Removal of toxic Co-EDTA complex by a halophilic solar-salt-pan isolate Pseudomonas aeruginosa SPB-1

In this study, a promising bioremediation approach was developed to remove [Co(III)-EDTA]− complex that is generated during the waste management process. Though several studies have been reported on bioremediation of cobalt, the removal of [Co(III)-EDTA]− complex has not been tested. A [Co(III)-EDTA]− resistant bacterium, Pseudomonas aeruginosa SPB-1 was isolated from the solar-salt-pan and physical parameters were optimized for its growth. The various studies showed that the removal of [Co(III)-EDTA]− from the bulk liquid was due to the adsorption of the complex by the biomass. Using absorption/desorption isotherm over a range of pH (1-8), the maximum adsorption of [Co(III)-EDTA]− was found to be at pH 7.0 and maximum desorption from the biomass occurred at pH 1.0, thus rendering an ion exchange property to P. aeruginosa SPB-1 biomass. P. aeruginosa SPB-1 biomass could be used as bio-resin that showed 80.4 ± 3.27% adsorption capacity up to fourth cycle and the biomass was viable till the ninth cycle with 10.5 ± 7.3% adsorption. Radiation tolerance potential i.e. D10 value for the strain was found to be ∼300 Gy, which suggests the potential use of the bacterium in bioremediation of moderately active nuclear waste.