Stability of culture Dunaliella viridis, which was previously adapted to growth in medium containing 20 mg/L copper sulfate, to high concentrations of copper ions – 75 mg/L copper sulfate was studied. It was shown that such culture is resistant to high concentrations of copper ions, i.e. it is able to develop the effect of hormesis. It was found that resistant to copper ions cells of D. viridis accumulated 2000 times more copper ions compared with the control culture cells. The carbonyl proteins content (products of free radical processes) increased only 2 times, the content of Cu²⁺ decreased in such cells in the process of cultivation. In CuR culture cells SOD activity increased and the content of free proline decreased twice. Hormesis effect is estimated to become apparent when cooperative behavior of all protection systems of cells occurs. Such behavior is characterized by emergent features (feature is impossible to predict proceeding from features of protection systems elements) but not summation of all protection elements.

Keywords: toxicity, hormesis, copper ions, Dunaliella viridis

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