Bioremediation of copper by active cells of Pseudomonas stutzeri LA3 isolated from an abandoned copper mine soil.

Copper bioremoval efficiency and bioaccumulation capacity of Pseudomonas stutzeri LA3 isolated from copper contaminated soil were investigated. P. stutzeri LA3 removed about 50% of Cu (II) at 50 mg l-1 of concentration and accumulated a maximum of 1.62 mg of Cu g-1 biomass dry weight. Bioremediation by P. stutzeri LA3 partially depended on the production of extracellular polymeric substances, composed of proteins and carbohydrates. Cell surface alterations were observed on the Cu (II) treated biomass through a scanning electron microscope (SEM). Energy dispersive spectrometer (EDX) investigation of Cu (II) treated biomass showed clear signals of Cu, confirming the presence of copper ions on the cell surface. Fourier transform infrared spectroscopy (FTIR) showed the contribution of functional groups such as hydroxyl (-OH), carboxyl (-COOH), amide and amine (-NH2) in the remediation process. Based on the results, the isolated strain P. stutzeri LA3 could serve as a potential candidate for copper due to its significant copper removal effeciency.