Copper tolerance and cotolerance to cadmium, cobalt and lead by Aspergillus nidulans.

ROMERO M.C., ; CORDOBA S.B., ; LEOTTA G.A., ; IRAZABAL G.B., ; REINOSO E.H.

Puerto Madryn, Chubut, Argentina

Congreso; XVIII Congreso Argentino de la Ciencia del Suelo; 2002

Centro Nacional Patagónico, CONICET. Universidad Nacional de la Patagónia

The fungus Aspergillus nidulans was trained after five to tolerate elevated concentrations of copper, and simultaneously acquired cotolerance to high levels of cadmium, cobalt and lead. The adaptation to copper was the result of physiological mechanisms rather than the selection of resistant cells or the mutation induction. The metal activated biochemical precesses that conferred resistance to copper as well as to the other heavy metals, like cadmium, cobalt and lead. Furthermore, the training to copper of the mycelia was also transferred to the sporangiospores; and these strains didi not seem to produce extracellular metabolites that complexed the ions. However, the mycelia of the trained fungus removed approximately twice as much copper from solution than of the nontrained parentals. These results attemped to emphasize the detoxification abilities of the studied fungus and the adaptation, even partially, to heavy metals satress suggesting that such tolerance and cotolerance could also be acquired in natural environments.