Mössbauer spectroscopic studies of iron in Proteus mirabilis

Mössbauer measurements of Proteus mirabilis cells grown in 57Fe-enriched media show that considerable quantities of iron are incorporated, particularly in the stationary phase of growth. A major part of the iron is in a form which shows magnetically split spectra at low temperatures. Fractionation of cells reveals that iron is present in both the soluble and particulate fractions, with the larger proportion being found in the soluble fraction. The iron in the particulate fraction is predominantly found in the outer membrane.