Study of bioaccumulation kinetics of chromium( vi ) in Acinetobacter beijerinckii type bacterium by Total Reflection X-Ray Fluorescence Spectrometry

Total Reflection X-Ray Fluorescence (TXRF) has been applied for the first time to evaluate the kinetic behavior of the Cr(vi) bioaccumulation process that the recently isolated bacterium, named ANCR (Acinetobacter beijerinckii type), presents. First, a qualitative study of the bacterium elemental profile detected by TXRF has been carried out. Second, detection limits and the uncertainty of the technique were evaluated for this case. Finally, an experiment was designed to evaluate the behavior of the chromium content by two ways: in the cultured medium of the experiment, evaluating its decrease, and bioaccumulated in the bacteria, evaluating its increase. The results demonstrate that this new strain of Acinetobacter bacterium is able to reduce the chromium present in the culture medium. As a consequence, it can be used as a promising microorganism for Cr(vi) bioremediation from polluted wastewaters. Finally, TXRF has shown its versatility, potential and sensitivity for the analytical evaluation of toxic metals in this kind of microbiological system.