Microplastic (MP) pollution has become a persistent environmental challenge, raising increasing concern due to its global distribution and potential risks to human health. Biological degradation, including microbial and insect mediated processes, represents a promising and environmentally sustainable strategy for mitigating plastic and MP pollution; however, its effectiveness remains highly variable and strongly context dependent. This review systematically summarizes recent advances in microbial degradation of plastic, as well as emerging research on insect mediated plastic biodegradation, focusing on degrading microorganisms, key enzymes, metagenomic discovery, and enzyme engineering strategies. A wide range of bacterial and fungal taxa capable of degrading major plastic polymers, including polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polystyrene (PS), polyvinyl chloride (PVC), polyurethane (PU), and polylactic acid (PLA), has been reported. In addition, several insect species capable of ingesting and transforming plastics have been identified as model systems for studying plastic degradation, where mechanical fragmentation, host digestive processes, and gut microbial metabolism jointly contribute to polymer transformation. Among these, PET degrading enzymes, particularly PETase, are the most extensively characterized, benefiting from detailed structural insights and intensive protein engineering efforts that have markedly enhanced catalytic efficiency and thermostability. In contrast, enzymatic mechanisms involved in the biodegradation of polyolefins such as PE and PP remain poorly understood, representing a major knowledge gap. Recent metagenomic approaches have substantially expanded the repertoire of candidate plastic degrading enzymes by accessing uncultured MP associated microbial communities and insect gut microbiomes. Nevertheless, functional validation and evaluation under environmentally relevant conditions remain critical bottlenecks. Moreover, most reported degradation efficiencies are derived from optimized laboratory settings and may substantially overestimate microbial performance under natural environmental constraints, including low temperature, high salinity, nutrient limitation, and mixed polymer substrates. Overall, this review highlights the gap between laboratory based biodegradation studies and real world applications and emphasizes the need for integrated strategies to advance scalable plastic and MP remediation solutions.

Microplastic contamination in aquatic ecosystems is a growing global concern, yet microplastic analysis remains constrained by labor-intensive pretreatment and inconsistency across operators and laboratories. Here, we report the application and validation of the first automatic microplastic pretreatment unit, Shimadzu's MAP-100, designed to standardize this critical step. The unit was evaluated using river water spiked with aged standard microplastics for controlled testing and field-collected seawater for real-sample validation. After automatic pretreatment, Fourier transform infrared (FT-IR) spectral integrity was preserved, enabling reliable polymer identification and recovery rate determination. Detection of soluble organic matter demonstrated effective organic matter removal. Mineral particles were completely eliminated, with zero residual mineral detection. The MAP-100 achieved a higher recovery of aged microplastics (95.6 ± 2.5%) than manual pretreatment (92.7 ± 3.0%), with the greatest improvement observed for small (≤1 mm) and high-density particles. In seawater samples, overall performance remained robust; however, foam microplastics showed reduced recovery due to the overflow tube's narrow diameter and sharp curvature, indicating a need for structural refinement. Despite this limitation, the closed-loop automatic workflow substantially reduces labor and processing time while improving reproducibility and operational safety for standardized microplastic monitoring.

Microplastic (MPs) pollution poses a global threat to ecosystems and human health. Traditional physicochemical methods face limitations like high cost, inefficiency, and secondary pollution, underscoring the need for green remediation. While microbial degradation holds promise, research remains largely limited to lab studies of single environments, lacking systematic multi-environment strain collections and practical application assessments. This review summarizes common screening/validation methods, degradation mechanisms, and influencing factors of microplastic-degrading microorganisms (MPDMs). By reviewing 78 studies, 197 degrading microorganisms/taxa from four typical environments (soil, marine, freshwater, animal gut) were sorted, with 152 analyzed for degradation efficiency. The degradation efficiencies across different environments were compared, with the maximum efficiency order being soil > freshwater > marine > animal gut, and the overall average efficiency order being soil ≈ freshwater > marine ≈ animal gut. Recommendations for efficient culture conditions were proposed for different environments, and high-potential strains were recommended, including multi-environment efficient ones (e.g., Bacillus and multiple bacterial consortia) and environment-specific superior strains (e.g., Rhodococcus, Oceanimonas, and Enterobacter). Finally, methods such as dominant strain screening, acclimatization, genetic engineering modification, and synthetic taxa construction via machine learning are proposed to enhance practical applicability. This study not only establishes a scenario-specific microbial remediation resource pool and quantifies their degradation efficiencies, providing critical data support and strategic guidance for the development of in-situ microbial remediation technologies at targeted contaminated sites, but also lays a solid foundation for translating laboratory findings into practical field applications in future research.

Microplastics (MPs), as emerging pollutants, accumulate extensively in aquaculture areas, yet their microbial ecological functions and associated risk mechanisms remain poorly understood. In this study, we collected water, sediment, organic, and MP samples across spring and autumn from a representative aquaculture area in southeastern China. Using high-throughput 16S rRNA sequencing, community ecological modeling, functional prediction, and network analysis, we systematically investigated the diversity, assembly mechanisms, and ecological functions of the "plastisphere" bacteria. Results indicated that habitat type was the primary driver of bacterial community structure, while season acted as a secondary factor modulating community composition across different environments. Although MPs shared certain core microbiota with organic, their attached bacterial communities differed markedly from those on water, sediment, and organic. Neutral model analysis revealed extremely low migration rates between MP and organic surfaces (m = 0.011), suggesting that MPs form an independent and dispersal-limited artificial niche. Co-occurrence network analysis further showed that MPs surfaces were dominated by potential plastic degrading bacteria and conditionally pathogenic taxa, whereas organic communities exhibited saprophytic traits. Functional prediction revealed that MPs were significantly enriched in human disease-related and hydrocarbon-degrading functions, maintaining stability across seasons. This study demonstrates that MP surfaces attached bacteria in marine aquaculture areas simultaneously possess pollution remediation potential and public health risk attributes, providing new insights for assessing the ecological effects of MPs and attached microbiota and informing aquaculture management strategies.

Marine plastic and microplastic (MP) pollution is widely recognized as an emerging issue that poses significant risks to marine organisms, particularly birds. However, little is known about MP exposure in migratory birds at their wintering grounds. This study, conducted at Swan Lake in Rongcheng city, China, is the first to investigate the occurrence of MPs in feces of migratory Whooper Swans, and assess the associated ecological risks. The mean abundance of MPs in fecal samples was 0.40 ± 0.40 items/g, with an overall detection rate of 76.67%. Fragment-shaped MPs were the predominant form in sediment and fecal samples, primarily composed of polypropylene (PP) and polyethylene (PE). Conversely, fibrous MPs, predominantly polyethylene terephthalate (PET), were the most abundant type in water. Principal Coordinate Analysis (PCoA) revealed that fecal MP composition overlapped with surrounding water and sediment. Our findings suggest that Whooper Swans may function as reliable bioindicators for monitoring environmental MP pollution within their wintering habitats. Evaluations using the Pollution Load Index (PLI), Polymer Hazard Index (PHI), and Potential Ecological Risk Index (PERI) collectively indicated that the overall ecological risk associated with MP abundance to wintering Whooper Swans remains low. Nevertheless, the presence of high-toxicity plastic polymers, such as polyacrylonitrile and polyurethane, were identified in specific regions of the lake. Source attribution analyses revealed that the predominant contributors to MP pollution in Swan Lake are linked to local fishery operations (e.g. linear PP, PE), small-scale runoff inputs (e.g. fibrous PET), and coastal beach tourism activities (e.g. fragmented PP, PE). Taken together, these findings offer essential scientific insights that support the conservation of Whooper Swans and inform the formulation of management strategies aimed at mitigating plastic and MP pollution in the wintering habitats for key migratory birds.

While global attention has centered on persistent microplastic (MP) hotspots, estuaries with strong tidal redistribution but no lasting concentration peaks remain poorly understood despite their critical role in land–sea MP exchange. We present a spring-tide flood–ebb sequence assessment of MP dynamics in the cross-border Shenzhen River, integrating coordinated surface and subsurface sampling. MP abundances ranged from 4.87 to 15.88 items/m3 (0.44–29.03 mg/m3) in manta-trawl surface samples and 110–340 items/m3 (92.36–673.66 mg/m3) in fixed-depth pump-filtration samples collected at 30 cm at the estuarine outlet. Polyethylene terephthalate (PET), polyethylene (PE), and polypropylene (PP) dominated, showing density- and morphology-driven vertical sorting. Our results revealed a dual-phase redistribution regulated by tidal forcing and salinity stratification, with PET resuspension during mid-to-high tides and lighter polymers retained near the surface. The Shenzhen River thus represents a dynamically responsive estuarine interface in which pollutant fate is governed by cyclic redistribution rather than net loading, providing a basis for the proposed Tide–Microplastic–Governance Triangle framework for adaptive MP management in transboundary estuaries.

Significant amount of microplastics (< 5 mm) were transported into the South China Sea via Pearl River Estuary. However, comprehensive studies on the occurrence and retention of microplastics in this estuarine system were still limited. To fill this gap, we investigated the distribution of microplastics in still-water ecosystems and running water ecosystems in the west bank of the Pearl River Estuary. Microplastics were found in both waterways and lakes. The results of the Manta trawl (330 μm mesh) yielded an average abundance of 0.66 ± 0.61 n/m3 in waterways and 5.66 ± 3.47 n/m3 in lakes. Polyethylene (PE) and polypropylene (PP) were the most abundant polymers in water bodies. The main source of microplastics in waterways was riverine inputs, and microplastics in lakes mainly originated from the surrounding terrestrial environment. Lakes, which were less mobile than rivers, tended to act as reservoirs for microplastic transport. This study highlights the diversity of riverine microplastics during transport and improves our knowledge of the sources and transport mechanisms of microplastics in estuarine waters.

Seagrass meadows are renowned for their associated ecosystem services and carbon sequestration capacity, with microorganisms playing a crucial role. However, the invasion of microplastics may disrupt these processes. Here, we conducted a one-month in-situ incubation of three prevalent types of microplastics in the seagrass meadow of Swan Lake, China. The results showed significant differences in microbial communities between the plastisphere and natural matrices. Cyanobacteria exhibited a strong preference for polyethylene terephthalate, and microplastic shape and their contact area with water may be key factors in shaping microbial communities. Meanwhile, microplastic invasion can shift carbon- and nitrogen-fixing microbes and related genes, thereby changing seagrass meadows’ carbon and nitrogen cycles. This may impact the carbon sequestration capacity of seagrass meadows and pose potential risks of water blooms. Additionally, the potential ecological risks posed by the large number of resistance genes adsorbed by microplastics in the ecosystem are also worthy of attention.

Microplastic pollution has emerged as an undeniable marine environmental issue. While a distribution map of microplastics in the upper ocean has been established, the patterns of microplastics within the water column remain unclear. In this study, a large-volume in situ filtration device with filtration efficiency of 30 m3/h was employed to investigate microplastics in the deep waters of the South China Sea. The abundance of microplastics ranged from 0.2 to 1.5 items per cubic meter (n/m3), with an average of 0.56 ± 0.40 n/m3. Microplastics are primarily fragments (72.58%) and fibers (20.97%), with the predominant polymer types being polypropylene (PP) and polyethylene terephthalate (PET). The average size of microplastics is 0.91 ± 0.97 mm, with no statistically significant differences observed across different water layers from 50 to 1000 meter (m). Non-metric Multidimensional Scaling (NMDS) analysis indicated that microplastics in the water column primarily originated from surface waters in the studied region. The occurrence of microplastics in the marine water column is a complex environmental process, influenced by a range of oceanographic mechanisms, including biological, chemical, and physical interactions. Our results provided reliable baseline data on microplastics in the water column of the South China Sea, contributing a better understanding to the vertical transport and fate of microplastics in this region.

Localised processing of waste into resources is a prime target towards circular economy, yet community-led composting programs have reported significant implementation challenges. There are no implementation process models or guidelines for programs spanning community, waste, governance, legislation domains: each community learns anew. Here we report a multi-case study of community-led composting program implementations in eight urban sites in China. In-depth key-informant interview information was analysed as cycles of activity towards increasingly-complex needs/targets (like simple recycling; complex composting). Cross-community comparisons suggest transferable implementation lessons: delegation of certain roles is more effective than simply involving stakeholders; enthusiasts can significantly mobilize stakeholders but cannot replace them; paperwork burden could negate funding availability benefits; access to specific expertise (technical, legal, operational) at crucial moments was key; stakeholder learning was most effective via personal meetings and introductions. City policies incorporating these implementation lessons could facilitate scaling-up in China. Future studies can investigate generalizability.

Being the transition zones between rivers and the ocean, estuaries are critical pathways for the transport of millions of tons of land-based microplastics (MPs) into the ocean. These dynamic systems facilitate significant transformation processes for MPs, particularly through their interactions with microbial communities. However, the dynamics of the Plastisphere, particularly how it varies across different types of estuaries and in response to seasonal environmental changes, remain poorly understood. To address this knowledge gap, comprehensive samples were collected from four major estuaries (Qiantangjiang, Jiaojiang, Oujiang, and Minjiang River Estuaries) in Southeast China during both spring and autumn. The diversity of microorganisms associated with water, sediment, MPs, and particulate organic matter (wood) surfaces was analyzed. Our results indicated that bacterial species on MPs varied across estuaries in spring but exhibited no significant variation in autumn. The bacterial diversity on MPs was significantly different from that in water or sediment samples, but exhibited a similar pattern to that on particulate organic matter, with dominant species being more abundant on MPs. Eukaryotic diversity on MPs closely mirrored that in water, although more specific fungal species were found in the water. Despite these similarities, bacteria on MP surfaces exhibited higher levels of xenobiotic biodegradation and metabolism compared to the other three matrices. Species classification and functional annotation revealed a higher proportion of potential plastic-degrading bacteria on MP surfaces, indicating that the enrichment of potential plastic-degrading bacteria on MPs was driven by their direct association with plastic degradation, rather than their planktonic state or surface attachment.

Waste management has emerged as a critical challenge in multiple countries, where governance structures frequently exhibit insufficient robustness. Environmental non-governmental organizations (ENGOs), as pivotal stakeholders in this domain, must assume a more substantial role. However, their contributions have historically been perceived as limited. Whether and how ENGOs can play an important role deserves the attention of researchers. This paper investigates the evolving role of China's ENGOs through a longitudinal case study of nine organizations, examining their transition from adversarial to co-productive strategies, thereby fostering a tripartite collaboration system among government, enterprises, and residents. The findings reveal a three-phase evolution in organizational structure, issue focus, and tactical approaches, culminating in a three-cycle co-production framework for waste management. This study not only enriches co-production theory but also provides valuable insights into the critical role of ENGOs, offering practical guidance for sustainable waste governance.

Pelagic microplastics (MPs) are ubiquitous in seawater worldwide, driven by global ocean currents and atmospheric circulation. A comprehensive evaluation of MP pollution in surface water near Xisha Islands of the South China Sea was conducted using a typical Manta trawl. The results indicated that the average abundance of MPs in this region was 0.61 +/- 0.87n/m3, demonstrating significant spatial heterogeneity. MPs were primarily composed of polypropylene (PP) and polyethylene (PE). The average size of MPs was 1.95 +/- 1.18 mm and approximately 90 % of all MPs were smaller than 3.80 mm. Additionally, there were significant differences in MP size between different shapes and polymers. The average sizes of MPs in shape of line and polymer of PS were largest. The type and ecological risk level of MP pollution in the water near Xisha Islands were classified as L-L (low MP abundance with low MP diversity) region and minor-risk, respectively, according to the microplastic diversity integrated index (MDII) and potential ecological risk index (PERI). Based on the map of ocean currents, the convergence effect of eddies may be a significant driving force behind the accumulation of MP pollution at individual stations. Our findings have enhanced the understanding of the current status, sources, and ecological risks of MP pollution in the South China Sea, providing valuable data and theoretical support for the promoting of MP pollution control in the region.

Marine microplastics (MPs) are recognized as a growing severe environmental concern. The vertical distribution pattern of MPs in the ocean is still elusive. Meanwhile, different sampling methods have been deployed in previous studies, resulting in difficulties in compiling data. In this study, for the first time, we explored ocean interior MP pollution in the Western Pacific Warm Pool simultaneously using both a CTD (Conductivity-temperature-depth) sampler and a large-volume in-situ filtration system. At the same sampling station, the average abundance of microplastics in the water column obtained by the two sampling methods was 0.37 +/- 0.44 n/m(3) (in-situ filtration) and 115.12 +/- 64.13 n/m(3) (CTD), respectively, which showed significant differences. Both methods found that the main chemical composition and shape of MPs were PET and fiber. Ocean current was identified as the dominant factor that impacted the horizontal distribution of MPs in the study area. The abundance of MPs in the surface layer was 5.4-703.8 times higher than that of the water column. The similar physical and chemical properties of MPs in the surface water and water column indicated that MPs in the water column originate from the sustained release from the surface layer.

Seagrass beds, as an important coastal blue carbon ecosystem, are excellent at storing organic carbon and mitigating the impacts of global climate change. However, seagrass beds are under threat due to increased human activities and ubiquitous presence of microplastics (MPs) in marine environments. Bibliometric analysis shows that the distribution and accumulation of microplastics in seagrass beds has been widely documented worldwide, but their impacts on seagrass beds, particularly on carbon sequestration capacity, have not been given sufficient attention. This review aims to outline the potential impacts of MPs on the carbon sequestration capacity of seagrass ecosystems across five key aspects: (1) MPs act as sources of organic carbon, contributing to direct pollution in seagrass ecosystems; (2) Impacts of MPs on seagrasses and their epiphytic algae, affecting plant growth and net primary productivity; (3) Impacts of MPs on microorganisms, influencing production of recalcitrant dissolved organic carbon and greenhouse gas; (4) Impacts of MPs on seagrass sediments, altering the quality, structure, properties and decomposition processes of plant litters; (5) Other complex impacts on the seagrass ecosystems, depending on different behaviors of MPs. Latest progress in these fields are summarized and recommendations for future work are discussed. This review can provide valuable insights to facilitate future multidisciplinary investigations and encourage society-wide implementation of effective conservation measures to enhance the carbon sequestration capacity of seagrass beds.

Municipal solid waste sorting is an essential element of urban sustainability as cities transition to a circular economy. As a mega-city, Shanghai has achieved remarkable milestones in its latest compulsory waste sorting program. This success has garnered widespread attention, and most studies have primarily focused on policy interventions from either a macro perspective or micro-analysis of individual behaviours. However, these studies have often overlooked the intricacies of multi-stakeholder coordination and the division of responsibilities, which frequently contributed to the failure of waste sorting initiatives. Furthermore, existing research lacks a systematic theoretical framework to elucidate multi-stakeholder accountability mechanisms. Therefore, this research adopts a case study approach to untangle the factors that led to Shanghai's success. Through the lens of accountability theory, this study systematically elaborates stakeholder accountability mechanisms and offers a distinctive multi-stakeholder perspective to explain Shanghai's success across vertical, horizontal, and felt accountability dimensions. This informative exemplar provides crucial empirical insights for other cities, especially those grappling with challenges in promoting and managing waste sorting initiatives.

Marine microplastic (MP) pollution represents a global environmental issue that has ignited considerable apprehension within the international community. Seagrass beds, which serve as nearshore marine ecosystems, have emerged as focal points of plastic and MP contamination due to the pronounced density of anthropogenic activities and the hydrological mitigating effects of submerged vegetation. Nevertheless, our comprehension of MPs within seagrass ecosystems remains constrained. In this study, we employed bibliometric analyses and comprehensive data exploration to summarize the historical progression of the development, pivotal areas of interest, and research deficiencies, followed by proposing future research directions for MP pollution in seagrass beds. The 37 selected papers were sourced from the Web of Science Core Collection scientific database as of December 31st, 2022. Based on the current evaluation, MPs are ubiquitously discovered within seagrass canopies, sediments, and marine organisms, while less than 15 % of seagrass species worldwide have been investigated. Moreover, methodological inconsistencies in sampling, processing and visualization between studies hindered the fusion and comparison of data. MPs in upper sediments and seagrass blades were the most widely investigated, with an average abundance of 263.4 ± 309.2 n/kg and 0.09 ± 0.03 n/blade. In all environmental compartments, the prevalent forms of MPs comprise fibrous and fragmented particles, encompassing the dominant polymers such as polypropylene, polyethylene and polyethylene terephthalate. However, the source of MPs in seagrass beds based on MP characteristics and local hydrodynamics has not been comprehensively analyzed in previous studies. The evidence for MPs acting as pollutants and contaminant carries impacting the growth and decline of seagrass is also weak. Currently, the precise implications of MPs on submerged vegetation, organisms, and the broader seagrass ecosystem remain inconclusive. However, considering the persistent accumulation of MPs, it is imperative to explore the ecological hazards they may pose within the foreseeable future.

Microplastics (MPs) are found in rivers and offshore areas. However, there is a lack of detailed research on the changes of surface microbial species attached to MPs when MPs enter the sea. Moreover, no study has been conducted on changes to plastic-degrading bacteria during this process. In this study, using rivers and offshore in Macau, China as examples, bacterial diversity and bacterial species composition attached to surface water and MPs at four river sampling stations and four offshore sampling stations around Macau were studied. Plastic-degrading bacteria, plastic-related metabolic processes, and plastic-related enzymes were analyzed. The results showed that MPs-attached bacteria in rivers and offshore were different with the planktonic bacteria (PB). The proportion of major families on the surface of MPs continued to increase from rivers to estuaries. MPs could significantly enrich plastic-degrading bacteria both in rivers and offshore. The proportion of plastic-related metabolic pathways on the surface bacteria of MPs in rivers was higher than that in offshore waters. Bacteria on the surface of MPs in rivers may induce higher plastic degradation than offshore. Salinity significantly alters the distribution of plastic-degrading bacteria. MPs may degrade more slowly in the oceans, posing a long-term threat to marine life and human health.

Environmental problems caused by microplastics (MPs) are attracting global attention. The ecological risks of bacteria attached to MPs have not been studied in detail under low temperature conditions. Here, MPs in surface water were sampled in winter from the Changjiang (or Yangtze) River Estuary. The physical and chemical characteristics of the MPs were identified, and the diversity and species composition of bacteria on the surface water MPs were analyzed. Phenotypic prediction analysis was used to analyze the potential risk of bacteria in the biofilm on the surfaces of MPs. The main chemical composition in the MPs in the surface water were PP (polypropylene), PE (polyethylene), PS (polystyrene) and other light weight MPs. Sampling sites played a decisive role in the bacterial species composition. The potential plastic-degrading bacterium Acinetobacter and the potential pathogenic bacterium Pseudomonas showed significant differences across different sampling sites. Microbial communities on the surfaces of MPs in winter were not significantly different from planktonic bacteria in the water body. Phenotypic prediction results showed that bacteria on the surface of MPs had a marked capacity to form biofilms, but a low pathogenicity risk. Based on the results of bio-diversity analysis and phenotypic prediction, the potential ecological risk of bacteria in biofilms on MP surfaces is lower at low temperatures. In addition, the numerical simulation results show that the possibility of bacteria attached to MPs from the Changjiang River entering the Pacific Ocean in winter is small. MPs attached bacteria in the Changjiang estuary have low ecological risk to the estuary and the Pacific Ocean in winter.

Economic incentive is thought a good intervention type that can encourage residents to do food waste sorting by many cities’ government in China. However, there is a lack of long-term, large-scale study. So the business-led incentive scheme was studied by a case study in Nanjing, China, which focuses on food waste sorting. The results showed that the incentive can encourage at most an average 37