| Full text | |
| Author(s): |
Goncalves Alho, Lays de Oliveira
;
Gebara, Renan Castelhano
;
Mansano, Adrislaine da Silva
;
Rocha, Giseli Swerts
;
Gama Melao, Maria da Graca
Total Authors: 5
|
| Document type: | Journal article |
| Source: | Environmental Toxicology and Chemistry; v. 41, n. 4, p. 12-pg., 2022-02-02. |
| Abstract | |
Manganese (Mn), an essential metal in trace amounts, and chromium (Cr), a nonessential metal to algae, are often found in effluent discharges and may co-occur in contaminated aquatic environments. Therefore, we investigated the effects of Mn and Cr, and their mixtures, on a freshwater Chlorophyceae, Raphidocelis subcapitata, using a multiple endpoint approach. Regarding the single exposure of metals, Mn was 4 times more toxic (median inhibitory concentration at 72 h [IC50(72 h)] = 4.02 +/- 0.45 mu M Mn) than Cr (IC50(72 h) = 16.42 +/- 4.94 mu M Cr) for microalgae, considering the effects on the relative growth rate. Moreover, this species was the most sensitive to Mn, according to the species sensitivity distribution curve. Overall, the tested metals did not lead to significant changes in reactive oxygen species production, cellular complexity, and cell relative size but significantly decreased the algal growth and the mean cell chlorophyll a (Chl a) fluorescence at the highest concentrations (3.64-14.56 mu M of Mn and 15.36-19.2 mu M of Cr). The decreased mean cell Chl a fluorescence indicates an impact on pigment synthesis, which may be related to the observed growth inhibition. In the mixture tests, the reference models concentration addition and independent action were used to analyze the data, and the independent action model was the best fit to describe our results. Therefore, the Mn and Cr mixture was noninteractive, showing additive effects. This is the first study to address the combined toxicity of Mn and Cr regarding freshwater Chlorophyceae. Environ Toxicol Chem 2022;00:1-12. (c) 2022 SETAC (AU) | |
| FAPESP's process: | 18/07988-5 - Bioprospecting, characterization and optimization of Brazilian microalgal strains for CO2 biofixation and bioproducts of commercial importance |
| Grantee: | Ana Teresa Lombardi |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 16/00753-7 - Toxic effects of emerging microcontaminants on planktonic food webs |
| Grantee: | Maria da Graça Gama Melão |
| Support Opportunities: | Regular Research Grants |