Copper affects biochemical and physiological responses of Selenastrum gracile (Reinsch).
Ecotoxicology
; 25(8): 1468-1477, 2016 Oct.
Article
em En
| MEDLINE
| ID: mdl-27439962
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 × 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.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fitoplâncton
/
Poluentes Químicos da Água
/
Testes de Toxicidade
/
Cobre
/
Clorófitas
Idioma:
En
Revista:
Ecotoxicology
Assunto da revista:
SAUDE AMBIENTAL
/
TOXICOLOGIA
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Estados Unidos