Biocumulation of copper and lead by Sphaerotilus natans.

The accumulation of copper and lead by the filamentous bacteria Sphaerotilus natans was studied. An increase in the amount of accumulated metal depending on the concentration of copper and lead in the medium was observed. The extent of accumulation also depended on the chemical form of the metal in the medium and time of its contact with the bacteria. Electron micrographs of S. natans revealed the presence of copper and lead in the mucous capsule, cell wall, cytoplasmic membrane and cytoplasm of the bacteria. Both copper and lead altered the growth curves of S. natans.