Bioaccumulation of copper, zinc, cadmium and lead by Bacillus sp., Bacillus cereus, Bacillus sphaericus and Bacillus subtilis

This work presents some results on the use of microbes from the genus Bacil lus for uptake of cadmium, zinc, copper and lead ions. Maximum copper bioac cumulations were 5.6 mol/g biomass for B. sphaericus, 5.9 mol/g biomass for B. cereus and B. subtilis, and 6.4 mol/g biomass for Bacillus sp. Maximum zinc bioaccumulations were 4.3 mol/g biomass for B. sphaericus, 4.6 mol/g b iomass for B. cereus, 4.8 mol/g biomass for Bacillus sp. and 5.0 mol/g biom ass for B. subtilis. Maximum cadmium bioaccumulations were 8.0 mol/g biomas s for B. cereus, 9.5 mol/g biomass for B. subtilis, 10.8 mol/g biomass for Bacillus sp. and 11.8 mol/g biomass for B. sphaericus. Maximum lead biomacc umulations were 0.7 mol/g biomass for B. sphaericus, 1.1 mol/g biomass for B. cereus, 1.4 mol/g biomass for Bacillus sp. and 1.8 mol/g biomass for B. subtilis. The different Bacillus strains tested presented distinct uptake c apacities, and the best results were obtained for B. subtilis and B. cereus .