Soil fungal hyphae bind and attack asbestos fibres.

Surface iron is considered to play a crucial role in asbestos carcinogenicity. Iron in asbestos promotes generation of free radicals, with consequent DNA damage, leading to mutations and cancer. Removal of iron from asbestos could thus result in a decrement in their carcinogenic potential. Iron being an essential element, several soil microorganisms produce iron-chelators able to uptake it from insoluble forms. Contacted with crocidolite (blue asbestos), some soil fungi produced metal-chelators and extracted iron from the fibers. After this treatment, the ability of the fibers to generate free radicals in aqueous suspensions was totally suppressed. Novel proteins were induced in fungi as a response to asbestos fibres, including the antioxidant Mn-superoxide dismutase, also expressed by mammalian cells challenged with asbestos. In liquid mycelial cultures the fibrils were cleared from the suspension and tightly bound to the fungal hyphae. By binding and depriving the fibrils of iron, selected species/strains of soil fungi might play a major role in the bioremediation of asbestos contaminated soils.