Toxic action of copper on the membrane system of a marine diatom measured by flow cytometry

Abstract

Flow cytometric measurements were used to investigate the toxic action of copper on some Phaeodactylum tricornutum membrane systems. Throughout the time of metal exposure, the percentage of viable cells decreased as copper concentration increased. The forward scatter signal increased as a result of copper exposure. After 72 h of metal exposure, cultures with 0.5 and 1 mg l-1 of copper showed an important increase in the peroxidase activity in comparison with control cells. Cells cultured with copper presented alterations in the membrane potential, increasing as copper concentration increased, after 96 h of metal exposure. Results obtained in this work showed that copper induced a degenerative process in P. tricornutum cells, closely related with alternations or disorders in membrane systems.