Abstract

The effects of copper toxicity on the content of bioactive compounds in Euglena graciliswere investigated using two CuSO₄ concentrations (0.4 and 0.8 mM) added in medium culture. Proline, phenolic compounds and antioxidant activity were measured after 72 h of copper stress. Results obtained in this study show that increasing levels of copper (0.4 and 0.8 mM) resulted in a general increased proline, total phenolic compound and antioxidant activity in the cells of E. gracilis exposed to doses of 0.4 mM Cu²⁺ in contrast one decreased significantly was observed when the doses was increasing to 0.8 mM with respect to control. These changes suggesting that the phenolic contents and the presence of proline as well as the synergistic effects among them affect the total antioxidant capacity of E. gracilis. Finally, these results provide useful and important information for researchers in order to increase the studies about antioxidant capacity and functional value of E. gracilis for bioremediation programs. Such information can be used to closely scrutinize the strategy of bioremediation programs for selecting E. gracilis strain for targeted biotechnologies purposes.

Key words: Heavy metals, tolerance, Euglena gracilis, bioactive compounds.