculaires d’Orsay (ISMO), CNRS, Université Paris-Sud, Université Paris-Saclay, F-91405 Orsay, France;4. LISA, Laboratoire Interuniversitaire des Systèmes Atmosphériques, UMR CNRS 7583, Université Paris-Est Créteil (UPEC) et Université Paris-Diderot (UPD), 61 Avenue du Général de Gaulle, 94010 Créteil Cedex, France;5. MONARIS, CNRS-Univ. Pierre et Marie Curie, UMR 8233, Paris, France;1. MaREI Centre, Environmental Research Institute, University College Cork, Cork, Ireland;2. Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University, Chongqing 400044, China;3. School of Engineering, University College Cork, Cork, Ireland;1. Biology Department, Brookhaven National Laboratory, 50 Bell Avenue, Building 463, Upton, NY 11973, USA;2. Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, USA;3. Institute for Genomics and Proteomics, University of California, Los Angeles, 611 Charles E. Young Drive East, Los Angeles, USA |
| |
| Abstract: | Here it is demonstrated that both Porphyra spp. and Enteromorpha spp. of macro-algae display similar and very marked seasonal variations in their concentration factor (CF) of Cu, Pb, Cd and Hg in field conditions. The CF variations are specific for each metal and reproducible over several years. The way variations in the biological activity affect the equilibrium and kinetics of the interaction between trace metals and live algae was studied in vitro. Natural seawater was used as the culture medium. Voltammetry was used for the determination of natural organic ligands and trace metals except Hg, which was determined by mercury cold vapour after on-line pre-concentration. Titrations with the relevant metal demonstrated that the maximum binding capacity of the algae was not significantly dependent on the season for Pb (ca. 100 μmol gdry algae?1), Cd (ca. 50 μmol g?1) and Hg (80–100 μmol g?1). Marked seasonal variations were observed for Cu (ca. 40 μmol g?1 in January; 70 μmol g?1 in May; and 100 μmol g?1 in August). The conditional stability constants of metal–algae complexation sites were seasonally independent and similar for both algae: logKMS′=8.5±0.3 (Cu), 5.6±0.2 (Pb), 5.3±0.2 (Cd) and 18.0±0.3 (Hg). Exudates with a strong Cu complexing capacity (logK′CuL=12.47±0.06) were determined in cultures with added Cu, Pb or Cd concentrations, and identified by cathodic stripping voltammetry (CSV) as cysteine or glutathione. All the tested metals promoted the liberation of exudates, both cysteine- and glutathione-like ligands were exuded in the presence of Cu, only cysteine-like ligands in the presence of Pb, and only glutathione-like ligands in the presence of Cd, the rise depending of the season of the year, particularly for Cu. Highest levels were produced in the presence of added Pb. When exposed to either 1- or 100-μM total dissolved metal concentrations, the metal uptake, and its rate, varied with the season and the algae. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
