The influence of copper ions on the cell surfaces was evaluated by means of electron microscope images. Fig. 7 shows damage on the surfaces of living cells visible as crateriform cavities by scanning EM. Similar damages in the form of caves were observed in the cell section images obtained with the TEM technique (Fig. 4). Cells on the pictures were in contact with the copper solution for 24 h. Probably because of the damage, the cells have partially lost their binding abilities resulting in higher metal concentration in solution after 24 h than after 10 min of bioaccumulation. Cell wall separation (Fig. 8), which