Influence of phosphorus on copper toxicity to Selenastrum gracile (Reinsch) Korshikov

Autor(es)

Rocha, Giseli S. ^[1] ; Lombardi, Ana T. ^[2] ; Melao, Maria da Graca G. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Dept Hidrobiol, Rodovia Washington Luis, Km 235, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Fed Sao Carlos, Dept Bot, Rodovia Washington Luis, Km 235, BR-13565905 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY; v. 128, p. 30-35, JUN 2016.
• Citações Web of Science: 6

Resumo

Microalgae need a variety of nutrients for optimal growth and health. However, this rarely occurs in nature, and if nutrient proportions vary, biochemical changes can occur in phytoplankton community. This may result in modifications of zooplankton food quality, affecting aquatic food chains. Our aim was to investigate the toxicity of copper (Cu) to Selenastrum gracile, a common freshwater Chlorophyceae, at different physiological status induced by varying phosphorus (P) concentration in culture medium. Phosphorus was investigated at 2.3 x 10(-4),1.1 x 10(-4), 2.3 x 10(-5), 4.6 x 10(-6) and 2.3 x 10(-6) mol L-1 and Cu at six concentrations, ranging from 6.9 x 10(-9) mol L-1 to 1.0 x 10(-7) mol L-1 free Cu2+ ions. To guarantee the cells would be in a physiological status that reflected the external P concentration, they were previously acclimated up to constant growth rate at each P concentration. Phosphorus acclimated cells were then exposed to Cu and toxicity was evaluated through population density, growth rates and chlorophyll a content. Free Cu2+ ions concentrations were calculated through the chemical equilibrium model MINEQL(+). The results showed that higher Cu toxicity was obtained in P-limited than in P-replete cells, and that chlorophyll a/cell was higher in P-limited cells and excess Cu than in P-replete cells. This confirms the importance of microalgae nutritional status to withstand the negative effects of the trace metal. (C) 2016 Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 08/02078-9 - Estudos ecofisiológicos e de processos produtivos do Anostraca dulcícola Dendrocephalus brasiliensis Pesta 1921 e suas implicações nas comunidades zooplanctônica e nectônica
• Beneficiário: Maria da Graça Gama Melão
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 09/15511-5 - Análise comparativa da composição bioquímica e do valor nutricional de Dendrocephalus brasiliensis, Daphnia laevis e Artemia salina alimentadas com algas cultivadas sob diferentes condições ambientais.
• Beneficiário: Giseli Swerts Rocha
• Modalidade de apoio: Bolsas no Brasil - Doutorado