摘要：AbstractA chromium-resistant bacterium was isolated indigenously from tannery effluent and identified asStaphylococcus sciuri. The optimum growth was observed at 37 °C and pH 7.S. sciuriwas able to resist Cr6+(25 mM) and other heavy metals such as As2+(19 mM), Pb2+(18.5 mM), Zn2+(17 mM), Cu2+(2.5 mM), Cd2+(3 mM), and Ni2+(1.5 mM). Biochemical characterization of chromate reductase revealed its optimal pH as 8.0 and temperature as 40 °C. The enzyme activity was stimulated only by Mg2+among other heavy metals tested.S. sciurishowed chromium biosorption proficiency (q) after 2, 4, 6 and 8 days as 42, 73, 85 and 31 mM/g, respectively. Cr6+did not stimulate activities of APOX, SOD and CAT significantly, however, only POX showed marked production (86%). Also, enhanced production of glutathione and other non-protein thiols significantly combat metal induced oxidative stress. Pilot study verified thatS. sciuriwas able to remove 93% Cr6+from tannery effluent within 6 days of incubation. Thus,S. sciuricould act as a potential candidate for the bioremediation of hexavalent chromium contaminated environmental sites.
