Changes in antioxidative enzymes of a cyanobacterium grown under heavy metal stress

Abstract

The effect of Cu and Cd ions on the cyanobacterium Plectonema boryanum Gom. was studied. Growth rate of algal biomass was strongly inhibited by cadmium—it was 50 % reduced at 200 μM CdCl2, while copper added into the nutrition medium caused just about 20% reduce of growth. Chlorophyll a content decreased at the same extent after Cu and Cd treatment—it was 35% lower than the control variants. Carotenoids were almost unaffected after Cu exposure but Cd led to a slight decrease of 15% as compared to control. The activities of antioxidative enzymes catalase (CAT) and glutathione peroxidase (GPER) were strongly increased following the increase of Cu concentration—they reached 100% and 180% above the control, respectively. Cd provoked 58% decrease of CAT activity and a slight enhancement of GPER at concentration 200 μM CdCl2. Glutathione reductase (GR) activity was not detected in algal cells of the all experimental variants. © 2009 Taylor and Francis Group, LLC.