Mossbauer Spectroscopy of Iron Biomineralization Products in Magnetotactic Bacteria

Mcissbauer spectroscopy is a nuclear i-rav resonance technique that has been extensively tv!i 'iill' s,,'stems. applied to the study of the electronic properties of iron in biological '. The power of the technique lies in its sensitivity to the effects of the physical environment (nature ]18 lw and disposition of ligands, magnetic structure, etc.) on 57Fe nuclei. Moreover, it is sensitive ' only to "'Fe so 11 is uot affected by other elements in the system, except as thev affect the f It llO y discriminatiDn nDnequivalent environment of the iron atoms. The technique allows i atio of o iron sites as opposed to magnetic susceptibiJitv or magnetization measurements which lump l logether contributions from all the sources in the sample. A.s extensive reviews of Moss­ /\ bauer spectmscop)' are available (Greenwood and Gibb, 1971: Bancroft, 1973: Cohen, 1976. y , 1981J we will only give a brief introduction here, focusing on 57Fe, This will be followed ) " biol11ineralization by a review of spectroscopy of iron in mineraliz t products, and of magnetic inclu­ sions in magnetotactic bacteria, l11agnetota u