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The extensive application of plastic products in daily human life has led to the accumulation of microplastics (MPs) in agricultural soil. However, little is known about the cross-generational toxicity of MPs on terrestrial invertebrates. In this study, two-generational Eisenia fetida was exposed to low-density polyethylene (LDPE, 0-5%, w/w) for 98 days to reveal the cross-generational toxicity and the underlying mechanisms. Results showed that LDPE-MPs not only perpetrated deleterious effects on the development, hatchability, and fecundity of the F0 generation but also stimulated the antioxidant defense activity, inhibited lipid peroxidation, and disordered neurotransmission in F1 generation individuals. The susceptibility of the epidermal-intestinal barrier to LDPE-MPs was dose-dependent. According to the transcriptomic analysis, the cross-generational earthworms confirmed significant perturbances in the cell cycle, neural activity-related pathways, and amino acid metabolism pathways ( p < 0.05). Nevertheless, the metabolomic profile of F1 generation individuals exhibited significant hyperactive responses in glutathione metabolism and alanine, aspartate, and glutamate metabolism ( p < 0.05). This study provides a comprehensive knowledge of LDPE-MPs toxicity on cross-generational earthworms and highlights the hyperactive responses in the antioxidant defense performance of the offsprings. Our findings also underscore the necessity for long-term investigations in assessing the adverse impacts of emerging pollutants.

The effects of endogenous mangrove litterfall (MF) inputs on organic matter transformation in sediment polluted by exogenous microplastics (MPs) were investigated in this work, and their linkage with microbial characteristics was also explored. MF inputs significantly affected organic carbon transformation in MPs-polluted sediment by improving humification, enzymatic activities and carbon utilisation capacity of microbes. Such effects were mainly linked with the enrichment of microbes responsible for organic substance decomposition induced by MF inputs. Indeed, MF addition increased the relative abundance of fermentation- and cellulysis-assoicated bacteria, together with Saprotrophic fungi. Moreover, dissolved matters derived from MF played a non-neglected role in regulating organic carbon transformation in MPs-polluted sediment. Besides, MF addition decreased the complexity of bacterial community network in MPs-polluted sediment but fungal community network became complicated. And the complexity of microbial network was MF amount-dependent. Even though stochastic process was dominated in sediment with or without MF, MF inputs enhanced the relative contribution of determinism and reduced the migration of microbial communities. A strong response of sediment microbes to MF affected sedimentary organic matters transformation driven by microbes. This work uncovered linkages between organic carbon transformation and microbes in sediment with endogenous litterfall and exogenous MPs inputs in mangroves., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Due to the widespread pollution, microplastics (MPs) have garnered increasing attention. Research has shown that MPs negatively affect many organisms. Microalgae are primary producers in aquatic environments and play a crucial role in the stability of aquatic ecosystems. However, research on the effects of MPs on microalgae is relatively limited. Haematococcus pluvialis is known for its ability to produce astaxanthin, a powerful antioxidant, in response to environmental stress. MP exposure is also an environmental stressor, and we are curious whether MP stress will affect astaxanthin synthesis in H. pluvialis. To investigate the effects and mechanisms of MPs on H. pluvialis growth and astaxanthin synthesis, we exposed H. pluvialis to 5 μm polystyrene MPs at different concentrations (0.1, 1, and 10 mg/L) for 18 days, followed by high light induction of astaxanthin synthesis. Growth and photosynthesis-related indicators suggested that PS-MPs had a hormesis-like effect on H. pluvialis, with short-term exposure stimulating photosynthetic activity and growth, and long-term exposure inhibiting them. Morphological observations, oxidative stress markers, soluble proteins, and extracellular polymeric substance indicators showed that prolonged PS-MP exposure primarily disrupted the morphology and normal physiological functions of H. pluvialis by inducing oxidative stress. Although H. pluvialis actively resists the oxidative stress caused by PS-MPs, it cannot fully counteract the adverse effects. Prolonged PS-MP exposure ultimately resulted in reduced levels of photosynthetic pigments and inhibited photosynthetic activity, as well as the decreased expression of genes related to astaxanthin synthesis and reduced astaxanthin production. Integrated biomarker response analysis further indicated that the overall toxic effects of MPs on H. pluvialis exhibit a dose-dependent pattern. MP exposure potentially weakens the survival capability of H. pluvialis under adverse conditions. These findings highlight the impact of MP pollution on the stability of aquatic ecosystems and underscore the urgent need for policies and actions to mitigate MP pollution and protect aquatic environments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Currently, information on microplastics (MPs) weathering characteristics and ecological functions driven by MPs-associated microbes in mangrove ecosystems remains unclear, especially in the degraded areas. Herein, we compared the weathering characteristics of MPs in both undegraded and degraded mangrove sediments, and then explored the potential interactions between their weathering characteristics and microbially-driven functions. After 70 days of incubation, different MPs (including polyethylene PE, polystyrene PS, and polylactic acid PLA) were strongly weathered in mangrove sediments, with significant erosion features. Interestingly, more obvious weathering characteristics were found for MPs in the undegraded mangrove sediments. O/C ratio value of MPs in the undegraded sediments was 2.3-3.0 times greater than that in the degraded ones. Besides, mangrove degradation reduced network complexity among MPs-associated microorganisms and affected their metabolic activities. Bacteria involved in carbon cycle process enriched on nondegradable MPs, whereas abundant bacteria responsible for sulphur cycle were observed on PLA-MPs. Moreover, these relevant bacteria were more abundant on MPs in the undegraded mangrove sediments. Mangrove degradation could directly and indirectly affect MPs weathering process and microbially-driven functions through regulating sediment properties and MPs-associated microbes. During weathering, contact angle and roughness of MPs were key factors influencing the colonisation of hydrocarbon degradation bacteria on MPs., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Microplastics (MPs) are classified as emerging pollutants and greatly threatens soil ecosystems. To determine the impact of microplastic migration on soil bacterial diversity, we conducted a 90-day indoor soil column simulation test. Soil and microplastic (granular polystyrene, polypropylene MPs) samples were collected from different soil layers on days 30, 60, and 90. The downward migration trend of MPs was obvious, and its surface functional groups, hydrophobic properties, and crystallinity changed. Bacterial diversity was significantly higher in the surrounding soil than on microplastic surfaces. Also, the topsoil has more bacterial diversity than the middle soil. A higher number of OTUs were detected on microplastic surfaces for the middle soil than in the topsoil. Proteobacteria abundance on microplastic surfaces in the topsoil gradually increased over the course of the experiment, while an opposite trend was observed for the middle soil. Nevertheless, Proteobacteria abundances in both layers were higher than in the surrounding soils. MPs alters the bacterial community composition of soils and provides unique substrates for colonization. The impacts of MPs on soil bacterial communities were better understood in this study. Our findings highlighted the relevance of MPs in soil ecosystems as well as the potential threats they pose., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Dissolved organic matter (DOM) chemodiversity plays an important role in regulating nutrient cycles and contaminant behavior in soil. However, how biodegradable microplastic (MPs) affect the DOM chemodiversity is still unknown, although developing biodegradable plastics are regarded as a promising strategy to minimize the risks of MPs residues in soil. Here, with the common poly (butylene adipate-co-terephthalate) (PBAT) as the model, the molecular effect of biodegradable MPs on soil DOM was explored by adding 0%, 5% and 10% (w/w) of PBAT to tropical latosol, respectively. The results showed that PBAT addition increased microbial activity and exoenzyme activity (e.g., rhizopus oryzae lipase, invertase and cellulose). As a result, the quantity and chemodiversity of soil DOM were changed. The multispectroscopic characterization showed that PBAT addition significantly increased the DOC molecules in soil, including condensed aromatic-like substances and carbohydrates. In contrast, the TDN molecules with high bioavailability and low aromaticity, such as amino acids, were decreased. The multivariate statistical analysis indicated that there were three mechanisms that drove the shift in DOM chemodiversity. Firstly, the degradation of PBAT by rhizopus oryzae lipase facilitated the release of exogenous aromatic molecules. Secondly, PBAT decomposition stimulated the selective consumption of native N-rich molecules by soil microbes. Thirdly, PBAT accelerated the enzymatic transformation of native aliphatic CH x and cellulose toward humic substances. In addition, concentration effect was also observed in the study that high-concentration PBAT were more likely to trigger the molecular shift in DOM chemodiversity. These findings provided a new insight into the impact of biodegradable MPs on soil DOM chemodiversity at molecular level, which will be beneficial to understanding the fate and biochemical reactivity of DOM in MPs-polluted soil., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021. Published by Elsevier B.V.)

This study investigates the occurrence and distribution of microplastics in water, sediment, and crayfish samples within pond and rice-crayfish co-culture breeding modes in Jianli prefecture, China. Microplastics in environmental and biological samples were systematically extracted by CaCl 2 solution, digested by H 2 O 2 and KOH, and identified by μ-FTIR. A cleansing treatment for crayfish was performed in pure water before dissection and microplastic accumulation in different tissues (gill, stomach, gut, and flesh) of non-cleansed and cleansed crayfish were compared. The average microplastic abundances were 1.3 ± 0.1-2.5 ± 0.1 particles/L, 0.03 ± 0.01-0.04 ± 0.02 particles/g, and 0.17 ± 0.07-0.92 ± 0.19 particles/individual in water, sediment, and crayfish samples, respectively. Microplastics were detected in all studied crayfish tissues, except the flesh. There were no significant differences in microplastic abundances in water (P = 0.82), sediment (P = 0.90), and crayfish (P = 0.47 for non-cleansed samples; P = 0.30 for cleansed samples) between two breeding modes despite the detection of relatively higher microplastic abundances in the samples from the pond breeding mode. Microplastic accumulation in non-cleansed crayfish stomachs and guts (0.71 ± 0.18 particles/individual) was higher (P < 0.01) than that recorded in their gills (0.13 ± 0.06 particles/individual). Moreover, microplastics present in the stomachs and guts of cleansed crayfish were significantly less abundant (P < 0.01) than in non-cleansed crayfish, although this was not observed in the gills (P = 0.99). The majority of microplastic particles in this study had fiber-like shapes, blue and transparent colors, a size smaller than 1 mm, and polymer types of PP:PE and PE. The results demonstrate that microplastics in the environment can accumulate in the internal tissues of crayfish, which may pose a potential risk to humans through food consumption without the removal of the gills, stomach, and guts. This study provides valuable information for understanding microplastic accumulation in the different tissues of crayfish and the potential risk of human exposure to microplastics from crayfish as a food supplement., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Over the past decades, mangrove ecosystem has been polluted by plastic debris and microplastics (MPs) due to anthropogenic activities. Yet, little information is available on the composition and functional diversity of microbial communities on the surface of MPs in this ecosystem. The present study aims to investigate the bacterial communities growing on the surface of polyethylene microplastics (PE-MPs) in water, surface sediments and at the water-sediment interface (WSI) of mangrove ecosystems. Obtained results showed distinct variations in the taxonomic composition of bacterial communities among water, surface sediments and PE-MPs exposed to the different sites in mangrove ecosystems. For PE-MPs deployed to water, the dominant phyla were Proteobacteria and Bacteroidetes, accounting for 89.2% of the total abundance, while a relatively high proportion of Proteobacteria (85.6 ± 8.4%) was found for PE-MPs in sediments. For PE-MPs at the WSI, the top five phyla were Proteobacteria, Bacteroidetes, Planctomycetes, Actinobacteria and Firmicutes. Relatively abundant microorganisms on PE-MPs at the WSI were mainly due to tidal ebb and flood increasing interactions of sediment bacteria and PE-MPs. Functional annotation of prokaryotic taxa (FAPROTAX) analysis demonstrated that the ecological functions of microbial communities inhabiting PE-MPs were exposure site-dependent. Bacteria living on PE-MPs in water and at the WSI mainly participated in carbon and nitrogen cycle process, whereas PE-MPs in sediments enriched bacteria responsible for sulphur cycle. These results presented here highlight the importance of the exposure sites to MPs-associated bacteria in mangrove ecosystems. [Display omitted] • Distinct microbes were found among water, sediments and PE-MPs exposed to the different sites in mangrove ecosystems. • Tide-induced resuspension favoured bacterial colonization of PE-MPs at the water-sediment interface. • Microbially-driven functions of PE-MPs varied as a function of exposure sites. [ABSTRACT FROM AUTHOR]

In this study, the distribution, abundance, morphology, and composition of microplastics (MPs) in surface seawater and sediment of Hainan Island were systematically investigated. Seawater and sediment samples were collected from six functional zones, including harbor, industrial district, sparsely populated area, tourist area, residential area, and aquaculture area. The abundance of MPs in seawater was 0.46–19.32 items/L, with an average of 2.59 ± 0.43 items/L, which were similar to those detected in the South China Sea (e.g., Nansha (1.25–3.20 items/L) and Xisha (2.57 ± 1.78 items/L)). The highest level was detected in Qinglan Bay Estuary, and the lowest was in Sanya West Island. The abundance of MPs in sediment was 41.18–750.63 items/kg, with an average of 372.47 ± 62.10 items/kg; the highest concentration was detected at Tanmen Port, and the lowest was in Lingao sea area. It was detected that the MPs with smaller size exhibited a higher concentration in seawater. MPs were commonly black and white, and predominantly linear and fragmented in shape. Polyethylene terephthalate (PET) was the dominant polymer, which might be derived from laundry wastewater. The petroleum concentration was 0.02–0.21 mg/L in the investigated area, with harbors being the most severely polluted areas. Furthermore, this study also found that MPs pollution was positively correlated with petroleum in seawater, indicating similarities between MPs and petroleum-based sources of pollution. This study identifies the contamination and characteristics of MPs and their correlation with petroleum in Hainan Island, the biggest island in the South China Sea, providing important data for further research on protecting marine ecosystems. [Display omitted] • Water quality of the coastal waters of Hainan Island was threatened by MPs. • The predominant color, shape and polymer type of MPs were black, linear and PET. • The highest abundance and diversity of MPs were detected in harbor area. • MPs abundance was positively correlated with petroleum in seawater. [ABSTRACT FROM AUTHOR]

Microplastics (MPs, plastic particles <5 mm) have been recognised as a novel ecological niche in the aquatic environments. Biofilm as a reservoir for opportunistic bacterial pathogens and MPs prevalence in the intensive mariculture could pose potential threats to the safety of cultured species. However, possible ecological consequences of biofilm colonising mariculture-associated MPs, such as effects on MPs fate, potential pathogens, and implications of extracellular polymeric substances (EPS) in biogeochemical cycles, are still unclear. The main objective of the present study was to investigate biota-MPs-EPS interactions in a mariculture pond. Polyethylene (PE) and polystyrene (PS), and biodegradable polylactic acid (PLA), with a mean size of ~1 mm, were exposed in situ to the pond after shrimp postlarvae were stocked. Several methods, including microscopy, spectroscopy, and high-throughput sequencing, were employed to investigate biota-MPs-EPS interactions with the shrimp growth. Genotypic data revealed distinct differences in bacterial compositions between MPs and pond water. Dissimilarities of microorganism compositions on MPs increased significantly as a function of exposure time, while microorganism abundance on MPs was co-determined by both exposure time and MPs type. Potential opportunistic pathogens, including Vibrio , Enterobacteriaceae and Tenacibaculum, were found in the mariculture-associated MPs biofilm. The attachment of predominant EPS (including proteins, polysaccharides and lipids) to MPs appeared to be reversible. Among these MPs, PE with large specific surface area exhibited higher biomass and EPS content than the other two MPs with smooth surface. Consequently, pronounced variations in physicochemical properties were observed for PE. This was the first study providing in-depth insights into the interactions of MPs-biota-EPS in the aquatic environment, which was beneficial to evaluate the seafood safety concern posed by MPs exposure to intensive mariculture. Given that the presence of pathogens on MPs surfaces and MPs covered by biofilm may raise a concern about the hazard potential of mariculture-associated MPs, efficient policies and technologies should be adopted to reduce MPs in aquaculture for facilitating sustainable and healthy development. [Display omitted] • Microbes inhabiting microplastics were taxonomically distinct from those in water. • Microbial abundance were co-determined by both microplastic type and time. • Extracellular polymeric substance content was linked to microplastic type and time. • Microbial compositions on microplastic surface were exposure time-dependent. • Changes in microplastic properties were due to microbial adhesion to their surface. [ABSTRACT FROM AUTHOR]

Over the last decade, microplastics (MPs, plastic particles <5 mm) as emerging contaminants have received a great deal of international attention, not only because of their continuous accumulation in both marine and terrestrial environment, but also due to their serious threats posed to the environment. Voluminous studies regarding sources, distribution characterization, and fate of MPs in the different environmental compartments (e.g., marine, freshwater, wastewater, and soil) have been reported since 2004, whereas MPs pollution in unique marine ecosystems (e.g., coastal mangrove habitat) receives little scientific attention. Mangrove ecosystem, an important buffer between the land and the sea, has been identified as a potential sink of MPs caused by both marine and land-based activities. Moreover, the source and distribution characteristics of MPs in this ecosystem are significantly different from other coastal habitats, mainly owing to its unique features of high productivity and biomass. With the impetus to provide a more integrated view of MPs pollution in mangrove habitats, a literature review was conducted based on the existing studies related to this topic. This is the first review to present the current state of MPs pollution in mangrove ecosystems, specially including (i) the possible sources of MPs in mangrove areas and their pathways entering into this habitat; (ii) MPs pollution in the different mangrove compartments (including surface seawater, sediments, and biotas); and (iii) factors influencing MPs distribution in mangrove areas. Toward that end, the research gaps are proposed to guide for future research priorities. Unlabelled Image • A first review to present the current state of MPs pollution in mangrove ecosystems; • MPs pollution and their impacts in global mangroves receive little scientific attention. • WWTPs, aquaculture and in-situ degradation of plastics are the main sources of MPs pollution in mangroves. • MPs with different shapes, polymers and size are found in the different compartments of mangroves. • MPs prevalence in mangroves is co-determined by anthropogenic activities of adjacent zones and natural factors. [ABSTRACT FROM AUTHOR]

Plastic litters have become the predominant components of marine debris due to extensive consumption plastics and mismanagement of plastic wastes. As part of the problem, microplastics (MPs) and nanoplastics (NPs) have generated special concerns due to their unique features that make them easy to transfer among oceans in the marine ecosystem, across different trophic levels inside the food web, and even across different tissues inside contaminated animals. Studies have demonstrated the almost omnipresence of MPs in the marine ecosystem, which present serious threats to the health of marine animals, causing symptoms such as malnutrition, inflammation, chemical poisoning, growth thwarting, decrease of fecundity, and death due to damages at individual, organ, tissue, cell, and molecule levels. The information on NPs in the marine ecosystem has been scarce due to the challenges in sampling and detecting these nano-scaled entities. In vitro and in vivo experiments have demonstrated that NPs have the potential to penetrate different biological barriers including the gastrointestinal barrier and the brain blood barrier and have been detected in many important organs such as brains, the circulation system and livers of sampled animals. Unlabelled Image • Sources and transfer of MPs and NPs has found in global marine environment. • MPs and NPs can distribute in seawaters, sediments, and organisms. • Threats of MPs and NPs on organisms are reviewed. [ABSTRACT FROM AUTHOR]