Microbial Reduction of Cr (VI) into Cr (III) by Locally Isolated Pseudomonas Aeruginosa

Chromium hexavalent, Cr (VI), has been known as the toxic agent for living organisms. Many methods have been exploited to remove Cr (VI) in the environment, including empowering bacteria as bioremediation agent. Here, this study aims at investigating the influence of Cr (VI) on growth of pseudomonas aeruginosa and its ability to convert Cr (VI) into Cr (III) on leather tannery effluent model. The dissolved of sodium dichromat (K2Cr2O7) was used as source of Cr (VI). The effect of Cr (VI) on Pseudomonas aeruginosa growth was checked by comparing the growth of Pseudomonas aeruginosa in medium containing certain concentration of chromium and in medium without chromium. Spectrophotometer analysis showed that the rate of pseudomonas aeruginosa growth decreased at the concentration of 100 ppm of Cr (VI). In addition, the reduction of Cr (VI) was monitored by growing Pseudomonas aeruginosa in the medium with K2Cr2O7. The result of AAS and spectrophotometer show the decreased of Cr (VI) concentration in the medium from 100 to 5.86 ppm with the conversion efficiency reach to 94.73% during 48 hours of the treatment. High efficiency conversion of Cr (VI) in to Cr (III) indicates the possibility of pseudomonas aeruginosa to be used as a bioremediation agent to reduce Cr (VI) in the polluted environment.