title: Biogeochemical spatio-temporal transformation of copper in Aspergillus niger colonies grown on malachite with different inorganic nitrogen sources.
abstract: This work elucidates spatio-temporal aspects of the biogeochemical transformation of copper mobilized from malachite (Cu2(CO3)(OH)2) and bioaccumulated within Aspergillus niger colonies when grown on different inorganic nitrogen sources. It was shown that the use of either ammonium or nitrate determined how copper was distributed within the colony and its microenvironment and the copper oxidation state and succession of copper coordinating ligands within the biomass. Nitrate-grown colonies yielded ∼1.7× more biomass, bioaccumulated ∼7× less copper, excreted ∼1.9× more oxalate and produced ∼1.75× less water-soluble copper in the medium in contrast to ammonium-grown colonies. Microfocus X-ray absorption spectroscopy revealed that as the mycelium matured, bioaccumulated copper was transformed from less stable and more toxic Cu(I) into less toxic Cu(II) which was coordinated predominantly by phosphate/malate ligands. With time, a shift to oxalate coordination of bioaccumulated copper occurred in the central older region of ammonium-grown colonies.
authors.affiliation: Geomicrobiology Group, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK.|Institute of Microbiology and Virology, NASU, Zabolotnogo st. 154, Kiev, 03680, Ukraine.
authors.forename: Marina
authors.initials: M
authors.lastname: Fomina
authors.affiliation: Geomicrobiology Group, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Bowen
authors.affiliation: School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Williamson Building, Oxford Road, Manchester, M13 9PL, UK.
authors.forename: John M
authors.initials: JM
authors.lastname: Charnock
authors.affiliation: Institute of Microbiology and Virology, NASU, Zabolotnogo st. 154, Kiev, 03680, Ukraine.
authors.forename: Valentin S
authors.initials: VS
authors.lastname: Podgorsky
authors.affiliation: Geomicrobiology Group, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK.|Laboratory of Environmental Pollution and Bioremediation, Xinjiang Institute of Ecology and Geography', Chinese Academy of Sciences, Urumqi, 830011, China.
authors.forename: Geoffrey M
authors.initials: GM
authors.lastname: Gadd
mesh_terms: D001234:Aspergillus niger / Q000254:growth & development / Q000378:metabolism*; D001711:Biotransformation; D003300:Copper / Q000378:metabolism*; D009566:Nitrates / Q000378:metabolism; D009584:Nitrogen / Q000032:analysis / Q000378:metabolism*; D009942:Organometallic Compounds; D010070:Oxalates / Q000378:metabolism
chemical_list: D009566:Nitrates; D009942:Organometallic Compounds; D010070:Oxalates; C520661:malachite; D003300:Copper; D009584:Nitrogen