Zinc and Cobalt: Effect on the Iron Metabolism of Ustilago sphaerogena.

The ferrichrome content of cells of the smut fungus Ustilago sphaerogena during growth in a medium deficient in zinc increases with increase in the cobalt of the medium from 0 to 3 X 10(-5)M. The addition of zinc to such cultures prevents the accumulation of ferrichrome. The results suggest that zinc is involved in the utilization of iron via a process which can be blocked by cobalt.