Reduction of Chromium(VI) by Locally Isolated Pseudomonas sp. C-171

Abstract

A strain of Pseudomonas sp. C-171 capable of tolerating hexavalent chromium (Cr+6) up to 2000 ppm as potassium dichromate was isolated from domestic sewage. The Cr+6 reduction was checked by growing the isolated strain in a medium containing potassium dichromate as Cr+6 source. The rate of growth of Pseudomonas sp. C-171 decreased with the increase in Cr+6 concentration of the medium. The maximum rate of chromium reduction was observed during the log phase of bacterium growth. The reduction of hexavalent chromium was inoculum concentration dependent. The accumulation of chromium hydroxide around the bacterial cells and slight elongation of cells were observed.