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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Copper and cadmium complexation by high molecular weight materials of dominant microalgae and of water from a eutrophic reservoir

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Author(s):
Gouvêa, S. P. [1] ; Vieira, A. A. H. [2] ; Lombardi, A. T.
Total Authors: 3
Affiliation:
[1] Universidade Federal de São Carlos (UFSCAR). Centro de Ciências Biológicas e da Saúde - Brasil
[2] Universidade Federal de São Carlos (UFSCAR). Centro de Ciências Biológicas e da Saúde - Brasil
Total Affiliations: 3
Document type: Journal article
Source: Chemosphere; v. 60, n. 9, p. 1332-1339, Sept. 2005.
Field of knowledge: Biological Sciences - Ecology
Abstract

High molecular weight materials (HMWM, >12 000–14 000 Da) excreted by the two cyanophyte species (Microcystis aeruginosa and Anabaena spiroides) and a diatom (Aulacoseira granulata) which are dominant phytoplankton species in a eutrophic reservoir, Barra Bonita, Brazil were investigated as copper (Cu) and cadmium (Cd) complexation agents and their monosaccharide and elemental analysis of C, H, N and S determined. Also, HMWM obtained from the reservoir water as well as from a mixture of the three algae materials were studied. The HMWM of the cyanophytes and the mixture of the three algae materials complexed Cu and Cd, whereas the HMWM of the diatom and that from the reservoir water complexed only Cu. Two classes of ligands of intermediate to weak binding strength were obtained after Scatchard plot analysis of the titration data. The cyanophytes and the mixture HMWM presented higher conditional stability constants for Cu class-1 ligands (–9.5) than the HMWM derived from the diatom and the reservoir water (–8.8). Higher proportions of acidic monosaccharides corresponded to higher of Cu and Cd complexation, yet no relation was observed among complexation parameters and elemental analysis. This study points out Cu ligands of intermediate to weak binding strength in the excreted HMWM of dominant microalgae and in the HMWM of the reservoir water, while Cd was solely complexed by ligands isolated from the cyanophyte HMWM. (AU)

FAPESP's process: 99/07766-0 - The production and fate of algal extracellular polysaccharides in an eutrophic reservoir of the Tietê River, SP, Brazil
Grantee:Armando Augusto Henriques Vieira
Support Opportunities: Research Projects - Thematic Grants