title: Fungal transformation of metallic lead to pyromorphite in liquid medium.
abstract: Many approaches have been proposed to reduce the toxicity of hazardous substances such as lead in the environment. Several techniques using microorganisms rely on metal removal from solution by non-specific biosorption. However, immobilization of metals through formation of biominerals mediated by metabolic processes offers another solution but which has been given limited attention. In this work, we have investigated lead biomineralization by Paecilomyces javanicus, a fungus isolated from a lead-contaminated soil, in a liquid medium. P. javanicus was able to grow in the presence of metallic lead, supplied as lead shot, and secondary lead minerals were deposited on the lead surfaces as revealed by scanning electron microscopy. Energy dispersive X-ray analysis and X-ray powder diffraction revealed that pyromorphite was formed in the presence of the fungus, but not in abiotic controls. Our results clearly demonstrate that fungal activities can play an important role in lead biocorrosion and biomineralization in an aqueous environment. These findings are relevant to bioremediation approaches for liquid wastes contaminated with lead, or other metals, and also to the immobilization and biorecovery of rare or valuable elements. They also provide further understanding of microbial roles in environmental lead cycling.
authors: Geomicrobiology Group, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK.
authors: Young Joon
authors: YJ
authors: Rhee
authors: The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, Scotland, UK; Department of Soil and Environment, Swedish University of Agricultural Sciences (SLU), P.O. Box 7014, SE-750 07 Uppsala, Sweden.
authors: Stephen
authors: S
authors: Hillier
authors: The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, Scotland, UK.
authors: Helen
authors: H
authors: Pendlowski
authors: Geomicrobiology Group, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK; Laboratory of Environmental Pollution and Bioremediation, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, People's Republic of China. Electronic address: g.m.gadd@dundee.ac.uk.
authors: Geoffrey Michael
authors: GM
authors: Gadd
mesh_terms: D001673:Biodegradation, Environmental; D007854:Lead / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D008903:Minerals / Q000378:metabolism*; D010143:Paecilomyces / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism*; D010758:Phosphorus / Q000378:metabolism*; D014961:X-Ray Diffraction
chemical_list: D008903:Minerals; D010710:Phosphates; C471364:pyromorphite; D010758:Phosphorus; D007854:Lead
keywords: Fungi; Geomycology; Lead; Pyromorphite