Biodegradation potential of bacterial isolates from tannery effluent with special reference to hexavalent chromium

The application of isolated bacterial culture as biological tool for hexavalent chromium removal from tannery industry waste water was investigated. A number of bacteria tolerant to high levels of chromate (>400μgml) were isolated from tannery effluents. These isolates showed varying degree of Cr (VI) reduction under oxic and anoxic conditions at room temperature. Ten isolates were found to be efficient in reducing 70% Cr (VI) under anoxic condition. This included 5 isolates of Pseudomonas, three isolates of Micrococcus and two isolates of Aeromonas. These isolates were subjected to further characterization for possible use in Cr (VI) detoxification of industrial wastes. These bacterial isolates were further examined for tolerance to a variety of other heavy metals. The study indicates the possible use of these bacterial isolates in environmental clean-up.