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.

Cadmium resistance mechanism in Escherichia coli P4 and its potential use to bioremediate environmental cadmium

“…Reduced glutathione (GSH), oxidized glutathione (GSSG) and total thiol contents were estimated according to Shamim and Rehman (2015). Briefly, bacterial isolate was grown in 100 mL of LB broth medium in a set of three 250-mL flasks at 30°C.…”

Crosstalk Between Decreased Anti-Oxidant and Increased Serum Angiogenesis in Renal Cell Carcinomas

“…[19] For preparation of reaction, the following components were added, 0.1 mM EDTA, 100 mM KH2PO4 buffer (pH 7.8), 60 mM riboflavin, 13 mM methionine, 2.25 mM NBT (Nitro blue tetrazolium) and remaining was serum. After mixing all the components, the reaction plate was exposed to light for 10 minutes.…”

“…[19] For preparation of reaction the added components are, 0.5 mM ascorbate, 0.3 mM H 2 O 2 , 100 mM KH 2 PO 4 buffer (pH 7.0) and remaining was serum. Optical density at 290 nm was taken after 3 minutes.…”

“…GSH assay was performed as reported previously [19] with slight modifications. Reaction was prepared by adding 1 mM EDTA, 0.5 mM oxidized glutathione, 100 mM KH 2 PO 4 buffer (pH 7.5) and remaining serum were added.…”

“…[19] Buffer used for reaction contain 12.5 mM H 2 O 2 in 50 mM KH 2 PO 4 (pH 7.0). 100ul serum was added in it.…”