Use of pelleted and immobilized yeast and fungal biomass for heavy metal and radionuclide recovery

Summary The biosorption of uranium, strontium and caesium by pelleted mycelium of two species of fungi,Rhizopus arrhizus andPenicillium chrysogenum and immobilizedSaccharomyces cerevisiae was evaluated in both batch and continuous flow systems where the presence of competing cations affected accumulation. The uptake mechanism for the pelleted fungal biomass differed from that of the immobilized yeast, the former being metabolism-independent biosorption of the metals while, in the presence of glucose, uptake in the latter organism was biphasic, surface biosorption being followed by energy-dependent influx. Removal of surface-bound metals was achieved by eluting with mineral acids or carbonate/bicarbonate solutions; a high degree of metal recovery was observed for uranium.