Bioaccumulation of lead, chromium, and nickel by bacteria from three different genera isolated from industrial effluent.

The potential of indigenous bacterial strains to accumulate three metals (Cr, Ni, Pb) was exploited here to remediate the polluted environment. In the present study, metal resistance profiles identified three most potential isolates which could tolerate 700-1000 μg/ml of Ni, 500-1000 μg/ml of Cr, and 1000-1600 μg/ml of Pb. These three bacterial strains were identified as Stenotrophomonas sp. MB339, Klebsiella pneumoniae MB361, and Staphylococcus sp. MB371. UV-Visible and atomic absorption spectrophotometric (AAS) analysis revealed gradual increase in percentage accumulation with increase in time due to increased biomass. Quantitative assessments exhibited maximum removal of Cr (83.51%) by Klebsiella pneumoniae MB361, Pb (85.30%), and Ni (48.78%) by Stenotrophomonas MB339, at neutral pH and 37 °C, whereas Staphylococcus sp. MB371 sorbed 88.33% of Pb at slightly acidic pH. The present study therefore supports the effective utilization of indigenous bacteria for comprehensive treatment of metal-rich industrial effluents.