title: CaCO3 and SrCO3 bioprecipitation by fungi isolated from calcareous soil.
abstract: The urease-positive fungi Pestalotiopsis sp. and Myrothecium gramineum, isolated from calcareous soil, were examined for their properties of CaCO3 and SrCO3 biomineralization. After incubation in media amended with urea and CaCl2 and/or SrCl2 , calcite (CaCO3 ), strontianite (SrCO3 ), vaterite in different forms [CaCO3 , (Cax Sr1-x )CO3 ] and olekminskite [Sr(Sr,Ca)(CO3 )2 ] were precipitated, and fungal 'footprints' were observed on mineral surfaces. The amorphous precipitate mediated by Pestalotiopsis sp. grown with urea and equivalent concentrations of CaCl2 and SrCl2 was identified as hydrated Ca and Sr carbonates by Fourier transform infrared spectroscopy. Liquid media experiments showed M. gramineum possessed the highest Sr(2+) removal ability, and ∼ 49% of supplied Sr(2+) was removed from solution when grown in media amended with urea and 50 mM SrCl2 . Furthermore, this organism could also precipitate 56% of the available Ca(2+) and 28% of the Sr(2+) in the form of CaCO3 , SrCO3 and (Cax Sr1-x )CO3 when incubated in urea-amended media and equivalent CaCl2 and SrCl2 concentrations. This is the first report of biomineralization of olekminskite and coprecipitation of Sr into vaterite mediated by fungi. These findings suggest that urease-positive fungi could play an important role in the environmental fate, bioremediation or biorecovery of Sr or other metals and radionuclides that form insoluble carbonates.
authors.affiliation: Geomicrobiology Group, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, Scotland, UK.
authors.forename: Qianwei
authors.initials: Q
authors.lastname: Li
authors.affiliation: Concrete Technology Group, Department of Civil Engineering, University of Dundee, Dundee, DD1 4HN, Scotland, UK.
authors.forename: Laszlo
authors.initials: L
authors.lastname: Csetenyi
authors.affiliation: Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 3UU, Scotland, UK.
authors.forename: Graeme Iain
authors.initials: GI
authors.lastname: Paton
authors.affiliation: 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, China.
authors.forename: Geoffrey Michael
authors.initials: GM
authors.lastname: Gadd
mesh_terms: D001203:Ascomycota / Q000302:isolation & purification / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002119:Calcium Carbonate / Q000378:metabolism*; D002254:Carbonates / Q000378:metabolism*; D008903:Minerals / Q000378:metabolism; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D017550:Spectroscopy, Fourier Transform Infrared; D013324:Strontium / Q000378:metabolism*; D014508:Urea / Q000378:metabolism; D014510:Urease / Q000378:metabolism
chemical_list: D002254:Carbonates; D008903:Minerals; D012987:Soil; C054286:strontium carbonate; D014508:Urea; D014510:Urease; D002119:Calcium Carbonate; D013324:Strontium