Fungal Mobilization of Selenium in the Presence of Hausmannite and Ferric Oxyhydroxides

Bioleaching of mineral phases plays a crucial role in the mobility and availability of various elements, including selenium. Therefore, the leachability of selenium associated with the surfaces of ferric and manganese oxides and oxyhydroxides, the prevailing components of natural geochemical barriers, has been studied in the presence of filamentous fungus. Both geoactive phases were exposed to selenate and subsequently to growing fungus Aspergillus niger for three weeks. This common soil fungus has shown exceptional ability to alter the distribution and mobility of selenium in the presence of both solid phases. The fungus initiated the extensive bioextraction of selenium from the surfaces of amorphous ferric oxyhydroxides, while the hausmannite (Mn3O4) was highly susceptible to biodeterioration in the presence of selenium. This resulted in specific outcomes regarding the selenium, iron, and manganese uptake by fungus and residual selenium concentrations in mineral phases as well. The adverse effects of bioleaching on fungal growth are also discussed.

Automated summary

The study investigated the leachability of selenium from the surfaces of ferric and manganese oxides and oxyhydroxides in the presence of filamentous fungus Aspergillus niger. The fungus showed exceptional ability to extract selenium from amorphous ferric oxyhydroxides and induce biodeterioration of hausmannite in the presence of selenium. The specific outcomes regarding selenium, iron, and manganese uptake by the fungus and residual selenium concentrations in mineral phases were discussed, along with the adverse effects of bioleaching on fungal growth.