Isolation of Cadmium-Resistant Bacteria and Their Resistance Mechanisms

Abstract

Abstract From the viewpoint of environmental decontamination, the ability of Cd-resistant bacteria to remove soluble cadmium (Cd) from soils heavily contaminated with Cd was examined. The highest Cd biosorption which was achieved by the use of Cd-sensitive bacteria CS-5 was approximately 48.0 mg Cdg-1 biomass, which would be sufficient for recycling as Cd resources. The higher the Cd-resistance of strains, the lower the Cd adsorption and uptake, which suggests the existence of a Cd efflux system. Coexisting zinc (Zn) inhibited the Cd biosorption by bacteria remarkably. Strains with a high Cd resistance were less affected by coexisting Zn than those with a low Cd resistance.