Biosorption of heavy metals by Pleurotus ostreatus.

Living and lyophilized mycelia of four wild syrian strains of the white rot fungus Pleurotus ostreatus were studied with the purpose of testing mycelia ability to grow on media containing different concentrations of heavy metals (cadmium and lead) and absorb them. The results show that with the increase of metal concentration a decrease of mycelium growth was evident, depending on the heavy metal and the strain used. Strains were more sensitive to Cd in comparison with Pb. Studies of absorption in batch show that the lyophilized mycelium is able to absorb the same percentage of Cd in the presence of increased concentrations of metal. In case of lead a greater adsorption (> 40%) was obtained in the presence of 10 ppm of metal; the quantity of Pb absorbed by lyophilized mycelium remained the same when the quantity of metal present in the batch increased.