Theeffectofdifferentinitialconcentrations(10–100μgmL −1) of lead and cadmium on the surface adsorption and intracellular uptake by N. muscorum cells is shown in Fig. 1.A concentration-dependent increase in the surface binding of both Pb and Cd was observed to reach a maximum level (275 and 250 μg mg −1 protein, respectively) at 100 μg mL −1 concentrationofeachmetal.Theresultsonintracellularuptake ofmetalsshowedthatuptakeofPb(14μgmg −1 protein)byN. muscorum cells was slightly higher than that of Cd (11 μg mg −1 protein) at their respective uptake rate saturating concentrations (60 and 80 μg mL −1, respectively). The result revealed that the surface-bound fraction of each metal was about 20 times higher than the intracellular fraction.