Science Serving Maryland's Coasts

Lauren Hunker, University of Minnesota Morris

Class Year: 

Project Title: 

Binding of Rare Earth Elements by Bacterial Siderophores


Marine bacteria produce siderophores in order to acquire iron (Fe), which has concentrations on the nanomolar scale in the ocean. Desferrioxamine B (DFOB), one type of siderophore, is readily available due to its use in chelation therapy for patients with iron-overload diseases. Like Fe(III), the rare earth elements (REE) have a 3+ charge. This allows complexation to also occur between DFOB and REE. The nature of complexation between DFOB and REE was investigated through the use of acid-base titrations as well as a cation-exchange resin and ICP-MS technique. Titrations were used to determine acid dissociation constants of the acidic functional groups on DFOB. The other method provides insight into the trend of complexation that occurs between DFOB and REE.