Biosorption of hexavalent chromium by paenibacillus pabuli and bacillus cereus isolated from alkaline industrial contaminated soil in Puducherry, India

Abstract

In the present study, we intended to remediate Cr(VI) with alkaliphilic bacteria Paenibacillus pabuli (JX561107) and Bacillus cereus (JX561108) isolated from alkaline industrial contaminated soil in Pondicherry. The isolated bacteria were tested for the removal efficiency of hexavalent chromium at different concentrations (50 mg/L, 200mg/L, 400mg/L). At 50 mg/L of hexavalent chromium concentration, Paenibacillus pabuli and Bacillus cereus were found to be highly efficient in removing Cr(VI) in 72 hrs at the inoculum rate of 1% of overnight grown bacterial cultures. The isolates could remove 98% and 74% of Cr(VI) within 72 hrs of treatment at 9.5 pH. When the concentration of the Cr(VI) was increased to 400 mg/L, there was a gradual decrease in Cr(VI) removal. SEM images were obtained from the tested bacteria to observe the bacterial cell surface for the changes in the morphology and EDX analysis were also carried out to confirm whether the adhered particles are of chromium.