Impact of Silver Nanoparticles on Microbial Communities in Aquatic Systems

Silver nanoparticles (AgNPs) are increasingly applied for their potent antimicrobial properties in medical, industrial and consumer products. Once released into aquatic environments through effluents or runoff, AgNPs undergo physical and chemical transformations—aggregation, dissolution to Ag⁺ ions and interaction with dissolved organic matter—that govern their bioavailability and toxicity. In planktonic and biofilm communities, AgNPs can attach to cell surfaces, penetrate membranes and induce oxidative stress via reactive oxygen species (ROS), leading to altered membrane integrity, enzyme inhibition and shifts in gene expression. Such impacts often manifest as reduced diversity and abundance of sensitive taxa, with consequences for critical ecosystem functions including nitrification, organic matter decomposition and nutrient cycling. Yet some microbial assemblages exhibit functional redundancy, whereby loss of sensitive groups is offset by tolerant populations, thereby maintaining process rates despite compositional change. The ecological risks posed by AgNPs are context dependent, reflecting nanoparticle size, concentration, water chemistry, community structure and exposure conditions (for example oxygen availability). Global significance arises from potential impairment of water treatment processes, disruption of biogeochemical cycles and the co-selection of antibiotic resistance determinants, which may disseminate through aquatic–terrestrial interfaces and ultimately affect human and animal health.

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Impact of Silver Nanoparticles on Microbial Communities in Aquatic Systems publication trend

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

Technical terms

Silver nanoparticles (AgNPs): Nanoscale particles of elemental silver known for broad-spectrum antimicrobial properties.

Reactive oxygen species (ROS): Highly reactive oxygen-containing molecules that can damage cellular components.

Biofilm: Structured microbial community adhered to surfaces and embedded within extracellular polymeric substances.

Nitrification: Two-step microbial oxidation of ammonia to nitrite and nitrate, essential for nitrogen cycling in aquatic systems.

Functional redundancy: Presence of multiple microbial taxa capable of performing similar ecological functions, providing resilience against community perturbations.

Antibiotic resistance determinants: Genetic elements, such as resistance genes and mobile genetic structures, that confer the ability to withstand antimicrobial agents.

References

1. Analytical methods for assessing antimicrobial activity of nanomaterials in complex media: advances, challenges, and perspectives. Journal of Nanobiotechnology (2023).
2. The impact of silver nanoparticles on microbial communities and antibiotic resistance determinants in the environment. Environmental Pollution (2021).
3. Nanosilver inhibits nitrification and reduces ammonia‐oxidising bacterial but not archaeal amoA gene abundance in estuarine sediments. Environmental Microbiology (2016).