Impact of Engineered Nanoparticles on Soil Microbial Communities

Engineered nanoparticles (ENPs) are increasingly incorporated into agricultural inputs, remediation agents and consumer products, leading to their unintentional release into terrestrial ecosystems. Once in soil, ENPs undergo transformations—aggregation, dissolution and surface modification—that determine their bioavailability and toxicity to microbial consortia. Key soil processes such as nitrification, denitrification, organic matter decomposition and nutrient mineralisation have been shown to be sensitive to metal- and metal-oxide nanoparticles, including copper oxide, zinc oxide, titanium dioxide and silver. Impacts range from enzyme inhibition and altered gene abundances in ammonia-oxidising archaea and bacteria to shifts in community composition, loss of functional diversity and reduced microbial biomass carbon. Soil physicochemical properties (texture, pH, organic matter content) and exposure dynamics (dose, duration, particle shape and surface coating) modulate these effects, leading to context-dependent outcomes that complicate risk assessment. Because soil microorganisms underpin plant productivity, carbon sequestration and biogeochemical cycling, perturbations induced by ENPs pose global concerns for ecosystem resilience and food security. Advances in characterising nanoparticle–microbe interactions now support the design of safer materials, adaptive management strategies and the development of environmental guidelines that balance technological innovation with soil health preservation.

Research from Nature Portfolio

Recent studies on titanium dioxide nanoparticles have explored their impact on agricultural soils over extended exposures. Experiments employing low, field-realistic concentrations of TiO₂ showed marked inhibition of nitrification enzyme activities and significant declines in amoA gene abundance among ammonia-oxidising archaea. Subsequent reductions in denitrification rates and shifts in bacterial community structure were evident within 90 days, indicating cascading effects through the nitrogen cycle and substantial reorganisation of microbial assemblages.
Investigations of iron oxide nanoparticles in arid sandy soils have demonstrated time-dependent toxicity to litter-degrading microbes. At high application rates (2 000 mg kg⁻¹), iron oxide particles reduced heterotrophic bacterial and fungal colony counts, lowered microbial biomass carbon by up to half, and suppressed CO₂ emissions and mineral nitrogen release over 180 days. These findings underscore the capacity of iron oxide ENPs to disrupt decomposition processes and nitrogen mineralisation, with potential implications for nutrient turnover in low-organic-matter soils.

Impact of Engineered Nanoparticles on Soil Microbial Communities publication trend

The graph below shows the total number of articles in impact of engineered nanoparticles on soil microbial communities across all publications each year (not limited to Nature Index journals).

Technical terms

Engineered nanoparticles (ENPs): Particles manufactured at the nanoscale (1–100 nm) with tailored chemical or physical properties.

Nitrification: Microbial oxidation of ammonia to nitrite and nitrate, a key step in the soil nitrogen cycle.

Denitrification: Microbial reduction of nitrate to gaseous nitrogen species, completing the nitrogen cycle and influencing greenhouse-gas fluxes.

Microbial biomass carbon: The total mass of living microbial cells in soil, indicative of microbial activity and soil health.

Functionalisation: Chemical modification of nanoparticle surfaces to alter stability, solubility or reactivity.

Ion dissolution: Release of metal ions from nanoparticles into soil solution, affecting toxicity and bioavailability.

Biogeochemical cycling: The movement and transformation of elements (e.g., C, N) through biological, geological and chemical processes in ecosystems.

References

1. Impacts of metal-based engineered nanomaterials on soil communities. Environmental Science Nano (2016).
2. Titanium dioxide nanoparticles strongly impact soil microbial function by affecting archaeal nitrifiers. Scientific Reports (2016).
3. Toxicity of iron oxide nanoparticles to grass litter decomposition in a sandy soil. Scientific Reports (2017).
4. Negative Effects of Copper Oxide Nanoparticles on Carbon and Nitrogen Cycle Microbial Activities in Contrasting Agricultural Soils and in Presence of Plants. Frontiers in Microbiology (2018).
5. Impact of silver nanoparticles (AgNP) on soil microbial community depending on functionalization, concentration, exposure time, and soil texture. Environmental Sciences Europe (2019).
6. Effects of Nanoparticles on Plant Growth-Promoting Bacteria in Indian Agricultural Soil. Agronomy (2019).