XANES spectra for <i>Serratia</i> biominerals, annotated with the edge position E<sub>0</sub> (eV) obtained from the position of the first peak in the first derivative.

<p>Precipitates from the uranyl phosphate (UP) biomineralisation experiments display the same features as the U(VI) standard. The precipitate from the aqueous U(VI) reduction experiment is similar to the U(IV) standard while that from the solid U(VI) reduction experiment is intermediate.</p>