Selective accumulation of heavy metals by three indigenous Bacillus strains, B. cereus, B. megaterium and B. sphaericus, from drain waters of a uranium waste pile

The interaction was studied of three Bacillus isolates, recovered from a uranium waste pile in Saxony, Germany, with different heavy metal ions present in the original ground water of the pile. Using 16S amplified ribosomal DNA restriction and random amplified polymorphic DNA analyses, the three isolates were classified as B. cereus, B. megaterium and B. sphaericus. The ability was investigated of vegetative cells and spores of the indigenous Bacillus strains as well as those of the corresponding reference strains B. cereus ATCC 4415, B. megaterium NRRL B5385, and B. sphaericus NCTC 9602 to accumulate Al, Ba, Cd, Co, Cr, Cs, Cu, Fe, Ga, Mn, Ni, Rb, Pb, Si, Sn, Sr, Ti, U, and Zn. It was clearly shown that all strains studied accumulated selectively large amounts of U, Pb, Cd, Cu and Al. Co, Mn, Ni, Zn, and Ga was only weakly accumulated. The binding of Ba, Ga, Mn, Ni, and Zn was species and in some cases even strain specific.