Biosorption of lead and uranium by Streptomyces sp.

Both Pb(II) and UO₂ ²⁺ were abstracted from aqueous solution by both living and dead biomasses of Streptomyces sp. The organisms were particularly effective in taking up UO₂ ²⁺ ions. Optimum pH for both metals was pH 5 to 6. For a UO₂ ²⁺ concentrations of 1 mmol L^?1 and a dead biomass concentration of 1 g L^?1, 60% of the UO₂ ²⁺ was removed from solution. If cell wall material of the organism was prepared from a killed biomass an equal weight of the material removed 90% of the UO₂ ²⁺ from solution. in this case accumulated U in the biomass was 0.9 mmol g^?1 of dry biomass. Electron micrographs showed clearly that the Pb abstracted was only in the microorganisms cell surface, but UO₂ ²⁺ uptake was also intracellular.