The redox chemistry of iron (Fe) plays a fundamental role in marine geochemistry, yet surprising little is known about these reactions in seawater. The oxidation kinetics and solubility of Fe suggests that Fe(II) should be insignificant in oxygenated seawater, yet unexpectedly high values have been reported. Although analytical artifacts are usually called upon to explain such measurements, scientists from the Woods Hole Oceanographic Institution have proposed an alternative explanation that in some conditions, Fe(II) chelation by ligands slows abiotic oxidation kinetics. Based on new evidence of a class of bacteria that directly participate in mineral dissolution Fe oxidation do so with the aid of Fe(II) binding ligands, they will study the interactions between Fe(II) and organic ligands to provide new insights into Fe coordination and redox chemistry. Using a unique model system will allow them to examine these processes in detail with an organism that appears remarkably well adapted, indeed thrives, in both high and low Fe conditions. Improved understanding of Fe redox chemistry has a broad impact, due to its central role in the physiology of all cells.
