title: Inhibition of sulfate reducing bacteria in aquifer sediment by iron nanoparticles.
abstract: Batch microcosms were setup to determine the impact of different sized zero valent iron (Fe(0)) particles on microbial sulfate reduction during the in situ bio-precipitation of metals. The microcosms were constructed with aquifer sediment and groundwater from a low pH (3.1), heavy-metal contaminated aquifer. Nano (nFe(0)), micro (mFe(0)) and granular (gFe(0)) sized Fe(0) particles were added to separate microcosms. Additionally, selected microcosms were also amended with glycerol as a C-source for sulfate-reducing bacteria. In addition to metal removal, Fe(0) in microcosms also raised the pH from 3.1 to 6.5, and decreased the oxidation redox potential from initial values of 249 to -226 mV, providing more favorable conditions for microbial sulfate reduction. mFe(0) and gFe(0) in combination with glycerol were found to enhance microbial sulfate reduction. However, no sulfate reduction occurred in the controls without Fe(0) or in the microcosm amended with nFe(0). A separate dose test confirmed the inhibition for sulfate reduction in presence of nFe(0). Hydrogen produced by Fe(0) was not capable of supporting microbial sulfate reduction as a lone electron donor in this study. Microbial analysis revealed that the addition of Fe(0) and glycerol shifted the microbial community towards Desulfosporosinus sp. from a population initially dominated by low pH and metal-resisting Acidithiobacillus ferrooxidans.
authors.affiliation: Flemish Institute for Technological Research (VITO), Mol, Belgium; CEREGE-UMR-7330, CNRS - Aix Marseille University, Aix-en-Provence, France; GDRi-iCEINT, International Consortium for the Environmental Implication of Nano Technology, France. Electronic address: kumar@cerege.fr.
authors.forename: Naresh
authors.initials: N
authors.lastname: Kumar
authors.affiliation: Flemish Institute for Technological Research (VITO), Mol, Belgium; School of Earth, Atmosphere and Environmental Sciences, University of Manchester, UK.
authors.forename: Enoma O
authors.initials: EO
authors.lastname: Omoregie
authors.affiliation: CEREGE-UMR-7330, CNRS - Aix Marseille University, Aix-en-Provence, France; GDRi-iCEINT, International Consortium for the Environmental Implication of Nano Technology, France.
authors.forename: Jerome
authors.initials: J
authors.lastname: Rose
authors.affiliation: CEREGE-UMR-7330, CNRS - Aix Marseille University, Aix-en-Provence, France; GDRi-iCEINT, International Consortium for the Environmental Implication of Nano Technology, France.
authors.forename: Armand
authors.initials: A
authors.lastname: Masion
authors.affiliation: School of Earth, Atmosphere and Environmental Sciences, University of Manchester, UK.
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Lloyd
authors.affiliation: Flemish Institute for Technological Research (VITO), Mol, Belgium.
authors.forename: Ludo
authors.initials: L
authors.lastname: Diels
authors.affiliation: Flemish Institute for Technological Research (VITO), Mol, Belgium.
authors.forename: Leen
authors.initials: L
authors.lastname: Bastiaens
mesh_terms: D042763:Acidithiobacillus / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001530:Belgium; D016000:Cluster Analysis; D017931:DNA Primers / Q000235:genetics; D019015:Geologic Sediments / Q000382:microbiology*; D060587:Groundwater / Q000382:microbiology*; D007501:Iron / Q000737:chemistry / Q000378:metabolism; D053768:Metal Nanoparticles / Q000737:chemistry*; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010459:Peptococcaceae / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013431:Sulfates / Q000378:metabolism*; D018508:Water Purification / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D017931:DNA Primers; D012336:RNA, Ribosomal, 16S; D013431:Sulfates; D007501:Iron
keywords: Nano iron toxicity; Sulfate reducing bacteria; Zero valent iron