Marine Fungi as Potential Eco-Sustainable Resource for Precious Metals Recovery from Electronic Waste

The recovery of valuable metals from waste electrical and electronic equipment (WEE or e-waste) might be achieved by bioleaching, a microbial-based technology which can substitute in the future chemical-based processes, reducing environmental impacts. Although marine fungi are still little exploited for such purposes, they are potential interesting targets. In the present study, we isolated marine fungi from contaminated sediments collected in two coastal areas (Bagnoli-Coroglio Bay, Italy; Bilbao estuary, Spain) and identified four high tolerant fungal taxa to high concentration of e-waste (100 g L-1). Such fungal taxa, belonging to the fungal families Dipodascaceae, Microascaceae, Gymnoascaceae and Trichocomaceae, were tested for their bioleaching and bioaccumulation potential of metals present in e-waste, using different experimental approaches. Results reported here indicate that the fungi are able to bioaccumulate metals released from e-waste with an efficiency depending from fungal strains and metals considered. Among precious elements, platinum was highly concentrated within fungal biomass (31-62%) across all strains. Our findings provide new insights on the potential of marine fungi inhabiting highly contaminated marine sediments as promising candidates to be used for the recovery of precious metals from electronic waste.