Influence of the microbial loop on trophodynamics and toxicity of cadmium complexed by cyanobacterium exudates

Autor(es)

Nogueira, Patricia F. M. ^[1] ; Nogueira, Marcelo M. ^[2] ; Lombardi, Ana T. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Dept Bot, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Sao Paulo, EESC, Nucleo Estudos Ecossistemas Aquat, BR-13560970 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ENVIRONMENTAL SCIENCE-PROCESSES & IMPACTS; v. 16, n. 5, p. 1029-1034, 2014.
• Citações Web of Science: 1

Resumo

Cadmium (Cd) is an important industrial and toxic metal. Its fate and toxicity in the environment may be mediated by association with dissolved organic materials excreted by phytoplankton. The aim of the present study was to investigate the trophodynamics and toxicity of Cd complexed with Cylindrospermopsis raciborskii exudates in a plankton food chain. The microbial loop involves heterotrophic bacteria as the primary consumer, which is supplemented with a Cd-exudate complex. The secondary consumer (protozoan Paramecium caudatum) was fed on the bacteria, and the tertiary consumer (copepod Mesocyclops longisetus) on the protozoa. The Cd complexing properties of the exudate were determined before the experiments, to ensure that all Cd was furnished to the organisms as the organic complex alone. The results showed that free Cd2+ ions caused the highest observed toxicity to bacteria, while Cd complexed to the cyanobacterial exudate was less toxic, but could be bioavailable and transferred through the food web. This study is a contribution to aquatic ecosystem management and to current knowledge of Cd dynamics, bioavailability and interaction with aquatic planktonic organisms. (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