Fungal transformations of uranium oxides

M. Fomina, J. M. Charnock, S. Hillier, R. Alvarez, G. M. Gadd

    Research output: Contribution to journalArticle

    62 Citations (Scopus)

    Abstract

    The biogeochemical activities of free-living and symbiotic fungi must be acknowledged in attempts to understand uranium cycling and dispersal in the environment. Although the near-surface geochemistry of uranium is very complex and a wide variety of mineral phases is known, uranium trioxide (UO3) and triuranium octaoxide (U(3)O(8)) can be used as well characterized models in the study of biotransformations. We have used a complex methodological approach involving advanced solid state speciation and scanning electron microscopy to study the ability of saprotrophic, ericoid and ectomycorrhizal fungi to transform these model oxides. This study has revealed that fungi exhibit a high uranium oxide tolerance, and possess the ability to solubilize UO3 and U(3)O(8) and to accumulate uranium within the mycelium to over 80 mg (g dry weight)(-1) biomass. X-ray absorption spectroscopy of uranium speciation within the biomass showed that in most of the fungi the uranyl ion was coordinated to phosphate ligands, but in ectomycorrhizal fungi mixed phosphate/carboxylate coordination was observed. Abundant uranium precipitates associated with phosphorus were found in the mycelium and encrusted the hyphae. Some of the fungi caused the biomineralization of well-crystallized uranyl phosphate minerals of the meta-autunite group. This is the first experimental evidence for fungal transformations of uranium solids and the production of secondary mycogenic uranium minerals.
    Original languageEnglish
    Pages (from-to)1696-1710
    Number of pages15
    JournalEnvironmental Microbiology
    Volume9
    Issue number7
    DOIs
    Publication statusPublished - Jul 2007

    Fingerprint

    Uranium
    uranium
    oxides
    oxide
    Fungi
    fungus
    fungi
    Minerals
    Mycelium
    Biomass
    phosphate
    X-Ray Absorption Spectroscopy
    Phosphates
    mycelium
    mineral
    autunite
    Hyphae
    phosphate minerals
    phosphates
    minerals

    Keywords

    • Absorptiometry, Photon
    • Biotransformation
    • Fungi
    • Microscopy, Electron, Scanning
    • Models, Biological
    • Phosphorus
    • Uranium Compounds

    Cite this

    Fomina, M. ; Charnock, J. M. ; Hillier, S. ; Alvarez, R. ; Gadd, G. M. / Fungal transformations of uranium oxides. In: Environmental Microbiology. 2007 ; Vol. 9, No. 7. pp. 1696-1710.
    @article{a032f30dc76345499a1a1be559df7503,
    title = "Fungal transformations of uranium oxides",
    abstract = "The biogeochemical activities of free-living and symbiotic fungi must be acknowledged in attempts to understand uranium cycling and dispersal in the environment. Although the near-surface geochemistry of uranium is very complex and a wide variety of mineral phases is known, uranium trioxide (UO3) and triuranium octaoxide (U(3)O(8)) can be used as well characterized models in the study of biotransformations. We have used a complex methodological approach involving advanced solid state speciation and scanning electron microscopy to study the ability of saprotrophic, ericoid and ectomycorrhizal fungi to transform these model oxides. This study has revealed that fungi exhibit a high uranium oxide tolerance, and possess the ability to solubilize UO3 and U(3)O(8) and to accumulate uranium within the mycelium to over 80 mg (g dry weight)(-1) biomass. X-ray absorption spectroscopy of uranium speciation within the biomass showed that in most of the fungi the uranyl ion was coordinated to phosphate ligands, but in ectomycorrhizal fungi mixed phosphate/carboxylate coordination was observed. Abundant uranium precipitates associated with phosphorus were found in the mycelium and encrusted the hyphae. Some of the fungi caused the biomineralization of well-crystallized uranyl phosphate minerals of the meta-autunite group. This is the first experimental evidence for fungal transformations of uranium solids and the production of secondary mycogenic uranium minerals.",
    keywords = "Absorptiometry, Photon, Biotransformation, Fungi, Microscopy, Electron, Scanning, Models, Biological, Phosphorus, Uranium Compounds",
    author = "M. Fomina and Charnock, {J. M.} and S. Hillier and R. Alvarez and Gadd, {G. M.}",
    year = "2007",
    month = "7",
    doi = "10.1111/j.1462-2920.2007.01288.x",
    language = "English",
    volume = "9",
    pages = "1696--1710",
    journal = "Environmental Microbiology",
    issn = "1462-2912",
    publisher = "Wiley",
    number = "7",

    }

    Fomina, M, Charnock, JM, Hillier, S, Alvarez, R & Gadd, GM 2007, 'Fungal transformations of uranium oxides', Environmental Microbiology, vol. 9, no. 7, pp. 1696-1710. https://doi.org/10.1111/j.1462-2920.2007.01288.x

    Fungal transformations of uranium oxides. / Fomina, M.; Charnock, J. M.; Hillier, S.; Alvarez, R.; Gadd, G. M.

    In: Environmental Microbiology, Vol. 9, No. 7, 07.2007, p. 1696-1710.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Fungal transformations of uranium oxides

    AU - Fomina, M.

    AU - Charnock, J. M.

    AU - Hillier, S.

    AU - Alvarez, R.

    AU - Gadd, G. M.

    PY - 2007/7

    Y1 - 2007/7

    N2 - The biogeochemical activities of free-living and symbiotic fungi must be acknowledged in attempts to understand uranium cycling and dispersal in the environment. Although the near-surface geochemistry of uranium is very complex and a wide variety of mineral phases is known, uranium trioxide (UO3) and triuranium octaoxide (U(3)O(8)) can be used as well characterized models in the study of biotransformations. We have used a complex methodological approach involving advanced solid state speciation and scanning electron microscopy to study the ability of saprotrophic, ericoid and ectomycorrhizal fungi to transform these model oxides. This study has revealed that fungi exhibit a high uranium oxide tolerance, and possess the ability to solubilize UO3 and U(3)O(8) and to accumulate uranium within the mycelium to over 80 mg (g dry weight)(-1) biomass. X-ray absorption spectroscopy of uranium speciation within the biomass showed that in most of the fungi the uranyl ion was coordinated to phosphate ligands, but in ectomycorrhizal fungi mixed phosphate/carboxylate coordination was observed. Abundant uranium precipitates associated with phosphorus were found in the mycelium and encrusted the hyphae. Some of the fungi caused the biomineralization of well-crystallized uranyl phosphate minerals of the meta-autunite group. This is the first experimental evidence for fungal transformations of uranium solids and the production of secondary mycogenic uranium minerals.

    AB - The biogeochemical activities of free-living and symbiotic fungi must be acknowledged in attempts to understand uranium cycling and dispersal in the environment. Although the near-surface geochemistry of uranium is very complex and a wide variety of mineral phases is known, uranium trioxide (UO3) and triuranium octaoxide (U(3)O(8)) can be used as well characterized models in the study of biotransformations. We have used a complex methodological approach involving advanced solid state speciation and scanning electron microscopy to study the ability of saprotrophic, ericoid and ectomycorrhizal fungi to transform these model oxides. This study has revealed that fungi exhibit a high uranium oxide tolerance, and possess the ability to solubilize UO3 and U(3)O(8) and to accumulate uranium within the mycelium to over 80 mg (g dry weight)(-1) biomass. X-ray absorption spectroscopy of uranium speciation within the biomass showed that in most of the fungi the uranyl ion was coordinated to phosphate ligands, but in ectomycorrhizal fungi mixed phosphate/carboxylate coordination was observed. Abundant uranium precipitates associated with phosphorus were found in the mycelium and encrusted the hyphae. Some of the fungi caused the biomineralization of well-crystallized uranyl phosphate minerals of the meta-autunite group. This is the first experimental evidence for fungal transformations of uranium solids and the production of secondary mycogenic uranium minerals.

    KW - Absorptiometry, Photon

    KW - Biotransformation

    KW - Fungi

    KW - Microscopy, Electron, Scanning

    KW - Models, Biological

    KW - Phosphorus

    KW - Uranium Compounds

    U2 - 10.1111/j.1462-2920.2007.01288.x

    DO - 10.1111/j.1462-2920.2007.01288.x

    M3 - Article

    C2 - 17564604

    VL - 9

    SP - 1696

    EP - 1710

    JO - Environmental Microbiology

    JF - Environmental Microbiology

    SN - 1462-2912

    IS - 7

    ER -