Mobilization of potentially toxic elements from mine drainage ochres by Aspergillus species

Ochreous precipitates in drainage ponds significantly contribute to removal and immobilization of potentially toxic elements from water-bodies in mining sites, therefore efficiently decrease their bioavailability. Associated elements with ochres may be remobilized into aquatic environments due to changes of ochres structural stability. The presence of microorganisms can induce remobilization of the potentially toxic elements due to their ability to dissolve and deteriorate the solid substrates by production of acidic, redox active and chelating metabolites. Our results highlighted that due to extensive leaching of iron from ferric ochres, filamentous fungi were capable of bioextracting arsenic antimony and zinc from this naturally occurring precipitate. Thus, our outcomes underline the relevance of Aspergillus strains activity and the composition of fungal community in situ for the mobilization of contaminants associated with ferric ochres at abandoned mining sites. Our results highlighted that due to extensive leaching of iron from ferric ochres, filamentous fungi were capable of bioextracting arsenic antimony and zinc from this naturally occurring precipitate. Thus, our outcomes underline the relevance of Aspergillus strains activity and the composition of fungal community in situ for the mobilization of contaminants associated with ferric ochres at abandoned mining sites. (authors)