Cylindrospermopsis raciborskii (Cyanobacteria) exudates: Chemical characterization and complexation capacity for Cu, Zn, Cd and Pb

Cylindrospermopsis raciborskii (Cyanobacteria) exudates: Chemical characterization and complexation capacity for Cu, Zn, Cd and Pb

Author Tonietto, Alessandra Emanuele Google Scholar
Lombardi, Ana Teresa Google Scholar
Henriques Vieira, Armando Augusto Google Scholar
Parrish, Christopher C. Google Scholar
Choueri, Rodrigo Brasil Autor UNIFESP Google Scholar
Institution Universidade Federal de São Carlos (UFSCar)
Mem Univ Newfoundland
Universidade Federal de São Paulo (UNIFESP)
Univ Santa Cecilia
Abstract Cylindrospermopsis raciborskii is a cosmopolitan and potentially toxic planktonic Cyanobacteria that produces and exudes copious amounts of dissolved organic materials. This organism dominates the eutrophic reservoir Barra Bonita (Brazil), where it normally blooms throughout the year. This investigation focused on the characterization of such exudates analyzing their capacity to complex copper, zinc, lead and cadmium through the determination of ligand concentration (C-L) and conditional stability constant (logK'mL), as well as elemental composition (C, H, N and S), the content of carbohydrates, proteins, lipids and dissolved organic carbon (DOC). the dissolved organic material was fractionated into 3 molecular weights (>30 kDa; 30-10 kDa; 10-3 kDa) and each fraction was analyzed. the results showed that in the >30 kDa and 30-10 kDa fractions carbohydrates dominate over proteins and lipids. Different CL and logK'mL were obtained for the different molecular weight fractions of the excreted organic materials, suggesting high diversity of ligands. in the >30 kDa, there were more complexing sites (CL) for Cu, but higher affinity (K') for Zn. in the 30-10 kDa fraction, the higher C-L was for Cd, but the greatest affinities were for Cu and Zn. in the 10-3 kDa fraction, higher C-L was obtained for Cd and Zn, while Cu and Cd had the highest strengths of association. in the environment, such diversity of ligands and strengths of association can result in a displacement of metals weakly bound to the EOM, and increase metal buffering capacity of the environment, supporting higher metal inputs before toxic effects are detected in the biota. (C) 2013 Elsevier B.V. All rights reserved.
Keywords Exudates
Complexation capacity
Heavy metal
Cylindrospermopsis raciborskii
Cyanobacteria
Language English
Sponsor Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Grant number FAPESP: 2005/51263-5
CNPq: 302837/20124
Date 2014-02-01
Published in Water Research. Oxford: Pergamon-Elsevier B.V., v. 49, p. 381-390, 2014.
ISSN 0043-1354 (Sherpa/Romeo, impact factor)
Publisher Elsevier B.V.
Extent 381-390
Origin http://dx.doi.org/10.1016/j.watres.2013.10.025
Access rights Closed access
Type Article
Web of Science ID WOS:000330601400034
URI http://repositorio.unifesp.br/handle/11600/37394

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