Shifts in photosynthetic parameters and lipid production of the freshwater microalgaSelenastrum gracile(Chlorophyceae) under cadmium exposure

Autor(es)

Rocha, Giseli Swerts ^[1] ; Parrish, Christopher C. ^[2] ; Espindola, Evaldo L. G. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sao Carlos Sch Engn, NEEA CRHEA, Ave Trabalhador Saocarlense 400, BR-13566590 Sao Carlos, SP - Brazil

^[2] Mem Univ Newfoundland, Dept Ocean Sci, St John, NF A1C 5S7 - Canada

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF APPLIED PHYCOLOGY; v. 32, n. 6, p. 4047-4055, DEC 2020.
• Citações Web of Science: 0

Resumo

The amount of metals released into the environment can increase with anthropogenic activities and different trophic levels can be affected. In the present study, we evaluated the changes in growth, chlorophyll content, photosynthetic parameters, and lipid and fatty acid (FA) contents of the freshwater microalgaSelenastrum gracile(Chlorophyceae) exposed to sublethal concentrations of cadmium for 72 h. Our results show that Cd negatively affected algal growth and chlorophyllaincreased per cell under Cd exposure. Photosynthetic parameters (maximum and operational yield, as well as quenching) were affected under Cd exposure, indicating damage to the photosynthetic apparatus. The amount of lipids and fatty acids increased with the increase of Cd in the medium. The most affected lipid classes under metal exposure were aliphatic hydrocarbon (HC), acetone mobile polar lipid (AMPL), and phospholipid (PL). Based on our results, we suggest that the production of algal lipids and fatty acids changed as a response to the amount of metal in the medium, avoiding photosynthetic damage at the lowest Cd concentration with the increase of polyunsaturated fatty acids (PUFA). However, at higher concentrations, the maintenance of the high values of PUFA was not observed and there was a decrease in the unsaturation of FA, resulting in higher amounts of MUFA. In addition, the percentage of structural lipids (sterol-ST-and PL) also decreased at the highest concentration. This, in combination with the decreased unsaturation of FA, suggests changes in membrane conformation and, consequently, damage to the photosynthetic machinery in the presence of Cd. (AU)

• Processo FAPESP: 15/25436-1 - Influência de cobre e cádmio em alga e seus efeitos ecotoxicológicos em zooplâncton de água doce
• Beneficiário: Giseli Swerts Rocha
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado