Removal and biomineralization of Pb2+ in water by fungus Phanerochaete chrysoporium

The removal and biomineralization of Pb2+ (200 mg/L) in water were investigated utilizing mature mycelia of Phanerochaete chrysoporium. Mycelial dosage, initial Pb2+ concentration, solution pH and treatment time all were shown to have an influence on Pb2+ removal. Granular, lead-containing precipitation was formed on the fungal hyphae upon exposure to lead nitrate, which was confirmed from scanning electron micrograph/Energy Dispersive Spectrometer (SEM/EDS). Energy dispersive X-ray spectroscopic analysis revealed the presence of lead (48.5% by weight) along with phosphorus in the precipitate. This extracellular precipitate was further identified as pyromorphite lead hydroxyphosphate [Pb5(PO4)3OH] by X-ray powder diffraction (XRD) analysis. During Pb2+ removal, size-enlarged mineral precipitation, and clustered nanospherical particles formed on the hyphae were revealed by SEM/XRD. A remarkable increase of mycelial phosphatase activity of 1.5 times that of the control and decreased phosphate concentration in solution (16.76 mg/L to 1.39 mg/L) initially upon exposure to Pb2+ suggested that phosphatase may hydrolyze organic phosphorus into inorganic phosphate and release it into solution, participating in the biomineralization of Pb2+. Toxicity tests showed that the toxicity of Pb2+ polluted water decreased after treatment. The results clearly demonstrate previously unknown lead biomineralization as pyromorphite through fungal phosphatase. [Display omitted] •Lead pollution poses a potential threat to human health and the environment.•The removal and biomineralization of Pb2+in water was performed by fungus P. chrysoporium.•XRD analysis demonstrated that Pb2+ was mineralized into Pb5(PO4)3OH.•The process involves the hydroxylation of organic phosphorus by phosphatase.•The Pb2+ mineralization to Pb5(PO4)3OH by a fungus has been shown firstly.