Sorption of cadmium by filamentous soil fungi

The article presents the evaluation of the short-term sorption of Cd by selected soil fungi. The Freundlich adsorption isotherm method for metal sorption modelling was applied. Fungal strains belonging to two classes, Zygomycetes and Ascomycetes, were used. Altogether, six species from Ascomycetes (A. niger, A. nidulans, Ps. boydii, T. koningii, P. janthinellum, P. verrucosum) and three from Zygomycetes (R. rhizopodiformis, R. oryzae, R. pusillus) were examined. These fungi were selected for experiments due to the differences in their cell wall compositions. The walls of Ascomycetes and Zygomycetes are in the chitin-glucan and in the chitosan-chitin groups, respectively. It was found that the biomass of A. nidulans and R. pusillus displayed the relatively high Cd sorption capacity. The sorption of Cd was similar among the fungi investigated. The metal accumulation by these fungi increased with increasing concentrations of Cd. The binding of Cd to the fungal biomass was an extremely rapid process. During the first 5 minutes, 72.75% of Cd was taken up by the fungal biomass. The fungal Cd sorption was increased in low pH (range from 3 to 5).