Bioremediation of Cr (VI) by Microbial consortium isolated from an Industrial waste water contaminated site for potential Industrial application

Present study involves isolation of bacterial strains with high tolerance to Chromium (Cr (VI)) from industrial waste water contaminated soils.Two isolates SBS1 & SBS3 were found to have Cr (VI) degrading capacity up to 2000 ppm, identified as Bacillus cereus, Bacillus thuringiensis by 16S rRNA sequencing.The strains when optimized for growth conditions showed optimal growth at 28 -37 ºC and pH 5 -7.5 respectively.The strains showed 90 % reduction of 2000 ppm Cr (VI) by 48 h.Bacterial consortium showed high degradation rate of 65 % in sporulation phase in industrial effluent with an initial Cr (VI) concentration of 1500 -2000 ppm when compared to individual cultures.Upon immobilization of the sporulating consortia in sodium alginate beads, bioreduction reached to 73 % in 24 h.ChrR encoding chromate reductase gene was detected in the plasmid and genomic DNA of both the cultures indicating its potential importance in bio-reduction.This study signifies the bio-reduction capacity of the bacterial consortia in sporulation phase at extreme Cr (VI) concentrations of up to 2000 ppm.The consortium may be applicable for biological treatment of Cr (VI) contaminated sites for bioremediation.