Using multiple endpoints to assess the toxicity of cadmium and cobalt for chlorophycean Raphidocelis subcapitata.

Autor: Reis LLD; Universidade Federal de São Carlos - UFSCar, Department of Hydrobiology, Rodovia Washington Luís, Km 235, Zip Code 13565-905, São Carlos, SP, Brazil; Post-Graduate Program in Ecology and Natural Resources (PPGERN), Universidade Federal de São Carlos (UFSCar), Rodovia Washington Luís, Km 235, Zip Code 13565-905, São Carlos, SP, Brazil. Electronic address: reis.lariluiza@gmail.com., Alho LOG; Universidade Federal de São Carlos - UFSCar, Department of Hydrobiology, Rodovia Washington Luís, Km 235, Zip Code 13565-905, São Carlos, SP, Brazil; Post-Graduate Program in Ecology and Natural Resources (PPGERN), Universidade Federal de São Carlos (UFSCar), Rodovia Washington Luís, Km 235, Zip Code 13565-905, São Carlos, SP, Brazil. Electronic address: laysalho90@gmail.com., Abreu CB; Universidade Federal de São Carlos - UFSCar, Department of Hydrobiology, Rodovia Washington Luís, Km 235, Zip Code 13565-905, São Carlos, SP, Brazil; Post-Graduate Program in Ecology and Natural Resources (PPGERN), Universidade Federal de São Carlos (UFSCar), Rodovia Washington Luís, Km 235, Zip Code 13565-905, São Carlos, SP, Brazil. Electronic address: cinthia.abreu123@gmail.com., Melão MDGG; Universidade Federal de São Carlos - UFSCar, Department of Hydrobiology, Rodovia Washington Luís, Km 235, Zip Code 13565-905, São Carlos, SP, Brazil. Electronic address: dmgm@ufscar.br.
Jazyk: angličtina
Zdroj: Ecotoxicology and environmental safety [Ecotoxicol Environ Saf] 2021 Jan 15; Vol. 208, pp. 111628. Date of Electronic Publication: 2020 Nov 13.
DOI: 10.1016/j.ecoenv.2020.111628
Abstrakt: Metals may cause damage to the biota of contaminated environments. Moreover, using multiple endpoints in ecotoxicological studies is useful to better elucidate the mechanisms of toxicity of these compounds. Therefore, this study aimed to evaluate the effects of cadmium (Cd) and cobalt (Co) on growth, biochemical and photosynthetic parameters of the microalgae Raphidocelis subcapitata, through quantification of lipid classes composition, chlorophyll a (Chl a) content, maximum (Φ M ) and effective (Φ' M ) quantum yields and efficiency of the oxygen-evolving complex (OEC). Both metals affected the algal population growth, with an IC 50-96h of 0.67 and 1.53 μM of Cd and Co, respectively. Moreover, the metals led to an increase in the total lipid content and reduced efficiency of OEC and Φ M . Cell density was the most sensitive endpoint to detect Cd toxicity after 96 h of treatment. Regarding Co, the photosynthetic parameters were the most affected and the total lipid content was the most sensitive endpoint as it was altered by the exposure to this metal in all concentrations. Cd led to increased contents of the lipid class wax esters (0.89 μM) and phospholipids (PL - at 0.89 and 1.11 μM) and decreased values of triglycerides (at 0.22 μM) and acetone-mobile polar lipids (AMPL - at 0.44 and 1.11 μM). The percentage of free fatty acids (FFA) and PL of microalgae exposed to Co increased, whereas AMPL decreased in all concentrations tested. We were able to detect differences between the toxicity mechanisms of each metal, especially how Co interferes in the microalgae at a biochemical level. Furthermore, to the best of our knowledge, this is the first study reporting Co effects in lipid classes of a freshwater Chlorophyceae. The damage caused by Cd and Co may reach higher trophic levels, causing potential damage to the aquatic communities as microalgae are primary producers and the base of the food chain.
(Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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