Iron and Fungal Physiology: A Review of Biotechnological Opportunities

Iron is an essential inorganic micronutrient. Because of its low toxicity only a few studies have dealt with the importance of iron in fungal physiology. Most of the studies published so far focus on iron sequestration by animal fungal pathogens, iron uptake by mycorrhizal fungi, or iron redox activities by fungal wood degraders. However, a general overview on the relationship between fungal physiology and iron is still lacking. In this review we present a summary of the types of physiological activities that participate in iron homeostasis in fungi and how these activities can be used for the development of original biotechnological applications in relationship to iron-containing matrices. Concrete examples of biotechnological applications involving iron and fungi are also discussed. In the last part, a specific research project in biotechnology focusing on the use of fungi for the conservation of archaeological objects in iron is described in detail. This project aims at developing a new conservation-restoration method to preserve archaeological iron artifacts exploiting the ability of fungi to transform and uptake iron. Preliminary results obtained in this project regarding iron-reduction, iron uptake, and biogenic formation of iron minerals are presented and discussed.