Uptake of Zinc by Fungi

Zinc has long been known to be essential for the growth of microorganisms including fungi and is important in the structure and function of many enzymes, nucleic acid metabolism, and cell division. Zinc is also important in the production of secondary metabolites including aflatoxins, other polyketides, ergot alkaloids, penicillin and extracellular polysaccharides such as scleroglucan from Sclerotium rolfsii. The complete inhibition of Zn²⁺ uptake in S. cerevisiae by uncouplers of oxidative phosphorylation such as DNP has been taken as evidence for the requirement of a transmembrane proton gradient but it should be noted that there are again potential nonspecific effects that can occur in intact cells. Uptake of Zn²⁺ into the vacuole was apparently an energydependent process requiring both ATPase activity and a proton gradient across the vacuolar membrane.