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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.)

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

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Author(s):
Nogueira, Patricia F. M. [1] ; Nogueira, Marcelo M. [2] ; Lombardi, Ana T. [1]
Total Authors: 3
Affiliation:
[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
Total Affiliations: 2
Document type: Journal article
Source: ENVIRONMENTAL SCIENCE-PROCESSES & IMPACTS; v. 16, n. 5, p. 1029-1034, 2014.
Web of Science Citations: 1
Abstract

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)