title: Influence of soil properties on the toxicity of TiO₂ nanoparticles on carbon mineralization and bacterial abundance.
abstract: Information regarding the impact of low concentration of engineered nanoparticles on soil microbial communities is currently limited and the importance of soil characteristics is often neglected in ecological risk assessment. To evaluate the impact of TiO2 nanoparticles (NPs) on soil microbial communities (measured on bacterial abundance and carbon mineralization activity), 6 agricultural soils exhibiting contrasted textures and organic matter contents were exposed for 90 days to a low environmentally relevant concentration or to an accidental spiking of TiO2-NPs (1 and 500mgkg(-1) dry soil, respectively) in microcosms. In most soils, TiO2-NPs did not impact the activity and abundance of microbial communities, except in the silty-clay soil (high OM) where C-mineralization was significantly lowered, even with the low NPs concentration. Our results suggest that TiO2-NPs toxicity does not depend on soil texture but likely on pH and OM content. We characterized TiO2-NPs aggregation and zeta potential in soil solutions, in order to explain the difference of TiO2-NPs effects on soil C-mineralization. Zeta potential and aggregation of TiO2-NPs in the silty-clay (high OM) soil solution lead to a lower stability of TiO2-NP-aggregates than in the other soils. Further experiments would be necessary to evaluate the relationship between TiO2-NPs stability and toxicity in the soil.
authors.affiliation: Université de Lyon, Lyon, France; Université Claude Bernard Lyon 1, Villeurbanne, France; CNRS, UMR 5557, Ecologie Microbienne, Université Lyon 1, Villeurbanne, France; UJF-Grenoble/CNRS-INSU/G-INP/IRD, LTHE UMR 5564, Grenoble F-38041, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Simonin
authors.affiliation: Université de Lyon, Lyon, France; Université Claude Bernard Lyon 1, Villeurbanne, France; CNRS, UMR 5557, Ecologie Microbienne, Université Lyon 1, Villeurbanne, France.
authors.forename: Julien P
authors.initials: JP
authors.lastname: Guyonnet
authors.affiliation: UJF-Grenoble/CNRS-INSU/G-INP/IRD, LTHE UMR 5564, Grenoble F-38041, France.
authors.forename: Jean M F
authors.initials: JM
authors.lastname: Martins
authors.affiliation: Université de Lyon, Lyon, France; Université Claude Bernard Lyon 1, Villeurbanne, France; CNRS, UMR 5557, Ecologie Microbienne, Université Lyon 1, Villeurbanne, France.
authors.forename: Morgane
authors.initials: M
authors.lastname: Ginot
authors.affiliation: Université de Lyon, Lyon, France; Université Claude Bernard Lyon 1, Villeurbanne, France; CNRS, UMR 5557, Ecologie Microbienne, Université Lyon 1, Villeurbanne, France. Electronic address: agnes.richaume@univ-lyon1.fr.
authors.forename: Agnès
authors.initials: A
authors.lastname: Richaume
mesh_terms: D000383:Agriculture; D001419:Bacteria / Q000187:drug effects*; D002244:Carbon / Q000737:chemistry*; D053758:Nanoparticles / Q000633:toxicity*; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000633:toxicity*; D014025:Titanium / Q000633:toxicity*
chemical_list: D012987:Soil; D012989:Soil Pollutants; C009495:titanium dioxide; D002244:Carbon; D014025:Titanium
keywords: Microbial community; Microbial ecotoxicology; Realistic exposure; TiO(2) nanomaterials