Evaluating Aspergillus brasiliensis (ATCC 16404) for the bioaccumulation and solubilization of selenium nanoparticles

Abstract The extensive application of selenium nanoparticles (Se-NPs) in research and industry for their antibacterial, antioxidant, and anticancer properties raises concerns about environmental contamination and ecological risks. This highlights the need for eco-friendly methods to remove its pollutants. This study evaluates the potential of A. brasiliensis for the solubilization and removal of myco-synthesized Se-NPs from aqueous solutions. Se-NPs were biosynthesized using Fusarium oxysporum and characterized by UV-Vis, FTIR, and TEM analyses. The effects of biomass weight, contact time, pH, and initial Se-NPs concentration were assessed to determine the optimal biosorption conditions. Biosorption parameters were optimized, achieving a 54% removal efficiency at an initial Se-NPs concentration of 100 ppm (pH 7, 30 min). Furthermore, during biomass dosage optimization, the process reached a maximum removal efficiency of 61.6% at an initial concentration of 160 ppm. A. brasiliensis displayed a strong solubilization capability (55.53%), evidenced by the formation of clear halo zones on agar plates compared to the control. Among the tested biomass forms, dried (dead), A. brasiliensis , exhibited the greatest removal efficiency, reaching 92.93%. Se-NPs were adsorbed onto the surface of fungal mycelium (SEM and EDX analyses) and/or accumulated into mycelium. These findings highlight the potential of A. brasiliensis as an effective and environmentally friendly biosorbent for mitigating Se-NPs contamination in aqueous environments.