title: Chromium (VI) reduction by cell free extract of Ochrobactrum anthropi isolated from tannery effluent.
abstract: Chromium-resistant bacteria isolated from industrial wastes can be used to detoxify toxic chromium from contaminated sources. From effluent of Shafiq Tannery, Kasur, Pakistan, bacterial strain STCr-1 that could endure 40 mg mL(-1) of potassium chromate in nutrient agar medium was isolated. STCr-1, identified as Ochrobactrum anthropi by 16S rRNA gene sequence homology, demonstrated substantial Cr(VI) reduction at pH 7 and temperature 37°C. It completely reduced 250 μg mL(-1) of Cr(VI) and showed 71.2 % Cr(VI) reduction at Cr(VI) concentrations of 550 μg mL(-1). Rate of Cr(VI) reduction increased with increase in cell and Cr(VI) concentration. The presence of Cu(2+), Co(2+) and Mn(2+) significantly stimulated Cr(VI) reduction. Assay with cell free extracts clearly indicated that Cr(VI) reduction was solely associated with the soluble fraction of the cell.
authors.affiliation: Department of Microbiology and Molecular Genetics, University of the Punjab, Quaid-e-Azam Campus, Lahore, 54590, Pakistan. sikandersultan@yahoo.com
authors.forename: Sikander
authors.initials: S
authors.lastname: Sultan
authors.forename: Shahida
authors.initials: S
authors.lastname: Hasnain
mesh_terms: D001483:Base Sequence; D001673:Biodegradation, Environmental; D002857:Chromium / Q000032:analysis / Q000378:metabolism*; D007220:Industrial Waste; D008969:Molecular Sequence Data; D020621:Ochrobactrum anthropi / Q000302:isolation & purification / Q000378:metabolism*; D010154:Pakistan; D013633:Tanning; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*
chemical_list: D007220:Industrial Waste; D014874:Water Pollutants, Chemical; D002857:Chromium