title: Titanium dioxide nanoparticles strongly impact soil microbial function by affecting archaeal nitrifiers.
abstract: Soils are facing new environmental stressors, such as titanium dioxide nanoparticles (TiO2-NPs). While these emerging pollutants are increasingly released into most ecosystems, including agricultural fields, their potential impacts on soil and its function remain to be investigated. Here we report the response of the microbial community of an agricultural soil exposed over 90 days to TiO2-NPs (1 and 500 mg kg-1dry soil). To assess their impact on soil function, we focused on the nitrogen cycle and measured nitrification and denitrification enzymatic activities and by quantifying specific representative genes (amoA for ammonia-oxidizers, nirK and nirS for denitrifiers). Additionally, diversity shifts were examined in bacteria, archaea, and the ammonia-oxidizing clades of each domain. With strong negative impacts on nitrification enzyme activities and the abundances of ammonia-oxidizing microorganism, TiO2-NPs triggered cascading negative effects on denitrification enzyme activity and a deep modification of the bacterial community structure after just 90 days of exposure to even the lowest, realistic concentration of NPs. These results appeal further research to assess how these emerging pollutants modify the soil health and broader ecosystem function.
authors.affiliation: Univ Lyon, Université Claude Bernard Lyon 1, UMR CNRS 5557, Laboratoire d'Ecologie Microbienne, UMR INRA 1418, bât G. Mendel, 43 boulevard du 11 novembre 1918, F-69622 Villeurbanne Cedex, France.|LTHE, UMR 5564 CNRS - Univ. Grenoble Alpes 38041 Grenoble Cedex 9, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Simonin
authors.affiliation: Univ Lyon, Université Claude Bernard Lyon 1, UMR CNRS 5557, Laboratoire d'Ecologie Microbienne, UMR INRA 1418, bât G. Mendel, 43 boulevard du 11 novembre 1918, F-69622 Villeurbanne Cedex, France.
authors.forename: Agnès
authors.initials: A
authors.lastname: Richaume
authors.affiliation: Univ Lyon, Université Claude Bernard Lyon 1, UMR CNRS 5557, Laboratoire d'Ecologie Microbienne, UMR INRA 1418, bât G. Mendel, 43 boulevard du 11 novembre 1918, F-69622 Villeurbanne Cedex, France.
authors.forename: Julien P
authors.initials: JP
authors.lastname: Guyonnet
authors.affiliation: Univ Lyon, Université Claude Bernard Lyon 1, UMR CNRS 5557, Laboratoire d'Ecologie Microbienne, UMR INRA 1418, bât G. Mendel, 43 boulevard du 11 novembre 1918, F-69622 Villeurbanne Cedex, France.
authors.forename: Audrey
authors.initials: A
authors.lastname: Dubost
authors.affiliation: LTHE, UMR 5564 CNRS - Univ. Grenoble Alpes 38041 Grenoble Cedex 9, France.
authors.forename: Jean M F
authors.initials: JM
authors.lastname: Martins
authors.affiliation: Univ Lyon, Université Claude Bernard Lyon 1, UMR CNRS 5557, Laboratoire d'Ecologie Microbienne, UMR INRA 1418, bât G. Mendel, 43 boulevard du 11 novembre 1918, F-69622 Villeurbanne Cedex, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Pommier