Detoxification hexavalent chromium by potential chromate reducing bacteria isolated from turnery effluent

Hexavalent chromium Cr6 + is a non-essential well known carcinogen and the actual mechanisms of chromium toxicity is unknown. Approaches were made for the isolation of Cr6 + resistant bacteria from tannery effluent in a common effluent treatment plant, located at Chrompet, Chennai. Five hexavalent chromium resistant bacterial strains such as V1, V2, V3, V4 and V5 were isolated. All the five strains exhibiting high level of resistant to hexavalent Chromium salts and could bear more than 50mg/L of K2CrO4 in Nutrient agar medium. Isolated bacterial strains were identified by various biochemical tests. Then the effectiveness of the bioremediation was evaluated with all the five strains. Based on the bioremediation efficiency, the strain (V3) Psedomonas sp. was selected for the detoxification experiment which exhibits maximum hexavalent chromium reduction. Hence we conclude that Psedomonas sp. isolated from tannery effluent have the potential for the bioremediation of heavy metal contamination.