Bioaccumulation of Cadmium by Pseudomonas Sp. Isolated From Metal Polluted Industrial Region

Abstract

In the present study, bacterial strains were isolated from soil, sediment and water samples of metal contaminated industrial area and investigated the heavy metal resistance and bioaccumulation potential of the isolates. Cadmium analysis of the samples revealed that Cd concentration varying from 2.31µg L^-1 to 8.96 µg L^-1 in water, 0.55µg g^-1 to 25.44µg g^-1 in soil and 0.45µg g^-1 to 22.90µg g^-1 in sediment. Cadmium resistance studies of the bacterial isolates showed that out of 164 isolates collected most of them showed  low resistance (<500µg/ml) and many isolates showed high resistance of  >1500µg/ml. Ten bacterial genera were represented in soil and 11 from water, while only 5 bacterial genera were recorded from sediment samples.  Bacillus, pseudomonas and Enterobacter were found in soil, sediment and water samples. Results of cadmium removal study revealed that with increase in time, the biomass of the selected Pseudomonas sp. increased. Correspondingly, with increase in biomass, the cadmium bioaccumulation was also increased. Relatively an Increased removal of cadmium was observed in the first day of the experiment. About 40% of the cadmium in the experimental flask was reduced while only 5% reduction occurs in the control flasks till the end of the experiment (74hours). Comparatively cadmium showed higher reduction at pH 7. From the results, it could be concluded that the selected bacterial isolates possessed potential in respect of bioaccumulation activity and thus, appeared to be an appropriate nominee in bioremediation processes.

DOI: http://dx.doi.org/10.5755/j01.erem.61.3.1268