Tolerance and biosorption of cadmium (II) ions by highly cadmium resistant bacteria isolated from industrially polluted estuarine environment

In the present study, totally 20 bacterial strains were isolated from two sites of study area and also screened their tolerance against cadmium (II) ions. Among the strains, 6 strains were screened as cadmium resistant and remaining 14 strains as cadmium sensitive. Colony morphology, staining and biochemical test showed that highly cadmium resistant bacteria (HCRB) NT-1, NT-5, NT-10, TT-5, TT-8 and TT-10 belongs to Bacillus sp. Enterobacter sp., Aeromonas sp., Bacillus sp., Aeromonas sp., and Pseudomonas sp. respectively. Biosorption potential of HCRB (NT-1, NT-5, NT-10 and TT-10) was assessed in the 100 mg/l Cd (II) ions containing marine broth. Strain TT-10 showed maximum percentage (99 %) of cadmium removal in CdCl2. 5H2O treated broth when compared to other resistant isolates. This study infers that cadmium resistant bacteria such as Pseudomonas sp. (TT-10) are valuable candidates for bioremediation of cadmium contaminated ecosystem.