Geomycology of vanadium

In recent years, increasing levels of vanadium in the environment have raised concern over its release from anthropogenic sources, mainly due to hydrocarbon fuel combustion, mining and industrial activities. Vanadium may be essential for some bacteria and fungi, but can have toxicological effects at high concentrations. It is known that several fungal species can bioaccumulate vanadium. In our research, we investigate some relationships between selected fungal species and vanadium in relation to growth responses, bioaccumulation, and mineral transformation. Six species of saprotrophic fungi (Aspergillus terreus, Cladosporium cladosporioides, Clonostachys rosea, Paecilomyces lilacinus, Penicillum citrinum, Rhizopus arrhizus), isolated from soil with high levels of potentially toxic elements, were tested and results revealed a tolerance to vanadium for all the fungi at concentrations up to 6 mM. In other experiments, Aspergillus niger, Aspergillus ustus, Clonostachys rosea, Paecilomyces lilacinus and Paecilomyces javanicus were able to solubilize a vanadium- and lead-containing insoluble apatite (vanadinite). A. niger was able to transform vanadinite to lead oxalate. Vanadium bioaccumulation and mineral biotransformation by fungi might be key factors underlying tolerance to anthropogenic contamination, their possible role in the environmental fate of vanadium, and in land management and bioremediation approaches.