ADSORPTION OF DESFERRIOXAMINE-B AND OXALATE LIGANDS ON Al-GOETHITES: IMPLICATIONS FOR MICROBIAL DISSOLUTION PROCESSES

摘要

Microorganisms and higher plants produce siderophores to facilitate the solubilization and uptake of Fe in aerobic environments. The mechanism for Fe acquisition by siderophores such as desferrioxamine, DFO, relies on the selectivity of these ligands for Fe(III) to form very stable complexes. In addition, aerobic organisms may enhance the dissolution of iron oxides by secreting organic ligands of smaller size and lower molecular mass (e.g., oxalate). Because Al-goethites with low substitution rates are common in soils, studying how the Al-content affects the dissolution rate of goethite in the presence of DFO and oxalate may help to understand the mechanism of Fe mobilization by aerobic microbial communities in widely diverse environments.