Microorganisms present many mechanisms of metal tolerance.
This last process may involve sequestration by the cell wall, vacuoles, polyphosphate bodies, or protein complexes. The important role played by fungi in biogeochemical cycles make them suitable candidates for performing studies of metal-microbe interactions. A better understanding of the factors for metal resistance may help in the application of fungal biomass for the treatment of metal-contaminated water, and also in enrichment or recycling of valuable metals. After repeated culturing in progressively higher concentrations of copper sulfate, a copper-tolerant Mucor rouxii strain was obtained. The copper-tolerant strain differed from the sensitive parental strain with respect to shape and size.