The importance of the bacterial cell wall in uranium (VI) biosorption

The bacterial cell envelope, in particular the cell wall, is considered the main controlling factor in the biosorption of aqueous uranium (VI) by microorganisms. However, the specific roles of the cell wall, associated biomolecules, and other components of the cell envelope are not well defined. Here we report findings on the biosorption of uranium by isolated cell envelope components and associated biomolecules, with P. putida 33015 and B. subtilis 168 investigated as representative strains for the differences in Gram-negative and Gram-positive cell envelope architecture, respectively. The cell wall and cell surface membrane were isolated from intact cells using a French Pressure Cell and characterised by X-Ray Photoelectron Spectroscopy (XPS) and Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FT-IR) spectroscopy. Uranium biosorption was investigated as a function of cell envelope component and pH, comparing with intact cells and was quantified by ICP-OES.

Supplementary information includes characterisation of XPS spectra, uranium speciation, additional adsorption isotherms, langmuir fittings and detailed FT-IR characterisation of cell envelope components.

Data includes raw XPS and FT-IR spectra, peak identifications and uranium isotherm fittings from data collected by ICP-OES.