Lake plastisphere as a new biotope in the Anthropocene: Potential pathogen colonization and distinct microbial functionality

Impacts of disinfectant and antipyretic on aged ethylene-vinyl acetate copolymer microplastics in hospital wastewater: Resistance genes, microbial community and carbon source metabolism

Global transmission of resistance genes (RGs) by non-antibiotic substances and microplastics (MPs) pollution deserves in-depth research and discussion. The impacts of the existence of benzethonium chloride (BZC) and acetaminophen (APAP) on pristine and aged ethylene-vinyl acetate copolymer (EVA) MPs in hospital wastewater had not been studied. In this study, RGs, microbial community composition and carbon source metabolism activity were explored on EVA plastisphere in hospital wastewater containing BZC and APAP. After aging treatment, EVA MPs showed an increase in particle size, cracks on the surface and changes in functional groups. Moreover, aged EVA MPs became an excellent carrier and transmitter of RGs and accelerated microbial colonization after soaking in wastewater containing BZC and APAP. The abundances of RGs in wastewater containing pollutants were 6.19-665.49 times higher than those in wastewater without pollutants. These results indicated that the coexistence of BZC and APAP had higher environmental risk compared with single existence. Furthermore, quaternary ammonium compounds RGs were enriched in wastewater and on plastisphere with the presence of BZC. Network analysis demonstrated that Nitrosomonas (5.76-25.25 %) and pathogen Legionella (0.01-40.75 %) had high abundances in wastewater and on plastisphere and the potential to transfer multiple RGs. This study will fill the knowledge gap on the changes in microbial community structure, RGs transmission and carbon source metabolism of pristine and aged EVA MPs in wastewater containing BZC and APAP.

Deciphering the effects of long-term exposure to conventional and biodegradable microplastics on the soil microbiome

Despite recent advances in the understanding of the impacts of microplastics (MPs) on the soil microbiome under short-term exposure, little information is known regarding the long-term ecological effects of MPs in soil, especially biodegradable MPs (BMPs). Here, we systematically compared the effects of four prevalent microplastics, including two conventional MPs (CMPs) and two BMPs, on the soil microbiome over short- and long-term exposure durations. The soil microbial community were not significantly affected by the MP addition under short-term exposure; however, the soil microbial composition was obviously impacted by MP exposure under long-term exposure, some MP-adapted microbes (e.g., the phyla Protobacteria and Actinobacteria) were enriched but the phyla Acidobacteriota declined. These results indicated that the effects of the MP exposure on the soil microbiome were time dependent. PERMANOVA analysis demonstrated that the exposure time played a more important role in the variation in soil microbiome than the polymer type. The soil microbes which were reshaped by MPs were specialized in genetic potential of lipid metabolism and xenobiotics degradation and metabolism and weakened in microbial genetic information process. The carbon metabolic capacity and nitrogen transformation of soil microbes were disturbed by MPs under long-term exposure. Compared with CMPs, many more MPs derivatives, such as dissolved organic matter and low molecular-weight oligomers, were released from BMPs during the long-term degradation process in soil; thus, BMPs had a stronger effect on the soil microbiome than CMPs under long-term exposure. This study underscores the potential risk of the replacement of conventional plastics with biodegradable plastics.

Effects of inescapable waste composition on microplastic release and sulfate reduction in landfill

This study systematically investigated the co-regulatory mechanism between waste composition, microplastic (MP) release, and sulfate reduction processes in simulated landfill environments under various waste composition conditions. Key findings include higher MP release and sulfate consumption in high-biodegradable waste groups compared to low-biodegradable waste ones, and a more sensitive coupling between sulfate concentration attenuation and MP release response in the low-biodegradable waste group. Biodegradable waste emerged as an inescapable source of MP release, contributing 17.42% of total MP release. Notably, high-biodegradable waste groups generated MP levels 2.75-2.38 times higher than their low-biodegradable counterparts. The abundant organic matter in biodegradable waste synergized with the sulfate reduction process, substantially exacerbating secondary MP release. Furthermore, leachate circulation enhanced the dynamic coupling between MP release and sulfate reduction. Based on these findings, a targeted strategy for waste source classification and leachate regulation was proposed to achieve coordinated control of new pollutants and legacy pollutants in landfills. This approach provides scientific support for pollution control and sustainable landfill management.

Marine plastic exposure triggers rapid recruitment of plastic-degrading bacteria and accelerates polymer-specific transformations

Plastic pollution in marine ecosystems is a growing concern, yet the degradation behavior of different plastic types and their interactions with microbial communities remain poorly understood. This study investigated the degradation kinetics and microbial colonization of four widely used plastic materials, surgical masks (most made of PP), PET bottles, PS foam, and PP cups, over 40 days of seawater exposure in the Central Atlantic of Morocco. Mass loss measurement revealed distinct degradation patterns, with PS foam showing the highest mass loss (13 %), followed by PET bottles (5 %), likely due to environmental stressors that promote mechanical fragmentation. Surgical masks and PP cups exhibited minimal degradation, retaining nearly all their original mass, as well as limited extent of biodegradation. Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD) analyses showed the formation of oxidative functional groups on PP cups and significant structural changes in PS foam and PET, particularly in their crystalline structures, correlating with their higher mass reduction rates. SEM/EDX biofilm imaging confirmed extensive microbial colonization, particularly on PS and PET surfaces. Using 16S rRNA metabarcoding, we identified a striking enrichment of Exiguobacterium, followed by Pseudomonas, Acinetobacter and Bacillus genera, containing reported plastic degrading strains, which were strongly correlated with the accelerated breakdown of plastics. However, its role in accelerating plastic breakdown in this study remains unclear and may warrant further investigation. Co-occurrence network analysis revealed a progressive shift in microbial community structure, evolving from highly interconnected networks at day 0 to more specialized, modular clusters by day 40, dominated by Proteobacteria and Firmicutes. Atomic Absorption Spectrometry (AAS) demonstrated significant heavy metal accumulation on plastic surfaces, potentially influencing microbial colonization and activity. While the observed fragmentation of PS foam and PET highlights the susceptibility of certain plastics to environmental stressors, this study also positions microbial colonization as a potential contributor to plastic surface changes, providing novel insights into the interplay between microbial communities and plastic degradation in marine environments.

Microplastics: Hidden drivers of antimicrobial resistance in aquatic systems

Microplastics (MPs) in aquatic ecosystems readily promote biofilm formation, creating the plastisphere, a dynamic interface that interacts with environmental pollutants and acts as a reservoir for microorganisms. Recent studies emphasize the plastisphere's contribution to the spread of pathogens, antibiotic-resistant genes (ARGs), and antimicrobial resistance (AMR) within aquatic organisms and across diverse environments, a phenomenon collectively called the 'Plastiome'. Although the prevalence and effects of the plastisphere have been studied extensively, a systematic synthesis of updated insights into the behavior of the plastiome is urgently needed. This review explores the development and behavior of plastics, focusing on its interactions with ARGs and pathogens within aquatic ecosystems. Microplastics selectively enrich ARGs and pathogenic microorganisms, fostering unique microbial communities distinct from those in surrounding waters. The plastiome facilitates horizontal ARG propagation, increasing the quantity of antibiotic-resistant pathogens and presenting substantial risks to the hydrosphere and public health. Additionally, key research opportunities are identified and strategies are recommended to advance our understanding of plastiome-driven antibiotic resistance in aquatic environments.

Microplastics in lakes: Distribution patterns and influencing factors

As a kind of new pollutants, microplastics (MPs) have aroused public concern due to their widespread presence and potential ecological risks. Lakes, as crucial freshwater ecosystems and important water resources, are particularly vulnerable to MPs pollution. While MPs are known to be unevenly distributed within lakes, their distribution patterns and influencing factors have not been thoroughly understood. This review analyzes 84 field studies across 64 lakes worldwide to elucidate MPs distribution patterns and their driving mechanisms. Analysis reveals that MPs abundance is typically highest near areas of intense human activity and major water inflows, though hydrodynamics and wind conditions also influence spatial patterns. MPs characteristics (shape, size, color, polymer type) show distinct distribution patterns influenced by source types, transport mechanisms, and degradation processes. While surface water MPs concentrations vary seasonally due to precipitation, wind, and human activities, sediment cores indicate increasing MPs abundance in recent deposits. Integration of water and sediment sampling reveals that MPs characteristics affect their vertical distribution, with denser particles prone to sedimentation. This review identifies key knowledge gaps, including limited data on vertical distributions and temporal variations, and emphasizes the need for standardized methods and quantitative analysis of driving factors. These reviewed findings provide a foundation for understanding MPs fate in lake ecosystems and improving risk assessment capabilities, offering valuable insights for future surveys on MPs.

Untargeted metabolomic insights into plastisphere communities in European rivers

Every year, rivers introduce a staggering amount of hundred kilotons of plastic into the Oceans. This plastic is inhabited by microorganisms known as the plastisphere, which can be transferred between different ecosystems through the transport of microplastics. Here, we simulated the microbial colonization of polyethylene-based plastic pellets that are classically used to manufacture large-scale plastic products. The pellets were immersed for 1 month in four to five sampling stations along the river-to-sea continuum of nine of the major European rivers. This study presents the first untargeted metabolomics analysis of the plastisphere, by using ultra high-performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS). The plastisphere metabolomes were similar in the Rhine and Rhone rivers, while being different from the Tiber and Loire rivers, which showed greater similarity to the Thames and Seine rivers. Interestingly, we found a clear distinction between plastisphere metabolomes from freshwater and marine water in most of the river-to-sea continuum, thus suggesting a complete segregation in plastisphere metabolites that is not consistent with a major transfer of microorganisms between the two contrasted ecosystems. Putative annotations of 189 discriminating metabolites suggested that lipid metabolism was significantly modulated. These results enlightened the relevance of using environmental metabolomic as complementary analysis to the current OMICs analysis.

Are we underestimating the driving factors and potential risks of freshwater microplastics from in situ and in silico perspective?

The high loads of heterogeneous microplastics (MPs) in water system sparked the exploration of MPs source and impact in the environment. However, the contributions of driving factors to MPs contamination and the potential risks posed by multidimensional characteristics are still poorly understood. By incorporating in situ investigation with machine learning predictions, this study reported widespread MPs contamination in both textile upstream and receiving watershed in the Yangtze River Delta. The dominant MPs categories were fibers (0.1-0.5 mm in size), transparent in color, and composed of polyethylene terephthalate. These morphological characteristics indicated a conditional fragmentation process, suggesting that larger MPs are more prone to fragmentation. Multivariable analysis revealed significant correlations between MPs occurrence and factors of metal concentrations, geographic locations, and water qualities, highlighting the roles of textile production and automotive tire wear in determining MPs abundance. Among five machine learning models, Random Forest outperformed others in predicting MPs abundance. The interpretable analysis indicated that longitude (35.3 %), TN (13.8 %) and Sb (13.4 %) were pivotal nodes in shaping the MPs abundance. Emission point sources from express, autotire and textile yield feature importance from 6.60 % to 7.88 %. A total 12.39 % of the predicted variability can be further explained by interaction effects. Besides, MPERI and MultiMP indices based on abundance, size, color, shape, and polymer distributions suggested that most sampling sites fell within moderate to high-risk categories. Artificial neural network-based assessment results are suitable for explaining the MPs induced risks and polymer type was the most influential variable in determining the risk values. These quantitative insights into the driving factors and potential risks behind MPs occurrence improve our knowledge to manage MPs pollution in large-scale watersheds, providing crucial information for the development of effective mitigation strategies.

Bacterium-Phage Symbiosis Facilitates the Enrichment of Bacterial Pathogens and Antibiotic-Resistant Bacteria in the Plastisphere

The plastisphere, defined as the ecological niche for microbial colonization of plastic debris, has been recognized as a hotspot of pathogenic and antibiotic-resistant bacteria. However, the interactions between bacteria and phages facilitated by the plastisphere, as well as their impact on microbial risks to public health, remain unclear. Here, we analyzed public metagenomic data from 180 plastisphere and environmental samples, stemming from four different habitats and two plastic types (biodegradable and nonbiodegradable plastics) and obtained 611 nonredundant metagenome-assembled genomes (MAGs) and 4061 nonredundant phage contigs. The plastisphere phage community exhibited decreased diversity and virulent proportion compared to those found in environments. Indexes of phage-host interaction networks indicated significant associations of phages with pathogenic and antibiotic-resistant bacteria (ARB), particularly for biodegradable plastics. Known phage-encoded auxiliary metabolic genes (AMGs) were involved in nutrient metabolism, antibiotic production, quorum sensing, and biofilm formation in the plastisphere, which contributed to enhanced competition and survival of pathogens and ARB hosts. Phages also carried transcriptionally active virulence factor genes (VFGs) and antibiotic resistance genes (ARGs), and could mediate their horizontal transfer in microbial communities. Overall, these discoveries suggest that plastisphere phages form symbiotic relationships with their hosts, and that phages encoding AMGs and mediating horizontal gene transfer (HGT) could increase the source of pathogens and antibiotic resistance from the plastisphere.

Effect of Multiyear Biodegradable Plastic Mulch on Soil Microbial Community, Assembly, and Functioning

The increasing use of biodegradable plastic mulch like polybutylene adipate terephthalate (PBAT) has raised concerns about its long-term environmental impact. In this study, we investigated the effects of multiyear PBAT mulch application on bacterial and fungal communities, assembly mechanisms, and key ecological functions. The microbial community diversity and composition were significantly altered after multiyear biodegradable plastic mulching. We observed that PBAT treatment enriched specific bacterial genera, such as Pantoea, potentially involved in plastic degradation, and fungal genera like Cephaliophora and Stephanosporaceae, which may play a role in organic matter decomposition. A null model analysis revealed that bacterial community assembly was largely shaped by deterministic processes, with stronger environmental selection pressures in PBAT-treated soils, while fungal communities were more influenced by stochastic processes. In addition, multiyear PBAT mulch application also impacted the functionality of the soil microbial communities. PBAT exposure enhanced biofilm formation in aerobic bacteria, promoting aerobic degradation processes while also reducing the abundance of stress-tolerant bacteria. Additionally, PBAT altered key microbial functions related to carbon, nitrogen, and sulfur cycling. Notably, the fungal communities exhibited functional shifts, with an increase in saprotrophic fungi being beneficial for nutrient cycling, alongside a potential rise in plant pathogenic fungi. These findings underscore the multiyear ecological impacts of biodegradable plastics, suggesting microbial adaptation to plastic degradation and changes in key ecological functions, with implications for agricultural sustainability and bioremediation strategies.

Selective enrichment of high-risk antibiotic resistance genes and priority pathogens in freshwater plastisphere: Unique role of biodegradable microplastics

Microplastics (MPs) has been concerned as emerging vectors for spreading antibiotic resistance and pathogenicity in aquatic environments, but the role of biodegradable MPs remains largely unknown. Herein, field in-situ incubation method combined with metagenomic sequencing were employed to reveal the dispersal characteristics of microbial community, antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), and virulence factors (VFs) enriched by MPs biofilms. Results showed that planktonic microbes were more prone to enrich on biodegradable MPs (i.e., polyhydroxyalkanoate and polylactic acid) than non-biodegradable MPs (i.e., polystyrene, polypropylene and polyethylene). Distinctive microbial communities were assembled on biodegradable MPs, and the abundances of ARGs, MGEs, and VFs on biofilms of biodegradable MPs were much higher than that of non-biodegradable MPs. Notably, network analysis showed that the biodegradable MPs selectively enriched pathogens carrying ARGs, VFs and MGEs concurrently, suggesting a strong potential risks of co-spreading antibiotic resistance and pathogenicity through horizontal gene transfer. According to WHO priority list of Antibiotic Resistant Pathogens (ARPs) and ARGs health risk assessment framework, the highest abundances of Priority 1 ARPs and Rank I risk ARGs were found on polylactic acid and polyhydroxyalkanoate, respectively. These findings elucidate the unique and critical role of biodegradable MPs for selective enrichment of high-risk ARGs and priority pathogens in freshwater environments.

Biofilm formation on microplastics and interactions with antibiotics, antibiotic resistance genes and pathogens in aquatic environment

Microplastics (MPs) in aquatic environments easily support biofilm development, which can interact with other environmental pollutants and act as harbors for microorganisms. Recently, numerous studies have investigated the fate and behavior of MP biofilms in aquatic environments, highlighting their roles in the spread of pathogens and antibiotic resistance genes (ARGs) to aquatic organisms and new habitats. The prevalence and effects of MP biofilms in aquatic environments have been extensively investigated in recent decades, and their behaviors in aquatic environments need to be synthesized systematically with updated information. This review aims to reveal the development of MP biofilm and its interactions with antibiotics, ARGs, and pathogens in aquatic environments. Recent research has shown that the adsorption capabilities of MPs to antibiotics are enhanced after the biofilm formation, and the adsorption of biofilms to antibiotics is biased towards chemisorption. ARGs and microorganisms, especially pathogens, are selectively enriched in biofilms and significantly different from those in surrounding waters. MP biofilm promotes the propagation of ARGs through horizontal gene transfer (HGT) and vertical gene transfer (VGT) and induces the emergence of antibiotic-resistant pathogens, resulting in increased threats to aquatic ecosystems and human health. Some future research needs and strategies in this review are also proposed to better understand the antibiotic resistance induced by MP biofilms in aquatic environments.

Selective colonization of microplastics, wood and glass by antimicrobial-resistant and pathogenic bacteria

The Plastisphere is a novel niche whereby microbial communities attach to plastic debris, including microplastics. These communities can be distinct from those found in the surrounding environment or those attached to natural substrates and may serve as a reservoir of both pathogenic and antimicrobial-resistant (AMR) bacteria. Owing to the frequent omission of appropriate comparator particles (e.g. natural substrates) in previous studies, there is a lack of empirical evidence supporting the unique risks posed by microplastics in terms of enrichment and spread of AMR pathogens. This study investigated selective colonization by a sewage community on environmentally sampled microplastics with three different polymers, sources and morphologies, alongside natural substrate (wood), inert substrate (glass) and free-living/planktonic community controls. Culture and molecular methods (quantitative polymerase chain reaction (qPCR)) were used to ascertain phenotypic and genotypic AMR prevalence, respectively, and multiplex colony PCR was used to identify extra-intestinal pathogenic Escherichia coli (ExPECs). From this, polystyrene and wood particles were found to significantly enrich AMR bacteria, whereas sewage-sourced bio-beads significantly enriched ExPECs. Polystyrene and wood were the least smooth particles, and so the importance of particle roughness on AMR prevalence was then directly investigated by comparing the colonization of virgin vs artificially weathered polyethylene particles. Surface weathering did not have a significant effect on the AMR prevalence of colonized particles. Our results suggest that the colonization of plastic and non-plastic particles by AMR and pathogenic bacteria may be enhanced by substrate-specific traits.

Metagenomic insights into ecological risk of antibiotic resistome and mobilome in riverine plastisphere under impact of urbanization

Microplastics (MPs) are of increasing concern due to their role as reservoirs for antibiotic resistance genes (ARGs) and pathogens. To date, few studies have explored the influence of anthropogenic activities on ARGs and mobile genetic elements (MGEs) within various riverine MPs, in comparison to their natural counterparts. Here an in-situ incubation was conducted along heavily anthropogenically-impacted Houxi River to characterize the geographical pattern of antibiotic resistome, mobilome and pathogens inhabiting MPs- and leaf-biofilms. The metagenomics result showed a clear urbanization-driven profile in the distribution of ARGs, MGEs and pathogens, with their abundances sharply increasing 4.77 to 19.90 times from sparsely to densely populated regions. The significant correlation between human fecal marker crAssphage and ARG (R2 = 0.67, P=0.003) indicated the influence of anthropogenic activity on ARG proliferation in plastisphere and natural leaf surfaces. And mantel tests and random forest analysis revealed the impact of 17 socio-environmental factors, e.g., population density, antibiotic concentrations, and pore volume of materials, on the dissemination of ARGs. Partial least squares-path modeling further unveiled that intensifying human activities not only directly boosted ARGs abundance but also exerted a comparable indirect impact on ARGs propagation. Furthermore, the polyvinylchloride plastisphere created a pathogen-friendly habitat, harboring higher abundances of ARGs and MGEs, while polylactic acid are not likely to serve as vectors for pathogens in river, with a lower resistome risk score than that in leaf-biofilms. This study highlights the diverse ecological risks associated with the dissemination of ARGs and pathogens in varied MPs, offering insights for the policymaking of usage and control of plastics within urbanization.

Regulatory path for soil microbial communities depends on the type and dose of microplastics

To reveal the feedbacks and regulating mechanisms of microplastic types and doses on microbial community, a microcosm experiment was carried out with two non-degradable microplastics [polyethylene (PE) and polyvinyl chloride (PVC)] and four biodegradable microplastics [poly(butylene succinate) (PBS), polyhydroxyalkanoates (PHA), poly(butyleneadipate-co-terephthalate) (PBAT), and polypropylene carbonate (PPC)] at different levels (1 %, 7 %, and 28 %). As a result, the content of total carbon (TC), soil organic carbon (SOC), and microbial biomass carbon (MBC) (expect MBC in PBS soil) increased with increasing doses of microplastics, and increased at the lowest PE dose rate. Biodegradable microplastics created a more active ecological niche while enriching more pathogens than non-degradable microplastics. Structural equation modeling indicated that microbial diversities were in a type-dependent assembly, whereas microbial compositions were more profoundly affected by the microplastic doses, ultimately. The standardized total effect coefficient of microplastic types on bacterial and fungal diversities was - 0.429 and - 0.282, and that of doses on bacterial and fungal compositions was 0.487 and 0.336, respectively. Both microplastic types and doses significantly impacted pH, electrical conductivity, total nitrogen, TC, SOC, and MBC, subsequently inhibiting microbial diversities and stimulating microbial compositions with particular pathways. The results provide a comprehensive understanding for evaluating the potential risk of microplastics.

Effects of micro-nano plastics on the environmental biogeochemical cycle of nitrogen: A comprehensive review

Micro-nano plastics (MNPs; size <5 mm), ubiquitous and emerging pollutants, accumulated in the natural environment through various sources, and are likely to interact with nutrients, thereby influencing their biogeochemical cycle. Increasing scientific evidences reveal that MNPs can affect nitrogen (N) cycle processes by affecting biotopes and organisms in the environmental matrix and MNPs biofilms, thus plays a crucial role in nitrous oxide (N2O) and ammonia (NH3) emission. Yet, the mechanism and key processes behind this have not been systematically reviewed in natural environments. In this review, we systematically summarize the effects of MNPs on N transformation in terrestrial, aquatic, and atmospheric ecosystems. The effects of MNPs properties on N content, composition, and function of the microbial community, enzyme activity, gene abundance and plant N uptake in different environmental conditions has been briefly discussed. The review highlights the significant potential of MNPs to alter the properties of the environmental matrix, microbes and plant or animal physiology, resulting in changes in N uptake and metabolic efficiency in plants, thereby inhibiting organic nitrogen (ON) formation and reducing N bioavailability, or altering NH3 emissions from animal sources. The faster the decomposition of plastics, the more intense the perturbation of MNPs to organisms in the natural ecosystem. Findings of this provide a more comprehensive analysis and research directions to the environmentalists, policy makers, water resources planners & managers, biologists, and biotechnologists to do integrate approaches to reach the practical engineering solutions which will further diminish the long-term ecological and climatic risks.

Freshwater plastisphere: a review on biodiversity, risks, and biodegradation potential with implications for the aquatic ecosystem health

The plastisphere, a unique microbial biofilm community colonizing plastic debris and microplastics (MPs) in aquatic environments, has attracted increasing attention owing to its ecological and public health implications. This review consolidates current state of knowledge on freshwater plastisphere, focussing on its biodiversity, community assembly, and interactions with environmental factors. Current biomolecular approaches revealed a variety of prokaryotic and eukaryotic taxa associated with plastic surfaces. Despite their ecological importance, the presence of potentially pathogenic bacteria and mobile genetic elements (i.e., antibiotic resistance genes) raises concerns for ecosystem and human health. However, the extent of these risks and their implications remain unclear. Advanced sequencing technologies are promising for elucidating the functions of plastisphere, particularly in plastic biodegradation processes. Overall, this review emphasizes the need for comprehensive studies to understand plastisphere dynamics in freshwater and to support effective management strategies to mitigate the impact of plastic pollution on freshwater resources.

Linking ecological niches to bacterial community structure and assembly in polluted urban aquatic ecosystems

Introduction

Bacterial communities play crucial roles in the functioning and resilience of aquatic ecosystems, and their responses to water pollution may be assessed from ecological niches. However, our understanding of such response patterns and the underlying ecological mechanisms remains limited.

Methods

In this study, we comprehensively investigated the effects of water pollution on the bacterial structure and assembly within different ecological niches, including water, sediment, submerged plant leaf surfaces, and leaf surfaces, using a 16S high-throughput sequencing approach.

Results

Ecological niches had a greater impact on bacterial community diversity than pollution, with a distinct enrichment of unique dominant phyla in different niches. This disparity in diversity extends to the bacterial responses to water pollution, with a general reduction in α-diversity observed in the niches, excluding leaf surfaces. Additionally, the distinct changes in bacterial composition in response to pollution should be correlated with their predicted functions, given the enrichment of functions related to biogeochemical cycling in plant surface niches. Moreover, our study revealed diverse interaction patterns among bacterial communities in different niches, characterized by relatively simply associations in sediments and intricate or interconnected networks in water and plant surfaces. Furthermore, stochastic processes dominated bacterial community assembly in the water column, whereas selective screening of roots and pollution events increased the impact of deterministic processes.

Discussion

Overall, our study emphasizes the importance of ecological niches in shaping bacterial responses to water pollution. These findings improve our understanding of the complicated microbial response patterns to water pollution and have ecological implications for aquatic ecosystem health.