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Microplastics and heavy metals are two different classes of pollutants that are often present in aquatic systems. However, the interaction between these two pollutants is poorly understood in freshwater systems. This research has examined the sorption of cadmium(II) ions onto polyethylene microplastic (PEMP) under freshwater conditions. The scanning electron microscope, X-ray diffraction, and Fourier transform infrared analyses confirmed the existence of different functional groups and the porous nature of the PEMP surface. The influences of physicochemical parameters such as the solution pH, contact time, and initial Cd(II) concentration have been examined. The Langmuir isotherm predicted the Cd(II) sorption capacity by PEMP at pH 5 as 1.37 mg/g. Several isotherm models were utilized, including the Freundlich, Langmuir, and Sips models. The results confirmed that the Sips model has been more appropriate for Cd(II)-PEMP isotherm based on percentage errors and correlation coefficient values. Furthermore, the pseudo-first kinetic model fitted Cd(II)-PEMP more accurately than the pseudo-second kinetic equation. Desorption experiments were conducted to release Cd(II) ions from Cd(II)-bearing PEMP using different chemical agents. The findings showed that using 0.01 M nitric acid resulted in a desorption efficiency exceeding 99.8%. This demonstrates that microplastics loaded with Cd(II) may release Cd(II) ions in highly acidic environments, potentially allowing for the uptake of Cd(II) ions by aquatic organisms in their digestive tracts. [ABSTRACT FROM AUTHOR]

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Approximately 99% of plastics produced worldwide were produced by the petrochemical industry in 2019 and it is predicted that plastic consumption may double between 2023 and 2050. The use of biodegradable bioplastics represents an alternative solution to petroleum-based plastics. However, the production cost of biopolymers hinders their real-world use. The use of waste biomass as a primary carbon source for biopolymers may enable a cost-effective production of bioplastics whilst providing a solution to waste management towards a carbon–neutral and circular plastics economy. Here, we report for the first time the production of poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) with a controlled molar ratio of 2:1 3-hydroxybutyrate:3-hydroxvalerate (3HB:3HV) through an integrated pre-treatment and fermentation process followed by alkaline digestion of cassava peel waste, a renewable low-cost substrate, through Cupriavidus necator biotransformation. PHBV was subsequently melt blended with a biodegradable polymer, polycaprolactone (PCL), whereby the 30:70 (mol%) PHBV:PCL blend exhibited an excellent balance of mechanical properties and higher degradation temperatures than PHBV alone, thus providing enhanced stability and controllable properties. This work represents a potential environmental solution to waste management that can benefit cassava processing industries (or other crop processing industries) whilst developing new bioplastic materials that can be applied, for example, to packaging and biomedical engineering. [ABSTRACT FROM AUTHOR]

The effectual prevention and control of microplastics (MPs) in an environment is of great significance and a challenging task. The extensive usage and improper disposal of plastic materials increased the quantity of MPs in the surroundings, which poses potential issues for both flora and fauna. A recent survey reported that MPs can easily accumulate in human and animal bodies, which causes several adverse health problems such as inflammation, chronic disease, neurotoxicity, oxidative stress, etc. MPs can also disturb the growth, reproduction, and survival of aquatic organisms, leading to a disruption of the food chain and ecosystem. Moreover, it acts as a toxin carrier and transports them into the biological system, leading to the accumulation of toxic compounds in the food chain that cause biomagnification. Therefore, effective MPs management is crucial to prevent and control the release of MPs into the environment. Strategies such as the 3R principle, public awareness, employing suitable solid waste management, and developing biodegradable alternatives to plastics can partially alleviate the hostile effect of MPs on the environment. However, this kind of strategy has not met the present-day demand to reduce waste MPs completely. In the future, available techniques like membrane filters, ultrasound, electrocoagulation, magnetic separation etc. must be combined with advanced technology like machine learning and artificial intelligence (MLAI) for the best performance to remove MPs. This review provides a source for further improvement for the effective prevention and control of waste MPs generation in an environment for sustainability, which can likely be achieved using appropriate technology. [ABSTRACT FROM AUTHOR]

Accumulation of polyethylene terephthalate (PET) polyester in ecosystems across the globe is a major pollution of concern. Microbial degradation recently generated novel insights into the biodegradation of varieties of plastics. In this study, a PET degrading bacterium Brucella intermedia IITR130 was isolated from a contaminated lake ecosystem at Pallikaranai, Chennai, India. Incubation of the bacterium along with the PET sheet (0.1 mm thickness) for 60 days resulted in 26.06% degradation, indicating a half-life of 137.8 days. Considerable changes in the surface morphology of the PET sheet were found as holes, pits, and cracks on incubation with strain IITR130, as revealed by scanning electron microscopy (SEM). After bacterial treatment of PET, the formation of new functional groups, most notably in the area of 3326 cm−1 suggestive of O–H stretch, leading to carboxylic acid and alcohol as products were suggested by fourier transform infrared (FTIR) analysis. Monomethyl terephthalate (MMT) and terephthalic acid (TPA) were identified by gas chromatography–mass spectrometry (GC–MS) analysis as PET degradation metabolites. Tributyrin clearance assay confirmed the presence of a lipase/esterase enzyme in the strain IITR130. In this study, a degradation pathway for PET by an isolated and identified bacterium Brucella intermedia IITR130 was characterized in detail. [ABSTRACT FROM AUTHOR]

Environmental pollution caused by petrochemical hydrocarbons (HC) and plastic waste is a pressing global challenge. However, there is a promising solution in the form of bacteria that possess the ability to degrade HC, making them valuable tools for remediating contaminated environments and effluents. Moreover, some of these bacteria offer far-reaching potential beyond bioremediation, as they can also be utilized to produce polyhydroxyalkanoates (PHAs), a common type of bioplastics. The accumulation of PHAs in bacterial cells is facilitated in environments with high C/N or C/P ratio, which are often found in HC-contaminated environments and effluents. Consequently, some HC-degrading bacteria can be employed to simultaneously produce PHAs and conduct biodegradation processes. Although bacterial bioplastic production has been thoroughly studied, production costs are still too high compared to petroleum-derived plastics. This article aims to provide a comprehensive review of recent scientific advancements concerning the capacity of HC-degrading bacteria to produce PHAs. It will delve into the microbial strains involved and the types of bioplastics generated, as well as the primary pathways for HC biodegradation and PHAs production. In essence, we propose the potential utilization of HC-degrading bacteria as a versatile tool to tackle two major environmental challenges: HC pollution and the accumulation of plastic waste. Through a comprehensive analysis of strengths and weaknesses in this aspect, this review aims to pave the way for future research in this area, with the goal of facilitating and promoting investigation in a field where obtaining PHAs from HC remains a costly and challenging process. [ABSTRACT FROM AUTHOR]

Plastic pollution has become a global problem since the extensive use of plastic in industries such as packaging, electronics, manufacturing and construction, healthcare, transportation, and others. This has resulted in an environmental burden that is continually growing, which has inspired many scientists as well as environmentalists to come up with creative solutions to deal with this problem. Numerous studies have been reviewed to determine practical, affordable, and environmentally friendly solutions to regulate plastic waste by leveraging microbes' innate abilities to naturally decompose polymers. Enzymatic breakdown of plastics has been proposed to serve this goal since the discovery of enzymes from microbial sources that truly interact with plastic in its naturalistic environment and because it is a much faster and more effective method than others. The scope of diverse microbes and associated enzymes in polymer breakdown is highlighted in the current review. The use of co-cultures or microbial consortium-based techniques for the improved breakdown of plastic products and the generation of high-value end products that may be utilized as prototypes of bioenergy sources is highlighted. The review also offers a thorough overview of the developments in the microbiological and enzymatic biological degradation of plastics, as well as several elements that impact this process for the survival of our planet. [ABSTRACT FROM AUTHOR]

The escalating worldwide concerns over the difficult degradation and pollution of plastic and its associated environmental and health risks have amplified the urgent need to develop biodegradable alternatives to traditional plastics. Polyhydroxyalkanoates (PHAs) have emerged as a promising class of biopolymers that offer a sustainable solution. Their commercial success in various applications has highlighted PHAs' potential to mitigate environmental impact. Critical to the economic feasibility of PHA production is the optimization of downstream processing methods, crucial for scaling operations from pilot to industrial scales. This paper reviews two decades of pilot-scale studies on PHA extraction, emphasizing the advancements and challenges encountered. It also discusses chemical extraction methods applied across different feedstock and microbial strains, highlighting their role in enhancing efficiency and sustainability. This comprehensive review underscores the imperative for advancing PHA technologies, particularly in refining extraction techniques, to facilitate broader adoption in industries seeking environmentally friendly alternatives to conventional plastics. [ABSTRACT FROM AUTHOR]

Non-recyclable fiber rejects from paper mills, particularly those from recycled linerboard mills, contain high levels of structural carbohydrates but are currently landfilled, causing financial and environmental burdens. The aim of this study was to develop efficient and sustainable bioprocess to upcycle these rejects into polyhydroxybutyrate (PHB), a biodegradable alternative to degradation-resistant petroleum-based plastics. To achieve high yields of PHB per unit biomass, the specific objective of the study was to investigate various approaches to enhance the hydrolysis yields of fiber rejects to maximize sugar recovery and evaluate the fermentation performance of these sugars using Escherichia coli LSBJ. The investigated approaches included size reduction, surfactant addition, and a chemical-free hydrothermal pretreatment process. A two-step hydrothermal pretreatment, involving a hot water pretreatment (150 °C and 15% solid loading for 10 min) followed by three cycles of disk refining, was found to be highly effective and resulted in an 83% cellulose conversion during hydrolysis. The hydrolysate obtained from pretreated biomass normally requires a detoxification step to enhance fermentation efficiency. However, the hydrolysate obtained from the pretreated biomass contained minimal to no inhibitory compounds, as indicated by the efficient sugar fermentation and high PHB yields, which were comparable to those from fermenting raw biomass hydrolysate. The structural and thermal properties of the extracted PHB were analyzed using various techniques and consistent with standard PHB. [ABSTRACT FROM AUTHOR]

The impact of ultrasound‐assisted fermentation using Lactobacillus species was investigated, for enhanced lactic acid production. The different ultrasound frequencies of 20, 30, and 40 Hz, with time intervals of 3, 4, and 5 min, and with corn steep liquor concentrations of 1%–3% were examined using response surface methodology‐Box–Behnken design. The growth of lactic acid production was modeled by Contois model (linear) and Baranyi–Roberts model (nonlinear), assessing the suitability of Lactobacillus paracasei, Lactobacillus plantarum, and Lactobacillus acidophilus for industrial processes. At 34 h, the maximal lactic acid generation of L. paracasei, L. plantarum, and L. acidophilus was 85.2%, 82.1%, and 79.4%, respectively. The R2, μmax, and Ks values for L. paracasei and L. plantarum were found to be 0.9158, 0.574 h−1, 54.27 g/L and 0.9426, 0.294 h−1, 22.66 g/L, respectively, using Contois model. The observed R2 values of Baranyi–Roberts model for the strains L. acidophilus, L. paracasei, and L. plantarum were 0.9947, 0.9954, and 0.9998, respectively. Practical Applications: Lactic acid is crucial in the fermentation process for products like yogurt, sauerkraut, kimchi, and pickles, enhancing flavor, texture, and shelf life. As a precursor to biodegradable plastics, lactic acid contributes to the development of sustainable packaging materials and environmentally friendly alternatives to traditional plastics. Utilizing waste corn steep liquor (CSL) as a growth medium presents a sustainable and cost‐effective solution for lactic acid production, capitalizing on its rich nutrient profile to enhance microbial growth. As a byproduct of corn wet milling, using CSL for fermentation processes promotes waste valorization and contributes to a circular economy. The optimization of fermentation conditions using the Box–Behnken design ensures maximum yield and efficiency by systematically evaluating the effects of key process variables. Integrating advanced growth curve models like the Contois and Baranyi models further refines the understanding and prediction of microbial dynamics, enabling precise control over the fermentation process. This comprehensive approach not only promotes the efficient use of industrial by‐products but also advances the development of environmentally friendly and economically viable bioprocesses. [ABSTRACT FROM AUTHOR]

BACKGROUND: Environmental and ecological hazards caused by the accumulation of polyethylene terephthalate (PET) are becoming a global concern. The use of enzymes to address the plastic crisis has achieved many successes, but the difficulty in degrading high‐crystallinity PET has limited its application. Numerous studies have investigated the degradation of PET with arbitrary crystallinity to bis‐2‐(2‐hydroxyethyl) terephthalate (BHET) using chemical pre‐treatment methods such as glycolysis, but few have tested its biocompatibility with enzymatic alliances. RESULTS: Herein, we report the enzymatic characterization and subsequent engineering of the state‐of‐the‐art IsPETasePA and MHETase (where MHET is mono(2‐hydroxyethyl) terephthalate), a dual‐enzyme system which can be used for the degradation from BHET to a single‐product terephthalate (TPA). Modulators, including surfactants, organic solvents and metal ions, enhanced the enzyme activity of IsPETasePA and MHETase by up to 1.1‐fold and 2.3‐fold, respectively. 100% TPA yield (BHET of 25 g L−1) was achieved within 5 h. We also analyzed the mechanism of optimal ion modulator modification by dynamics simulation, and it synergistically achieved enhancement of MHET degradation ability by improving stability and binding energy. CONCLUSION: The introduction of modulators improves the efficiency of the dual‐enzyme system in degrading BHET. This work provides a valuable strategy for the complete degradation of BHET to TPA, laying the groundwork for the realization of PET recycling. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Myco degradation is an effective technique for breaking down waste plant substances made of lignin, cellulose, and hemicellulose, which are collectively known as lignocellulose. This abundant organic material is found throughout the world. Due to its recalcitrant nature, lignocellulose poses a challenge for efficient conversion into biofuels, biochemicals, and other valuable products. Myco degradation, which involves the use of fungi to degrade lignocellulosic materials, offers a sustainable and cost‐efficient resolution to this challenge. This review provides an overview of the mechanisms and applications of myco degradation for lignocellulosic biomass degradation. The review discusses the various types of fungi involved in lignocellulose degradation, their enzymatic systems, and the factors that influences their performance. Furthermore, the potential applications of myco degradation products, such as biofuels, enzymes, and bioplastics, are reviewed. It also highlights the implications of myco degradation for waste management and sustainable development. Overall, myco degradation represents a promising technology for the efficient deprivation of lignocellulosic waste biomass, and further research in this field holds great potential for the sustainable creation of bio‐based products. [ABSTRACT FROM AUTHOR]

Mulching is a common method increasing crop yield and achieving out-of-season production; nevertheless, their removal poses a significant environmental danger. In this scenario, the use of biodegradable plastic mulches comes up as a solution to increase the sustainability of this practice, as they can be tilled in soil without risk for the environment. In this context, it is important to study the microbial response to this practice, considering their direct involvement in plastic biodegradation. This study evaluated the biodegradation of three commercial mulch residues: one conventional non-biodegradable mulch versus two biodegradable ones (white and black compostable Mater-Bi mulches). The experiment was conducted under three incubation temperatures (room temperature 20–25 °C, 30 °C, and 45 °C) for a 6-month trial using fallow agricultural soil. Soil without plastic mulch residues was used as a control. White mater-bi biodegradable mulch residues showed higher degradation rates up to 88.90% at 30 °C, and up to 69.15% at room temperature. Furthermore, incubation at 45 °C determines the absence of degradation for all types of mulch considered. Moreover, bacterial alpha diversity was primarily influenced by plastic type and temperature, while fungal populations were mainly affected by temperature. Beta diversity was impacted by all experimental variables. Predicted functional genes crucial for degrading complex substrates, including those encoding hydrolases, cutinases, cellobiosidases, and lipases, were derived from 16S rRNA gene sequencing data. Cluster analysis based on predicted enzyme-encoding gene abundance revealed two clusters, mainly linked to sampling time. Finally, core microbiome analysis identified dominant bacterial and fungal taxa in various soil-plastic ecosystems during degradation, pinpointing species potentially involved in plastic breakdown. The present study allows an assessment of how different temperatures affect the degradation of mulch residues in soil, providing important insights for different climatic growing zones. It also fills a gap in the literature by directly comparing the effects of biodegradable and polyethylene mulches on soil microbial communities. [ABSTRACT FROM AUTHOR]

Graphene oxide nanosheet (GO) is a multifunctional platform for binding with nanoparticles and stacking with two dimensional substrates. In this study, GO nanosheets were sonochemically decorated with zinc oxide nanoparticles (ZnO) and self-assembled into a hydrogel of GO–ZnO nanocomposite. The GO–ZnO hydrogel structure is a bioinspired approach for preserving graphene-based nanosheets from van der Waals stacking. X-ray diffraction analysis (XRD) showed that the sonochemical synthesis led to the formation of ZnO crystals on GO platforms. High water content (97.2%) of GO–ZnO hydrogel provided good property of ultrasonic dispersibility in water. Ultraviolet-visible spectroscopic analysis (UV–vis) revealed that optical band gap energy of ZnO nanoparticles (∼3.2 eV) GO–ZnO nanosheets (∼2.83 eV). Agar well diffusion tests presented effective antibacterial activities of GO–ZnO hydrogel against gram-negative bacteria (E. coli) and gram-positive bacteria (S. aureus). Especially, GO–ZnO hydrogel was directly used for brush painting on biodegradable polylactide (PLA) thin films. Graphene-based nanosheets with large surface area are key to van der Waals stacking and adhesion of GO–ZnO coating to the PLA substrate. The GO–ZnO/PLA films were characterized using photography, light transmittance spectroscopy, coating stability, scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopic mapping (EDS), antibacterial test and mechanical tensile measurement. Specifically, GO–ZnO coating on PLA substrate exhibited stability in aqueous food simulants for packaging application. GO–ZnO coating inhibited the infectious growth of E. coli biofilm. GO–ZnO/PLA films had strong tensile strength and elastic modulus. As a result, the investigation of antibacterial GO–ZnO hydrogel and GO–ZnO coating on PLA film is fundamental for sustainable development of packaging and biomedical applications. [ABSTRACT FROM AUTHOR]

The accumulation of plastic waste poses a pressing environmental challenge. Catalytic conversion stands out as an ideal approach for plastics upcycling, particularly through solar‐driven plastics photoreforming. However, due to the common effects of multiple reactive oxygen species (ROS), selectively generating high‐value chemicals becomes challenging. In this study, we developed a universal strategy to achieve >85 % selective production of diesel olefins (C15–C28) from polyolefin waste plastics via single ROS. Using tetrakis (4‐carboxyphenyl) porphyrin supramolecular (TCPP) with different central metals as an example to regulate single ROS generation, results show Ni‐TCPP facilitates triplet exciton production, yielding 1O2, while Zn‐TCPP generates ⋅O2− due to its strong built‐in electric field (IEF). 1O2 directly dechlorinates polyvinyl chloride (PVC) due to the electro‐negativity of chlorine atoms and the low dissociation energy of C−Cl bonds, while ⋅O2− promotes direct dehydrogenation of polyethylene (PE) due to the electro‐positivity of hydrogen atoms and the high dissociation energy of C−H bonds. This method is universally applicable to various single ROS systems. Installation experiments further affirm the application potential, achieving the highest diesel olefin production of 76.1 μmol h−1. Such a universally adaptive approach holds promise for addressing the global plastic pollution problem. [ABSTRACT FROM AUTHOR]

Biodegradable plastics, hailed for their environmental friendliness, may pose unforeseen risks as they undergo gastrointestinal degradation, forming oligomer nanoplastics. Despite this, the influence of gastrointestinal degradation on the potential human toxicity of biodegradable plastics remains poorly understood. To this end, the impact of the murine in vivo digestive system is investigated on the biotransformation, biodistribution, and toxicity of PLA polymer and PLA oligomer MPs. Through a 28‐day repeated oral gavage study in mice, it is revealed that PLA polymer and oligomer microplastics undergo incomplete and complete degradation, respectively, in the gastrointestinal tract. Incompletely degraded PLA polymer microplastics transform into oligomer nanoplastics, heightening bioavailability and toxicity, thereby exacerbating overall toxic effects. Conversely, complete degradation of PLA oligomer microplastics reduces bioavailability and mitigates toxicity, offering a potential avenue for toxicity reduction. Additionally, the study illuminates shared targets and toxicity mechanisms in Parkinson's disease‐like neurotoxicity induced by both PLA polymer and PLA oligomer microplastics. This involves the upregulation of MICU3 in midbrains, leading to neuronal mitochondrial calcium overload. Notably, neurotoxicity is mitigated by inhibiting mitochondrial calcium influx with MCU‐i4 or facilitating mitochondrial calcium efflux with DBcAMP in mice. These findings enhance the understanding of the toxicological implications of biodegradable microplastics on human health. [ABSTRACT FROM AUTHOR]

Oxidative degradation is a powerful method to degrade plastics into oligomers and small oxidized products. While thermal energy has been conventionally employed as an external stimulus, recent advances in photochemistry have enabled photocatalytic oxidative degradation of polymers under mild conditions. This tutorial review presents an overview of oxidative degradation, from its earliest examples to emerging strategies. This review briefly discusses the motivation and the development of thermal oxidative degradation of polymers with a focus on underlying mechanisms. Then, we will examine modern studies primarily relevant to catalytic thermal oxidative degradation and photocatalytic oxidative degradation. Lastly, we highlight some unique studies using unconventional approaches for oxidative polymer degradation, such as electrochemistry. [ABSTRACT FROM AUTHOR]

Sustainable production of 1,4-pentanediol (1,4-PDO) from biomass is of great importance because 1,4-PDO is a monomer of degradable polyesters and plastics. This paper reviews the conversion of biomass-derived levulinic acid (LA) and furfural as well as their derivatives alkyl levulinate, γ-valerolactone (GVL) and furfuryl alcohol (FAL) into 1,4-PDO. MoOx or ReOx modified noble metal catalysts and non-noble metal catalysts with core–shell and alloy structures show a high 1,4-PDO yield and stability in LA hydrogenation under severe hydrothermal conditions. The conversion of furfural to 1,4-PDO involves the initial C＝O bond hydrogenation to form FAL, the consecutive acid-catalyzed ring-opening and the final hydrogenation. Therefore, it needs a bifunctional catalyst composed of metallic species and acid sites to improve the 1,4-PDO yield. Efforts are made here to highlight the employed catalysts, structure–performance relationship, reaction pathway and reaction mechanism in detail. The current challenges for large-scale applications of conversion of LA and furfural to 1,4-PDO have been proposed, including process development, catalyst cost, solvent and active site distribution. We believe that this review will provide new opportunities and expand the options for the production of 1,4-PDO via biorefining processes. [ABSTRACT FROM AUTHOR]

The accumulation of plastic packaging wastes in the natural environment highlights the significance of sustainable alternatives. Paper is widely used as a biodegradable packaging material, but poor mechanical strength, barrier properties, and water resistance limit its utility. Typical paper coating materials applied to overcome such drawbacks, such as polyethylene (PE) and ethylene vinyl alcohol (EVOH), are not desirable for sustainability due to environmental persistence. Here, we report a biodegradable, biocompatible, robust, and high-barrier paper coating strategy using boric acid-crosslinked poly(vinyl alcohol) (PVA). Various crosslinked-PVA solutions were prepared using boric acid (BA) and hydrochloric acid (HCl) as a crosslinker and an acid catalyst, respectively. The solutions were coated onto the Kraft paper (KP) through facile bar coating with epichlorohydrin (ECH) as a binder (henceforth referred to as coated papers). The coated papers (KP-P, KP-PB, KP-PBH) show remarkably improved oxygen (∼0.89 cc m−2 d−1) and water vapor (∼5.17 g m−2 d−1) barrier properties as well as tensile strength (∼53.0 MPa) that is retained in moist conditions. The coated papers were significantly mineralized into CO2 (59.2–81.6% over 111 d) in the simulated marine environment biodegradation test. Depolymerization of polymer chains and surface degradation of coated papers are evidenced via FT-IR and SEM, respectively. The microcosm test revealed that the intensive disintegration of the coated papers is synergistically driven by both biotic and abiotic factors (i.e., mechanical stress). Moreover, the in vitro biocompatibility tests employing human embryonic kidney and mouse embryonic fibroblast cells, and in vivo biocompatibility test with mice suggest that the coated papers are highly biocompatible. This work provides a promising strategy for paper packaging that enhances packaging performance without compromising environmental sustainability. [ABSTRACT FROM AUTHOR]

Aliphatic‐aromatic copolyesters offer a promising solution to mitigate plastic pollution, but high content of aliphatic units (>40 %) often suffer from diminished comprehensive performances. Poly(butylene oxalate‐co‐furandicarboxylate) (PBOF) copolyesters were synthesized by precisely controlling the oxalic acid content from 10 % to 60 %. Compared with commercial PBAT, the barrier properties of PBOF for H2O and O2 increased by more than 6 and 26 times, respectively. The introduction of the oxalic acid units allowed the water contact angle to be reduced from 82.5° to 62.9°. Superior hydrophilicity gave PBOF an excellent degradation performance within a 35‐day hydrolysis. Interestingly, PBO20F and PBO30F also displayed obvious decrease of molecular weight during hydrolysis, with elastic modulus >1 GPa and tensile strength between 35–54 MPa. PBOF achieved the highest hydrolysis rates among the reported PBF‐based copolyesters. The hydrolytic mechanism was further explored based on Fukui function analysis and density functional theory (DFT) calculation. Noncovalent analysis indicated that the water molecules formed hydrogen bonding interaction with adjacent ester groups and thus improved the reactivity of carbonyl carbon. PBOF not only meet the requirements of the high‐performance packaging market but can quickly degrade after the end of their usage cycles, providing a new choice for green and environmental protection. [ABSTRACT FROM AUTHOR]

Polyethylene (PE), a highly prevalent non‐biodegradable polymer in the field of plastics, presents a waste management issue. To alleviate this issue, bio‐based PE (bio‐PE), derived from renewable resources like corn and sugarcane, offers an environmentally friendly alternative. This review discusses various production methods of bio‐PE, including fermentation, gasification, and catalytic conversion of biomass. Interestingly, the bio‐PE production volumes and market are expanding due to the growing environmental concerns and regulatory pressures. Additionally, the production of PE and bio‐PE biocomposites using agricultural waste as filler materials, highlights the growing demand for sustainable alternatives to conventional plastics. According to previous studies, addition of ≈50% defibrillated corn and abaca fibers into bio‐PE matrix and a compatibilizer, results in the highest Young's modulus of 4.61 and 5.81 GPa, respectively. These biocomposites have potential applications in automotive, building construction, and furniture industries. Moreover, the advancement made in abiotic and biotic degradation of PE and PE biocomposites is elucidated to address their environmental impacts. Finally, the paper concludes with insights into the opportunities, challenges, and future perspectives in the sustainable production and utilization of PE and bio‐PE biocomposites. In summary, production of PE and bio‐PE biocomposites can contribute to a cleaner and sustainable future. [ABSTRACT FROM AUTHOR]

Pyrolytic synergistic interactions, in which the production of pyrolyzates is enhanced or inhibited, commonly occur during the co-pyrolysis of different polymeric materials, such as plastics and biomass. Although these interactions can increase the yield of desired pyrolysis products under controlled degradation conditions, the desired compounds must be separated from complex pyrolyzates and further purified. To balance these dual effects, this study was aimed at examining pyrolytic synergistic interactions during slow heating co-pyrolysis of biodegradable plastics including polylactic acid (PLA) and poly(3-hydroxybutyrate-co-3-hydroxyhexaoate) (PHBH) and petroleum-based plastics including high-density polyethylene (HDPE), polypropylene (PP), and polystyrene (PS). Comprehensive investigations based on thermogravimetric analysis, pyrolysis–gas chromatography/mass spectrometry, and evolved gas analysis-mass spectrometry revealed that PLA and PHBH decompose at lower temperatures (273–378 °C) than HDPE, PP, and PS (386–499 °C), with each polymer undergoing independent decomposition without any pyrolytic interactions. Thus, the independent pyrolysis of biodegradable plastics, such as PLA and PHBH, with common plastics, such as HDPE, PP, and PS, can theoretically be realized through temperature control, enabling the selective recovery of their pyrolyzates in different temperature ranges. Thus, pyrolytic approaches can facilitate the treatment of mixed biodegradable and common plastics. [ABSTRACT FROM AUTHOR]

Poly(3-hydroxybutyrate) (P(3HB)) is an attractive biodegradable plastic alternative to petroleum-based plastic. However, the cost of microbial-based bioplastic production mainly lies in the cultivation medium. In this study, we screened the isolates capable of synthesizing P(3HB) using sugarcane bagasse (SCB) waste as a carbon source from 79 Bacillus isolates that had previously shown P(3HB) production using a commercial medium. The results revealed that isolate S356, identified as Bacillus cereus using 16S rDNA and gyrB gene analysis, had the highest P(3HB) accumulation. The highest P(3HB) yield (5.16 g/L, 85.3% of dry cell weight) was achieved by cultivating B. cereus S356 in an optimal medium with 1.5% total reducing sugar with SCB hydrolysate as the carbon source and 0.25% yeast extract as the nitrogen source. Transmission electron microscopy analysis showed the accumulation of approximately 3–5 P(3HB) granules in each B. cereus S356 cell. Proton nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy analyses confirmed that the polymer extracted from B. cereus S356 was P(3HB). Notably, during cultivation for P(3HB) plastic production, B. cereus S356 also secreted bacteriocin, which had high antibacterial activity against the same species (Bacillus cereus). Overall, this work demonstrated the possibility of co-producing eco-friendly biodegradable plastic P(3HB) and bacteriocin from renewable resources using the potential of B. cereus S356. [ABSTRACT FROM AUTHOR]

The global trend towards conscious consumption plays an important role in consumer preferences regarding both the composition and quality of food and packaging materials, including sustainable ones. The development of biodegradable active packaging materials could reduce both the negative impact on the environment due to a decrease in the use of oil-based plastics and the amount of synthetic preservatives. This review discusses relevant functional additives for improving the bioactivity of biopolymer-based films. Addition of plant, microbial, animal and organic nanoparticles into bio-based films is discussed. Changes in mechanical, transparency, water and oxygen barrier properties are reviewed. Since microbial and oxidative deterioration are the main causes of food spoilage, antimicrobial and antioxidant properties of natural additives are discussed, including perspective ones for the development of biodegradable active packaging. [ABSTRACT FROM AUTHOR]

Extremophilic microorganisms play a key role in understanding how life on Earth originated and evolved over centuries. Their ability to thrive in harsh environments relies on a plethora of mechanisms developed to survive at extreme temperatures, pressures, salinity, and pH values. From a biotechnological point of view, thermophiles are considered a robust tool for synthetic biology as well as a reliable starting material for the development of sustainable bioprocesses. This review discusses the current progress in the biomanufacturing of high-added bioproducts from thermophilic microorganisms and their industrial applications. [ABSTRACT FROM AUTHOR]

In this work, a novel electrospun nanofiber (PAN/TpBD; 2,4,6‐triformylphloroglucinol [Tp] and benzidine [BD]; polyacrylonitrile [PAN]) was fabricated via a facile electrospinning method and utilized as adsorbent in thin film microextraction (TFME) of phthalate esters (PAEs) (dimethyl phthalate, diethyl phthalate, diallyl phthalate, dibutyl phthalate, and dioctyl phthalate) in biodegradable plastics. The prepared PAN/TpBD combines the strong stability of nanofibers with increased exposure sites for covalent organic frameworks and enhanced interactions with the target, thus improving the enrichment effect on the target. The extraction efficiency of PAN/TpBD reached above 80%. Based on PAN/TpBD, a TFME‐high‐performance liquid chromatography method was established, and the experimental parameters were optimized. Under the optimal extraction conditions, the PAEs of this method varied linearly in the range of 10–10 000 µg/L with low detection limits (0.69–2.72 µg/L). The intra‐day and inter‐day relative standard deviation values of the PAEs were less than 8.04% and 8.73%, respectively. The adsorbent can achieve more than 80% recovery of the five targets after six times reuse. The developed method was successfully applied for the determination of trace PAEs in biodegradable plastics with recoveries ranging from 80.1% to 113.4% and relative standard deviations were less than 9.45%. The as‐synthesized PAN/TpBD adsorbent exhibited great potential in PAE analysis. [ABSTRACT FROM AUTHOR]

This document discusses the ecological effects of micro(nano)plastics in the water environment. It highlights the accumulation and degradation of plastic products in aquatic systems, leading to the creation of micro- and nanoplastics. The document presents findings from a special issue collection, including studies on the impact of plastic litter on marine biodiversity, the toxicity of plastic additives to freshwater animals, the combined effect of microplastics and organic micropollutants on crustaceans, the toxic potential of conventional and compostable plastic particles for goldfish, the avoidance of plastic particles by climbing perch, and a method for detecting micro- and nanoplastics using the phototrophic behavioral response of crustaceans. The document concludes that more research is needed to understand the long-term effects of micro- and nanoplastics on aquatic species and calls for standardized testing methods for risk assessment of plastic contaminants in aquatic systems. [Extracted from the article]

Biodegradable plastics are gaining popularity as environmentally friendly functional materials. This study focuses on the preparation of aluminum hydroxide (Al(OH)3) reinforced cellulose acetate composite films using a cost‐effective approach. The process involves synthesizing bamboo‐derived cellulose acetate (BDCA), dissolving it in tetrahydrofuran with glycerol as a plasticizer, and incorporating Al(OH)3 particles into the casting solution to reinforce the cellulose acetate film. Analyses on microstructure and characteristics of the films were conducted through various techniques, including scanning electron microscopy (SEM), Fourier transform infrared (FT‐IR) spectroscopy, x‐ray diffraction (XRD), water contact angle measurement, and tensile testing. The results indicate that the Al(OH)3 particles were well‐dispersed in the composite films, leading to a strong interaction with the cellulose acetate matrix. As a result, the prepared composite films exhibited significantly higher tensile strength compared to pure bamboo‐derived cellulose film. Additionally, they demonstrated improved anti‐ultraviolet properties and a lower water vapor transmission rate, despite being more hydrophilic. This method holds significant potential for commercial applications in producing high‐performance cellulose acetate‐based composite films. Highlights: Bamboo‐derived cellulose acetate was synthesized through chemical processes.BDCA based composite film reinforced with Al(OH)3 was prepared by casting method.The Al(OH)3 significantly enhance the functional properties of the composite film.Composite films showed good performances for packaging according to the results. [ABSTRACT FROM AUTHOR]

The ubiquitous incorporation of plastics into daily life, coupled with inefficient recycling practices, has resulted in the accumulation of millions of metric tons of plastic waste, that poses a serious threat to the Earth's sustainability. Plastic pollution, a global problem, disrupts the ecological balance and endangers various life forms. Efforts to combat plastic pollution are underway, with a promising avenue being biological degradation facilitated by certain insects and their symbiotic gut microorganisms, particularly bacteria. This review consolidates existing knowledge on plastic degradation by insects and their influence on gut microbiota. Additionally, it delves into the potential mechanisms employed by insects in symbiosis with gut bacteria, exploring the bioconversion of waste plastics into value‐added biodegradable polymers through mineralization. These insights hold significant promise for the bio‐upcycling of plastic waste, opening new horizons for future biomanufacturing of high‐value chemicals from plastic‐derived compounds. Finally, we weigh the pros and cons of future research endeavors related to the bioprospection of plastic‐degrading bacteria from underexplored insect species. We also underscore the importance of bioengineering depolymerases with novel characteristics, aiming for their application in the remediation and valorization of waste plastics. [ABSTRACT FROM AUTHOR]

A fully biodegradable, ultra‐sensitive, and soft strain sensor is pivotal for temporary, real‐time monitoring of microdeformations, crucial in disease diagnosis, surgical precision, and prognosis of muscular, and vascular conditions. Nevertheless, the strain sensitivity of previous biodegradable sensors, denoted by gauge factor (GF) up to ≈100, falls short of requirements for complex biomedical monitoring scenarios, specifically monitoring cardio‐cerebrovascular diseases with microscale variations in vascular surface strain. Here, a fully biodegradable, ultra‐sensitive crack‐based flexible strain sensor is introduced achieving GF of 1355 at 1.5% strain through integration of molybdenum (Mo) film, molybdenum trioxide (MoO3) adhesion layer, and polycaprolactone (PCL) substrate. Analysis of crack morphology of biodegradable thin‐film metals, including Mo, tungsten (W), and magnesium (Mg), reveals material‐dependent sensitivity and repeatability of crack‐based strain sensors. The effect of the adhesion layer and polymer substrate is also investigated. Overall morphological studies on the sensor present a comprehensive understanding of metal film cracking behavior and corresponding performance characterization, showing significant potential for highly sensitive sensors. A hybrid membrane composed of candelilla wax (Cw), beeswax (Bw), and polybutylene adipate‐co‐terephthalate (PBAT) is introduced to provide hydrophobic, yet flexible encapsulation. In vivo, short‐term (≈3 days) monitoring of vascular pulsatility underscores the potential of the sensing tool for rapid, accurate, and temporal disease diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Arbitrary disposal of plastic waste into landfills and oceans can disturb the ecological system and even challenge human survival. Centralized plastic recycling process only works for selected types of plastics (e.g., polyethylene) with limited contribution (<10%), because of high infrastructure requirement. Comparatively, photoreforming of plastic waste for commodity and fuels production is much more facile and decentralizable, and thus holds great potential to mitigate the plastic waste challenge. To this end, a fully solar powered photoelectrochemical system is developed to selectively upgrade polyimide waste (often appears in electronic waste) into valuable commodity chemicals, including succinic acid, acetic acid, and formic acid, and cogenerating green hydrogen fuels. It is also demonstrated that one of the key monomer, pyromellitic acid, and the precious metals (in electronic waste) can be fully recycled. This proof‐of‐concept demonstration provides a new viewpoint for designing decentralized photoelectrochemical system for simultaneous plastic waste upcycling and renewable fuel synthesis, critical for a sustainable plastic economy. Selective cleavage of benzene ring also opens a green route for other benzene ring‐containing waste upgrading. [ABSTRACT FROM AUTHOR]

Microplastic particles appear in great abundance and variety in freshwater ecosystems across the globe, spanning lakes and rivers, with increasingly frequent exposure of aquatic organisms. Studies on the mechanisms of any effects of plastic particles are still scarce, particularly in relation to the regenerative capacity of biota, for which there is no established model organism; however, planaria have shown sensitivity for assessing these risks to the aquatic environment. Thus, the present study aimed to investigate the behavioral and regeneration responses of the freshwater planaria Girardia tigrina exposed to polyethylene (PE) microplastics (MPs) incorporated into their food source. The greatest effect was observed on planarian regeneration, which was manifested at 10 μg/mg liver. Planaria reproduction and fertility were affected at 50 μg/mg liver; however, planaria locomotion was not affected at the concentrations evaluated. Mid-infrared absorption spectroscopy (FT-IR) was used to identify the constituent polymers, and ingestion of the polyethylene microplastic by the planaria was confirmed by infrared spectroscopy. The results highlight the potential adverse effects of exposure to polyethylene microplastic and show that the reproductive behavior and regeneration of a freshwater organism can be indicators of toxicity resulting from environmental pollution. [ABSTRACT FROM AUTHOR]

In the natural environment, plastics and microplastics (MPs) are difficult to break down due to their hydrophobicity, the presence of persistent covalent bonds, and their functional groups' resistance to attack. The destiny of both organic and inorganic pollutants at contaminated areas can be influenced by MPs ability to absorb them. Because of their enormous surface to volume ratio and chemical surface characteristics, MPs are able to absorb dangerous substances from their surroundings. Accordingly, the study's main objectives were to provide a concise review of characterization techniques of MP biodegradation techniques, including the nano‐enabled methods, and the gaps in current research were outlined. This review paper summarizes the degradation mechanism and efficiency of MPs in different circumstances. For the purpose of eliminating plastic pollution, this work will help for the further studies. [ABSTRACT FROM AUTHOR]

Although biomass‐based alternatives for the manufacturing of bioplastic films are an important aspect of a more sustainable future, their physicochemical properties need to be able to compete with the existing market to establish them as a viable alternative. One important factor that is often neglected is the long‐term stability of renewables‐based functional materials, as they should neither degrade after a day or week, nor last forever. One material showing high potential in this regard, also due to its intrinsic biodegradability and antibacterial properties, is chitosan, which can form stable, self‐standing films. We previously showed that green additives introduce a broad tunability of the chitosan‐based material properties. In this work, we investigate the long‐term stability and related degradation processes of chitosan‐based bioplastics by assessing their physicochemical properties over 400 days. It was found that the film properties change similarly for samples stored in the fridge (4 °C, dark) as at ambient conditions (20 °C, light/dark cycles of the day). Additives with high vapor pressure, such as glycerol, evaporate and degrade, causing both brittleness and discoloration. In contrast, films with the addition of crosslinking additives, such as citric acid, show high stability also over a long time, bearing great preconditions for practical applications. This knowledge serves as a stepping‐stone to utilizing chitosan as an alternative material for renewable‐resourced bioplastic products. [ABSTRACT FROM AUTHOR]

Virgin and environmentally aged polypropylene (PP) micropowders (V-PP and E-PP, respectively) were used as reference microplastics (MPs) in comparative photo- and thermo-oxidative ageing experiments performed on their mixtures with a natural ferrous sand (NS) and with a metal-free silica sand (QS). The ferrous NS was found to catalyze the photo-oxidative degradation of V-PP after both UV and simulated solar light irradiation. The catalytic activity in the V-PP/NS mixture was highlighted by the comparatively higher fraction of photo-oxidized PP extracted in dichloromethane, and the higher carbonyl index of the bulk polymer extracted with boiling xylene, when compared with the V-PP/QS mixture. Similarly, NS showed a catalytic effect on the thermal degradation (at T = 60 °C) of E-PP. The results obtained indicate that, under suitable environmental conditions (in this case, an iron-containing sediment or soil matrix, combined with simulated solar irradiation), the degradation of some types of MPs could be much faster than anticipated. Given the widespread presence of iron minerals (including the magnetite and iron-rich serpentine found in NS) in both coastal and mainland soils and sediments, a higher than expected resilience of the environment to the contamination by this class of pollutants is anticipated, and possible routes to remediation of polluted natural environments by eco-compatible iron-based minerals are envisaged. [ABSTRACT FROM AUTHOR]

Platforms are structures built by coypus for various purposes, such as reproduction, resting, and thermoregulation. In a coastal wetland of central Italy, during a study aimed at investigating the characteristics of coypu's platforms, it was recorded, for the first time worldwide, the presence of plastic in these structures. Through a transect survey, we censused 83 platforms, among which three (3.61%) were found with presence of macro- and megaplastics (polystyrene, polypropylene, and low-density polyethylene in film form; polyester, polyamide, and expanded polystyrene in fragments). Through the FTIR spectra, it was possible to highlight the degradation of the polymeric materials. To stimulate possible in-depth investigations at the level of the food chain (e.g., coypu predators, including canids) in wet habitats, we discussed possible causes and implications of plastic presence in coypus' nest structures. [ABSTRACT FROM AUTHOR]

A flexible and stretchable vitrimer was synthesized using exclusively biobased building blocks and following green chemistry principles. Epoxidized soybean oil (ESO), vanillin, the biobased diamine, Priamine®, and oleic acid were used to create a material that can replace fossil-derived, non-biodegradable packaging. Vanillin and Priamine® were used to develop a crosslinker that could react with the epoxide groups of ESO without the need for solvents, with a catalystfree synthesis that does not generate any waste or byproducts. Oleic acid was incorporated, to tune the properties of the final material, since it can react with ESO and control the crosslink density. The vitrimers produced in this work showed excellent reprocessability and recyclability. They possess the ability to be molded, and they can also strongly adhere on surfaces. Moreover, they exhibited oxygen and water vapor barrier comparable to low density polyethylene, while showing very low migration into food simulant, which position them as a promising material for flexible food and general packaging market. The vitrimers showed also the capability of biodegradation in seawater, providing a safe end of life in case of mismanagement [ABSTRACT FROM AUTHOR]

Increasing toughness of brittle polymer without losing modulus of elasticity and tensile strength is highly important for enlarging the range of applications. In this study, polylactic acid (PLA) modified with epoxidized linseed oil (ELO) and polypropylene-grafted maleic anhydride (PPgMA) with a good balance of toughness and rigidity was successfully prepared by melt mixing procedure. The addition of PPgMA/ELO with appropriate proportions (3:1, 5:1, and 5:5 wt %) resulted in PLA modified samples with significant ductility improvement (around 2200% of elongation at break and 1800% of tensile toughness compared to the neat PLA) with low decrease in Young modulus and tensile strength. This feature was attributed to improved interfacial interactions and the formation of crosslinked structures at the interface that also increased viscosity of the melting system and cold crystallization temperature of PLA. The scanning electron microscopy revealed the presence of small domains of modified systems. The effectiveness of reactive compatibilization among the components was also suggested by Fourier transform infrared (FTIR) spectroscopy and thermal degradation analysis. The combination of toughness, modulus of elasticity and good thermal properties make this low-cost and scalable ecofriendly material a promising candidate for use as biodegradable plastic in several fields including medical applications and packaging. [ABSTRACT FROM AUTHOR]

Plastic has become part of daily life because it is used in all industrial applications. Although it is beneficial and practical, it is the material that generates the most pollution in ecosystems. Therefore, the main objective of this research is to produce plastic films capable of degrading the environment in a shorter time (bioplastics). For this purpose, different samples were made with cassava starch (pulp or commercial), using amounts in the solution of 4% w/v and 30% w/w of cassava starch and glycerol, respectively, considering variations between the percentages of chitosan. The results showed that it is possible to obtain bioplastic by the casting method with the mixture of cassava starch (pulp or commercial), glycerol, and chitosan. Likewise, thanks to the laboratory tests carried out, was possible to determine that the use of commercial starch to produce biodegradable plastic films significantly favors moisture adsorption, solubility, and biodegradability, compared to starch extracted from cassava by hand, with good statistics validity of the analyzed data. [ABSTRACT FROM AUTHOR]

With the growing global demand for biodegradable plastics, the hydrogenation of dimethyl maleate (DMM) to produce 1,4-butanediol (BDO), raw materials for poly(butylene succinate), has become one of the hot spots in chemical industry. In this work, we synthesized a series of Cu@C/ZnO–Sx catalysts by the method of sorbitol modification for the liquid-phase hydrogenation of DMM. The modification with appropriate sorbitol led to a decoration of carbon on catalyst surface, which improved the copper dispersion and Cu+/(Cu0 + Cu+) molar ratio in the Cu@C/ZnO–S0.08 catalyst. The carbon decoration not only promoted the formation of more copper species having stronger interaction with ZnO, but also enhanced the absorption of ester on catalyst surface. These distinctive properties contributed to the high performance of the Cu@C/ZnO–S0.08 catalyst in DMM hydrogenation, achieving an excellent BDO yield of 98.4% and superior reusability. The insights into the roles of sorbitol modification could give valuable guidance to the further design of high performance catalysts for esters hydrogenation. [ABSTRACT FROM AUTHOR]

As a way to reduce microplastics or nano-plastics in the ocean, it is of interest to develop biodegradable paper-based drinking straws to replace non-degradable plastic drinking straws. Primary questions to be addressed include how to design suitable coatings for paper drinking straws. Such coatings not only need to resist water. In addition, consumers have high expectations for the strength of a drinking straw. It is proposed here to replace non-biodegradable polypropylene, which is presently the main component of straws, with biodegradable and hydrophobic coating components via an entropy-driven approach. It is further proposed to develop colored paper-based drinking straws with cellulose nematic liquid crystal photonic pigments as a way to make the product stand out visibly, while at the same time mediating the usage of toxic chemical pigments. [ABSTRACT FROM AUTHOR]

In recent years, there has been continuous growth in the market for polylactide/poly(lactic acid) (PLA) which can be attributed to the increasing preference for environmentally friendly products derived from renewable resources. Apart from its established biomedical applications, polylactide is being considered as a replacement for petroleum-based polymers in various industries, including packaging, electronics, automotive, and textiles. However, PLA modification is necessary to meet the properties of common thermoplastics for target applications. One of the modification methods involves the synthesis of PLA block copolymers, including widely exploited polymers of vinyl monomers (PVM). This review article covers a wide range of applications suggested for PLA/PVM block copolymers as discussed in recent articles. A brief overview of the synthesis methods for PLA/PVM block copolymers is provided. The tendency of block copolymers to self-assemble, leading to specific morphologies, is discussed, and applications that take advantage of this behavior, such as polymeric micelles or porous materials, are highlighted. Examples of using micelles for the delivery of biologically active compounds are presented. Other biomedical applications, such as materials for tissue engineering and medical devices, are also discussed. Finally, the article covers materials for common plastic applications obtained through reactive blending/extrusion, which produces PLA/PVM copolymers in situ. [ABSTRACT FROM AUTHOR]

The capture and reduction of atmospheric dinitrogen gas to ammonium can be accomplished through the enzyme nitrogenase in a process known as biological nitrogen fixation (BNF), by a class of microbes known as diazotrophs. The diazotroph Azotobacter vinelandii is a model organism for the study of aerobic nitrogen fixation, and in recent years has been promoted as a potential producer of biofertilizers. Prior reports have demonstrated the potential to partially deregulate BNF in A. vinelandii, resulting in accumulation and extracellular release of ammonium. In many cases, deregulation requires the introduction of transgenic genes or elements to yield the desired phenotype, and the long‐term stability of these strains has been reported to be somewhat problematic. In this work, we constructed two strains of A. vinelandii where regulation can be precisely controlled without the addition of any foreign genes or genetic markers. Regulation is maintained through native promoters found in A. vinelandii that can be induced through the addition of extraneous galactose. These strains result in varied degrees of regulation of BNF, and as a result, the release of extracellular ammonium is controlled in a precise, and galactose concentration‐dependent manner. In addition, these strains yield high biomass levels, similar to the wild‐type A. vinelandii strain and are further able to produce high percentages of the bioplastic polyhydroxybutyrate. [ABSTRACT FROM AUTHOR]

Poly(3-hydroxybutyrate) (PHB) is a biobased and biodegradable polymer with properties comparable to polypropylene and therefore has the potential to replace conventional plastics. PHB is intracellularly accumulated by prokaryotic organisms. For the cells PHB functions manly as carbon and energy source, but all possible functions of PHB are still not known. Synechocystis (cyanobacteria) accumulates PHB using light as energy and CO2 as carbon source. The main trigger for PHB accumulation in cyanobacteria is nitrogen and phosphorous depletion with simultaneous surplus of carbon and energy. For the above reasons, obtaining knowledge about external factors influencing PHB accumulation is of highest interest. This study compares the effect of continuous light exposure and day/night (16/8 h) cycles on selected physiology parameters of three Synechocystis strains. We show that continuous illumination at moderate light intensities leads to an increased PHB accumulation in Synechocystis salina CCALA 192 (max. 14.2% CDW – cell dry weight) compared to day/night cycles (3.7% CDW). In addition to PHB content, glycogen and cell size increased, while cell density and cell viability decreased. The results offer new approaches for further studies to gain deeper insights into the role of PHB in cyanobacteria to obtain bioplastics in a more sustainable and environmentally friendly way. [ABSTRACT FROM AUTHOR]

Biodegradable films are considered an alternative to petroleum‐based plastics to solve environmental problems. In this study, potato flour films are prepared with dispersions at pH 3, 5, 7, 9, and 11. The film‐forming dispersion at pH 7 shows the highest apparent viscosity. Dispersions at alkaline conditions show a reduction in particle size, resulting in a smooth film surface. Films at alkaline conditions present a yellow appearance and have the lower transmittance. The film at pH 5 has the highest retrogradation enthalpy and glass transition temperature, while its moisture content and solubility are the lowest. The water contact angle increases from 33.33° to 93.67° with the increase in pH. However, pH has no significant effect on the water vapor permeability. The tensile strength and elongation at break increase slightly with the increase in pH. Overall, pH modifies the properties of potato flour films. Film with appropriate performance can be selected based on actual needs, such as the use of packaging materials for food preservation. [ABSTRACT FROM AUTHOR]

Poly(lactic acid) (PLA) is known for its excellent overall properties and is widely used as a degradable material. However, PLA has poor toughness due to its inherent brittleness and low ductility. Poly(butylene adipate-co-butylene terephthalate) (PBAT) has good toughness and can be used to toughen PLA, while the poor compatibility between the two materials leads to ineffective toughening of PLA by PBAT, which needs to be modified by adding compatibilizers during processing. In this study, high-toughness PLA-based blends were prepared by in-situ polymerization using lactide as the reactive monomer and PBAT as the toughening agent, with the addition of industrial-grade epoxy oligomers ADR and PLA-PBAT-PLA triblock copolymers as solo or synergistic compatibilizers, to investigate the effects of ADR and PLA-PBAT-PLA on the compatibility and properties of PLA and PBAT. The inclusion of compatibilizers enhanced the interfacial bonding between PLA and PBAT and boosted the toughness of PLA/PBAT blends, and the addition of 0.15 wt% ADR or 0.15 wt% PLA-co-PBAT resulted in the impact strength of PLA/PBAT (75/25) blends reaching 150.09 kJ/m2 and 100.39 kJ/m2, respectively. The epoxy group of ADR reacted with the terminal hydroxyl or terminal carboxyl group of PLA and PBAT to form a chemical bond, which enhanced the melt strength and water absorption. PLA-PBAT-PLA forms a block structure between PLA and PBAT, which improves the fluidity and tensile strength of the blends. These findings provide fundamental data for PLA/PBAT compatibility studies and provide further development for PLA blend modification studies. [ABSTRACT FROM AUTHOR]

Poly(propylene carbonate-co-phthalate) (PPC-P) is an amorphous copolymer of aliphatic polycarbonate and aromatic polyester; it possesses good biodegradability, superior mechanical performances, high thermal properties, and excellent affinity with CO2. Hence, we fabricate PPC-P foams in an autoclave by using subcritical CO2 as a physical blowing agent. Both saturation pressure and foaming temperature affect the foaming behaviors of PPC-P, including CO2 adsorption and desorption performance, foaming ratio, cell size, porosity, cell density, and nucleation density, which are investigated in this research. Moreover, the low-cost PPC-P/nano-CaCO3 and PPC-P/starch composites are prepared and foamed using the same procedure. The obtained PPC-P-based foams show ultra-high expansion ratio and refined microcellular structures simultaneously. Besides, nano-CaCO3 can effectively improve PPC-P's rheological properties and foamability. In addition, the introduction of starch into PPC-P can lead to a large number of open cells. Beyond all doubt, this work can certainly provide both a kind of new biodegradable PPC-P-based foam materials and an economic methodology to make biodegradable plastic foams. These foams are potentially applicable in the packaging, transportation, and food industry. [ABSTRACT FROM AUTHOR]

Polyester plastics, constituting over 10% of the total plastic production, are widely used in packaging, fiber, single‐use beverage bottles, etc. However, their current depolymerization processes face challenges such as non‐broad spectrum recyclability, lack of diversified high‐value‐added depolymerization products, and crucially high energy consumption. Herein, an efficient strategy is developed for dismantling the compact structure of polyester plastics to achieve diverse monomer recovery. Polyester plastics undergo swelling and decrystallization with a low depolymerization energy barrier via synergistic effects of polyfluorine/hydrogen bonding, which is further demonstrated via density functional theory calculations. The swelling process is elucidated through scanning electron microscopy analysis. Obvious destruction of the crystalline region is demonstrated through X‐ray crystal diffractometry curves. PET undergoes different aminolysis efficiently, yielding nine corresponding high‐value‐added monomers via low‐energy upcycling. Furthermore, four types of polyester plastics and five types of blended polyester plastics are closed‐loop recycled, affording diverse monomers with exceeding 90% yields. Kilogram‐scale depolymerization of real polyethylene terephthalate (PET) waste plastics is successfully achieved with a 96% yield. [ABSTRACT FROM AUTHOR]

The presence of perfluoroalkyl substances (PFAS) in the environment poses a significant threat to ecological safety and environmental health. Widespread microplastics (MPs) have been recognized as vectors for emerging contaminants due to human activities. However, the adsorption behaviors of PFAS on MPs, especially on aged MPs, have not been extensively investigated. This study aimed to investigate the adsorption behaviors of perfluorooctanoic acid (PFOA) on aged MPs (polystyrene, polyethylene, and polyethylene terephthalate) treated with UV irradiation and persulfate oxidation under salinity and dissolve organic matter (DOM) condition. Carbonyl index values of MPs increased after the aged treatment, indicating the production of oxygen‐containing groups. The PFOA adsorption on aged MPs was impacted by the co‐existence of Na+ ions and DOM. As PFOA adsorption onto aged MPs was mainly controlled by hydrophobic interaction, the electrostatic interaction also made a contribution, but there was no significant change in PFOA adsorption behavior between the pristine and aged MPs. While these findings provide insight into PFAS adsorption on aged MPs, further research is necessary to account for the complexity of the real environment. Practitioner Points: Adsorption behaviors of perfluorooctanoic acid (PFOA) on aged microplastics were investigated.Hydrophobic interaction mainly controlled PFOA adsorption on aged microplastics (MPs).Co‐existence dissolve organic matter and salinity influenced PFOA adsorption behaviors on aged MPs. [ABSTRACT FROM AUTHOR]

This study assessed bioplastics made from different mass proportions of commercial chitosan and banana plant pseudostem-derived hemicelluloses. The bioplastics were prepared by the casting method and characterized for moisture content, water solubility, opacity, water absorption, tensile strength, and thermogravimetric properties. The formulations with hemicelluloses addition showed higher moisture content and water solubility than the chitosan-only bioplastic, the maximum values of these properties (22.3 and 22.4%) were achieved when hemicelluloses were added at the proportion of 10 and 5%, respectively. A positive linear correlation (r = 0.86) was found between added hemicelluloses and opacity, with the highest opacity (1.95 mm−1) achieved in the formulation with the maximum hemicellulose incorporation. The bioplastics containing hemicelluloses exhibited lower swelling (water absorption) than that made only of chitosan, with the formulation featuring the highest hemicelluloses content showed the lowest swelling (229.2%). A negative linear correlation (r = 0.95) was observed between added hemicelluloses and swelling values. The formulation with the highest hemicelluloses content demonstrated statistically significant differences and exhibited the highest tensile strength (18.7 MPa) and Young's modulus (66.1 MPa). Thermogravimetric analysis revealed four stages of mass loss in the bioplastics. Hemicelluloses addition decreased the temperature at maximum mass loss, and the formulation with the lowest hemicelluloses content showed a higher degradation rate than the others. [ABSTRACT FROM AUTHOR]