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The impact of biodegradable microplastics on the microbial community and dissolved organic matter (DOM) in latosol has not been well reported. In this study, an incubation experiment at 25 ºC for 120 days using latosol amended with low (5%) and high (10%) concentrations of polybutylene adipate terephthalate (PBAT) microplastics was carried out to explore the impacts of PBAT microplastics on soil microbial communities and DOM chemodiversity, and the intrinsic interactions between their shifts. The main bacterial and fungal phyla in soil, namely Chloroflexi , Actinobacteria , Chytridiomycota , and Rozellomycota showed a nonlinear relationship with PBAT concentration and played a pivotal role in shaping DOM chemodiversity. A higher decreased levels of lignin-like compounds and increased levels of protein-like and condensed aromatic compounds in the 5% treatment were observed than that in the 10% treatment. Furthermore, a higher increase relative abundance of CHO compounds in the 5% treatment than in the 10% treatment was ascribed to its higher oxidation degree. Co-occurrence network analysis suggested that bacteria formed more complex relationships with DOM molecules than fungi did, indicating their critical roles in DOM transformation. Our study has important implications for understanding the potential influence of biodegradable microplastics on carbon biogeochemical roles in soil. [Display omitted] • Impacts of PBAT on latosol bacterial and fungal richness were different. • Microbes showing nonlinear relationships with PBAT played a key role in shaping DOM. • Low concentration of PBAT increased the relative abundance of CHO category. • Interactions between bacteria and DOM molecules were much more complex than fungal. [ABSTRACT FROM AUTHOR]

It has been increasingly documented that the hydroxyl radical (•OH) can promote the transformation of organic contaminants such as microplastics (MPs) in various environments. However, few studies have sought to identify an ideal strategy for accelerating in situ MPs degradation through boosting the process of •OH production in practical applications. In this work, iron-mineral-supplemented thermophilic composting (im TC) is proposed and demonstrated for enhancing in situ degradation of sludge-based MPs through strengthening •OH generation. The results show that the reduction efficiency of sludge-based MPs abundance was about 35.93% in im TC after treatment for 36 days, which was 38.99% higher than that of ordinary thermophilic composting (o TC). Further investigation on polyethylene-microplastics (PE-MPs) suggested that higher abundance of •OH (the maximum value was 408.1 μmol·kg−1) could be detected on the MPs isolated from im TC through microbially-mediated redox transformation of iron oxides, as compared to o TC. Analyses of the physicochemical properties of the composted PE-MPs indicated that increased •OH generation could largely accelerate the oxidative degradation of MPs. This work, for the first time, proposes a feasible strategy to enhance the reduction efficiency of MPs abundance during composting through the regulation of •OH production. [Display omitted] • Fe mineral-supplemented composting (im TC) is used for enhancing in situ MPs removal. • The critical role of hydroxyl radical in MPs degradation was disclosed during im TC. • Microbial-driven Fenton reaction mechanism was proposed for MPs degradation in im TC. [ABSTRACT FROM AUTHOR]

Anthropogenic activities such as in situ straw incineration and the widespread use of agricultural film led to the accumulation of polycyclic aromatic hydrocarbons (PAHs) and microplastics (MPs) in agricultural soils. In this study, four biodegradable MPs (BPs), including polylactic acid (PLA), polybutylene succinate (PBS), poly-β-hydroxybutyric acid (PHB) and poly (butylene adipate-co-terephthalate) (PBAT) and non-biodegradable low-density polyethylene (LDPE) were selected as representative MPs. The soil microcosm incubation experiment was conducted to analyze MPs effects on PAHs decay. MPs did not influence PAHs decay significantly on day 15 but showed different effects on day 30. BPs reduced PAHs decay rate from 82.4% to 75.0%− 80.2% with the order of PLA < PHB < PBS < PBAT while LDPE increased it to 87.2%. MPs altered beta diversity and impacted the functions to different extents, interfering in PAHs biodegradation. The abundance of most PAHs-degrading genes was increased by LDPE and decreased by BPs. Meanwhile, PAHs speciation was influenced with bioavailable fraction elevated by LDPE, PLA and PBAT. The facilitating effect of LDPE on 30-d PAHs decay can be attributed to the enhancement of PAHs-degrading genes and PAHs bioavailability, while the inhibitory effects of BPs were mainly due to the response of the soil bacterial community. [Display omitted] • MPs impacted the bacterial community functions, interfering in PAHs degradation. • PAHs-degrading gene abundance was increased by LDPE but reduced by biodegradable MPs. • PAHs speciation was affected with bioavailability elevated by LDPE, PLA and PBAT. • Biodegradable MPs decelerated PAHs decay while non-biodegradable LDPE accelerated it. [ABSTRACT FROM AUTHOR]

Polyethylene (PE) is one of the most common synthetic polymers, and PE waste pollution has been an environmental and health concern for decades. Biodegradation is the most eco-friendly and effective approach for plastic waste management. Recently, an emphasis has been placed on novel symbiotic yeasts isolated from termite guts as promising microbiomes for multiple biotechnological applications. This study might be the first to explore the potential of a constructed tri-culture yeast consortium, designated as DYC, isolated from termites for the degradation of low-density polyethylene (LDPE). The yeast consortium DYC stands for the molecularly identified species Sterigmatomyces halophilus, Meyerozyma guilliermondii, and Meyerozyma caribbica. The LDPE-DYC consortium showed a high growth rate on UV-sterilized LDPE as a sole carbon source, resulting in a reduction in tensile strength (TS) of 63.4% and a net LDPE mass reduction of 33.2% compared to the individual yeasts. All yeasts, individually and in consortium, showed a high production rate for LDPE-degrading enzymes. The hypothetical LDPE biodegradation pathway that was proposed revealed the formation of several metabolites, including alkanes, aldehydes, ethanol, and fatty acids. This study emphasizes a novel concept for using LDPE-degrading yeasts from wood-feeding termites for plastic waste biodegradation. [Display omitted] • Plastics-degrading yeast strains were isolated from termite gut. • LDPE-DYC consortium showed a high growth rate on LDPE as a sole carbon source. • LDPE-DYC consortium showed a high production rate for LDPE-degrading enzymes. [ABSTRACT FROM AUTHOR]

The disposal of vulcanized rubber waste is difficult due to the presence of three-dimensional crosslinking network structure. Here, we report that a bacterium Acinetobacter sp. BIT-H3, isolated from the gut of plastic-eating mealworm, can grow on and degrade vulcanized poly(cis-1,4-isoprene) rubber (vPR). Scanning electronic microscopy (SEM) shows that strain BIT-H3 can penetrate into the vPR and produce craters and cracks. The tensile strength and the crosslink density of vPR decreased by 53.2% and 29.3% after ten weeks' incubation, respectively. The results of Horikx analysis, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, and X-ray absorption near-edge structure (XANES) spectroscopy reveal that strain BIT-H3 can break down both sulfide bridges and double bonds of polymeric backbone within vPR. Sulfate and oligo(cis -1,4 isoprene) with terminal aldehyde and keto groups were identified as metabolic products released during vPR degradation. Through genomic and transcriptional analyses, five enzymes of dszA, dszC1, dszC2, Laccase2147, and Peroxidase1232 were found to be responsible for vPR degradation. Based on the chemical structure characterizations and molecular analyses, a vPR biodegradation pathway was proposed for strain BIT-H3. These findings pave a way for exploiting vulcanized rubber-degrading microorganisms from insect gut and contribute to establish a biodegradation method for vulcanized rubber waste disposal. [Display omitted] • A bacterium Acinetobacter sp. BIT-H3 isolated from mealworm' gut can grow on and degrade vPR. • Strain BIT-H3 can break down both sulfide bridges and polymeric backbone within vPR. • Sulfate and oligo(cis -1,4 isoprene) with terminal aldehyde and keto were released from vPR degradation. • The dszA, dszC1, dszC2, Laccase2147, and Peroxidase1232 were responsible for vPR degradation. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic has led to explosive growth in the production and consumption of disposable medical masks, which has caused new global environmental problems due to the improper disposal of these masks and lack of effective mask recycling methods. To reduce the environmental load caused by the inability of synthetic plastics to degrade, polylactic acid (PLA) masks, as a biodegradable environmentally friendly plastic, may become a solution. This study simulated the actual degradation process of new PLA masks in different environments by soaking them in various solutions for 4 weeks and explored the influence of the treated PLA fabric fibers on the growth of winter ryegrass. The results show that the weathering degradation of PLA fibers in water mainly occurs through the hydrolysis of ester bonds, and weathering leads to cheese-like and gully-like erosion on the surface of the PLA fiber fabric layer and finally to fiber fracture and the release of microplastics (MPs). The average number of MPs released within 4 weeks is 149.5 items/piece, the particle size is 20–500 µm (44%), and 63.57% of the MPs are transparent fibers. The outer, middle, and inner layers of weathered PLA masks tend to be hydrophilic and have lower mechanical strength. PLA fibers after different treatment methods affect the growth of winter ryegrass. PLA masks are undoubtedly a greener choice than ordinary commercial masks, but in order to confirm this, the entire degradation process, the final products, and the impact on the environment need to be further studied. In the future, masks may be developed to be made from more environmentally friendly biodegradable materials that can have good protecting effects and also solve the problem of end-of-life recycling. Simulation of the actual degradation process of PLA masks and exploration of the influence of mask degradation on the growth of winter ryegrass. [Display omitted] • The degradation of PLA masks is mainly due to the fracture of ester bond. • PLA masks release less microplastics than commonly used commodity masks. • The degradation degree of PLA masks in artificial aquaculture water is higher. • Degradation of PLA masks cause the fragility and hydrophilicity to be strengthened. • The aging environment of PLA fiber fabric inhibits the activities of winter ryegrass. [ABSTRACT FROM AUTHOR]

Micro and macroplastics are emerging contaminants in agricultural settings, yet their impact on nitrogen (N) cycling and partitioning in plant-soil-microbial systems is poorly understood. In this mesocosm-scale study, spring barley (Hordeum vulgare L.) was exposed to macro or microplastic produced from low density polyethylene (LDPE) or biodegradable plastic at concentrations equivalent to 1, 10 and 20 years of plastic mulch film use. Partitioning of 15N-labelled fertiliser into plant biomass, soil and leachate yielded a partial mass balance. Soil N partitioning was probed via compound-specific 15N-stable isotope analyses of soil microbial protein. Concentration-dependent decreases in plant 15N uptake occurred with increased leached nitrogen for LDPE microplastic. Assimilation into soil microbial protein was higher for biodegradable plastics, which we associate with early-stage biodegradable plastic degradation. Partitioning of 15N into inorganic soil N pools was affected by LDPE size, with lower assimilation into the microbial protein pool. While microplastics and macroplastics altered soil N cycling, the limited impacts on plant health indicated the threshold for negative effects was not reached at agriculturally relevant concentrations. This study highlights the difference between conventional and biodegradable plastics, and emphasises that the interplay of micro and macroplastics on soil N cycling must be considered in future studies. [Display omitted] • Barley was exposed to biodegradable and LDPE macro and microplastic. • 15N-tracing indicated LDPE microplastic reduced plant 15N uptake due to N losses. • LDPE plastics altered partitioning of 15N within soil N pools. • Biodegradable macro and micro plastic increased microbial N uptake. • Biodegradable and LDPE plastics had differing impacts on plant-soil N partitioning. [ABSTRACT FROM AUTHOR]

The accumulation of microplastics poses potential risks to soil health. Here, we did a preliminary exploration on the potential of Lumbricus terrestris (Oligochaeta) to reduce low-density polyethylene (LDPE), polylactic acid (PLA), and polybutylene adipate terephthalate (PBAT) microplastic (20–648 µm) contamination in soils. The ingestion of microplastics-contaminated soil (1% of microplastics, dw/dw) in a mesocosm system and the ingestion of pure microplastics in the Petri Dish by earthworms were studied. Results show that earthworms survived in the microplastics-contaminated soil (0% mortality in 35 days) but barely when exposed solely to microplastics (30–80% mortality in 4 days). Size-dependent ingestion of microplastics was not observed. The fragmentation of LDPE microplastics in the gizzard facilitated by soil was confirmed by the significantly increased ratio of small-sized (20–113 µm) microplastics from the bulk soil to the gut (from 8.4% to 18.8%). PLA and PBAT microplastics were fragmented by gizzard without the facilitation of soil, the ratios of small-sized (20–113 µm) PLA and PBAT microplastics in the gut were 55.5% and 108.2% higher than in respective pristine distributions. Substantial depolymerization of PLA (weight-average molar mass reduced by 17.7% with shift in molecular weight distribution) and suspected depolymerization of PBAT were observed in the worm gut, while no change in the molar mass was observed for PLA and PBAT microplastics buried in the soil for 49 days. Our results suggest that ingested microplastics could undergo fragmentation and depolymerization (for certain polymers) in the earthworm gut. Further research is needed to reveal the mechanisms of polymer depolymerization in the earthworm gut and to evaluate the feasibility of microplastic bioremediation with earthworms. [Display omitted] • Lumbricus terrestris could survive in the soil contaminated with 1% (dw/dw) of LDPE, PLA and PBAT microplastics. • The ingestion of microplastics by earthworms was not size-dependent. • Microplastics were fragmented in the earthworm gizzard with/without the help of sand grains, depending on polymer types. • Depolymerization of PLA and PBAT microplastics did not happen in the soil, but only in the earthworm's gut. • The gut-related processes inside earthworms provide potential for microplastic bioremediation in the soil. [ABSTRACT FROM AUTHOR]

Recently, biodegradable plastics (BPs) are emerging as a sustainable alternative to traditional plastics. When released into an aquatic environment, the biodegradable performance of BPs is influenced by biochemical processes, especially the developed plastisphere. However, studies addressing the biodegrading capacity of BPs and traditional plastics within the plastisphere are still limited. Here, we investigated plastisphere community variations and their capacity to biodegrade polyethylene terephthalate (PET) and starch-based plastics (SBP) for four time periods (15, 30, 45, and 80 days) in three freshwaters. Unexpectedly, there is no significant difference in the microbial communities and network structure of the plastisphere between SBP and PET. Moreover, SBP tended to age rapidly at the early stage (0–15 days), while the aging degree of SBP and PET did not display an obvious difference at 80 days. Partial least squares path modeling suggested that plastic aging was mainly dominated by keystone taxa of network and aquatic environmental factors. These results suggest that the aging rate of commercial BPs may not be as fast as we imagine in freshwaters (SBP ≈ PET), and the environmental behaviors of BPs in the aquatic environment should be paid more attention to. [Display omitted] • Studied effects of microbial succession on aging of BPs and PET in freshwaters. • Similar microbial community and structure of plastisphere observed on SBP and PET. • Similar aging degree of SBP and PET was observed at 80 days in freshwaters. • Microbial keystone taxa and environmental factors co-dominated the plastic aging. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) that enter the soil can alter the physicochemical and biochemical properties of soil and affect speciation of heavy metals (HMs), thereby perturbing the bioavailability of HMs. However, the mechanisms underlying these effects are not understood. Therefore, we investigated the effects of MPs from poly (butyleneadipate-co-terephthalate)-based biodegradable mulch (BM) and polyethylene mulch (PM) in Cd- or As-contaminated soil on soil properties and speciation of HMs. MPs were characterised using Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The addition of MPs reduced the bioavailability of HMs in soil and promoted the transformation of HMs into inert fractions. The mechanisms underlying the reduction of the bioavailability of HMs in soils could be as follows: (1) the entry of MPs into the soil changed its properties, which reduced the bioavailability of HMs; (2) FTIR and XPS analyses revealed that the hydroxyl and carboxyl groups and benzene ring present on the surface of aged MPs stabilized complexes (As(V)-O) with As(V) may have directly reduced the bioavailability of As(V) in soil; (3) aged BM exposed more amounts and types of reactive functional groups and was more effective in stabilising soil HMs than PM. Overall, this study provides new insights regarding the complexation mechanisms of soil HMs by MPs from different plastic mulch sources. [Display omitted] • Biodegradable microplastics increased Cd and As organic-bound partition. • Biodegradable microplastics could better stabilize heavy metals than polyethylene. • Microplastics addition increased soil total and dissolved organic carbon content. • Cd and As in soil mainly interacted with hydroxyl and carboxyl on microplastics. [ABSTRACT FROM AUTHOR]

Dissolved organic matter (DOM) leaching from biodegradable microplastics (BMPs) and its characteristics and corresponding environmental implication are rarely investigated. In this study, the main component of DOM leachate from the two BMPs (polyadipate/butylene terephthalate (PBAT)/polycaprolactone (PCL)) was verified by using excitation-emission matrix-parallel factor analysis (EEM-PARAFAC). The PBAT-DOM (PBOM) was aromatized and terrestrial. Comparatively, PCL-DOM (PLOM) had low molecular weight. PBOM contained protein-like components while PLOM contained tryptophan and tyrosine components. Interestingly, both PBOM and PLOM could accelerate the decomposition and oxidation of coexisting polystyrene (PS) under light irradiation. Further, the difference in composition and the properties of BMPs-DOM significantly affected its photochemical activity. The high territoriality and protein-like component of PBOM significantly promoted the generation of 1O 2 and O 2 •-, which caused faster disruptions to the backbone of PS. Simultaneously, the microbial community's richness, diversity, and metabolism were obviously improved under the combined pressure of aged PS and BMPs-DOM. This study threw light on the overlooked contribution of DOM derived from BMPs in the aging process of NMPs and their impact on the microbial community and provided a promising strategy for better understanding of combined MPs' fate and environmental risk. [Display omitted] • The components of DOM leaching from BMPs were identified. • The photo-aging process of PS induced by BMPs-DOM was quantitatively investigated. • The presence of BMPs-DOM accelerated the decomposition and oxidation of PS. • The properties and components of BMPs-DOM affected the production of ROS. • The microbial metabolism was altered under the pressure of BMPs-DOM and aged PS. [ABSTRACT FROM AUTHOR]

Biodegradable plastics, if they are not properly managed at their end-of-life, can have the same hazardous environmental consequences as conventional plastics. This study investigates the treatment of the main biodegradable plastics under mesophilic and thermophilic anaerobic digestion using biochemical methane potential test and the microorganisms involved in the process using amplicon sequencing of the 16 S rRNA. Here we showed that, only PHB and TPS undergone important and rapid biodegradation under mesophilic condition (38 °C). By contrast, PCL and PLA exhibited very low biodegradation rate as 500 days were required to reach the ultimate methane yield. Little or no degradation occurred for PBAT and PBS at 38 °C. Under thermophilic conditions (58 °C), TPS, PHB, and PLA reached high levels of biodegradation in a relatively short period (< 100 d). While PBS, PBAT, and PCL could not be converted into methane at 58 °C. PHB degraders (Enterobacter and Cupriavidus) and lactate-utilizing bacteria (Moorella and Tepidimicrobium) appeared to play an important role in the PHB and PLA degradation, respectively. This work not only provides crucial data on the anaerobic digestion of the main biodegradable plastics but also enriches the understanding of the microorganisms involved in this process, which are of great importance for future development of the treatment of biodegradable plastics in anaerobic digestion systems. [Display omitted] • High yields and rates of biodegradation were measured for PHB and TPS at 38 °C and 58 °C; • Low or zero biodegradation rates were measured for PLA, PCL, PBAT, and PBS at 38 °C; • The biodegradation rate of PLA was greatly enhanced at 58 °C; • Two lactate-utilizing bacteria were predominant during the thermophilic AD of PLA; • Two PHB degraders were correlated with the methane production from PHB. [ABSTRACT FROM AUTHOR]

Currently, microplastic pollution is more serious and complicates the toxic effects of other co-existing pollutants in the environment. However, the effect and mechanism of biodegradable plastics on the growth and metabolism of probiotic remain unclear. This work selected Bacillus amyloliquefaciens as model bacterium for a three-day exposure experiment to probe the issues. The results showed that 100 mg/L polylactic acid microplastics (PLA MPs) (3–4 mm, flake shape) caused oxidative damage to cell membranes, disrupted cell wall composition and inhibited cell growth by 21.2–27.5 %. The toxicity was not simply additive or synergistic effects when PLA MPs (100 mg/L) and copper ions (10 mg/L) coexisted. PLA MPs did not significantly increase the toxicity of copper to bacteria, instead triggered some mechanisms to resist the toxicity of copper. The bacteria formed spores to resist PLA MPs, while the copper ions toxicity was weaken by chelation and efflux. It is worth noting that copper ions instead increased the expression of genes related fengycin and iturin then improving the bacteriostatic activity of the probiotic. This paper deeply analyzes the toxicity mechanism of combined pollution on Bacillus amyloliquefacien, and also provides new perspective for helping to inhibit pathogenic bacteria under biodegradable microplastics and metal stress. [Display omitted] • Paper discussed the toxicity of biodegradable microplastics and copper on probiotic. • Polylactic acid microplastics still had a certain toxicity to bacteria. • The toxicity of combined pollutants was not simple synergistic or additive effects. • Pollutants might instead improve the bacteriostatic effect of inoculants. [ABSTRACT FROM AUTHOR]

Biodegradable plastics (BDP) are increasingly applied; however, there has been of concerns about their environmental safety, especially from nondegradable additive compositions. Until now, data of ecotoxicity of BDP additives is scarce. Here, nematode C. elegans was used to comparatively evaluate toxicity of an isocyanate additive, i.e. , Hexamethylene diisocyanate (HDI), a maleic anhydride, i.e. , Diallyl maleate (DIM), and other four BDP organic additives. These additives caused lethality of nematodes at µg L-1 level, of lowest LC 50 value of HDI/DIM. Uniform exposure to these additives resulted in various degrees of inhibitions in body volumes and longevity, indicating developmental toxicity. Moreover, BDP additives induced significant elevations of gst-4 expression, especially mean 123.54 %/234.29 % increase in HDI/DIM group, but reduced ges-1 expression, which indicates oxidative damages and mitochondrial dysfunction. BDP additives further caused inhibition in locomotor and food intake/excretion behavior, and related damages of glutamatergic neurons and GABAergic neurons, indicating their neurotoxicity. We found HDI and DIM presented relatively strong effects on susceptible endpoints including lethality, gst-4 , mean lifespan, food intake and excretion behavior. Overall, this study suggests prominent ecotoxic risk of isocyanates and maleic anhydrides as BDP additives, which is significant for the selection of environmentally friendly BDP additives. [Display omitted] • Six biodegradable plastic (BDP) additives caused lethality of C. elegans at µg L-1 level. • BDP additives increased gst-4 , but reduced ges-1 expression and lifespan, of various degrees. • BDP additives caused inhibition in locomotor and food intake/excretion behavior. • BDP additives induced damages in glutamatergic neurons and GABAergic neurons. • Isocyanates/maleic anhydrides showed strong toxicity compared to other BDP additives. [ABSTRACT FROM AUTHOR]

The inhomogeneity of plastisphere and soil may result in different microbial communities, thus potentially affecting soil functions. Biodegradable plastics offer an alternative to conventional plastics, nevertheless, the inadequate end-of-life treatment of biodegradable plastics may release more microplastics. Herein, we collected PE and PBAT/PLA microplastics in plastic-mulching farmland in Hebei, China. The bacterial communities of soil, PE and PBAT/PLA plastisphere were investigated using 16 S high-throughput sequencing. We found that the structure of bacterial communities in PBAT/PLA plastisphere were significantly distinct from PE plastisphere and soil. The alpha diversities in PBAT/PLA plastisphere were significantly lower than PE plastisphere and soil. Statistical analysis of differentially ASVs suggested that PBAT/PLA microplastics act as a filter, enriching taxa with the capability to degrade plastic polymers such as Proteobacteria and Actinobacteria. Compared to PE plastisphere, PBAT/PLA plastisphere has networks of less complexity, lower modularity, and more competitive interactions. Predicted metabolic pathways involved in human diseases, carbohydrate metabolism, amino acid metabolism, and xenobiotic biodegradation and metabolism were promoted in PBAT/PLA plastisphere, along with the facilitation in abundance of genes associated with carbon and nitrogen cycling. Our results highlighted the uniqueness of plastisphere of biodegradable microplastics from conventional microplastics and their potential impact on soil functions. [Display omitted] • Microbial community on PBAT/PLA microplastics differed structurally from soil and PE microplastics. • Potential plastic-degrading bacteria were enriched in PBAT/PLA plastisphere. • PBAT/PLA plastisphere has networks of less complexity and more competitive interactions. • Keystone species were Proteobacteria and Actinobacteriota. • Bacterial multifunctionality was promoted in PBAT/PLA plastisphere. [ABSTRACT FROM AUTHOR]

Although biodegradable plastics are considered an environmentally-friendly alternative to conventional plastics, the effects of biodegradable microplastics (BMPs) on soil faunal communities are poorly understood, especially under field conditions. Here, we investigated the loading impacts of two conventional low-density polyethylene (LDPE) and polypropylene (PP) MPs as well as two biodegradable polylactic acid (PLA) and polybutylene succinate (PBS) MPs at concentrations of 0, 5, 10, and 15 g/m2 on soil fauna communities. After 40 d, all MP types did not affect the soil fauna communities. After 130 d, conventional MPs (LDPE-15 and PP-5) significantly increased the abundance of overall soil fauna—attributed mainly to changes in the abundance of Collembola; however, BMPs did not affect the soil fauna communities. Interestingly, MP-induced changes in the abundance and diversity of soil fauna showed a strong tendency to increase over time. Overall, these results indicate that the short-term effects of all MP types on soil faunal communities are inapparent, while soil fauna responses to conventional MPs and BMPs showed slight differences over time. Given these time-dependent soil fauna responses to MPs, we recommend an evaluation of the long-term effects of MPs on soil organisms to gain a comprehensive understanding of their effects on soil ecosystems. [Display omitted] • We explored soil fauna responses to conventional and biodegradable microplastics. • After 40 d, all microplastic types did not affect the soil faunal communities. • After 130 d, conventional microplastics increased the abundance of soil fauna. • Soil fauna responses to microplastics were time-dependent under field conditions. [ABSTRACT FROM AUTHOR]

Plastic is exceedingly abundant in soils, but little is known about its ecological consequences for soil microbiome functioning. Here we report the impacts of polyethylene and biodegradable Ecovio and BI-OPL plastic films buried in alpine soils for 5 months on the genetic potential of the soil microbiome using shotgun metagenomics. The microbiome was more affected by Ecovio and BI-OPL than by polyethylene. Fungi, α- and β-Proteobacteria dominated on the biodegradable films. Ecovio and BI-OPL showed signs of degradation after the incubation, whereas polyethylene did not. Genes involved in cellular processes and signaling (intracellular trafficking, secretion, vesicular transport), as well as metabolism (carbohydrate, lipid and secondary metabolism), were enriched in the plastisphere. Several α/β-hydrolase gene families (cutinase_like, polyesterase-lipase-cutinase, carboxylesterase), which encode enzymes essential to plastic degradation, and carbohydrate-active genes involved in lignin and murein degradation increased on Ecovio and BI-OPL films. Enriched nitrogen fixation and organic N degradation and synthesis genes and decreased nitrification genes on Ecovio altered the biogeochemical cycling, leading to higher ammonium concentrations and depletion of nitrite and nitrate in the soil. Our results indicate that plastics affect the alpine soil microbiome and its functions and suggest that the plastisphere has an untapped microbial potential for plastic biodegradation. [Display omitted] • We studied the microbial genetic potential of the plastisphere in alpine soil. • Biodegradable plastics led to strong changes in the gene structure. • α/β-hydrolase genes were enriched in the plastisphere of biodegradable plastics. • Biodegradable plastics affected C- and N-cycling in the soil. • The alpine soil plastisphere is an untapped source of plastic-degrading enzymes. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the pyrolysis products of polyhydroxyalkanoates (PHA s), polyethylene terephthalate (PET), carbon fiber reinforced composite (CFRC), and block co-polymers (PS-b-P2VP and PS-b-P4VP). The studied PHA samples were produced at temperatures of 15 and 50 oC (PHA15 and PHA50), and commercially obtained from GlasPort Bio (PHAc). Initially, PHA samples were analyzed by nuclear magnetic resonance (NMR) spectroscopy and size exclusion chromatography (SEC) to determine the molecular weight, and structure of the polymers. Thermal techniques such as thermogravimetry (TG) and differential scanning calorimetry (DSC) analyses were performed for PHA , CFRC , and block co-polymers to investigate the degradation temperature range and thermal stability of samples. Fast pyrolysis (500 oC, ∼102 °C s−1) experiments were conducted for all samples in a wire mesh reactor to investigate tar products and char yields. The tar compositions were investigated by gas chromatography–mass spectrometry (GC–MS), and statistical modeling was performed. The char yields of block co-polymers and PHA samples (<2 wt. %) were unequivocally less than that of the PET sample (~10.7 wt. %). All PHA compounds contained a large fraction of ethyl cyclopropane carboxylate (~ 38–58 %), whereas PAH15 and PHA50 additionally showed a large quantity of 2-butenoic acid (~8–12 %). The PHAc sample indicated the presence of considerably high amount of methyl ester (~15 %), butyl citrate (~12.9 %), and tributyl ester (~17 %). The compositional analyses of the liquid fraction of the PET and block co-polymers have shown carcinogenic and toxic properties. Pyrolysis removed matrices in the CRFC composites which is an indication of potential recovery of the original fibers. [Display omitted] • Fast pyrolysis led to the conversion of PHA into value-added liquid compounds. • Pyrolysis can potentially remove polymer matrices in the CRFC composites. • Recovered CRFC carbon fibers retained length and position in a bundle after pyrolysis. • The liquid fraction of block co-polymers comprise toxic and carcinogenic compounds. • Fast pyrolysis of PHA and block co-polymers led to char yield of < 2wt. %. [ABSTRACT FROM AUTHOR]

Recently, biodegradable plastics (BPs) as an alternative of conventional plastics have been widely advocated and applied. However, there is still a large research gap between the formation of secondary microplastics (MPs) and colonized microorganisms on their surface under long-term aging in different environments. In this study, the generation of secondary MPs and the formation of surface biofilms on the micro-sized (3–5 mm) biodegradable plastic poly (butyleneadipate-co-terephthalate) (BP-PBAT) and conventional plastic polyvinyl chloride (CP-PVC) under long-term UV aging was investigated. The results showed that hundreds and even thousands of MPs (185.53 ± 85.73 items/g - 1473.27 ± 143.67 items/g) were generated by BP-PBAT and CP-PVC after aged for 90 days, and the abundance of MPs produced by BP-PBAT was significantly higher than that of CP-PVC. Moreover, the α diversities and detected OTU number of biofilm communities formed on MPs increased with MPs-aging. The genes related to the formation of biofilms was significantly expressed on aged MPs and the genes related to human pathogens and diseases were also detected in enriching on MPs surface. Overall, BPs may lead to greater ecological risks as it releases thousands of secondary MPs after being aged, and their environmental behavior needs to be further explored. [Display omitted] • Hundreds of secondary microplastics were generated per gram of plastic after aging. • Aging of biodegradable plastic produced more secondary microplastics. • Microplastics biofilm community structure changed dramatically with aging time. • Human pathogens were enriched in microplastics biofilm. [ABSTRACT FROM AUTHOR]

The emerging demand for the enhancement of biodegradation of persistent organic pollutants from marine oil spills using oil-treating agents to minimize the environmental impacts promotes the development of green dispersants. Shrimp waste is a potential raw material to generate green dispersants. The biodegradability of dispersed oil and dispersants themselves are key factors for the national consideration of the approval, stockpile, and usage of dispersants. However, it is unknown whether shrimp-waste-based dispersant (SWD) has high bioavailability or facilitates the biodegradation of dispersed oil. In this study, we tackled the biodegradation of oil dispersed by a purified SWD. Furthermore, the SWD biodegradability was evaluated by exploring the degradation genes via metagenomic sequencing, analyzing the enzymatic activities for dispersant biodegradation by molecular docking, and discussing the SWD toxicity. We discovered that the SWD facilitated the biodegradation of two crude oils (Alaska North Slope and Marine Fuel-No.6). The metagenomic analysis with molecular docking showed that fresh seawater had feasible enzymes to degrade the SWD to safety components. Additionally, the SWD was low toxic and high bioactive. The findings helped confirm that the purified SWD is an effective and eco-sustainable marine oil spill treating agent and tracked the biodegradation of dispersed oil and the SWD. [Display omitted] • A purified shrimp-waste-based dispersant was generated to treat oil spill. • The new dispersant could enhance the biodegradation of the dispersed oil. • An advanced oil fingerprinting method was used to track oil biodegradation. • Atlantic seawater contains multiple biodegradation genes to degrade the dispersant. • The dispersant has low toxicity, high bioavailability, and high efficiency. [ABSTRACT FROM AUTHOR]

Biodegradable plastics have emerged as an ecological alternative to conventional petroleum-based plastics. Despite the recent advances in the effects of conventional microplastic on soil ecosystems, the ecological impact of biodegradable microplastics in soil environments remains poorly understood. Here, we performed soil microcosms with conventional (polyethylene and polystyrene) and biodegradable (polybutylene succinate and polylactic acid) microplastics to estimate their effects on the success patterns, co-occurrence networks, and the assembly mechanisms of soil bacterial communities. Biodegradable microplastics significantly altered the soil bacterial community composition with steeper temporal turnovers (rate: 0.317 – 0.514) compared to the conventional microplastic treatments (rate: 0.211 – 0.220). Network under biodegradable microplastics showed greater network complexity, including network size, connectivity, average clustering coefficient, and the number of keystone species, as compared with the conventional microplastic treatments. Additionally, the biodegradable microplastic network had higher robustness, which may be potentially due to the enhanced dissolved organic carbon contents in the soil treated with biodegradable microplastics. The bacterial community assembly was initially governed by deterministic homogeneous selection (93 – 100 %) under the stress of microplastics, but was progressively structured by increasing stochastic homogeneous dispersal (17.8 – 73.3 %) over time. The normalized stochasticity ratio also revealed that the application of microplastics increased the importance of stochastic processes following incubation. These findings greatly enhanced our understanding of the ecological mechanisms and interactions of soil bacterial communities in response to microplastic stress. [Display omitted] • Effects of diverse microplastics on soil bacterial community were estimated. • Biodegradable microplastics alter the community with steeper temporal turnovers. • Biodegradable microplastic network had greater complexity and robustness. • Homogeneous dispersal mainly contributed to community assembly after exposure. • Values of normalized stochasticity ratio increased following the incubation. [ABSTRACT FROM AUTHOR]

Nanoplastics (NPs) are derived from microplastics and may cause health problems. We previously showed that 100 nm polystyrene (PS)-NPs enter cells, including mouse embryonic fibroblasts (MEFs), and their intracellular accumulation induces inflammatory and oxidative stress. Moreover, PS-NP uptake was found to occur via endocytosis, and they accumulated mostly at the juxtanuclear position, but never within the nucleus. We speculated that PS-NPs were cleared from cells when they were no longer exposed to PS-NPs. However, the effects of PS-NPs on the cellular machinery remain unknown. The accumulation of PS-NPs at the juxtanuclear position may be due to retrograde transport along microtubules. To confirm this, we treated PS-NP-exposed MEFs with inhibitors of histone deacetylase 6 (HDAC6), dynein, or microtubule polymerization and found greatly diminished intracellular and juxtanuclear accumulation. Moreover, rapid clearance of PS-NPs was observed when MEFs were treated with an HDAC6 inhibitor. PS-NPs were removed by exocytosis, as confirmed by treatment with an exocytosis inhibitor. Furthermore, inhibiting the retrograde transport of PS-NPs alleviated the activation of the antioxidant response pathway, inflammatory and oxidative stress, and reactive oxygen species generation. In summary, inhibition of the retrograde transport of non-biodegradable PS-NPs leads to their rapid export by exocytosis, which may reduce their cytotoxicity. [Display omitted] • PN-NPs entering the cell undergo retrograde transport along microtubules. • Dynein and HDAC6 are responsible for PS-NP accumulation in the perinuclear region. • HDAC6 inhibition hinders retrograde transport of PS-NPs to the perinuclear region. • HDAC6 inhibition results in the rapid export of PS-NPs from cells by exocytosis. • The rapid export of PS-NPs alleviates oxidative and inflammatory stress. [ABSTRACT FROM AUTHOR]

The degradable plastic poly(butylene adipate-co-terephthalate) (PBAT) is considered a potential replacement for low-density polyethylene (LDPE) as the main component of mulch film. However, it is not clear whether PBAT is harmful to the plant-soil system. Thus, we determined the effects of LDPE microplastics (LDPE-MPs) and PBAT microplastics (PBAT-MPs) on the growth of Arabidopsis. The inhibitory effect of PBAT-MPs was greater than that of LDPE-MPs on the growth of Arabidopsis. Transcriptome analysis showed that PBAT-MPs severely disrupted the photosynthetic system of Arabidopsis and increased the expression levels of genes in drug transport-related pathways. PBAT-MPs increased the relative abundances of Bradyrhizobium , Hydrogenophaga , and Arthrobacter in the bulk soil and rhizosphere soil. The abundances of Variovorax , Flavobacterium , and Microbacterium increased in the plant root zone only under PBAT-MPs. Functional prediction analysis suggested that microorganisms in the soil and plant root zone could degrade xenobiotics. Furthermore, the degradation products from PBAT comprising adipic acid, terephthalic acid, and butanediol were more toxic than PBAT-MPs. Our findings demonstrate that PBAT-MPs may be degraded by microorganisms to produce chemicals that are highly toxic to plants. Thus, biodegradable plastics may pose a great risk to the environment. [Display omitted] • Toxic effects of PBAT-MPs greater than those of LDPE-MPs on growth of Arabidopsis. • Expression levels of genes in Arabidopsis photosynthetic system severely disrupted by PBAT-MPs. • PBAT-MPs altered microbial community structure and functions in the bulk soil, rhizosphere soil, and plant root zone. • Degradation products from PBAT comprising adipic acid, phthalic acid, and butanediol toxic in Arabidopsis. [ABSTRACT FROM AUTHOR]

Freshwater ecosystems are subjected to plastic extensive pollution because they are the direct link between plastic wastes and marine ecosystems. The aim of this study was to assess the impacts of different sizes of polyethylene plastics (micro: µPs and macroplastics: PBs) on freshwater decomposers of plant litter. We exposed leaf associated microbial assemblages to µPs (0.5 or 1.5 g L-1) and discs of PBs as follows: green plastic bags (PB-G) alone or in mixtures with transparent plastic bags (PB-Mix). Then, we conducted a feeding preference experiment with the invertebrate shredder Limnephilus sp. to assess their capacity to distinguish leaf discs from PB discs of the same size (12 mm). Leaf decomposition, activities of fungal enzymes and sporulation were inhibited by µPs and PB-Mix, and shifts in fungal community composition were observed. The invertebrate shredders preferred to feed on leaves treated with µPs avoiding those exposed to PB-G/PB-Mix. Our results demonstrated that plastics can have a direct effect on stream-dwelling microbial decomposers and an indirect effect on higher trophic levels (shredders), highlighting that trophic transfer is a route of plastic exposure. The plastic properties (size, concentration, colour) appear to influence plastic toxicity to microbes and shredders, indicating the importance of considering physicochemical properties when assessing their risks to freshwater ecosystems. [Display omitted] • Impacts of micro and macroplastics were assessed on a stream detrital food-chain. • Micro and macroplastics inhibited microbial decomposer activities. • Shredders fed on leaves treated with microplastics and avoided the macroplastics. • Plastic properties (size, concentration and colour) influenced the toxicity. [ABSTRACT FROM AUTHOR]

The uncontrolled release of plastics in the environment has rendered them ubiquitous around the planet, threatening the wildlife and human health. Biodegradation and valorization of plastics has emerged as an eco-friendly alternative to conventional management techniques. Discovery of novel polymer-degrading enzymes with diversified properties is hence an important task in order to explore different operational conditions for plastic-waste upcycling. In the present study, a barely studied psychrophilic enzyme (MoPE) from the Antractic bacterium Moraxella sp. was heterologously expressed, characterized and its potential in polymer degradation was further investigated. Based on its amino acid composition and structure, MoPE resembled PET-degrading enzymes, sharing features from both mesophilic and thermophilic homologues. MoPE hydrolyzes non-biodegradable plastics, such as polyethylene terephthalate and polyurethane, as well as biodegradable synthetic polyesters, such as polycaprolactone, polyhydroxy butyrate, polybutylene succinate and polylactic acid. The mass fraction crystallinity of the aliphatic polymers tested ranged from 11% to 64% highlighting the potential of the enzyme to hydrolyze highly crystalline plastics. MoPE was able to degrade different types of amorphous and semi-crystalline PET, releasing water-soluble monomers and showed synergy with a feruloyl esterase of the tannase family for the release of terephthalic acid. Based on the above, MoPE was characterized as a versatile psychrophilic polyesterase demonstrating a broad-range plastics degradation potential. [Display omitted] • Moraxella sp. esterase (MoPE) was found capable of degrading a broad range of synthetic polymers. • Plastics were ranked based on glass transition temperature, crystallinity and molecular weight. • MoPE was capable of hydrolyzing high crystallinity PBS while PCL suffered the highest mass loss. • MoPE mode of action was elucidated by using PET model substrates. • Terephthalic acid was released from PET by the synergistic action of MoPE with a feruloyl esterase. [ABSTRACT FROM AUTHOR]

The use of biodegradable plastics (BPs) has been widely promoted in recent years, but before their complete degradation, the phase of microplastics (MPs) is inevitable. However, little information concerning the production of MPs from blended polymers is available. This study aimed to explore the characteristics of MPs produced from blended plastics and the development of biofilms on plastic surfaces under long-term aging. Here, three blended materials (i.e., PBAT (53%)+PLA (10%)+Starch (20%), PBAT (80%)+Starch (20%), HDPE (60%)+CaCO 3 (40%)) were aged for 90 days in air, deionized (DI) water and seawater. The results showed massive production of MPs (9653 ± 3920–20,348 ± 5857 items/g) from blended plastics accompanied by a large quantity of flocculent substances during 90 days aging period. Furthermore, the richness of bacteria communities on hydrophobic plastics (i.e., PBAT (53%)+PLA (10%)+Starch (20%), PBAT (80%)+Starch (20%)) was higher than hydrophilic plastics (i.e., HDPE (60%)+CaCO 3 (40%)), and bacterial communities attached to blended plastics exhibited significantly variation with aging times. Overall, promoting the marketable application of blended plastics is risky if their environmental behavior is not effectively addressed. [Display omitted] • Tens of thousands of microplastics per gram blended plastic are formed after aging. • Microplastics are produced highest in the air environment. • Higher richness of bacterial communities was found on hydrophobic blended plastics. • Bacteria attached to blended plastic exhibited significant changes with aging time. [ABSTRACT FROM AUTHOR]

The ability of microplastics (MPs) to interact with environmental pollutants is of great concern. Riverine sediments, as sinks for multi-pollutants, have been rarely studied for MPs risk evaluation. Meanwhile, MPs generated from biodegradable plastics are questioning the safety of the promising materials. In this study, we investigated the effects of typical non-degradable polyethylene (PE) and biodegradable polylactic acid (PLA) MPs on sediment enzymes, arsenic (As) fractionation, and microbial community structures in As-contaminated riverine sediments. The results indicated that the presence of MPs (1% and 3%, w/w) led As transformed into more labile and bioavailable fractions in riverine sediments, especially under higher As and MPs levels. Analysis on microbial activities and community structures confirmed the strong potential of MPs in inhibiting microbial activities and shifting bacterial community succession patterns through enrichment of certain microbiota. Moreover, biodegradable PLA MPs presented stronger alterations in arsenic fractionation and microbial community structures than PE MPs did, which might be jointly attributed to adsorption behaviors, microbial alterations, and potential PLA degradation behaviors. The study indicated that MPs contamination increased As mobility and bioavailability, and shifted microbial communities in riverine sediments. Moreover, biodegradable MPs might lead to stronger microbial alterations and increases in As bioavailability, acting as a threat to ecological safety, which needed further exploration. [Display omitted] • Impacts of two types of microplastics in arsenic-polluted sediments were explored. • Microplastics inhibited microbial activities in arsenic-polluted sediments. • Microplastics led arsenic transformed to more bioavailable fractions in sediments. • Microplastics shifted sediment bacterial communities in arsenic-polluted sediments. • Biodegradable microplastics had stronger negative impacts than conventional ones. [ABSTRACT FROM AUTHOR]

Removing microplastics (MPs) from water has been a huge challenge due to their inherent features including small size and high stability. In this research, inspired by the active adsorption and passive adhesion mechanisms of corals to MPs, a new strategy to fabricate polydopamine enhanced magnetic chitosan (PDA-MCS) aerogels was developed with a target to match the surface properties of MPs, achieving high MPs removal efficiency. PDA-MCS aerogels were highly efficient in adsorbing polyethylene terephthalate (PET) microplastics in water at pH values of 6–9, with a removal efficiency of up to 91.6%. Even after three recycles, PDA-MCS aerogels still displayed comparatively high removal efficiency (83.4%). Kinetic and isothermal experiments showed that the adsorption process was the result of electrostatic interactions and physical adhesion between aerogels and microplastics. Moreover, PDA-MCS aerogels maintained high removal efficiency under simulated environmental conditions, and the removal efficiency of PET, polyethylene (PE) and polystyrene (PS) microplastics in waters reached 97.3%, 94.6%, and 92.3%, respectively. Therefore, high-efficiency environmentally durable aerogels adsorbent materials have the potential for the removal of MPs from the aquatic environment. [Display omitted] • Coral bio-inspired aerogels based on polydopamine and chitosan were produced for microplastics removal. • The adsorption mechanisms of the aerogels for microplastics were investigated. • Comparatively high removal efficiency of the aerogels was observed for multiple microplastics. • Environmental durability and reusability of the aerogels were possessed. [ABSTRACT FROM AUTHOR]

Composting is the last "barrier" for microplastics (MPs) in the entry of organic solid wastes into the environment. The transformation of MPs is thought to be mainly driven by microorganisms during composting, whereas the contribution of abiotic processes that involve free radicals is often overlooked. Herein, we provide initial evidence for the generation of free radicals during sludge composting, including environmental persistent free radicals and reactive oxygen species, which accelerate the oxidative degradation of MPs. The · OH yield of composting fluctuated greatly from 23.03 to 277.18 μmol/kg during composting, which was closely related to the dynamic changes in Fe(II) (R2 = 0.926). Analyses of the composted MPs physicochemical properties indicated that MPs were aged gradually with molecular weights decrease from 18% to 27% and carbonyl index value increase from 0.23 to 0.52. Further investigation suggested that the microbially-mediated redox transformation of iron oxides could occur on the MPs surface accompanied by the production of abundant free radicals, thereby leading to the damage of MPs during composting. These results reveal the critical role of free radicals in MPs ageing under oxic/anoxic alternation conditions of composting and provide new insights into the bio-chemical mechanism of contaminant removal or transformation during sludge composting. [Display omitted] • The dynamic changes of free radicals were detected during composting. • The·OH with maximum yield of 277.18 μmol/kg during the thermophilic phase. • Free radicals accelerate ageing of MPs of during sludge composting. • The bio-chemical mechanism of MPs ageing during sludge composting was proposed. [ABSTRACT FROM AUTHOR]

Biodegradable plastics would be gradually degraded by microbes after being used and discarded, forming biodegradable microplastics (BMPs). It is however not clear if it, like conventional microplastics, can affect the original soil ecological balance. In this study, the non-degradable LDPE (low density polyethylene) was used as the reference primary microplastic, and the BMP PBAT (polyadipate/butylene terephthalate) was used as the test object. The effects of the amount of PBAT on soil physical-chemical properties, bacterial community were investigated using high throughput sequencing. The results showed that when the highest amount of PBAT applied was up to 250 times higher than the normal application amount, resulted in a certain dose-effect, and a higher amount of PBAT would reduce the content of NO 3 --N and TP. The lower amount of PBAT relatively increased the diversity of soil bacterial communities, and the relative abundance of the unique Azotobacter increased with increasing PBAT amount. The abundance of bacterial community in soil with different PBAT amounts was significantly correlated with the soil's physical-chemical properties. In addition, Mesorhizobium , TM7a and Azotobacter were observed to be highly tolerant bacteria in PBAT containing soil which can be actively explored to study the biodegradation of BMPs PBAT. [Display omitted] • A higher amount of BMP PBAT would reduce the content of NO 3 --N and TP. • Excessive BMP PBAT decreased the diversity and richness of soil bacterial community. • The soil produced a certain dose-effect after adding different amounts of BMP PBAT. • The unique Azotobacter genus were observed in the soil sample containing PBAT. [ABSTRACT FROM AUTHOR]

Reusable plastic sports bottles are used extensively worldwide, and little is known about the migration of chemicals from the bottles into drinking water. In this study, we investigated the chemical migration into drinking water stored for 24 h in new bottles, used bottles and bottles washed in the dishwasher. Non-target screening (NTS) by liquid-chromatography – high-resolution mass spectrometry (LC-HRMS) was performed to identify these compounds. We detected > 3500 dishwasher related compounds, with 430 showing migration even after subsequent flushing of the bottles. In addition, more than 400 plastic related compounds were detected, with high peaks for oligomers suspected to originate from the biodegradable polyester polycaprolactone, and aromatic amines, which may have been introduced as slip agents or antioxidants. These compounds have never been reported before in bottled water. Most of the identified compounds migrating out of the used bottles were plasticizers, antioxidants or photoinitiators. The presence of photoinitiators are of particular concern, due to possible endocrine disrupting effects. Furthermore, diethyltoluamide (DEET) was detected, which may have been formed from the plasticizer laurolactam. Typically, the dishwashing process enhanced the leaching of plastic related compounds, and even after additional water flushing, the average peak intensity of these compounds was only reduced by half. [Display omitted] • Migration of > 400 plastic related and > 3500 dishwasher related compounds. • The dishwashing process increased the migration of plastic related compounds. • Oligomers suspected from polycaprolactone (PCL) were migrating. • Three of the identified photoinitiators have possible endocrine disrupting effects. • Diethyltoluamide (DEET) may have been formed from the plasticizer laurolactam. [ABSTRACT FROM AUTHOR]

The omnipresent accumulation and non-degradable nature of plastics in the environment are posing an ever-increasing ecological threat. In this study, a total of 97 bacteria were isolated from macroplastic debris collected from the coastal environments of Andaman Island. The isolates were screened for LDPE degradation potential and were identified based on phenotypic, biochemical, and molecular characterization. 16S rDNA-based identification revealed that three-three isolates of each belong to the genus Oceanimonas and Vibrio , two were closely related to the genus Paenibacillus whereas, one-one was associated with the genus Shewanella, Rheinheimera, and Bacillus , respectively. A bacterial consortium was formulated using the top four isolates based on their individual LDPE degradation potentials. A significant increase (p < 0.05) in the mean LDPE degradation (47.07 ± 6.67% weight-loss) and change in thickness was observed after 120 days of incubation. FTIR spectrum, 13C NMR, and TG-DSC analyses demonstrated changes in the LDPE sheets' functional groups, crystallinity, and in thermal properties after 120 days of incubation. The SEM and AFM images confirmed bacterial attachments, an increase in surface roughness and deformities on LDPE sheets. This study reports a bacterial consortium that can efficiently degrade the plastics and can be used in providing eco-friendly mitigation of plastic waste. [Display omitted] • The marine bacterial consortium was formulated from plastisphere. • Low-density polyethylene degradation by the bacterial consortium was assessed. • Change/shift in functional groups of LDPE was observed. • A significant increase in biofilm and deterioration on LDPE sheets was observed. • The bacterial consortium can efficiently degrade LDPE. [ABSTRACT FROM AUTHOR]

The caterpillar larvae of the greater wax moth (Galleria mellonella) are avid plastivores, as when provided a diet of low-density polyethylene (LDPE) they actively feed on it. Recent work has highlighted the importance of their microbiome in the putative biodegradation of this plastic polymer, though the impact of plastic metabolism on the insect host is less clear. In the present study, we undertook an integrative approach spanning all levels of biological organization to explore the effects of a plastic diet on the metabolic physiology of this animal model of plastic biodegradation. We demonstrate that an LDPE diet is not sufficient to maintain optimal larval growth and survival. In addition, we confirm that plastic fed waxworms retain their fat body lipid stores in a manner proportional to their individual polyethylene consumption suggesting a direct effect of LDPE biodegradation. At the functional level, the oxidative capacity of the fat body of LDPE-fed larvae is maintained reflecting unaltered metabolic function of the tissue. Finally, metabolomic analyses confirmed fat body lipid stores maintenance in LDPE-fed worms, but uncovered various other nutritional deficiencies. Overall, this work unveils novel insights in the complex interplay between LDPE biodegradation and the metabolic physiology of this model plastivore. [Display omitted] • LDPE diet reduces fitness and growth of G. mellonella. • Fat body is the only organ maintained in LDPE-fed G. mellonella. • Oxidative ability is maintained in fat body mitochondria of LDPE-fed waxworms. • LDPE fed caterpillars maintain lipid reserves at detriment of other metabolites. [ABSTRACT FROM AUTHOR]

Personal protective equipment (PPE) such as face masks is vital in battling the COVID-19 crisis, but the dominant polypropylene-based PPE are lack of antiviral/antibacterial activities and environmental friendliness, and have hazardous impact on the soil and aquatic ecosystems. The work presented herein focused on developing biodegradable, antiviral, and antibacterial cellulose nonwovens (AVAB-CNWs) as a multi-functional bioprotective layer for better protection against coronavirus SARS-CoV-2 and addressing environmental concerns raised by the piling of COVID-19 related wastes. Both guanidine-based polymer and neomycin sulfate (NEO) were reactive-modified and covalently grafted onto the surface of cellulose nonwovens, thereby conferring outstanding antiviral and antibacterial activities to the nonwovens without deteriorating the microstructure and biodegradability. Through adjusting the grafting amount of active components and selecting appropriate reagents for pretreatment, the antimicrobial activity and hydrophobicity for self-cleaning of the nonwovens can be tuned. More importantly, we demonstrated for the first time that such multi-functional nonwovens are capable of inactivating SARS-CoV-2 instantly, leading to high virucidal activity (> 99.35%), which is unachievable by conventional masks used nowadays. Meanwhile, the robust breathability and biodegradability of AVAB-CNWs were well maintained. The applications of the as-prepared nonwovens as high-performance textile can be readily extended to other areas in the fight against COVID-19. [Display omitted] • Enable to instantly inactivate SARS-CoV-2 (> 99.35%) and HCoV-229E (> 98.27%). • Excellent growth inhibition (> 99.99%) towards both E. coli and S. aureus. • Tunable hydrophobicity for self-cleaning of the PPE outer layer. • Address the environmental concerns raised by non-biodegradable PPE materials. • Development of safe, comfortable, and biodegradable textiles for PPE. [ABSTRACT FROM AUTHOR]

Environmental concerns with liberal petroleum-based plastic use have led to demand for sustainable biodegradable alternatives. However, the inadequate end-of-life treatment of plastics may emit microplastics, either conventional or biodegradable, to the terrestrial environment. It is essential to evaluate the possible effects of conventional and biodegradable microplastics on the composition and function of soil microbial communities. Therefore, we conducted a soil microcosm experiment with polyethylene (PE), polystyrene (PS), polylactide (PLA), or polybutylene succinate (PBS) microplastics. The soil microbiome and metabolome were evaluated via 16S rRNA gene sequencing, metagenomics, and untargeted metabolomics. We reported that the presence of conventional or biodegradable microplastics can significantly alter soil microbial community composition. Compared to the control soils, the microbiome in PBS and PLA amended soils exhibited higher potential for uptake of exogenous carbohydrates and amino acids, but a reduced capacity for related metabolic function, potentially due to catabolite repression. No differences in soil metabolome can be observed between conventional microplastic treatments and the control. The potential reason may be that the functional diversity was unaffected by PE and PS microplastics, while the biodegradable particles promoted the soil microbial multifunctionality. Our findings systematically shed light on the influence of conventional and biodegradable microplastics on soil microorganisms, facilitating microplastic regulation. [Display omitted] • Multi-omics were used to estimate the effects of diverse microplastics on soil. • Microbial communities were affected by biodegradable and conventional plastics. • Conventional microplastics induced no differences in soil metabolome. • Biodegradable plastics promoted the soil microbial multifunctionality. [ABSTRACT FROM AUTHOR]

Biodegradation of plastic polymers by plastic-eating insects such as the greater wax moth (Galleria mellonella) might be promising for reducing plastic pollution, but direct in vivo evidence along with the related metabolic pathways and role of gut microbiota require further investigation. In this study, we investigated the in vivo degradation process, underlying potential metabolic pathways, and involvement of the gut microbiota in polystyrene (PS) biodegradation via enforcing injection of G. mellonella larvae (Tianjin, China) with PS microbeads (0.5 mg/larva; M n : 540 and M w : 550) and general-purpose PS powders (2.5 mg/larva; M n : 95,600 and M w : 217,000). The results indicated that the PS microplastics were depolymerized and completely digested independent of gut microbiota in G. mellonella although the metabolism could be enhanced by gut microbiota. Based on comparative metabolomic and liquid chromatography analyses, we proposed two potential metabolic pathways of PS in the intestine of G. mellonella larvae: the styrene oxide–phenylacetaldehyde and 4-methylphenol–4-hydroxybenzaldehyde–4-hydroxybenzoate pathways. These results suggest that the enzymes of G. mellonella are responsible for the efficient biodegradation of PS. Further study is needed to identify these enzymes and investigate the underlying catalytic mechanisms. [Display omitted] • Biodegradation of PS in G. mellonella was confirmed by various methods. • The depolymerization of PS in G. mellonella was gut microbe-independent. • The metabolism of PS oligomers and monomers was enhanced by gut microbiota. • Two metabolic pathways were proposed in the biodegradation of PS in G. mellonella. [ABSTRACT FROM AUTHOR]

Microplastics have attracted widespread attention due to their detrimental effects on organisms, and their efficient removal poses great challenges, especially those smaller than 3 µm that are more harmful for aquatic biota. Herein, the chitin based sponges with interconnected pores, excellent elasticity and mechanical durability were fabricated and composed with graphene oxide (GO) and oxygen-doped carbon nitride (O-C 3 N 4). The chitin based sponges could effectively remove different functionalized microplastics (~1 µm) at pH 6–8, including carboxylate-modified polystyrene (PS-COOH), amine-modified polystyrene (PS-NH 2), and polystyrene (PS). Notably, the removal efficiency of three microplastics by the chitin based sponges reached up to 71.6–92.1% at an environmentally relevant concentration of 1 mg L−1 in water system. The potential driving forces of the adsorption were electrostatic interactions, hydrogen bond interactions, and π-π interactions. In addition, the chitin based sponges are reusable and after re-used for 3 cycles due to their excellent compressibility. The algae toxicity test demonstrated good biocompatibility of the chitin based sponges and they are also biodegradable in a natural soil. This study provides a green and promising method for fabricating environmentally friendly adsorbents for small-size microplastics removal, and expands the insights into the mechanisms of microplastic adsorption onto the sponge materials. [Display omitted] • Chitin based sponges possess excellent elasticity and mechanical durability. • The sponges composited with GO or O-C 3 N 4 can effectively adsorb microplastics. • Adsorption mechanisms involve hydrogen bonds, electrostatic, and π-π interactions. • The sponges showed good reusability, biocompatibility, and biodegradability. [ABSTRACT FROM AUTHOR]

Different plastic types considered as compostable are found on the market such as petro-based (e.g., polybutylene adipate terephthalate (PBAT)) or bio-based plastics (e.g., polylactic acid, (PLA)). Even if their degradation has been confirmed in industrial compost conditions, investigation of their degradation in natural marine environment has been limited. To better understand biodegradation into natural marine environment, commercial compostable (PBAT, semi-crystalline and amorphous PLA) and non-compostable polymers (low density polyethylene, polystyrene, polyethylene terephthalate, polyvinyl chloride) were submerged in situ on the sediment and in the water column in the Mediterranean Sea. These samples were studied by chemical and microbiological approaches. After 82 days of immersion, no significant bacterial degradation of the different polymers was observed, except some abiotic alterations of PBAT and LDPE probably due to a photooxidation process. However, after 80 days in an enrichment culture containing plastic films as a main carbon source, Marinomonas genus was specifically selected on the PBAT and a weight loss of 12% was highlighted. A better understanding of the bacterial community colonizing these plastics is essential for an eco-design of new biodegradable polymers to allow a rapid degradation in aquatic environment. [Display omitted] • The sample position in the water column influences the abiotic degradation and the bacterial community. • The composition of plastic-associated microbial communities is not plastic nature dependent. • Plastics are mainly used as a support for the bacterial community. • Marinomonas genus was selected on polybutylene adipate terephthalate after enrichment culture. • The eco-design of new polymers with optimized properties is essential to improve the plastic biodegradation in environments. [ABSTRACT FROM AUTHOR]