title: Influence of organic matters on AsIII oxidation by the microflora of polluted soils.
abstract: The global AsIII-oxidizing activity of microorganisms in eight surface soils from polluted sites was quantified with and without addition of organic substrates. The organic substances provided differed by their nature: either yeast extract, commonly used in microbiological culture media, or a synthetic mixture of defined organic matters (SMOM) presenting some common features with natural soil organic matter. Correlations were sought between soil characteristics and both the AsIII-oxidizing rate constants and their evolution in accordance with inputs of organic substrates. In the absence of added substrate, the global AsIII oxidation rate constant correlated positively with the concentration of intrinsic organic matter in the soil, suggesting that AsIII-oxidizing activity was limited by organic substrate availability in nutrient-poor soils. This limitation was, however, removed by 0.08 g/L of added organic carbon. In most conditions, the AsIII oxidation rate constant decreased as organic carbon input increased from 0.08 to 0.4 g/L. Incubations of polluted soils in aerobic conditions, amended or not with SMOM, resulted in short-term As mobilization in the presence of SMOM and active microorganisms. In contrast, microbial AsIII oxidation seemed to stabilize As when no organic substrate was added. Results suggest that microbial speciation of arsenic driven by nature and concentration of organic matter exerts a major influence on the fate of this toxic element in surface soils.
authors.affiliation: BRGM, 3 Avenue Claude Guillemin, 45060, Orléans, France.|ISTO, UMR 7327, BRGM, BP 36009, 45060, Orléans, France.|LIEC UMR 7360, CNRS-Université de Lorraine, Campus Bridoux, rue du Général Delestraint, 57070, Metz, France.|Agence de l'Environnement et de la Maîtrise de l'Energie, 20 Avenue du Grésillé, BP 90406, 49004, Angers Cedex 01, France.
authors.forename: T
authors.initials: T
authors.lastname: Lescure
authors.affiliation: BRGM, 3 Avenue Claude Guillemin, 45060, Orléans, France.
authors.forename: J
authors.initials: J
authors.lastname: Moreau
authors.affiliation: BRGM, 3 Avenue Claude Guillemin, 45060, Orléans, France.
authors.forename: C
authors.initials: C
authors.lastname: Charles
authors.affiliation: BRGM, 3 Avenue Claude Guillemin, 45060, Orléans, France.
authors.forename: T
authors.initials: T
authors.lastname: Ben Ali Saanda
authors.affiliation: BRGM, 3 Avenue Claude Guillemin, 45060, Orléans, France.|ISTO, UMR 7327, BRGM, BP 36009, 45060, Orléans, France.
authors.forename: H
authors.initials: H
authors.lastname: Thouin
authors.affiliation: BRGM, 3 Avenue Claude Guillemin, 45060, Orléans, France.
authors.forename: N
authors.initials: N
authors.lastname: Pillas
authors.affiliation: LIEC UMR 7360, CNRS-Université de Lorraine, Campus Bridoux, rue du Général Delestraint, 57070, Metz, France.
authors.forename: P
authors.initials: P
authors.lastname: Bauda
authors.affiliation: INRA Centre de Versailles-Grignon, RD 10, 78026, Versailles Cedex, France.
authors.forename: I
authors.initials: I
authors.lastname: Lamy
authors.affiliation: BRGM, 3 Avenue Claude Guillemin, 45060, Orléans, France. f.battaglia@brgm.fr.|ISTO, UMR 7327, BRGM, BP 36009, 45060, Orléans, France. f.battaglia@brgm.fr.
authors.forename: F
authors.initials: F
authors.lastname: Battaglia-Brunet
mesh_terms: D001151:Arsenic / Q000737:chemistry / Q000378:metabolism*; D003470:Culture Media; D005602:France; D064307:Microbiota / Q000502:physiology; D009930:Organic Chemicals / Q000737:chemistry*; D010084:Oxidation-Reduction; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000737:chemistry
chemical_list: D003470:Culture Media; D009930:Organic Chemicals; D012987:Soil; D012989:Soil Pollutants; D001151:Arsenic
keywords: Arsenic; AsIII oxidation; Microorganisms; Organic matter; Polluted soils