0
Article Tier 2 Sign in to save

Divergent impacts of microplastics and related leachates on sediment carbon and nitrogen transformation by regulating microbial communities and functions

AI summary Read the abstract

Scientists found that different types of plastic pollution affect soil and sediment health in surprisingly different ways: plastic made from corn-based material (PLA) seemed to support healthier soil, while nitrogen-containing nylon-type plastic (PA) disrupted natural nitrogen cycling that plants and ecosystems depend on. This matters because as microplastics keep breaking down in our environment, they may be quietly altering the natural processes that keep soil fertile and ecosystems balanced — effects that could eventually ripple through our food and water systems.

Polymers
Study Type Environmental

Microplastics (MPs) are recognized as potential disruptors of biogeochemical cycles. However, the differential impacts of MPs types and related leachates remain poorly understood, particularly for nitrogen-containing MPs. This study compared the variational responses in sediment carbon and nitrogen transformation to 1% aged MPs (AMPs), leachates (LMPs), washed aged MPs particles (WMPs) derived from nitrogen-containing polyamide (PA) and non-nitrogen-containing polylactic acid (PLA) under natural exposure and freeze-thaw cycles (FTCs). The results showed that the Carbon Pool Management Index (CPMI) in PLA groups was always higher than corresponding PA groups, indicating better sediment quality in the PLA groups. Under natural exposure, LPA and LPLA respectively increased CPMI by 3.4% and 93.6% due to containing biologically available organic matter. FTCs increased CPMI by 34.1% in control groups, whereas only CMPI in AMPs was higher than control groups. Besides, the PLA group reduced the nitrogen mineralization rate by possibly inhibiting the macromolecular organic matter decomposition, and might have reduced the narG/H/I and nirB/D genes, thereby indirectly maintaining the nitrification rate. While the PA group increased the nitrogen mineralization rate by possibly inhibiting the amoA/B/C genes to reduce nitrification rate and enriching ureolytic microorganisms. FTCs mitigated these disparities by intensifying microbial interactions. PLS-SEM suggested that APLA was most strongly associated with carbon and nitrogen transformation within the PLA treatments, whereas the apparent effect of APA was jointly shaped by the opposite associations of WPA and LPA. These findings provide new insights into the complex ecological effects of MPs and their leachates on sediment carbon and nitrogen transformations.

More Papers Like This

Article Tier 2

Unveiling the impact of microplastics with distinct polymer types and concentrations on tidal sediment microbiome and nitrogen cycling

AI summary Read the abstract

Researchers tested how five different types of microplastics at varying concentrations affect microbial communities and nitrogen cycling in tidal sediments over 30 days. They found that microplastics generally reduced microbial diversity and enhanced nitrogen fixation, with biodegradable PLA plastic showing concentration-dependent effects. The study suggests that microplastic contamination in coastal sediments can disrupt important nutrient cycling processes driven by microorganisms.

Article Tier 2

Insights into soil microbial assemblages and nitrogen cycling function responses to conventional and biodegradable microplastics

AI summary Read the abstract

Researchers compared how biodegradable polylactic acid and conventional PVC microplastics affect soil bacteria and nitrogen cycling processes. They found that both types of microplastics altered microbial communities, but biodegradable plastics had distinct effects on nitrogen-processing bacteria and did not simply behave as a harmless alternative. The study suggests that switching to biodegradable plastics may change rather than eliminate the impact of microplastic contamination on soil health.

Article Tier 2

Effects of microplastics on nitrogen and phosphorus cycles and microbial communities in sediments

AI summary Read the abstract

Researchers found that PVC, PLA, and polypropylene microplastics altered nitrogen and phosphorus cycling in freshwater sediments by shifting microbial community composition, with effects varying by polymer type and biodegradability.

Article Tier 2

Distinct responses of soil microbial communities and nitrogen cycle genes to PBAT and PLA microplastics

AI summary Read the abstract

A study of soil broke down two types of biodegradable microplastics, called PBAT and PLA, and found they degraded differently. The two plastics also had different effects on soil microbial communities and on genes involved in soil nitrogen cycling.

Article Tier 2

Differential impacts of polyethylene microplastic and additives on soil nitrogen cycling: A deeper dive into microbial interactions and transformation mechanisms

AI summary Read the abstract

This study tested how polyethylene microplastics, their base resin, and plastic additives each affect nitrogen cycling in soil -- a process essential for plant growth. All three altered the soil's nitrogen balance and microbial communities in different ways, with microplastics increasing certain nitrogen transformation rates the most. These findings matter because disrupted nitrogen cycling in farmland could affect crop nutrition and ultimately the quality of food humans eat.

Research digests by email

When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.

Email me about

Share this paper