Toxic effect of metal cation binary mixtures to the seaweed Gracilaria domingensis (Gracilariales, Rhodophyta)

Autor(es)

Mendes, Luiz Fernando ^[1] ; Stevani, Cassius Vinicius ^[2] ; Zambotti-Villela, Leonardo ^[1] ; Yokoya, Nair Sumie ^[3] ; Colepicolo, Pio ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Quim, Dept Bioquim, BR-05599970 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Inst Quim, Dept Quim Fundamental, BR-05599970 Sao Paulo - Brazil

^[3] Inst Bot, Nucleo Pesquisa Ficol, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Environmental Science and Pollution Research; v. 21, n. 13, p. 8216-8223, JUL 2014.
• Citações Web of Science: 6

Resumo

The macroalga Gracilaria domingensis is an important resource for the food, pharmaceutical, cosmetic, and biotechnology industries. G. domingensis is at a part of the food web foundation, providing nutrients and microelements to upper levels. As seaweed storage metals in the vacuoles, they are considered the main vectors to magnify these toxic elements. This work describes the evaluation of the toxicity of binary mixtures of available metal cations based on the growth rates of G. domingensis over a 48-h exposure. The interactive effects of each binary mixture were determined using a toxic unit (TU) concept that was the sum of the relative contribution of each toxicant and calculated using the ratio between the toxicant concentration and its endpoint. Mixtures of Cd(II)/Cu(II) and Zn(II)/Ca(II) demonstrated to be additive; Cu(II)/Zn(II), Cu(II)/Mg(II), Cu(II)/Ca(II), Zn(II)/Mg(II), and Ca(II)/Mg(II) mixtures were synergistic, and all interactions studied with Cd(II) were antagonistic. Hypotheses that explain the toxicity of binary mixtures at the molecular level are also suggested. These results represent the first effort to characterize the combined effect of available metal cations, based on the TU concept on seaweed in a total controlled medium. The results presented here are invaluable to the understanding of seaweed metal cation toxicity in the marine environment, the mechanism of toxicity action and how the tolerance of the organism. (AU)

• Processo FAPESP: 09/54718-4 - Efeitos de metais mono-, bi e trivalentes sobre a fisiologia de algas
• Beneficiário: Luiz Fernando Mendes
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado