Antonio de Freitas Goncalves Junior, Alex Lucas Hanusch, Rafael Cosme Machado, Thiago Lopes Rocha, Gabriel Luis Castiglioni, Maria do Carmo Bittencourt-Oliveira, Jayme Cunha Bastos and Simone Maria Teixeira de Saboia-Morais
Federal University of Goi�¡s (UFG), Brazil
University of S�£o Paulo, Brazil
State University of Rio de Janeiro, Brazil
The organophosphate agrochemical glyphosate can be used as nutrient by cyanobacteria species capable of producing cyanotoxins, which has been reported to toxic effects on vertebrates. The aim of this study was to compare the influence of a glyphosate-based herbicide (GBH) in the proliferation of three cyanobacteria species (Anabaena sp., Cylindrospermopsis raciborskii and Microcystis aeruginosa) and evaluate the toxicity of microcystin and GBH in the female guppy Poecilia reticulata. Cyanobacteria strains were inoculated in culture medium with different concentrations of GBH (0.5, 1, 2 and 4 mg GLY L-1) and the cyanobacteria density was quantified every 5 days of exposure. The evaluation of the GBH and microcystin toxicity in P. reticulata was estimated by the determining of LC50/96h, behavioural analysis and estimation of micronuclei (MN) and nuclear alterations frequency. The results showed that GBH induces a concentration-dependent increase of cyanobacteria growth and that C. raciborskii is the one that have faster growth. The GBH concentration of 4 mg L-1 was the most effective for the cyanobacteria growth. The toxicological evaluation of GBH and microcystin in P. reticulata showed a LC50/96h of 4.44 mg GLY L-1 and 3.29 �¼g L-1, respectively. Both microcystin as GBH induced behavioural changes and increase of the MN and nuclear erythrocyte alteration frequency in P. reticulata. We conclude that GBH increases the growth of cyanobacteria capable of producing cyanotoxins and both GBH as microcystin induced toxic effect on P. reticulata.
Email: antonioefasd@gmail.com
