On the Immobilization of Desferrioxamine-Like Siderophores for Selective Metal Binding

Abstract

Gordonia rubripertincta CWB2 produces hydroxamate-type siderophores. Therefore it was cultivated under iron limitation. Analytical reversed-phase HPLC allowed determining a single peak of ferric iron chelating compounds from culture broth. The elution profile and its absorbance spectrum were similar to those of desferrioxamine B. The latter is a commercial available metal chelating agent which is of interest for industries. We successfully developed an HPLC protocol to separate metal-free and metal-loaded desferrioxamines. Further, we aimed to increase the re-usability of desferrioxamines as metal chelators by immobilization on silica based carriers. The siderophores of strain CWB2 have been covalently linked to the carrier with a high yield (up to 95%). Metal binding studies demonstrated that metals can be bound to non-immobilized as well as to the covalently linked desferrioxamines.