Cylindrospermopsis raciborskii exudate-Cu complexes: impact on copper dynamics and bioavailability in an aquatic food chain

Autor(es)

Nogueira, P. F. M. ; Lombardi, A. T. ; Nogueira, M. M.

• Tipo de documento: Artigo Científico
• Fonte: Environmental Science and Pollution Research; v. 19, n. 4, p. 7-pg., 2012-05-01.

Resumo

The increasing contamination of aquatic environments motivates studies on the interactions among natural dissolved organic matter, metals, and the biota. This investigation focused on the organic exudates of the toxic cyanobacteria Cylindrospermopsis raciborskii as a Cu carrier through a three-level aquatic trophic chain (bacteria, protozoa, and copepod). The effects of bacteria activity and growth on the metal-organic complexes were evaluated through changes in free Cu2+ ions, total dissolved, and total particulate Cu. To be sure that the added copper would be complexed to the exudates, its complexing properties were previously determined. The cyanobacteria exudate-Cu complexes were furnished to bacteria that were further used as a food source to the protozoan Paramercium caudatum. This was then furnished as food to the copepod Mesocyclops sp. The results showed that, in general, the cyanobacterial exudates decreased Cu bioavailability and toxicity to the first trophic level (bacteria), but because the heterotrophic bacteria accumulated Cu, they were responsible for the transference for the otherwise low availability metal form. Both the bacteria and protozoan organisms accumulated Cu, but no metal accumulation was detected in the copepods. (AU)

• Processo FAPESP: 07/53235-4 - Efeito da biodegradação de exopolissacarídeos produzidos pela cianobactéria tóxica Cylindrospermopsis raciborskii na biodisponibilidade de metais em uma cadeia alimentar aquática
• Beneficiário: Patricia Franklin Mayrink Nogueira
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 08/03487-0 - Cultivo de microalgas em fotobiorreator como ferramenta para o sequestro do CO2 atmosférico
• Beneficiário: Ana Teresa Lombardi
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOEN - PITE