Isolation and characterization of arsenite oxidizing Pseudomonas lubricans and its potential use in bioremediation of wastewater

A bacterium, Pseudomonas lubricans , isolated from heavy metal laden industrial wastewater, has been shown to tolerate multiple heavy metals suggesting its importance in bioremediation of industrial effluents. P. lubricans tolerated As(III) up to 3 mg ml -1 , Cu 2+ up to 0.7 mg ml -1 , Hg 2+ up to 0.4 mg ml -1 , Ni 2+ up to 0.4 mg ml -1 and Cr 6+ up to 0.5 mg ml -1 . P. lubricans showed optimum growth at pH 7 while optimum temperature for growth was 30°C. P. lubricans could oxidize As(III) 42% (42 μg mg -1 of protein), 78% (78 μg mg -1 of protein) and 95% (95 μg mg -1 of protein) from the medium after 24, 48 and 72 h of incubation at optimal conditions, respectively. The arsenite oxidizing ability shown by P. lubricans indicates its potential application in biological treatment of wastewaters contaminated with arsenic.