In the recent investigation, chromium tolerant strains were isolated from tannery effluent collected from Dindigul district. Six chromium tolerant strains were isolated from potassium dichromate amended Nutrient agar plates and their maximum tolerance were determined. The strain TE-2 and TE-6 exhibited maximum tolerance upto 500 ppb. The two chromium tolerant strains were identified as Bacillus subtilis and Pseudomonas aeruginosa on the basis of phenotypic and biochemical characteristics. In the present investigation, the chromium reduction for Pseudomonas aeruginosa was performed two different concentration of potassium dichromate (200 ppb and 400 ppb). The AAS analysis was performed to analyze hexavalent chromium and role of microorganisms in biodegradation process. Pseudomonas aeruginosa revealed a reduction in total chromium of 0.016 ppb when compared with control which revealed 0.019 ppb. On analysis with 400 ppb after 15 days of exposure a remarkable reduction of 0.020 ppb rather compared with compared (0.024ppb). The extraction of chromate reeducates enzyme was performed which revealed that the crude enzyme had a total chromate reeducates activity of 0.014 µ moles min-1 and the total protein concentration of 0.25 mg respectively. The specific activity of µ moles min-1 mg-1 was recorded for crude chromate reeducates enzyme. The effect of temperature on chromate reductase was performed with temperature ranging from 20oC to 70oC. Pseudomonas aeruginosa exhibited an optimum temperature of activity of 50oC with 0.106 µ moles min-1. Pseudomonas aeruginosa was found to be a versatile microorganism which can tolerate up to 500 ppb concentration and can be used for bioremediation process.
