We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Nanoplastics enhance the denitrification process and microbial interaction network in wetland soils
Summary
This study found that nanoplastics in wetland soils increased denitrification -- the process that converts nitrates into nitrogen gas -- by reshaping the microbial community and strengthening cooperative networks among bacteria. While this is primarily an environmental finding, changes to nitrogen cycling in wetlands can affect water quality in ways that ultimately influence human drinking water sources.
With the widespread presence of plastic waste in ecosystems, it is imperative to understand the response of natural processes to micro- and nanoplastic pollution pressures. However, the effects of nanoplastics on biogeochemical cycles are still overlooked and controversial. This study investigated the effects of three particle sizes (100 μm, 7 μm, and 80 nm) of polystyrene (PS) micro/nanoplastics (0.08 % of mass concentration) on denitrification processes and nirS/nirK denitrifying bacterial communities in wetland soils. The results indicated that PS nanoplastics were found to significantly enhance denitrification rates from 21.30 to 54.73 μmol N·h·kg, increasing by 1.57 times compared to the control. Exposure to nanoplastics caused shifts in the composition and structure of the nirS-type denitrifier community. LEfSe analysis, random forest, and Mantel tests revealed that nirS denitrifying bacteria, especially Sideroxydans, played a pivotal role in driving denitrification rates (Mantel's R = 0.24, p = 0.002), likely due to the faster release of organic substrates from nanoplastics. Microbial co-occurrence networks demonstrated that nanoplastic amendments fostered a denser denitrifier network and led to shifts in keystone species. Sideroxydans appeared more likely to cooperate with other bacteria, such as Burkholderiales, to complete denitrification processes. This study suggests that nanoplastics are a potentially stronger driver of denitrification than microplastics, providing insight into the impact of plastic pollutants on biogeochemical cycling in natural wetland ecosystems. Given the widespread distribution of wetlands, the potential increase in gaseous nitrogen emissions due to nanoplastics pollution warrants attention.
Sign in to start a discussion.
More Papers Like This
Nanoplastics Disturb Nitrogen Removal in Constructed Wetlands: Responses of Microbes and Macrophytes
The impact of nanosized plastics on nitrogen removal in constructed wetlands was investigated by examining microbial community responses and denitrification processes. Nanoplastics disturbed biological nitrogen removal in the wetland system, with microorganisms showing altered community structure and reduced denitrification efficiency.
Nitrogen metabolic responses of non-rhizosphere and rhizosphere microbial communities in constructed wetlands under nanoplastics disturbance
Researchers compared how microbial communities in plant root zones versus non-root zones of constructed wetlands respond to nanoplastic contamination. They found that nanoplastics reduced beneficial nitrogen-processing bacteria near roots by nearly 18%, while non-root microbes showed greater adaptability, even using nanoplastics as a carbon source. The findings suggest that constructed wetlands, which are important for water treatment, may have their nitrogen-removal capabilities impaired by nanoplastic pollution.
Impact and microbial mechanism of continuous nanoplastics exposure on the urban wastewater treatment process
Researchers investigated the effects of continuous nanoplastic exposure on wastewater treatment over 200 days, finding that while total nitrogen removal was not significantly inhibited, nanoplastics altered microbial community composition and affected nitrification and denitrification processes.
Biofilms in plastisphere from freshwater wetlands: Biofilm formation, bacterial community assembly, and biogeochemical cycles
Researchers studied how bacteria form biofilms on microplastic surfaces in freshwater wetlands and found that these plastic-associated communities differ significantly from natural soil bacteria. The microplastic biofilms had lower diversity but higher activity in carbon processing and nitrogen cycling genes. This means microplastics in wetlands can alter natural nutrient cycles, potentially affecting water quality in ecosystems that many communities rely on.
Impaired denitrification of aerobic granules in response to micro/nanoplastic stress: Insights from interspecies interactions and electron transfer processes
This study found that micro- and nanoplastics in wastewater disrupt the ability of beneficial bacteria to remove nitrogen through a process called denitrification. After 90 days of plastic exposure, the communication system bacteria use to coordinate their activity broke down, leading to an imbalance where some bacteria stopped contributing while still consuming shared resources. This reduced the overall efficiency of biological wastewater treatment, a system many communities rely on to clean their water.