title: Antioxidative enzyme profiling and biosorption ability of Cupriavidus metallidurans CH34 and Pseudomonas putida mt2 under cadmium stress.
abstract: Cupriavidus metallidurans CH34 and Pseudomonas putida mt2 were used as cadmium (Cd)-resistant and -sensitive bacteria, respectively, to study their biosorption ability and their antioxidative enzymes. The minimal inhibitory concentration of C. metallidurans CH34 for Cd was found to be 30 mM, and for P. putida mt2 it was 1.25 mM. The tube dilution method revealed the heavy-metal resistance pattern of C. metallidurans CH34 as Ni(2+) (10 mM)>Zn(2+) (4 mM)>Cu(2+) (2 mM)>Hg(2+) (1 mM)>Cr(2+) (1 mM)>Pb(2+) (0 mM), whereas P. putida mt2 was only resistant to Zn(2+) (1 mM). Under Cd stress, the induction of GSH was higher in C. metallidurans CH34 (0.359 ± 0.010 mM g(-1)  FW) than in P. putida mt2 (0.286 ± 0.005 mM g(-1)  FW). Glutathione reductase was more highly expressed in the mt2 strain, in contrast to non-protein thiols and peroxidase. Unlike dead bacterial cells, live cells of both bacteria showed significant Cd biosorption, i.e. more than 80% at 48 h. C. metallidurans CH34 used only catalase, whereas P. putida mt2 used superoxide dismutase and ascorbate peroxidase to combat Cd stress. This study investigated the Cd biosorption ability and enzymes involved in the Cd detoxification mechanisms of C. metallidurans CH34 and P. putida mt2.
authors.affiliation: Department of Microbiology and Molecular Genetics, University of the Punjab, New Campus, Lahore, Pakistan; Department of Environmental Microbiology-UMB, Helmholtz Center for Environmental Research-UFZ, Leipzig, Germany.
authors.forename: Saba
authors.initials: S
authors.lastname: Shamim
authors.forename: Abdul
authors.initials: A
authors.lastname: Rehman
mesh_terms: D060387:Ascorbate Peroxidases / Q000378:metabolism; D001673:Biodegradation, Environmental; D002104:Cadmium / Q000378:metabolism* / Q000494:pharmacology*; D002374:Catalase / Q000378:metabolism; D049921:Cupriavidus / Q000737:chemistry / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D024881:Drug Resistance, Bacterial; D005980:Glutathione Reductase / Q000235:genetics / Q000378:metabolism*; D019216:Metals, Heavy / Q000378:metabolism / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D009195:Peroxidase / Q000378:metabolism*; D016958:Pseudomonas putida / Q000737:chemistry / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D013312:Stress, Physiological; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism*
chemical_list: D019216:Metals, Heavy; D013438:Sulfhydryl Compounds; D002104:Cadmium; D060387:Ascorbate Peroxidases; D002374:Catalase; D009195:Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase
keywords: Antioxidative enzymes; Bioremediation; Biosorption; Cadmium; Glutathione