Analysis of desferrioxamine-like siderophores and their capability to selectively bind metals and metalloids: Development of a robust analytical RP-HPLC method

Publication date: Available online 20 August 2018Source: Research in MicrobiologyAuthor(s): Ringo Schwabe, Marlene Kirstin Anke, Katarzyna Szymańska, Oliver Wiche, Dirk TischlerAbstractThe Actinobacterium Gordonia rubripertincta CWB2 (DSM 46758) produces hydroxamate-type siderophores (188 mg L-1) under iron limitation. Analytical reversed-phase HPLC allowed determining a single peak of ferric iron chelating compounds from culture broth which was confirmed by the Fe-CAS assay. Elution profile and its absorbance spectrum were similar to those of commercial (des)ferrioxamine B which was used as reference compound. This confirms previously made assumptions and shows for the first time that the genus Gordonia produces desferrioxamine-like siderophores. The reversed-phase HPLC protocol was optimized to separate metal-free and -loaded oxamines. This allowed to determine siderophore concentrations in solutions as well as metal affinity. The metal loading of oxamines was confirmed by ICP-MS. As a result, it was demonstrated that desferrioxamine prefers trivalent metal ions (Fe3+> Ga3+> V3+> Al3+) over divalent ones. In addition, we aimed to show the applicability of the newly established reversed-phase HPLC protocol and to increase the re-usability of desferrioxamines as metal chelators by immobilization on mesocellular silica foam carriers. The siderophores obtained from strain CWB2 and commercial desferrioxamine B were successfully linked to the carrier with a high yield (up to 95%...

Source: Research in Microbiology - August 20, 2018 Category: Microbiology Source Type: research