Siderophores are water-soluble low molecular weight organic molecules secreted by microbes and graminaceous plants which strongly  (Kb ~ 1030) chelate Fe3+ in order to meet biological need for iron.  We use the fungal tri-hydroxamate siderophore desferrioxamine B (DFOB) and its iron-chelated counterpart ferrioxamine B (FOB), along with others such as ferrichrome, rhodotorulic acid, and pyoverdine, to better understand what experimental variables affect siderophore-promoted Fe dissolution from smectite clay minerals.  We show that many factors influence the rate and/or extent of Fe release from ferruginous smectite SWa-1 and Manito nontronite, including:  clay particle size, redox cycling of the clays, clay solution concentration, siderophore concentration, and siderophore type.  As Fe release is dependent on siderophore adsorption to mineral surfaces, we analyze our experimental results in the context of ion exchange on smectite between the cationic DFOB and FOB species and Ca2+.

Factors influencing siderophore-promoted Fe(III) dissolution from smectite clays

239th National Meeting (2010)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.