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Equipe de Recherche Groupes fonctionnels du cycle de l’azote

Marie Simonin



  • Thèmes de recherches :
    1. Ecotoxicologie : Impact des nanoparticules sur les communautés microbiennes du sol
    2. Cycle de l’azote : Relations abondance-fonctionnement et diversité-fonctionnement chez les communautés nitrifiantes (AOA et AOB) et dénitrifiantes
    3. Ecodynamique des contaminants : Transfert/Mobilité des nanoparticules dans les sols

Parcours scientifique

  • Master EBE (Ecologie, Biodiversité, Evolution) - Université Paris 6 Pierre et Marie Curie


  • Biologie Végétale 1 (TP - L1)
  • Microbiologie 1 (TP - L2)
  • Pédologie (TP -L3, M1 IG2E)
  • Système Sol Plante Agronomie (TP -M1)



  • Simonin, M., Martins, J.M.F., Le Roux, X., Uzu, G., Calas, A., Richaume, A., 2017. Toxicity of TiO2 nanoparticles on soil nitrification at environmentally relevant concentrations: Lack of classical dose–response relationships. Nanotoxicology 1-9.
    Résumé : Titanium-dioxide nanoparticles (TiO2-NPs) are increasingly released in agricultural soils through, e.g. biosolids, irrigation or nanoagrochemicals. Soils are submitted to a wide range of concentrations of TiO2-NPs depending on the type of exposure. However, most studies have assessed the effects of unrealistically high concentrations, and the dose–response relationships are not well characterized for soil microbial communities. Here, using soil microcosms, we assessed the impact of TiO2-NPs at concentrations ranging from 0.05 to 500 mg kg−1 dry-soil, on the activity and abundance of ammonia-oxidizing archaea (AOA) and bacteria (AOB), and nitrite-oxidizing bacteria (Nitrobacter and Nitrospira). In addition, aggregation and oxidative potential of TiO2-NPs were measured in the spiking suspensions, as they can be important drivers of TiO2-NPs toxicity. After 90 days of exposure, non-classical dose–response relationships were observed for nitrifier abundance or activity, making threshold concentrations impossible to compute. Indeed, AOA abundance was reduced by 40% by TiO2-NPs whatever the concentration, while Nitrospira was never affected. Moreover, AOB and Nitrobacter abundances were decreased mainly at intermediate concentrations nitrification was reduced by 25% at the lowest (0.05 mg kg−1) and the highest (100 and 500 mg kg−1) TiO2-NPs concentrations. Path analyses indicated that TiO2-NPs affected nitrification through an effect on the specific activity of nitrifiers, in addition to indirect effects on nitrifier abundances. Altogether these results point out the need to include very low concentrations of NPs in soil toxicological studies, and the lack of relevance of classical dose–response tests and ecotoxicological dose metrics (EC50, IC50…) for TiO2-NPs impact on soil microorganisms.
    Mots-clés : #5, Microbial ecotoxicology, nanomaterial, Nitrification, Structural equation modeling.


  • Simonin, M., Martins, J.M.F., Uzu, G., Vince, E., Richaume, A., 2016. Combined Study of Titanium Dioxide Nanoparticle Transport and Toxicity on Microbial Nitrifying Communities under Single and Repeated Exposures in Soil Columns. Environmental Science & Technology 50, 10693-10699.
    Résumé : Soils are exposed to nanoparticles (NPs) due to their increasing use in many commercial products. Adverse effects of NPs on soil microorganisms have been reported in several ecotoxicological studies using microcosms. Although repeated exposures are more likely to occur in soils, most of these previous studies were performed as a single exposure to NPs. Contrarily to single contamination, the study of multiple NP contaminations in soils requires the use of specialized setups. Using a soil column experiment, we compared the influence of single and repeated exposures (one, two or three exposures that resulted in the same final concentration) on the transport of titanium dioxide NPs (TiO2-NPs) through soil and the effect of these different exposure scenarios on the abundance and activity of soil nitrifying microbial communities after a 2-month incubation period. The transport of TiO2-NPs was very limited under both single and repeated exposures and was highest for the lowest concentration injected during the first application. Significant decreases in nitrification activity and ammonia-oxidizing archaea and bacteria populations were observed only for the repeated exposure scenario (three TiO2-NP contaminations). These results show that under repeated exposures, the transport of TiO2-NPs to deep soil layers and groundwater is limited and that a chronic TiO2-NPs contamination is more harmful for the soil microbiological functioning than a single exposure.
    Mots-clés : #5.

  • Simonin, M., Richaume, A., Guyonnet, J.P., Dubost, A., Martins, J.M.F., Pommier, T., 2016. Titanium dioxide nanoparticles strongly impact soil microbial function by affecting archaeal nitrifiers. Scientific Reports 6, 33643.
    Mots-clés : #5, #ibio.


  • Simonin, M., Guyonnet, J.P., Martins, J.M.F., Ginot, M., Richaume, A., 2015. Influence of soil properties on the toxicity of TiO2 nanoparticles on carbon mineralization and bacterial abundance. Journal of Hazardous Materials 283, 529-535.
    Résumé : 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.
    Mots-clés : #5.

  • Simonin, M., Le Roux, X., Poly, F., Lerondelle, C., Hungate, B.A., Nunan, N., Niboyet, A., 2015. Coupling Between and Among Ammonia Oxidizers and Nitrite Oxidizers in Grassland Mesocosms Submitted to Elevated CO2 and Nitrogen Supply. Microbial Ecology 70, 809-818.
    Résumé : Many studies have assessed the responses of soil microbial functional groups to increases in atmospheric CO2 or N deposition alone and more rarely in combination. However, the effects of elevated CO2 and N on the (de)coupling between different microbial functional groups (e.g., different groups of nitrifiers) have been barely studied, despite potential consequences for ecosystem functioning. Here, we investigated the short-term combined effects of elevated CO2 and N supply on the abundances of the four main microbial groups involved in soil nitrification: ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB), and nitrite-oxidizing bacteria (belonging to the genera Nitrobacter and Nitrospira) in grassland mesocosms. AOB and AOA abundances responded differently to the treatments: N addition increased AOB abundance, but did not alter AOA abundance. Nitrobacter and Nitrospira abundances also showed contrasted responses to the treatments: N addition increased Nitrobacter abundance, but decreased Nitrospira abundance. Our results support the idea of a niche differentiation between AOB and AOA, and between Nitrobacter and Nitrospira. AOB and Nitrobacter were both promoted at high N and C conditions (and low soil water content for Nitrobacter), while AOA and Nitrospira were favored at low N and C conditions (and high soil water content for Nitrospira). In addition, Nitrobacter abundance was positively correlated to AOB abundance and Nitrospira abundance to AOA abundance. Our results suggest that the couplings between ammonia and nitrite oxidizers are influenced by soil N availability. Multiple environmental changes may thus elicit rapid and contrasted responses between and among the soil ammonia and nitrite oxidizers due to their different ecological requirements.
    Mots-clés : #5, Ammonia oxidizers, ecology, Geoecology/Natural Processes, Global change, Grasslands, microbial ecology, Microbiology, Nature Conservation, Niche differentiation, Nitrification, nitrite oxidizers, Water Quality/Water Pollution.

  • Simonin, M., Richaume, A., 2015. Impact of engineered nanoparticles on the activity, abundance, and diversity of soil microbial communities: a review. Environmental Science and Pollution Research 1-14.
    Résumé : This report presents an exhaustive literature review of the effects of engineered nanoparticles on soil microbial communities. The toxic effects on microbial communities are highly dependent on the type of nanoparticles considered. Inorganic nanoparticles (metal and metal oxide) seem to have a greater toxic potential than organic nanoparticles (fullerenes and carbon nanotubes) on soil microorganisms. Detrimental effects of metal and metal oxide nanoparticles on microbial activity, abundance, and diversity have been demonstrated, even for very low concentrations (<1 mg kg−1). On the opposite, the negative effects of carbon nanoparticles are observed only in presence of high concentrations (>250 mg kg−1), representing a worst case scenario. Considering that most of the available literature has analyzed the impact of an acute contamination of nanoparticles using high concentrations in a single soil, several research needs have been identified, and new directions have been proposed. The effects of realistic concentrations of nanoparticles based on the concentrations predicted in modelization studies and chronic contaminations should be simulated. The influence of soil properties on the nanoparticle toxicity is still unknown and that is why it is crucial to consider the ecotoxicity of nanoparticles in a range of different soils. The identification of soil parameters controlling the bioavailability and toxicity of nanoparticles is fundamental for a better environmental risk assessment.
    Mots-clés : #5, Atmospheric Protection/Air Quality Control/Air Pollution, Ecotoxicology, Environment, general, Environmental Chemistry, Environmental Health, Microbial ecotoxicology, Nanomaterials, Nanoscale zero valent iron, Risk assessment, Soil pollution, Terrestrial ecosystem, Waste Water Technology / Water Pollution Control / Water Management / Aquatic Pollution.

Chapitre d’ouvrages


Communications Orales



  • Simonin, M., 2014. Disturbance of soil nitrogen cycle by titanium dioxide (TiO2) nanoparticles, dans: . BES Lille.
    Mots-clés : #5, #ibio, #poster.