Extracellular iron chelation in Cryptococcus neoformans.

Low-iron minimal medium supported growth of Cryptococcus neoformans but spent medium contained no hydroxamates, organic acids or other iron chelators. Exogenous deferoxamine stimulated growth in extreme iron-limitation, while neither organic acids nor quartersaturated transferrins were stimulatory. These results suggest two iron uptake mechanisms, one dependent upon exogenous hydroxamate, the other hydroxamate-independent.