Chromium reduction in Pseudomonas putida

Abstract

Reduction of hexavalent chromium (chromate) to less-toxic trivalent chromium was studied by using cell suspensions and cell-free supernatant fluids from Pseudomonas putida PRS2000. Chromate reductase activity was associated with soluble protein and not with the membrane fraction. The crude enzyme activity was heat labile and showed a K(m) of 40 μM CrO42-. Neither sulfate nor nitrate affected chromate reduction either in vitro or with intact cells.