Types Of Plastic Research Articles

Metabolic activity of gut microbial enrichment cultures from different marine species and their transformation abilities to plastic additives

The role of the gut microbiota in host physiology has been previously elucidated for some marine organisms, but little information is available on their metabolic activity involved in transformation of environmental pollutants. This study assessed the metabolic profiles of the gut microbial cultures from grouper (Epinephelus coioides), green mussel (Perna viridis) and giant tiger prawn (Penaeus monodon) and investigated their transformation mechanisms to typical plastic additives. Community-level physiological profiling analysis confirmed the utilization profiles of the microbial cultures including carbon sources of carbohydrates, amines, carboxylic acids, phenolic compounds, polymers and amino acids, and the plastic additives of organophosphate flame retardants, tetrabromobisphenol A derivates and bisphenols. Using in vitro incubation, triphenyl phosphate (TPHP) was found to be rapidly metabolized into diphenyl phosphate by the gut microbiota as a representative ester-containing plastic additive, whereas the transformation of BPA (a representative phenol) was relatively slower. Interestingly, all three kinds of microbial cultures efficiently transformed the hepatic metabolite of BPA (BPA-G) back to BPA, thereby increasing its bioavailability in the body. The specific enzyme analysis confirmed the ability of the gut microbiota to perform the metabolic reactions. The results of 16S rRNA sequencing and network analysis revealed that the genera Escherichia-Shigella, Citrobacter, and Anaerospora were functional microbes, and their collaboration with fermentative microbes played pivotal roles in the transformation of the plastic additives. The structure-specific transformations by the gut microbiota and their distinct bioavailability deserve more attention in the future.

Effect of molecular weight and chemical structure of plasticizer on suspension property, binder removal, and sintered performance for zirconia toughened alumina ceramics fabricated by vat photopolymerization

Adding plasticizer is an appealing strategy to optimize binder removal for ceramic components fabricated by vat photopolymerization (VPP). However, so far the studies for effect mechanism of plasticizer on whole technological process of VPP are comparatively very limited, especially through analysis of physical and chemical properties of plasticizers. Herein, the effect of molecular weight and chemical structure of plasticizer on suspension property, binder removal, and sintered performance of zirconia toughened alumina (ZTA) ceramics was comprehensively investigated. Two types of plasticizers, namely, polyethylene glycol (PEG) and polypropylene glycol (PPG), with various molecular weights from 200 to 600 were used. Interestingly, only after adding PEG200 or PPG200, the suspensions still exhibited desired rheological and photocuring behavior, and the superior surface quality was still observed. More importantly, PPG200 proved to be the most effective plasticizer to achieve the most excellent and stable mechanical performances, as well as the highest debinding efficiency.

Temporal changes in microalgal biomass and species composition on different plastic polymers in nutrient-enriched microcosm experiments

Marine plastic debris (MPD) is a potential threat to marine ecosystems, but its function as a vector for the transportation of harmful microalgae and its impact on the habitats of other marine organisms are uncertain. To address this gap in knowledge, we performed month-long experiments in 30 L microcosms that contained plates made of six different plastic polymers (polypropylene [PP], low-density polyethylene [LDPE], high-density polyethylene [HDPE], polyvinyl chloride [PVC], polyethylene terephthalate [PET], and polystyrene [PS]), and examined the time course of changes in planktonic and periphytic microalgae. There were no significant differences in the composition of periphytic microalgae or biomass among the different plastic polymers (p > 0.05). Nutrient depletion decreased the abundance of planktonic microalgae, but increased the biomass of attached periphytic microalgae (p < 0.05). In particular, analysis of the plastic plates showed that the abundance of benthic species that are responsible for harmful algal blooms (HABs), such as Amphidinium operculatum and Coolia monotis, significantly increased over time (days 21–28; p < 0.05). Our findings demonstrated that periphyton species, including benthic microalgae that cause HABs, can easily attach to different types of plastic and potentially spread to different regions and negatively impact these ecosystems. These observations have important implications for understanding the potential role of MPD in the spread of microalgae, including HABs, which pose a significant threat to marine ecosystems.

Effect of polyethylene terephthalate plastics on nitrogen, sulphur and chlorine contaminants via sludge pyrolysis and Pb/Cu adsorption properties of biochar

ABSTRACT Pyrolysis is an effective process for disposing of municipal sewage sludge (SS). Plastics can affect the SS pyrolysis behaviour and pyrolysis products due to their low ash and high hydrocarbon ratio. The secondary pollutants from the pyrolysis process may also be affected. Therefore, polyethylene terephthalate (PET), a typical plastic, was chosen to investigate the release characteristics of pollutants containing nitrogen, sulphur, and chlorine via SS pyrolysis, and the changes of biochar to adsorb two typical heavy metals, Pb and Cu. The pyrolysis of PET plastics facilitates the migration of N toward solid and liquid-phase products, S and Cl to the gas-phase products via pyrolysis. Oxygenated compounds of pyrolytic volatiles decreased from 38.18% to 28.43%, concurrently promoting the formation of phenolic compounds. The co-pyrolysis improved the quality of biochar and the ability to adsorb Pb and Cu. This systematic study can provide some support for the further improvement of SS pyrolysis technology, and will also be beneficial for subsequent applications.

Supercritical Water Liquefaction of Mixed Waste Polystyrene, Polypropylene, and Polyethylene for Production of High Yield Oils.

Supercritical water liquefaction of different plastic wastes has been investigated under high-temperature and high-pressure conditions. The supercritical water liquefaction of commonly used plastic types, comprising polystyrene (PS), polypropylene (PP), and low-density polyethylene (LDPE) as well as their mixtures, is reported. The experiments were carried out at varying feedstock-to-water ratios with a residence time of 60 min under supercritical water reaction conditions. The process produced high oil yields of over 97 wt %, with the highest yields obtained at a plastic:water ratio of 1:3; at higher levels of input water, the yield of oil decreased slightly. The gas phase mainly consisted of light hydrocarbons such as methane, ethane, propane, and butane, with propane found to be the most abundant gas component. Aromatic hydrocarbons and alicyclic hydrocarbons were the major products in the product oil from the supercritical water liquefaction of polystyrene and polypropylene, whereas alkanes were predominant in the oil obtained from LDPE. Analysis of the oil obtained from binary (1:1) and ternary (1:1:1) plastic mixtures showed it exhibited aromatic hydrocarbons as the major constituent, indicating synergistic interaction. It was found that the incorporation of PP in the mixture facilitated the production of cyclic compounds and suppressed the production of alkanes. Supercritical water liquefaction offers an effective solution to plastic pollution, producing valuable products without the need for catalysts.

Microwave Pyrolysis of Automotive Polypropylene Based on a Microwave Atmosphere Tube Furnace

Plastics have light weight and excellent performance, which are widely used in all kinds of automobiles. Polypropylene (PP) and its reinforcing materials are used in automotive components, where the surfaces of bumpers and fenders are coated with paint. Traditional recycling can frequently generate various pollutants, such as paint sludge. Microwave pyrolysis is a more environmentally friendly pyrolysis method with a higher heating coefficient than traditional electric pyrolysis. This study first explores the elemental composition of two types of automotive PP plastics and uses thermo-gravimetric analysis and the Kissinger-Akahira-Sunose method to preliminarily calculate the activation energy of automotive PP. The calculation results show that the activation energy of PP containing paint ranges from 189.145 kJ/mol- 199.513 kJ/mol, with an average value of 193.903 kJ/mol. The activation energy of PP without paint is between 215.506 kJ/mol-265.794 kJ/mol, with an average value of 242.425kJ/mol. Then, pyrolysis experiments on PP for vehicles without paint are conducted using a microwave atmosphere tube furnace at different temperatures and microwave powers. The experimental results showed that, when the pyrolysis temperature increased from 500oC to 620 oC, the total proportion of gas products rose from 0.75 wt.% to 4.81 wt.%, and the content of alkanes in the liquid products improved from 26.21 wt.% to 34.37 wt.%; when the microwave power increased from 900 W to 1100 W, the gas product rose to 20.77 wt.%, and the content of aromatic compounds in the liquid product improved to 17.78 wt.%. In addition, the pyrolysis experiment of automotive PP containing paint showed that paint had a relatively minor effect on the pyrolysis products of automotive PP. This study shows that using microwave pyrolysis to treat automotive PP and PP with paint is feasible, which provides a reference for the clean treatment of automotive polymers.

Development of an optical fiber core sensor integrated with silver film for chloride ion measurement

This study introduced an optical fiber core sensor designed to measure chloride ions by removing the fiber's coating and cladding, allowing direct interaction between the fiber core and external solutions, thereby enhancing measurement sensitivity. Two types of fibers, plastic and quartz, were evaluated for their efficacy as sensors. Experimental results demonstrated that the fabricated plastic core fiber failed to accurately reflect alterations in external solutions onto the spectrum, making it unsuitable for sensor applications. Conversely, the quartz fiber core, when treated with chloroform to dissolve its cladding, exhibited superior performance due to its wider transmission wavelength range and higher durability. The integration of a silver film on the core further improved the sensor's sensitivity through surface plasmon resonance. The study also explored the impact of thin-film and thick-film formations on sensor performance, with the thin film providing rapid response times and the thick film offering enhanced durability. This advancement holds significant potential for applications in environmental monitoring and the early detection of chloride-induced corrosion in various structural materials.

Biofilms on Plastic Debris and the Microbiome.

Plastic pollution has become a global environmental problem, and the large number of microorganisms attached to plastic debris in the environment has become a hot topic due to their rapid response to pollutants and environmental changes. In this study, we used high-throughput sequencing to investigate the microbial community structure of and explore the metagenome in the biofilm of two types of plastic debris, polystyrene (PS) and polyethylene terephthalate (PET), and compared them with a water sample collected at the sampling site. The phylum Proteobacteria dominated both the PET and PS samples, at 93.43% and 65.95%, respectively. The metagenome data indicated that the biofilm is enriched with a number of hydrocarbon (petroleum, microplastics, etc.) degrading genes. Our results show that the type of plastic determined the bacterial community structure of the biofilm, while the environment had relatively little effect.

Effect of plasticizers on the rheological properties of xanthan gum - starch biodegradable films

The effect of plasticizers, namely glycerol, sorbitol, and citric acid, on the structural and mechanical properties of biodegradable films obtained from xanthan gum (XG) and starch was studied. The plasticizing effect of glycerol, sorbitol, and citric acid on XG-starch films is justified by the destruction of intermolecular contacts between starch and XG macromolecules and the redistribution of hydrogen bonds in the system as a result of the hydrotropic action of plasticizer molecules. The use of glycerol proved to be the most effective for regulating the deformation of films, while the use of sorbitol to preserve strength. The dependence of the film roughness on the type and concentration of plasticizers was characterized. The smallest values of protrusions on the surface of XG-starch films were found in the presence of sorbitol. Considering the effect of the concentration of plasticizers on the stickiness of the surface of XG-starch films and their structural and mechanical properties, 1.5 % concentration of glycerol, sorbitol and citric acid was determined as optimal.

Evidence of microplastic contamination in the food chain: an assessment of their presence in the gastrointestinal tract of native fish

This research study focused on the primary freshwater surface sources of Khyber Pakhtunkhwa (KP) province, Pakistan—Swat and Kabul rivers. The study aimed to assess microplastic (MP) contamination of fish in the Swat and Kabul rivers. Understanding this contamination is vital for evaluating the environmental and health risks associated with consuming contaminated fish and contributing to the ongoing conservation efforts. The study’s objective was to investigate the presence of MPs in the gastrointestinal tracts (GIT) of fish and to delineate the identified MP types. Samples of local dominant fish (Schizothorax plagiostomus [Swatay] and Racoma labiata [Chunr], Cyprinus carpio [Common Carp], and Clupisoma naziri [Sher Mayai]) were collected, and their body weight and length assessed to gauge the overall health. The GIT samples were processed, digested and filtered before microscopic examination to detect MPs. Subsequently, the identified MPs were subjected to attenuated total reflectance–Fourier transform infrared spectroscopy for characterization by analyzing their absorption bands. Results of the study showed the presence of MPs in fish samples, predominantly identified as polyethylene (PE), with polypropylene (PP) being the subsequently prevalent plastic type, which manifested fish contamination with MPs. The study revealed MP pollution in both Swat and Kabul rivers, with fish ingesting these particles. This poses potential health risks for fish and health of the ecosystem.

The Effect of Sub-Acute Inhalation Exposure to Polyethylene Micro-Nano Plastics on the Histopathological Features of the Mammary Glands in Female Wistar White Rats (Rattus Norvegicus)

The majority of household appliances are made of plastic derived from synthetic petroleum and the result of polymerization processes. One type of plastic is Polyethylene (PE). Polyethylene (PE) contains antimony trioxide compounds that are carcinogenic in the body if ingested in excessive amounts, triggering cancer and oxidative stress, which can be observed by measuring the levels of malondialdehyde (MDA) in the body. This study aims to determine the proliferation of abnormal cells in the lactiferous ducts and mammary gland acini as well as the increase in MDA levels. The research method used is a true experimental design with a Randomized Post Test Only Group Design. This study used the mammary organs and blood of female white rats that had been exposed to PE for 28 days. The number of samples used in this study was 12 female white rats. The results showed that there were significant differences in the histopathological features and MDA levels in the mammary glands. Based on the results of the Independent T-Test on the number of cell layers in the lactiferous ducts, acini, and the number of acini (p&lt;0.05) and the Mann-Whitney test on MDA levels (p&lt;0.05). There were significant changes in the histopathological features and MDA levels in the mammary glands exposed to Polyethylene (PE) plastic. Exposure to micro-nano plastics of PE type at a dose of 15 mg/m3 for 28 days differed significantly in the MDA levels of mammary glands, histopathological picture of mammary glands at cell proliferation events, both in the lactiferous ducts and acini cells. In addition, exposure to PE plastic has the potential to cause health problems in the breast organs if exposed for a long time and in excess doses.

BIODEGRADABLE PACKAGING : A KEY TO ENVIRONMENTAL SUSTAINABILITY

Pollution is a global crisis that has been seen in current times from past few decades. Many kinds of pollution crisis are arising day by day, such as soil, air, water, noise and radioactive pollution. Soil, air and water pollution mainly cause by plastic. Plastic takes approximately 20 to 500 years to decompose. Several types of plastics take different time to decompose. Micro plastic is tiny particles of plastic which is broken down in small pieces or they are conventionally made like that. It is found in ocean which affects marine animals and plants and in food packaging which is toxic, harmful and hazardous to human beings. We have seen throughout the years that plastic bags, food container, fast food packages and plastic wrappers are just roaming around roads, grounds, land fields, lakes, ponds, rivers and oceans as well. We should opt for alternatives of conventional plastic packages, such as packaging made from plant-based materials, which can also decompose easily in the soil, that shows biodegradable properties. Many plants and materials used for plastic alternatives are discussed in this paper. Different materials and methodology required for making plant-based packaging are listed in the paper as well. Bio-degradable packaging is not only helpful and doing good to the environment, but also for humans as well, as we consume less micro plastics, and live a healthy life.

Efficient biodegradation of Polyethylene terephthalate (PET) plastic by Gordonia sp. CN2K isolated from plastic contaminated environment

Since we rely entirely on plastics or their products in our daily lives, plastics are the invention of the hour. Polyester plastics, such as Polyethylene Terephthalate (PET), are among the most often used types of plastics. PET plastics have a high ratio of aromatic components, which makes them very resistant to microbial attack and highly persistent. As a result, massive amounts of plastic trash accumulate in the environment, where they eventually transform into microplastic (<5 mm). Rather than macroplastics, microplastics are starting to pose a serious hazard to the environment. It is imperative that these polymer microplastics be broken down. Through the use of enrichment culture, the PET microplastic-degrading bacterium was isolated from solid waste management yards. Bacterial strain was identified as Gordonia sp. CN2K by 16 S rDNA sequence analysis and biochemical characterization. It is able to use polyethylene terephthalate as its only energy and carbon source. In 45 days, 40.43 % of the PET microplastic was degraded. By using mass spectral analysis and HPLC to characterize the metabolites produced during PET breakdown, the degradation of PET is verified. The metabolites identified in the spent medium included dimer compound, bis (2-hydroxyethyl) terephthalate (BHET), mono (2-hydroxyethyl) terephthalate (MHET), and terephthalate. Furthermore, the PET sheet exposed to the culture showed considerable surface alterations in the scanning electron microscope images. This illustrates how new the current work is.

Impact of Protein Corona Formation and Polystyrene Nanoparticle Functionalisation on the Interaction with Dynamic Biomimetic Membranes Comprising of Integrin.

Plastics, omnipresent in the environment, have become a global concern due to their durability and limited biodegradability, especially in the form of microparticles and nanoparticles. Polystyrene (PS), a key plastic type, is susceptible to fragmentation and surface alterations induced by environmental factors or industrial processes. With widespread human exposure through pollution and diverse industrial applications, understanding the physiological impact of PS, particularly in nanoparticle form (PS-NPs), is crucial. This study focuses on the interaction of PS-NPs with model blood proteins, emphasising the formation of a protein corona, and explores the subsequent contact with platelet membrane mimetics using experimental and theoretical approaches. The investigation involves αIIbβ3-expressing cells and biomimetic membranes, enabling real-time and label-free nanoscale precision. By employing quartz-crystal microbalance with dissipation monitoring studies, the concentration-dependent cytotoxic effects of differently functionalised ~210 nm PS-NPs on HEK293 cells overexpressing αIIbβ3 are evaluated in detail. The study unveils insights into the molecular details of PS-NP interaction with supported lipid bilayers, demonstrating that a protein corona formed in the presence of exemplary blood proteins offers protection against membrane damage, mitigating PS-NP cytotoxicity.

Common genetic variants associated with urinary phthalate levels in children: A genome-wide study

IntroductionPhthalates, or dieters of phthalic acid, are a ubiquitous type of plasticizer used in a variety of common consumer and industrial products. They act as endocrine disruptors and are associated with increased risk for several diseases. Once in the body, phthalates are metabolized through partially known mechanisms, involving phase I and phase II enzymes. ObjectiveIn this study we aimed to identify common single nucleotide polymorphisms (SNPs) and copy number variants (CNVs) associated with the metabolism of phthalate compounds in children through genome-wide association studies (GWAS). MethodsThe study used data from 1,044 children with European ancestry from the Human Early Life Exposome (HELIX) cohort. Ten phthalate metabolites were assessed in a two-void pooled urine collected at the mean age of 8 years. Six ratios between secondary and primary phthalate metabolites were calculated. Genome-wide genotyping was done with the Infinium Global Screening Array (GSA) and imputation with the Haplotype Reference Consortium (HRC) panel. PennCNV was used to estimate copy number variants (CNVs) and CNVRanger to identify consensus regions. GWAS of SNPs and CNVs were conducted using PLINK and SNPassoc, respectively. Subsequently, functional annotation of suggestive SNPs (p-value < 1E-05) was done with the FUMA web-tool. ResultsWe identified four genome-wide significant (p-value < 5E-08) loci at chromosome (chr) 3 (FECHP1 for oxo-MiNP_oh-MiNP ratio), chr6 (SLC17A1 for MECPP_MEHHP ratio), chr9 (RAPGEF1 for MBzP), and chr10 (CYP2C9 for MECPP_MEHHP ratio). Moreover, 115 additional loci were found at suggestive significance (p-value < 1E-05). Two CNVs located at chr11 (MRGPRX1 for oh-MiNP and SLC35F2 for MEP) were also identified. Functional annotation pointed to genes involved in phase I and phase II detoxification, molecular transfer across membranes, and renal excretion. ConclusionThrough genome-wide screenings we identified known and novel loci implicated in phthalate metabolism in children. Genes annotated to these loci participate in detoxification, transmembrane transfer, and renal excretion.

The use of vibrational spectroscopy and supervised machine learning for chemical identification of plastics ingested by seabirds

Plastic pollution is now ubiquitous in the environment and represents a growing threat to wildlife, who can mistake plastic for food and ingest it. Tackling this problem requires reliable, consistent methods for monitoring plastic pollution ingested by seabirds and other marine fauna, including methods for identifying different types of plastic. This study presents a robust method for the rapid, reliable chemical characterisation of ingested plastics in the 1–50 mm size range using infrared and Raman spectroscopy. We analysed 246 objects ingested by Flesh-footed Shearwaters (Ardenna carneipes) from Lord Howe Island, Australia, and compared the data yielded by each technique: 92 % of ingested objects visually identified as plastic were confirmed by spectroscopy, 98 % of those were low density polymers such as polyethylene, polypropylene, or their copolymers. Ingested plastics exhibit significant spectral evidence of biological contamination compared to other reports, which hinders identification by conventional library searching. Machine learning can be used to identify ingested plastics by their vibrational spectra with up to 93 % accuracy. Overall, we find that infrared is the more effective technique for identifying ingested plastics in this size range, and that appropriately trained machine learning models can be superior to conventional library searching methods for identifying plastics.

Assessment of fishes, sediment and water from some inland rivers across the six geopolitical zones in Nigeria for microplastics.

In Nigeria, limited research has been conducted on Microplastics (MPs) in inland rivers, necessitating a comprehensive assessment to understand the extent of contamination. This study aimed to assess the abundance, distribution, and composition of MPs in fishes, sediment, and water from inland rivers across Nigeria's six geopolitical zones. Samples were collected from selected rivers in each geopolitical zone (Rivers Yauri, Benue, Argungu, Jamare, Ogun, Ethiope and Orashi). MPs were isolated using a combination of filtration, density separation, and visual identification. MPs abundance, distribution, shapes, colors, and chemical composition were determined using microscopy and Fourier-transform infrared spectroscopy. The study presents the first report of MPs in six in land rivers in Nigeria and found that MPs were present in all the fishes, sediments and river waters studied across all the rivers. The abundance and composition of MPs varied among the different sample types, with fibers being the most abundant shape in both water and fish samples. PET, PP, and PE were the most prevalent types of plastics found in fish samples, while PE/PA/Nylon, PVA, and PVC were predominant in water samples. PA/Nylon, PUR, PVC, and PET were the most common in sediment samples. Source analysis by Principal component analysis (PCA) and Hierarchical Cluster Analysis (HCA) indicated that the presence of MPs was mainly influenced by local anthropogenic activities. However, estimated daily intakes are generally low, indicating that daily consumption of the samples is not likely to be harmful. The widespread presence of MPs in inland rivers across Nigeria highlights the urgent need for effective waste management strategies and environmental conservation efforts to mitigate plastic pollution.

Exposure Pathways and Toxicity of Microplastics in Terrestrial Insects.

The detrimental effects of plastics on aquatic organisms, including those of macroplastics, microplastics, and nanoplastics, have been well established. However, knowledge on the interaction between plastics and terrestrial insects is limited. To develop effective strategies for mitigating the impact of plastic pollution on terrestrial ecosystems, it is necessary to understand the toxicity effects and influencing factors of plastic ingestion by insects. An overview of current knowledge regarding plastic ingestion by terrestrial insects is provided in this Review, and the factors influencing this interaction are identified. The pathways through which insects interact with plastics, which can lead to plastic accumulation and microplastic transfer to higher trophic levels, are also discussed using an overview and a conceptual model. The diverse impacts of plastic exposure on insects are discussed, and the challenges in existing studies, such as a limited focus on certain plastic types, are identified. Further research on standardized methods for sampling and analysis is crucial for reliable research, and long-term monitoring is essential to assess plastic trends and ecological impacts in terrestrial ecosystems. The mechanisms underlying these effects need to be uncovered, and their potential long-term consequences for insect populations and ecosystems require evaluation.

Combined environmental pressure induces unique assembly patterns of micro-plastisphere biofilm microbial communities in constructed wetlands

The characteristics and dynamics of micro-plastisphere biofilm on the surface of microplastics (MPs) within artificial ecosystems, such as constructed wetlands (CWs), remain unclear, despite these ecosystems’ potential to serve as sinks for MPs. This study investigates the dynamic evolution of micro-plastisphere biofilm in CWs, utilizing simulated wastewater containing sulfamethoxazole and humic acid, through physicochemical characterization and metagenomic analysis. Two different types of commercial plastics, including non-degradable polyethylene and degradable polylactic acid, were shredded into MPs and studied. The findings reveal that the types, shape and incubation time of MPs, along with humic acid content in wastewater, affected the quantity and quality of biofilms, such as the biofilm composition, spatial structure and microbial communities. After just 15 days into incubation, numerous microbials were observed on MP samples, with increases in biofilms content and enhanced humification of extracellular polymeric substances over time. Additionally, microbial communities on polylactic acid MPs, or those incubated for longer time, exhibit higher diversity, connectivity and stability, along with reduced vulnerability. Conversely, biofilms on polyethylene MPs were thicker, with higher potential for greenhouse gas emission and increased risk of antibiotic resistance genes. The addition of humic acid demonstrated opposite effects on biofilms across environmental interfaces, possibly due to its dual potential to produce light-induced free radicals and serve as a carbon source. Binning analysis further uncovered a unique assembly pattern of nutrients cycle genes and antibiotic resistance genes, significantly correlated within micro-plastisphere microbial communities, under the combined stress of nutrition and sulfamethoxazole. These results emphasize the shaping of micro-plastisphere biofilm characteristics by unique environmental conditions in artificial ecosystems, and the need to understand how DOM and other pollutants covary with MP pollution.

The retention of plastic particles by macrophytes in the Amazon River, Brazil.

This study evaluated the presence of plastics and microplastics in macrophytes in an urbanized sector of the Amazon River. A total of 77 quadrats in 23 macrophyte banks were sampled during the dry (September 2020) and rainy (June 2021) season. Five species were identified: Paspalum repens, Pontederia rotundifolia, Pistia stratiotes, Salvinia auriculata and Limnobium laevigatum, with P. repens being dominant during the dry season (47.54%) and P. rotundifolia during the rainy season (78.96%). Most of the plastic particles accumulated in Paspalum repens (49.3%) and P. rotundifolia (32.4%), likely due to their morphological structure and volume. The dry season showed a higher accumulation of plastic particles than the rainy season. Microplastics were found in most samples, during both the dry (75.98%) and rainy seasons (74.03%). The upstream macrophyte banks retained more plastic particles compared to the downstream banks. A moderate positive correlation was observed between the presence of plastic particles and macrophyte biomass, and a weak positive correlation between the occurrence of microplastics and mesoplastics. White and blue fragments, ranging from 1 to 5mm were the most common microplastics found in the macrophyte banks. Green fragments and green and blue fibers were identified as polypropylene, blue and red fragments as polyethylene, and white fragments as polystyrene. Therefore, the results of this study highlight the first evidence of the retention of plastic particles in macrophytes of the Amazon and highlight a significant risk due to the harmful effects that this type of plastic can cause to the fauna and flora of aquatic ecosystems.