Analysis of Cr(VI) Bioremediation by Citrobacter freundii Using Synchrotron Soft X-ray Scanning Transmission X-ray Microscopy

Scanning transmission X-ray microscopy (STXM) was utilized for analysing the bioremediation of Cr(VI) by Citrobacter freundii, a species gram-negative bacteria. The biosorption and bioreduction processes were analysed chemical mapping cells biosorbed at different concentrations Cr(VI). STXM spectromicroscopy images recorded O K-edge Cr L-edge. A thorough analysis absorption features corresponding to oxidation states in cell indicated coexistence Cr(III) higher concentrations. This signifies presence partially reduced addition In addition, signal is intense compared with regions indicating excess Cr. Speciation adsorbed spectral comparison standards. Analysis onset, L3/L2 ratio fine structure concludes that predominantly present as hydroxide or oxyhydroxide. evolution duration process also studied. These time lapse studies depict gradual decrement proceeds. strong evidence interaction material observed. obtained results provide insights into speciation on cells.