Isolation and Characterization of Nickel Uptake by Nickel Resistant Bacterial Isolate （NiRBI）

INTRODUCTION Today indiscriminate and uncontrolled discharge of metal-contaminated industrial effluent in the environment has become an issue of major concern. Heavy metals are the major toxicants found in industrial waste water. Nickel toxicity is comparable to cobalt but its toxic effect on humans is better documented, up to 20% of the populations in industrially developed countries have positive results in epidermal testing[1]. Many industries such as electroplating, paint, pigments, b…

Isolation and characterization of nickel uptake by nickel resistant bacterial isolate (NiRBI)

Objective Bioremediation technology has gained importance because microbes could be the convenient source of bio-absorption/bioaccumulation of metals from effluent streams. Methods The nickel-resistant bacterial isolates (NiRBI) were selected from various bacterial isolates from industrial effluent and grown in nutrient broth containing different concentrations of nickel sulfate (0.3-3.0 mmol/L) and their capability of accumulating metal from the medium. Results Well-defined growth of NiRBI was observed in the medium containing up to 2.5 mmol/L of nickel. The isolate was identified using 16S rRNA and closely related to Pseudomonas fragi. Maximum accumulation of nickel (0.59 mg/g dry weight of bacterial cells) was observed when NiRBI was grown in media containing 2 mmol/L of nickel. The protein profile of the NiRBI cellular extract by SDS-PAGE showed two metal stress-induced proteins of molecular weight 48 KD and 18 KD with a simultaneous down regulation of four proteins of 46.7 KD, 42.2 KD, 19.7 KD, and 4.0 KD. Conclusion 48 KD and 18 KD proteins play a role in metal resistance mechanism by NiRBI.