Copper affects biochemical and physiological responses of Selenastrum gracile (Reinsch)

Author(s)

Rocha, Giseli S. ; Parrish, Christopher C. ; Lombardi, Ana T. ; Melo, Maria da G. G.

• Document type: Journal article
• Source: ECOTOXICOLOGY; v. 25, n. 8, p. 1468-1477, OCT 2016.
• Web of Science Citations: 5

Abstract

Copper is an essential metal for several physiological and metabolic processes, but a narrow range regulate its effect in phytoplankton cells. It can affect the production of biomolecules and be toxic at concentrations slightly above those required, e.g. decreasing photosynthesis and increasing respiration. The aims of this study were to analyse the changes in growth and chlorophyll a synthesis, and in biochemistry (total carbohydrates, proteins, lipids and fatty acids) of the freshwater microalga Selenastrum gracile after exposure to copper. Exponentially growing cells were exposed to 5 concentrations of free copper ions (Cu2+) ranging from 0.7 (control) to 13 x 10(-8) M for up to 120 h. Free Cu2+ ion concentrations were calculated through the chemical equilibrium model MINEQL(+). We observed that copper was responsible for a decrease in cell density and an increase in total protein and lipid production, but no effect on total carbohydrates was detected. The increase in phospholipids and sterols and a decrease in saturated fatty acids under copper exposure suggest a change in conformation of the cell membrane, by decreasing its fluidity. We suggest this serves the cell as a system to avoid the internalization of metal, thereby acting as a detoxifying mechanism. (AU)

• FAPESP's process: 08/02078-9 - Ecophysiological and production studies of the freshwater Anostraca Dendrocephalus brasiliensis Pesta 1921 and its implications on zooplanktonic and nektonic communities
• Grantee: Maria da Graça Gama Melão
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 09/15511-5 - Comparative analysis of biochemical composition and nutritional value of Dendrocephalus brasiliensis, Daphnia laevis and Artemia salina fed with algae growth under different environmental conditions.
• Grantee: Giseli Swerts Rocha
• Support Opportunities: Scholarships in Brazil - Doctorate