Title : Impact of Zinc Oxide nanoparticles on nitrifying bacteria in soil
Abstract:
The use of metal oxide nanoparticles (MeO NPs) in a wide range of commercial products has grown exponentially in recent years. Consequently, these NPs are indirectly discharged in agricultural soils through irrigation or sewage-sludge application and directly as nanofertilizers or nanopesticides. The introduction of MeO NPs into agricultural soils can be toxic to microorganisms carrying out important biogeochemical processes within the soil ecosystem, including nitrification. Our current understanding of the inhibitory effects of MeO NPs and the mechanism of toxicity towards nitrifying bacteria is limited. To address these research gaps and to better understand the impact of MeO NPs on soil nitrification processes, we will investigate the effects of ZnO NPs and CuO NPs, along with bulk ZnO and CuO, on the physiological, transcriptional and metabolic responses of nitrifying bacteria in agricultural soils. Subsequently, we will develop a path analysis to integrate the different variables measured in our study to assess the multifaceted consequences of MeO NPs on nitrifying communities. We will study the interactions of nitrifying bacteria, in lab-scale soil microcosms, with MeO NPs for environmentally relevant concentrations and transformations of these nanoparticles in soils. We will also compare how the nature (bulk versus particle) of MeO affects the nitrifying communities. The coupling of advanced molecular biology and conventional biochemical tools to develop causal models represents a potentially transformative step forward in evaluating the effects of nanoparticles on microbial processes in soils.
