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Fully biodegradable packaging materials are demanded to resolve the issue of plastic pollution. However, the fresh food storage performance of biodegradable materials is generally much lower than that of plastics due to their high permeability, microbial friendliness, and limited stretchability and transparency. Here a biodegradable packaging material is reported with high fresh food storage performance based on an oil‐infused bacterial cellulose (OBC) porous film. The oil infusion significantly improved cellulose's food‐keeping performance by reducing its gas permeability, increasing its stretchability and transparency, and enabling the active release of green vapor‐phase preservative molecules, while maintaining its intrinsically high degradability. Strawberries stored in a container with the OBC lid at 23 °C after 5 days exhibited a moldy rate of 0%, in contrast to the 100% moldy rate of those stored by poly(ethylene). Enhanced storage performance is also obtained on tomatoes, pork, and shrimp. The OBC film is naturally degraded after being buried in wet soil at 30 °C for 9 days, identical to the degradation rate of bacterial cellulose. The liquid seal strategy broadly applies to different celluloses, providing a general option for developing cellulose‐based biodegradable packaging materials. [ABSTRACT FROM AUTHOR]

Global concern about plastic pollution is forcing new policies and modifications of human consumption as well as promoting new research lines aiming at the replacement of non-degradable plastics with other polymers more environmentally friendly. Addressing food waste and promoting circular economy strategies, among other approaches, are crucial in reducing environmental impacts and fostering sustainability in several sectors like the agri-food industry. The European Union’s Circular Economy Action Plan is a significant initiative in this direction. Biotechnological processes, especially the valorisation of agri-food waste to produce highly marketed biomolecules like poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) using microorganisms as cellular factories, offer promising avenues for achieving these goals. PHBV is a biodegradable polymer firstly characterised as an isolated biopolymer from bacterial biomass. This biopolymer shows interesting physicochemical properties making possible immense potential in various applications due to its biocompatibility and sustainability, thus revealing it as a good candidate to replace plastics produced by chemical synthesis from petroleum (which are highly recalcitrant and consequently pollutants). This review critically analyses the PHBV synthesis and end-of-life scenarios from their synthesis using chemical and biological pathways, through the forms of biotechnological operation and production, to the forms described until the moment of recycling. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are gaining global attention in recent years due to its widespread distribution and potential health impacts. The present study focuses on the distribution and characterisation of microplastics in the sediments and its transfer into the organisms living in Kavvayi and Kumbla backwaters of Northern Malabar region, Kerala, India. MP isolation procedures including density separation, organic matter digestion, and membrane filtration followed by visual and spectral analyses using optical microscope and confocal Raman spectroscopy have been utilised for the microplastic evaluation. Microplastics of size range up to 1 μm was analysed, and the presence of MPs was detected in all samples with an average abundance of 99.5 ± 69.43 particles/kg and 96.57 ± 29.96 particles/kg in Kavvayi and Kumbla backwaters respectively. Raman spectral analysis confirmed that almost 50% of MPs to be synthetic elastomers with the remaining half encompassed by polyamide, polyethylene, polyester, polyurethane, and polypropylene. Higher abundance of MPs in the edible aquatic organisms like clams, prawns, and fishes confirmed the transfer of MP from the environment into living organisms envisages the need of further investigation on toxicological impacts and management strategies. [ABSTRACT FROM AUTHOR]

The environmental pressure to reduce the use of fossil fuels such as gasoline generates the need to search for new fuels that have similar characteristics to conventional fuels. In this sense, the objective of the present study is the use of commercial gasoline in mixtures with pyrolytic oil from plastic waste and the addition of γ-Fe2O3 nanoparticles (NPs) in a spark ignition engine to analyze both the power generated in a real engine and the emissions resulting from the combustion process. The pyrolytic oil used was obtained from thermal pyrolysis at low temperatures (450 °C) of a mixture composed of 75% polystyrene (PS) and 25% polypropylene (PP), which was mixed with 87 octane commercial gasoline in 2% and 5% by volume and 40 mg of γ-Fe2O3 NPs. A standard sample was proposed, which was only gasoline, one mixture of gasoline with bio-oil, and a gasoline, bio-oil, and NPs mixture. The bio-oil produced from the pyrolysis of PS and PP enhances the octane number of the fuel and improves the engine's power performance at low revolutions. In contrast, the addition of iron NPs significantly improves gaseous emissions with a reduction in emissions of CO (carbon monoxide), NOx (nitrogen oxide), and HCs (hydrocarbons) due to its advantages, which include its catalytic effect, presence of active oxygen, and its large surface area. [ABSTRACT FROM AUTHOR]

Rapid industrial growth is associated with an increase in the production of environmentally harmful waste. A potential solution to significantly reduce pollution is to replace current synthetic materials with readily biodegradable plastics. Moreover, to meet the demands of technological advancements, it is essential to develop materials with unprecedented properties to enhance their functionality. Polysaccharide composites demonstrate significant potential in this regard. Polysaccharides possess exceptional film-forming abilities and are safe for human use, biodegradable, widely available, and easily modifiable. Unfortunately, polysaccharide-based films fall short of meeting all expectations. To address this issue, the current study focused on incorporating carbon quantum dots (CQDs), which are approximately 10 nm in size, into the structure of a starch/chitosan biocomposite at varying concentrations. This modification has improved the mechanical properties of the resulting nanocomposites. The inclusion of nanoparticles led to a slight reduction in solubility and an increase in the swelling degree. The optical characteristics of the obtained films were influenced by the presence of CQDs, and the fluorescence intensity of the nanocomposites changed due to the specific heavy metal ions and amino acids used. Consequently, these nanocomposites show great potential for detecting these compounds. Cellular viability assessments and comet assays confirm that the resulting nanocomposites do not exhibit any cytotoxic properties based on this specific analytic method. The tested nanocomposites with the addition of carbon quantum dots (NC/CD II and NC/CD III) were characterised by greater genotoxicity compared to the negative control. The positive control, the starch/chitosan composite alone, was also characterised by a greater induction of chromatin damage in mouse cells compared to a pure mouse blood sample. [ABSTRACT FROM AUTHOR]

Biobased and biodegradable plastics have emerged as promising alternatives to conventional plastics offering the potential to reduce environmental impacts while promoting sustainability. This study focuses on the production of multilayer blown films with enhanced functional properties suitable for food packaging applications. Films were developed through co-extrusion in a three-layer film configuration, with Polybutylene Succinate (PBS) and Polybutylene Succinate Adipate (PBSA) as the external and internal layers, respectively. The functional layer consisted of Polyhydroxybutyrate (PHB) enhanced with nanoclays Cloisite® 30B at varying weight ratios. Films were also processed by manipulating the extruder screw speed of the functional layer to investigate its impact on the functional properties. Rheology, mechanical strength, and barrier performance were characterised to establish correlations between processing conditions and functional layer blends (Cloisite® 30B/PHB) on the properties of the resultant films. Rheological test results indicated that the system with 5% Cloisite® had the best polymer/nanofiller matrix dispersion. Mechanical and permeability tests showed that by varying the process conditions (the alteration of the thickness of the functionalized layer) resulted in an improvement in mechanical and barrier properties. Furthermore, the addition of the nanofiller resulted in a stiffening of the film with a subsequent decrease in permeability to oxygen and water vapour. [ABSTRACT FROM AUTHOR]

Plastics have become indispensable in modern society; however, the proliferation of their waste has become a problem that can no longer be ignored as most plastics are not biodegradable. Depolymerization/degradation through sustainable processes in the context of the circular economy are urgent issues. The presence of multiple types of plastic materials makes it necessary to study the specific characteristics of each material. This mini-review aims to provide an overview of technological approaches and their performance for the depolymerization and/or degradation of one of the most widespread plastic materials, polypropylene (PP). The state of the art is presented, describing the most relevant technologies focusing on advanced oxidation technologies (AOT) and the results obtained so far for some of the approaches, such as ozonation, sonochemistry, or photocatalysis, with the final aim of making more sustainable the PP depolymerization/degradation process. [ABSTRACT FROM AUTHOR]

The aerobic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) plays a pivotal role in the synthesis of renewable, biodegradable plastics and sustainable chemicals. Although supported gold nanoclusters (NCs) exhibit significant potential in this process, they often suffer from low selectivity. To address this challenge, a series of gold-M (M means Ni, Fe, Cu, and Pd) bimetallic NCs catalysts were designed and synthesized to facilitate the selective oxidation of HMF to FDCA. Our findings indicate that the introduction of doped metals, particularly Ni and Pd, not only improves the reaction rates for HMF tandem oxidation but also promotes high yields of FDCA. Various characterizations techniques, including X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), in situ diffuse reflectance infrared Fourier transform spectroscopy of CO adsorption (CO-DRIFTS), and temperature-programmed desorption of oxygen (O2-TPD), were employed to scrutinize the structural and electronic properties of the prepared catalysts. Notably, an electronic effect was observed across the Au-based bimetallic catalysts, facilitating the activation of reactant molecules and enhancing the catalytic performance. This study provides valuable insights into the alloy effects, aiding in the development of highly efficient Au-based bimetallic catalysts for biomass conversions. [ABSTRACT FROM AUTHOR]

While the brittle polylactide (PLA) has a high durability among bioplastics, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) with certain ductility exhibits facile compostability. The addition of polybutylene adipate terephthalate (PBAT) may also be used to improve the ductility and toughness of brittle bioplastics. Binary and ternary blends of PLA/PBAT/PHBH based on either PLA or PHBH as the matrix have been manufactured using a twin-screw extruder. The melt rheological, mechanical, and morphological properties of the processed samples were examined. Binary blends of PLA/PHBH show superior strength, with the PLA75/PHBH25 blend exhibiting a tensile strength of 35.2 ± 3.0 MPa, which may be attributed to miscible-like morphology. In contrast, blends of PLA with PBAT demonstrate low strength, with the PLA50/PBAT50 blend exhibits a tensile strength of 9.5 ± 2.0 MPa due to the presence of large droplets in the matrix. PBAT-containing blends exhibit lower impact strengths compared to PHBH-containing blends. For instance, a PLA75/PBAT25 blend displays an impact strength of 1.76 ± 0.1 kJ/m2, whereas the PHBH75/PBAT25 blend displays an impact strength of 2.61 ± 0.3 kJ/m2, which may be attributed to uniformly dispersed PBAT droplets. [ABSTRACT FROM AUTHOR]

Seaweed, a diverse and abundant marine resource, holds promise as a renewable feedstock for bioplastics due to its polysaccharide-rich composition. This review explores different methods for extracting and processing seaweed polysaccharides, focusing on the production of alginate plastic materials. Seaweed emerges as a promising solution, due to its abundance, minimal environmental impact, and diverse industrial applications, such as feed and food, plant and soil nutrition, nutraceutical hydrocolloids, personal care, and bioplastics. Various manufacturing techniques, such as solvent casting, injection moulding, and extrusion, are discussed for producing seaweed-based bioplastics. Alginate, obtained mainly from brown seaweed, is particularly known for its gel-forming properties and presents versatile applications in many sectors (food, pharmaceutical, agriculture). This review further examines the current state of the bioplastics market, highlighting the growing demand for sustainable alternatives to conventional plastics. The integration of seaweed-derived bioplastics into mainstream markets presents opportunities for reducing plastic pollution and promoting sustainability in material production. [ABSTRACT FROM AUTHOR]

Globally, the demand for single-use plastics has increased due to the rising demand for food delivery and household goods. This has led to environmental challenges caused by indiscriminate dumping and disposal. To address this issue, non-degradable plastics are being replaced with biodegradable alternatives. Polylactic acid (PLA) is a type of biodegradable plastic that has excellent mechanical properties. However, its applications are limited due to its low crystallinity and brittleness. Studies have been conducted to combat these limitations using carbon or inorganic nucleating agents. In this study, waste cement and PLA were mixed to investigate the effect of the hybrid inorganic nucleating agent on the crystallinity and mechanical properties of PLA. Waste cement accelerated the lamellar growth of PLA and improved its crystallinity. The results indicate that the flexural and impact strengths increased by approximately 3.63% and 76.18%, respectively. [ABSTRACT FROM AUTHOR]

High-molecular-weight poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) (PLLA-PEG-PLLA) is a flexible and biodegradable bioplastic that has promising potential in flexible food packaging but it has no antibacterial ability. Thus, in this work, the effect of zinc oxide nanoparticles (nano-ZnOs) which have antimicrobial activity on various properties of PLLA-PEG-PLLA was determined. The addition of nano-ZnOs enhanced the crystallization, tensile, UV-barrier, and antibacterial properties of PLLA-PEG-PLLA. However, the crystallization and tensile properties of nanocomposite films decreased again as the nano-ZnO increased beyond 2 wt%. The nano-ZnO was well distributed in the PLLA-PEG-PLLA matrix when the nano-ZnO content did not exceed 2 wt% and exhibited some nano-ZnO agglomerates when the nano-ZnO content was higher than 2 wt%. The thermal stability and moisture uptake of the PLLA-PEG-PLLA matrix decreased and the film's opacity increased as the nano-ZnO content increased. The PLLA-PEG-PLLA/ZnO nanocomposite films showed good antibacterial activity against bacteria such as Escherichia coli and Staphylococcus aureus. It can be concluded that nano-ZnOs can be used as a multi-functional filler of the flexible PLLA-PEG-PLLA. As a result, the addition of nano-ZnOs as a nucleating, reinforcing, UV-screening, and antibacterial agent in the flexible PLLA-PEG-PLLA matrix may provide protection for both the food and the packaging during transportation and storage. [ABSTRACT FROM AUTHOR]

Today, 98% of all plastics are fossil-based and non-biodegradable, and globally, only 9% are recycled. Microplastic and nanoplastic pollution is just beginning to be understood. As the global demand for sustainable alternatives to conventional plastics continues to rise, biobased and biodegradable plastics have emerged as a promising solution. This review article delves into the pivotal concept of carbon recycling as a pathway towards achieving a zero-waste future through the production and utilization of high-value bioplastics. The review comprehensively explores the current state of bioplastics (biobased and/or biodegradable materials), emphasizing the importance of carbon-neutral and circular approaches in their lifecycle. Today, bioplastics are chiefly used in low-value applications, such as packaging and single-use items. This article sheds light on value-added applications, like longer-lasting components and products, and demanding properties, for which bioplastics are increasingly being deployed. Based on the waste hierarchy paradigm—reduce, reuse, recycle—different use cases and end-of-life scenarios for materials will be described, including technological options for recycling, from mechanical to chemical methods. A special emphasis on common bioplastics—TPS, PLA, PHAs—as well as a discussion of composites, is provided. While it is acknowledged that the current plastics (waste) crisis stems largely from mismanagement, it needs to be stated that a radical solution must come from the core material side, including the intrinsic properties of the polymers and their formulations. The manner in which the cascaded use of bioplastics, labeling, legislation, recycling technologies, and consumer awareness can contribute to a zero-waste future for plastics is the core topics of this article. [ABSTRACT FROM AUTHOR]

Bacterial contamination is a hazard in many industries, including food, pharmaceuticals, and healthcare. The availability of a rapid and simple method for detecting this type of contamination in sterile areas enables immediate intervention to avoid or reduce detrimental effects. Among these methods, colorimetric indicators are becoming increasingly popular due to their affordability, ease of use, and quick visual interpretation of the signal. In this article, a bacterial contamination indicator system was designed by incorporating MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) into an electrospun PADAS matrix, which is a biodegradable poly(ester amide) synthesized from L-alanine, 1,12-dodecanediol, and sebacic acid. Uniaxial stress testing, thermogravimetric analysis and scanning electron microscopy were used to examine the mechanical properties, thermal stability, and morphology of the mats, respectively. The capacity for bacterial detection was not only analyzed with agar and broth assays but also by replicating important environmental conditions. Among the MTT concentrations tested in this study (0.2%, 2%, and 5%), it was found that only with a 2% MTT content the designed system produced a color response visible to the naked eye with optimal intensity, a sensitivity limit of 104 CFU/mL, and 86% cell viability, which showed the great potential for its use to detect bacterial contamination. In summary, by means of the process described in this work, it was possible to obtain a simple, low-cost and fast-response bacterial contamination indicator that can be used in mask filters, air filters, or protective clothing. [ABSTRACT FROM AUTHOR]

With a growing population of about 7.8 billion, humans are generating tons of waste in the form of non-biodegradable plastics on a daily basis that ends up in landfills and oceans. The introduction of packaging has been a blessing to mankind by facilitating the ease of convenience in transportation, delivery and general usage. The downside, however, is that majority of the packaging currently available is harmful to the environment and takes thousands of years to decay. This paper discusses the use of chitosan from shrimp shells and other marine animals' exoskeleton waste in food packaging industries. Chitosan extracted from marine organisms is modulated in the form of packaging material. Compared to conventional packaging, chitosan films are 73.4% biodegradable in soil under laboratory conditions whereas 100% degraded in an open field. Chitosan with metal oxides, essential oils, natural extracts, proteins and other polymers show enhanced tensile strength, water vapor permeability, oxygen and ultraviolet barrier. Chitosan and composite film show antimicrobial activity against gram positive and negative bacteria. Comparative approaches on environmental impacts between conventional plastics and chitosan films are enlightened, thereby highlighting the importance of natural polymers as packaging films that are considered economic based on the addition of additives. [ABSTRACT FROM AUTHOR]

Polyethylene (PE) mulches are widely used in strawberry (Fragaria × ananassa Duch) production for weed suppression and crop growth optimization. However, PE mulches are not biodegradable and contribute to plastic pollution. Our objective was to develop and test biodegradable liquid-applied 'hydromulches' (HMs) as a sustainable alternative to PE mulch. HM weed suppression efficacy, strawberry plant growth, and yield were evaluated. HMformulations consisted of shredded newsprint paper (NP), water, and a tackifier, either guar gum (GG) or psyllium husk (PH) added at 2 or 6%. Experiments were conducted at two environmentally distinct locations: northwest Washington (WA) and eastern North Dakota (ND). Five HM formulations were compared to black PEmulch within a randomized complete block design with four replications. PEmulch suppressed weeds completely at peak weed emergence and peak weed vegetative growth at both locations. Formulations of HM containing GG provided superior weed suppression compared to other HM formulations at peak weed emergence (4-6 vs. 18-22 plants m-2, respectively). At peak vegetative growth, HM formulations containing GG had the lowest weed density compared to other HMs in ND (1 vs. 9-12 plants m-2), whereas these differences were not observed in WA. Total weed biomass did not differ among HMs across both locations. GG HM formulations deteriorated similarly to PE mulch (3-5% vs. 2%, respectively) in ND, whereas other HMs deteriorated more substantially. In WA, all HMs deterioratedmore than PEmulch (6-12% vs. 1%, respectively). Fruit yield did not differ among treatments inweedy and weed-free subplots (194-254 g plant-1) inWA. In ND, yield was greater in all HM treatments compared to PE mulch in both weedy andweed-free subplots. Across both locations, strawberry canopy coverwas greater in PE mulch (56.1% canopy cover) compared to 2%GG and NP (42.4 and 39.8% canopy cover). Strawberry plant biomass was similar among mulch treatments. However, strawberry leaf and crown biomass were slightly lower in 2%PH compared to other mulch treatments. Results demonstrate HMs with GG tackifier are a promising alternative to PE mulch in organic strawberry systems based on ability to suppress weeds, enhance strawberry growth, and maintain yield. [ABSTRACT FROM AUTHOR]

The rising use of plastic results in an appalling amount of waste which is scattered into the environment. One of these plastics is PET which is mainly used for bottles. We have identified and characterized an esterase from Streptomyces, annotated as LipA, which can efficiently degrade the PET-derived oligomer BHET. The Streptomyces coelicolorScLipA enzyme exhibits varying sequence similarity to several BHETase/PETase enzymes, including IsPETase, TfCut2, LCC, PET40 and PET46. Of 96 Streptomyces strains, 18% were able to degrade BHET via one of three variants of LipA, named ScLipA, S2LipA and S92LipA. SclipA was deleted from S. coelicolor resulting in reduced BHET degradation. Overexpression of all LipA variants significantly enhanced BHET degradation. All variants were expressed in E. coli for purification and biochemical analysis. The optimum conditions were determined as pH 7 and 25 °C for all variants. The activity on BHET and amorphous PET film was investigated. S2LipA efficiently degraded BHET and caused roughening and indents on the surface of PET films, comparable to the activity of previously described TfCut2 under the same conditions. The abundance of the S2LipA variant in Streptomyces suggests an environmental advantage towards the degradation of more polar substrates including these polluting plastics. A comprehensive study on the identification and characterization of PETase-like enzymes in Streptomyces indicates the presence of strain specific variants of a conserved BHET-degrading esterase. [ABSTRACT FROM AUTHOR]

Starch based bioplastics were prepared and characterized with fillers carboxy methyl cellulose (CMC), chitosan (CS) and nanochitosan (NCS); plasticizer sorbitol and cross‐linking agent citric acid (CA) at different loading levels. Structural, water resistance, water vapor permeability, solubility, mechanical, antimicrobial and biodegradation properties of the bioplastics were investigated. FTIR confirmed bonding of starch with cross‐linking agent, fillers and plasticizer. The water uptake of the CMC bioplastics was decreased up to 70 % with 20 % CA addition. Bioplastics with CS and NCS showed lesser water uptake, only 12.5 % for CS bioplastic. The water vapour permeability (WVP) of all bioplastics was low in the range 2.16×10−7–6.29×10−7 gday−1 m−1 Pa−1. The CA addition increased water resistance and lowered WVP of the bioplastics by restricting the hydrophilic functional groups and forming more tight structures. The fillers CS and NCS additions enhanced the mechanical strength attributing to more hydrogen bonding between NH3+ of chitosan and OH− of starch. All bioplastics demonstrated good antimicrobial activities. These bioplastics offer an attractive alternative to non‐biodegradable plastics used in food packaging due to its enhanced water resistance, antibacterial properties and biodegradability. [ABSTRACT FROM AUTHOR]

Porous materials are commonly employed to combat marine pollution by absorbing oil. However, the release of microplastics or nanoparticles from their synthetic components further exacerbates environmental concerns. In this study, a sustainable and reusable pollen sponge derived from eco‐friendly pollen grains and fabricated using a directional freeze‐drying method is introduced for the first time. These grains undergo a defatting process followed by a controlled hydrolysis process, transforming them into a pollen microgel made of sporopollenin, the primary constituent of a pollen grain's outer layer. The directional freeze‐drying technique is used to fabricate porous structures with controlled orientation using the pollen microgel. The application of a chemical vapor deposition with dodecyltrimethoxysilane (DDTS) grants sponge hydrophobic properties, making it ideal for selective oil absorption. This modified pollen sponge boasts superior absorption capacities (15–59 times its weight) compared to most natural sponges. Additionally, its excellent durability and ability to recover up to 65% of deformation even after 60% strain compression are remarkable with the silanization process tripling the recoverability of pollen sponges. Remarkably, the silanized directional pollen sponge (SDPS) retains this resilience after 100 compression cycles. Therefore, the SDPS emerges as an eco‐conscious solution for repeated and selective oil absorption tasks. [ABSTRACT FROM AUTHOR]

The development of an efficient and environmentally sustainable chemical hydrolysis process for recycling waste plastics, based on green chemistry principles, is a key challenge. In this work, we investigated the role of subcritical CO2 on the hydrolysis of polyethylene terephthalate (PET) into terephthalic acid (TPA) at 180–200 °C for 10–100 min. The addition of CO2 into the reaction mixture led to the in situ formation of carbonic acid that helps to catalyze PET hydrolysis relative to hot compressed H2O (i.e. N2– H2O). The highest TPA yield of 85.0 ± 1.3% was obtained at 200 °C, PET loading of 2.5 g PET in 20 mL H2O for 100 min, and 208 psi of initial CO2 pressure. In addition, the subcritical CO2–H2O system demonstrated high selectivity toward hydrolyzing PET in a mixture with polyethylene (PE) at 200 °C for 100 min, thus providing “molecular sorting” capabilities to the recycling process. The robustness of the process was also demonstrated by the ability to hydrolyze both colored Canada Dry and transparent Pure Life® waste PET bottles into high yields of TPA (>86%) at 200 °C. In addition, subcritical CO2–H2O hydrolysis of colored PET bottles resulted in a white TPA product similar to that generated from transparent PET bottles. Overall, this work shows that, under optimized reaction conditions, subcritical CO2 can provide acid tunability to the reaction medium to favor waste PET hydrolysis for subsequent recycling. [ABSTRACT FROM AUTHOR]

Thermochemically upcycling waste plastics to value-added products is emerging to alleviate the waste crisis. This study aims to develop highly active and stable Ni-based catalysts for coupling pyrolysis and catalytic reforming of waste plastics to produce syngas. A series of confined NiO@S-1 catalysts with various Ni loadings (5%, 10%, 15%, and 20%) were constructed by employing dissolution-recrystallization strategy. They were in situ reduced and 15%NiO@S-1 sample showed the highest catalytic activity in terms of yield of syngas with high CO selectivity and was superior to 15%NiO/S-1 and 15%NiO/SiO 2 samples prepared by impregnation method. The TEM images of 15%NiO@S-1 catalyst after reaction showed that metallic Ni nanoparticles with average size of 10.1 nm were kept dispersive due to the confinement effect. In contrast, the apparent agglomeration of Ni nanoparticles with average size of 54.9 nm were found on the surface of 15%NiO/S-1 after reaction. This provides an effective strategy for design robust Ni-based confined catalysts for thermochemically upcycling waste plastics. [Display omitted] • Pyrolysis and catalytic O 2 reforming technology was used to produce syngas from polypropylene. • NiO@S-1 catalyst showed higher catalytic activity than NiO/S-1 and NiO/SiO 2. • The migration and agglomeration of Ni particles was limited in NiO@S-1 catalyst. • No evident coke was observed on the surface of NiO@S-1 catalyst after reaction. [ABSTRACT FROM AUTHOR]

Modifying plant fibers before their incorporation into the polymer matrix is a crucial factor that influences the characteristics of the resulting composites. This article reports on a study that investigated how modifying ground corn stalks impacted certain properties of a biodegradable polymer composite. The composite was made up of a mixture of polylactide and polycaprolactone in a ratio of 70:30, and the filler was modified using dopamine hydrochloride to create a thin polymer layer of polydopamine on the surface of the particles. The study evaluated the structural, mechanical, thermal, and thermomechanical properties of composites that contained 30%, 40%, or 50% of the filler by weight. Additionally, the tests to determine how well the composites would compost in an industrial setting were conducted. The results of the study showed that modifying the filler particles had a positive impact on most of the properties tested, including tensile strength, flexural strength, Young's modulus, storage modulus, and impact strength. Interestingly, despite concerns about the antibacterial properties of polydopamine, the composting tests revealed that the modification of the filler particles did not have any negative effects on the industrial composting process. [ABSTRACT FROM AUTHOR]

The current study focuses on the engine performance and emission analysis of a 4-stroke compression ignition engine powered by waste plastic oil (WPO) obtained by the catalytic pyrolysis of medical plastic wastes. This is followed by their optimization study and economic analysis. This study demonstrates the use of artificial neural networks (ANN) to forecast a multi-component fuel mixture, which is novel and reduces the amount of experimental effort required to determine the engine output characteristics. The engine tests were conducted using WPO blended diesel at various proportions (10%, 20%, 30% by volume) to acquire the required data for training the ANN model, which enables better prediction for the engine performance by making use of the standard back-propagation algorithm. Considering supervised data obtained from repeated engine tests, an artificial intelligence-based model of ANN was designed to select different parameters of performance and emission as output layers; at the same time, engine loading and different blending ratios of the test fuels were taken as the input layers. The ANN model was built up making use of 80% of testing outcomes for training. The ANN model forecasted engine performance and exhaust emission with regression coefficients (R) at 0.989–0.998 intervals and a mean relative error from 0.002 to 0.348%. Such results illustrated the effectiveness of the ANN model for estimating emissions and the performance of diesel engines. Moreover, the economic viability of the use of 20WPO as an alternative to diesel was justified by thermo-economic analysis. [ABSTRACT FROM AUTHOR]

The availability of compostable plastic bags has increased greatly in the past few years, as it is perceived that this type of bags will be degraded after disposal. However, there are some knowledge gaps regarding the potential effects on the soil ecosystems. We assessed the rate of degradation of samples of four different types of commercial compostable bags in vermicomposting systems with the earthworm species Eisenia andrei. We also evaluated the biological response of E. andrei (survival and reproduction) to microplastics (MPs) from fragments of the plastic bags (<2000 µm) and assessed seedling emergence in common garden cress (Lepidium sativum L.) exposed to micronized plastic (<250 µm) and the respective leachate, following OECD and ISO guidelines, respectively. The rate of degradation differed significantly depending on the type of plastic rather than the substrate in the vermicomposting system. This finding suggests that the degradation process is more dependent on the microbial community colonizing the different plastic types than on earthworm activity. Regarding the biological response of the soil system, L. sativum seedling emergence was not significantly affected; however, earthworm reproduction was affected, suggesting that although compostable, some of the formulations may potentially be toxic to soil fauna. [ABSTRACT FROM AUTHOR]

The pervasive utilization of plastics and their integration into ecosystems has resulted in significant environmental issues, particularly the pollution of microplastics (MPs). In aquaculture, high‐fat feed (HFD) is frequently employed to enhance the energy intake and economic fish production. This study utilized zebrafish as a model organism to investigate the impact of concurrent exposure to HFD and MPs on fish intestinal pathology damage and intestinal microbiome. The experimental design involved the division of zebrafish into two groups: one receiving a normal diet (ND) and the other receiving HFD. The zebrafish were exposed to a control group, as well as polystyrene (PS) MPs of varying sizes (5 and 50 μm). Histopathological examination revealed that the combination of 5 μm MPs and HFD resulted in the most significant damage to the zebrafish intestinal tract. Furthermore, gut microbiome assays indicated that exposure to MPs and HFD altered the composition of the gut microbiome. This study demonstrates that in aquaculture, the issue of HFD must be considered alongside concerns about MPs contamination, as both factors appear to have a combined effect on the intestinal pathology damage and intestinal microbiome. The findings of this research offer valuable insights for the improvement of fish farming practices. [ABSTRACT FROM AUTHOR]

Contamination with plastics of small dimensions (<1 µm) represents a health concern for many terrestrial and aquatic organisms. This study examined the use of plastic-binding peptides as a coating probe to detect various types of plastic using a plasmon nano-gold sensor. Plastic-binding peptides were selected for polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), and polystyrene (PS) based on the reported literature. Using nAu with each of these peptides to test the target plastics revealed high signal, at 525/630 nm, suggesting that the target plastic limited HCl-induced nAu aggregation. Testing with other plastics revealed some lack of specificity but the signal was always lower than that of the target plastic. This suggests that these peptides, although reacting mainly with their target plastic, show partial reactivity with the other target plastics. By using a multiple regression model, the relative levels of a given plastic could be corrected by the presence of other plastics. This approach was tested in freshwater mussels caged for 3 months at sites suspected to release plastic materials: in rainfall overflow discharges, downstream a largely populated city, and in a municipal effluent dispersion plume. The data revealed that the digestive glands of the mussels contained higher levels of PP, PE, and PET plastic particles at the rainfall overflow and downstream city sites compared to the treated municipal effluent site. This corroborated earlier findings that wastewater treatment could remove nanoparticles, at least in part. A quick and inexpensive screening test for plastic nanoparticles in biological samples with plasmonic nAu-peptides is proposed. [ABSTRACT FROM AUTHOR]

The article describes a green and efficient synthesis method for pyrano[2,3-c]-pyrazoles, employing DL-alpha-tocopherol methoxypolyethylene glycol succinate solution (TPGS-750-M) as a green and biodegradable surfactant in water. The utilization of water as a reaction medium and TPGS-750-M as a surfactant obviates the necessity for organic solvents, thereby enhancing the environmental sustainability of the synthesis. The compounds synthesized using this novel method was characterized using various spectroscopic techniques, including 1H-NMR, 13C-NMR, and mass spectrometry. [ABSTRACT FROM AUTHOR]

Chemical upcycling of plastics provides an important direction for solving the challenging issues of plastic pollution and mitigating the wastage of carbon resources. Among them, catalytic oxidative cracking of plastics to produce high–value chemicals, such as catalytic oxidation of polyethylene (PE) to produce fatty dicarboxylic acids, catalytic oxidation of polystyrene (PS) to produce benzoic acid, and catalytic oxidation of polyethylene terephthalate (PET) to produce terephthalic acid under mild conditions has attracted increasing attention, and some exciting progress has been made recently. In this article, we will review recent progresses on the catalytic oxidation upcycling of plastics and provide our understanding on the current challenges in catalytic oxidation upcycling of plastics. [ABSTRACT FROM AUTHOR]

The transition towards a sustainable bioeconomy requires the development of highly efficient bioprocesses that enable the production of bulk materials at a competitive price. This is particularly crucial for driving the commercialization of polyhydroxyalkanoates (PHAs) as biobased and biodegradable plastic substitutes. Among these, the copolymer poly(hydroxybutyrate‐co‐hydroxyhexanoate) (P(HB‐co‐HHx)) shows excellent material properties that can be tuned by regulating its monomer composition. In this study, we developed a high‐cell‐density fed‐batch strategy using mixtures of fructose and canola oil to modulate the molar composition of P(HB‐co‐HHx) produced by Ralstonia eutropha Re2058/pCB113 at 1‐L laboratory scale up to 150‐L pilot scale. With cell densities >100 g L−1 containing 70–80 wt% of PHA with tunable HHx contents in the range of 9.0–14.6 mol% and productivities of up to 1.5 g L−1 h−1, we demonstrate the tailor‐made production of P(HB‐co‐HHx) at an industrially relevant scale. Ultimately, this strategy enables the production of PHA bioplastics with defined material properties on the kilogram scale, which is often required for testing and adapting manufacturing processes to target diverse applications. [ABSTRACT FROM AUTHOR]

Poly‐L‐lactic acid (PLLA) is currently the most abundant bioplastic; however, limited environmental biodegradability and few recycling options diminish its value as a biodegradable commodity. Enzymatic recycling is one strategy for ensuring circularity of PLLA, but this approach requires a thorough understanding of enzymatic mechanisms and protein engineering strategies to enhance activity. In this study, we engineer PLLA depolymerizing subtilisin enzymes originating from Bacillus species to elucidate the molecular mechanisms dictating their PLLA depolymerization activity and to improve their function. The surface‐associated amino acids of two closely related subtilisin homologues originating from Bacillus subtilis (BsAprE) and Bacillus pumilus (BpAprE) were compared, as they were previously engineered to have nearly identical active sites, but still varied greatly in PLLA depolymerizing activity. Further analysis identified several surface‐associated amino acids in BpAprE that lead to enhanced PLLA depolymerization activity when engineered into BsAprE. In silico protein modelling demonstrated increased enzyme surface hydrophobicity in engineered BsAprE variants and revealed a structural motif favoured for PLLA depolymerization. Experimental evidence suggests that increases in activity are associated with enhanced polymer binding as opposed to substrate specificity. These data highlight enzyme adsorption as a key factor in PLLA depolymerization by subtilisins. [ABSTRACT FROM AUTHOR]

Microplastic has emerged as a global threat owing to its chronic ubiquity and persistence. Microplastics' small size expedites their ingestion at each trophic level causing biomagnification and bioaccumulation, which has raised public concerns. The present study isolated, quantified and characterized the abundance, shape, size, color, and chemical composition of the microplastics from water and sediments of the Hirakud Reservoir through a scanning electron microscope and FTIR. The ecological risk associated with the microplastics was assessed using the species sensitivity distribution (SSD) method to derive the Predicted No-Effect Concentration (PNEC) value and risk quotient (RQ). The abundance of microplastics in the surface water and sediments of the Hirakud Reservoir was estimated at 82-89 particles/L and 159-163 particles/kg, respectively. Fiber-shaped microplastics dominated both surface water (46.21%) and sediment samples (44.86%). Small-sized microplastics (53-300 μm) prevailed in all samples. Color delineation exhibited an abundance of transparent microplastics. Chemical characterization indicated the dominance of polypropylene (38%), followed by high-density polyethylene, low-density polyethylene, and polystyrene. The calculated PNEC value was 3,954 particles/m³, and the RQ was estimated to be 0.02073-0.04122 indicating negligible ecological risk to freshwater species in all the sampling sites. [ABSTRACT FROM AUTHOR]

Plastic pollution of the ocean is a major environmental threat. In this context, a better understanding of the microorganisms able to colonize and potentially degrade these pollutants is of interest. This study explores the colonization and biodegradation potential of fungal communities on foamed polystyrene and alternatives biodegradable plastics immersed in a marina environment over time, using the Brest marina (France) as a model site. The methodology involved a combination of high-throughput 18S rRNA gene amplicon sequencing to investigate fungal taxa associated with plastics compared to the surrounding seawater, and a culture-dependent approach to isolate environmentally relevant fungi to further assess their capabilities to utilize polymers as carbon sources. Metabarcoding results highlighted the significant diversity of fungal communities associated with both foamed polystyrene and biodegradable plastics, revealing a dynamic colonization process influenced by the type of polymer and immersion time. Notably, the research suggests a potential for certain fungal species to utilize polymers as a carbon source, emphasizing the need for further exploration of fungal biodegradation potential and mechanisms. [ABSTRACT FROM AUTHOR]

Being a bio-sourced and biodegradable polymer, polylactic acid (PLA) has been considered as one of the most promising substitutes for petroleum-based plastics. However, its wide application is greatly limited by its very poor ductility, which has driven PLA-toughening modifications to be a topic of increasing research interest in the past decade. Toughening enhancement is achieved often at the cost of a large sacrifice in strength, with the toughness–strength trade-off having remained as one of the main bottlenecks of PLA modification. In the present study, a bio-elastomeric material of epoxidized soybean oil (ESO) crosslinked with sebacic acid (SA) and enhanced by graphene oxide (GO) nanoparticles (NPs) was employed to toughen PLA with the purpose of simultaneously preserving strength and achieving additional functions. The even dispersion of GO NPs in ESO was aided by ultrasonication and guaranteed during the following ESO-SA crosslinking with GO participating in the carboxyl–epoxy reaction with both ESO and SA, resulting in a nanoparticle-enhanced and dynamically crosslinked elastomer (GESO) via a β-hydroxy ester. GESO was then melt-blended with PLA, with the interfacial reaction between ESO and PLA offering good compatibility. The blend morphology, and thermal and mechanical properties, etc., were evaluated and GESO was found to significantly toughen PLA while preserving its strength, with the GO loading optimized at ~0.67 wt%, which gave an elongation at break of ~274.5% and impact strength of ~10.2 kJ/m2, being 31 times and 2.5 times higher than pure PLA, respectively. Moreover, thanks to the presence of dynamic crosslinks and GO NPs, the PLA-GESO blends exhibited excellent shape memory effect and antistatic properties. [ABSTRACT FROM AUTHOR]

Plastic pollution is becoming a major health issue due to the recent discovery of microplastics and nanoplastics in living organisms and the environment, calling for advanced technologies to remove plastic waste. Here we review enzymes that degrade plastics with focus on plastic properties, protein engineering and polymers such as poly(ethylene terephthalate), poly(butylene adipate-co-terephthalate), poly(lactic acid), polyamide and polyurethane. The mechanism of action of natural and engineered enzymes has been probed by experimental and computation approaches. The performance of polyester-degrading enzymes has been improved via directed evolution, structure-guided rational design and machine learning-aided strategies. The improved enzymes display higher stability at elevated temperatures, and tailored substrate-binding sites. [ABSTRACT FROM AUTHOR]

Microplastics are micrometre-sized emerging pollutants produced by plastic fragmentation. They have been recently detected in most ecosystems, even in remote areas. Here, we review microplastics with emphasis on sources, occurrence, transport, detection methods, policies, toxicity, and management methods. In the transport section, we discuss sorption kinetics, layered microplastics, and influencing factors such as biofilm formation. Microplastic management can be done by adsorption, filtration, oxidation, and biodegradation. Microplastic interaction is influenced by temperature, pH, salinity, and dissolved organic matter. [ABSTRACT FROM AUTHOR]

The global plastic production has steadily increased from 1.7 million tons in 1950 to over 400 million tons in 2022, with about 60% of plastic ultimately ending up in landfills and oceans. There is also growing evidence that microplastics exert negative effects on biota and ecosystems. Biodegradable plastics may represent a safe alternative, yet their potential adverse effects have not been comprehensively analyzed. Here, we reviewed biodegradable plastics, with focus on their conversion into microplastics, their interactions with pollutants, and their combined toxicity for aquatic biota. Biodegradable plastics include polylactic acid, polyhydroxyalkanoates, polybutylene succinate, poly(butylene adipate-co-terephthalate), and poly(ε-caprolactone). We found that some biobased plastics are hardly biodegradable. Some biobased plastics are compostable but require specific environmental conditions for their biodegradation. Biobased plastics can generate microplastics when released into the environment, which can impact biota. Contrary to the common public belief, biodegradable plastics may not only originate from biosources but can be synthesized from fossil fuels. Microplastics originating from biodegradable plastics can interact with pollutants, adsorbing and transporting these pollutants, resulting in synergistic or antagonistic effects on exposed organisms. Biofilm formation on microplastics impacts their degradation and pollutant interactions. [ABSTRACT FROM AUTHOR]

Human activity has led to microplastic contamination throughout the marine environment. As a result of widespread contamination, microplastics are ingested by many species of wildlife, including fish, cephalopods, and shellfish. Taiwan is surrounded by oceans that offer a rich range of seafood. Taiwanese residents can easily acquire seafood as a source of dietary protein. A recent research project by Greenpeace shows that the Taiwanese eat 16,000 microplastic particles per year. There is concern regarding microplastic physical and chemical toxicity, which poses potential health risks to the local community via food chains. Thus, monitoring microplastic contamination in seafood is imperative to provide helpful information for the government and local communities. Efforts should be taken to reduce microplastic pollution at the source to minimize potential effects on ecological and health safety. This review article emphasizes the urgent need for further research on microplastic pollution in Taiwan, highlights the potential challenges to mitigate this emerging environmental threat, and analyzes food safety hazards as well as microplastic contamination in seafood. [ABSTRACT FROM AUTHOR]

Galleria mellonella is a pest of honeybees in many countries because its larvae feed on beeswax. However, G. mellonella larvae can also eat various plastics, including polyethylene, polystyrene, and polypropylene, and therefore, the species is garnering increasing interest as a tool for plastic biodegradation research. This paper presents an improved genome (99.3% completed lepidoptera_odb10 BUSCO; genome mode) for G. mellonella. This 472 Mb genome is in 221 contigs with an N50 of 6.4 Mb and contains 13,604 protein-coding genes. Genes that code for known and putative polyethylene-degrading enzymes and their similarity to proteins found in other Lepidoptera are highlighted. An analysis of secretory proteins more likely to be involved in the plastic catabolic process has also been carried out. [ABSTRACT FROM AUTHOR]

To improve the shortcomings of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), such as brittleness, large grain size and high crystallinity, a kind of bio-based engineering polyester elastomer (BEPE) was incorporated into PHBV by melting blending method with benzoyl peroxide (BPO) as the initiator. With the addition of BPO, the interfacial adhesion between PHBV and BEPE was improved, and BPO hindered the crystallization and reduced the crystallinity of PHBV/BEPE blends. At the same time, the gel content, the dynamic complex viscosity and dynamic elastic modulus of blends were increased significantly in low-frequency region with 0.7-phr BPO. Compared to that of neat PHBV, the elongation at break and impact strength of PHBV/BEPE/BPO (0.7 phr) blends were increased by 373.6 and 158.7%, respectively. Compared to that of PHBV/BEPE blends, the elongation at break and impact strength of the PHBV/BEPE/BPO (0.7 phr) blends were increased by 44.3 and 122.7%, respectively. The above phenomena were resulted from the formation of chemical micro-crosslinking between PHBV and BEPE. The main mechanism can be explained, PHBV and BEPE polymer radicals were generated by BPO initiator, and then, PHBV and BEPE polymer radicals recombined to form carbon–carbon crosslinking. [ABSTRACT FROM AUTHOR]

Polystyrene has been extensively used in various industries and consumer products, leading to high quantities of waste. In areas with improper waste management, plastic products reach water systems. Various substances can migrate from plastics into water and become part of a fraction, generically named fluorescent dissolved organic matter. The aim of this study is to determine the level of fluorescent organic matter that leaches from polystyrene into lake water samples, which have a relatively high natural organic matter content. Thus, coffee cup lids have been added to triplicate water samples and compared to a control sample, over a period of 3 weeks. Results show that fluorescent substances migrate from plastic into lake water samples. Styrene oligomers, toluene, and phenol derivates have been proposed as substances that potentially leach from polystyrene products. These compounds may have an impact on fluorescence properties of dissolved organic matter, by potentially inhibiting the microbial activity in water or by forming complex compounds. [ABSTRACT FROM AUTHOR]

In this study we prepared a poly(lactic acid)/ethyl cellulose (PLA/EC) bioplastic blend film by melt pressing after solvent casting and investigated the optical, thermal, and mechanical properties in relation to the structural changes revealed by various microscopies and scattering measurements. Despite the immiscibility of PLA and EC, the blend film exhibited good optical transparency due to the close match in their refractive indices. A second run of differential scanning calorimetry during heating revealed a decrease in the glass transition temperature ( T g PLA ) and melting point ( T m PLA ) of PLA with EC although EC had the higher values. Thermomechanical analysis suggested that these decreases were due to the negative pressure generated due to the suppression of PLA shrinkage below T g EC and above T g PLA during cooling. Furthermore, ductile drawing of the blend film (70/30) at an optimal temperature of 70 °C above T g PLA resulted in a uniform whitening near 100% strain. Delamination at the interface between the PLA matrix and EC domain led to the formation of micrometer-sized oriented voids, which enhanced the refractive index difference in the phase-separated structure, thereby scattering light and achieving the uniform and oriented white blend film. [ABSTRACT FROM AUTHOR]

The exploitation of exciting features of plastics for diverse applications has resulted in significant plastic waste generation, which negatively impacts environmental compartments, metabolic processes, and the well-being of aquatic ecosystems biota. A shotgun metagenomic approach was deployed to investigate the microbial consortia, degradation pathways, and enzyme systems involved in the degradation of plastics in a tropical lentic pond sediment (APS). Functional annotation of the APS proteome (ORFs) using the PlasticDB database revealed annotation of 1015 proteins of enzymes such as depolymerase, esterase, lipase, hydrolase, nitrobenzylesterase, chitinase, carboxylesterase, polyesterase, oxidoreductase, polyamidase, PETase, MHETase, laccase, alkane monooxygenase, among others involved in the depolymerization of the plastic polymers. It also revealed that polyethylene glycol (PEG), polyhydroxyalkanoates (PHA), polyhydroxybutyrate (PHB), polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polyethylene terephthalate (PET), and nylon have the highest number of annotated enzymes. Further annotation using the KEGG GhostKOALA revealed that except for terephthalate, all the other degradation products of the plastic polymers depolymerization such as glyoxylate, adipate, succinate, 1,4-butanediol, ethylene glycol, lactate, and acetaldehyde were further metabolized to intermediates of the tricarboxylic acid cycle. Taxonomic characterization of the annotated proteins using the AAI Profiler and BLASTP revealed that Pseudomonadota members dominate most plastic types, followed by Actinomycetota and Acidobacteriota. The study reveals novel plastic degraders from diverse phyla hitherto not reported to be involved in plastic degradation. This suggests that plastic pollution in aquatic environments is prevalent with well-adapted degrading communities and could be the silver lining in mitigating the impacts of plastic pollution in aquatic environments. [ABSTRACT FROM AUTHOR]

Millions of tons of plastic products are produced globally each year; however, the low degradation rate of plastics results in an accumulation of these products in almost every ecosystem on the planet, causing enormous environmental harm. In this study, we isolated three fungal strains found growing on a piece of foam and sought to determine if these fungi have the capacity to degrade plastic. According to multigene (ITS, LSU, TEF1-α and TUB2) phylogenetic analyses and morphological studies, the three fungal strains were identified as two distinct species: Lasiodiplodia iraniensis and Mortierella alpina. The strains were inoculated on potato dextrose agar (PDA), malt extract agar (MEA), and malt agar medium containing chloramphenicol (CMEA) and covered with polyurethane (PU) films and incubated for four months. It was found that Mortierella alpina (ZHKUCC 22–0283) contributed to the PU mass loss of 26.30% on CMEA at 32°C, while Lasiodiplodia iraniensis (ZHKUCC 22–0282) accounted for the PU mass loss of 13.55% on MEA at 32°C. The surface hyphae were washed off by the PU films, and scanning electron microscope (SEM) imaging was used to check the fungal degradation of the PU films. Full descriptions, illustrations, phylogenetic trees to show the position of the two fungal species and SEM images of PU films are provided. [ABSTRACT FROM AUTHOR]

Waste plastic oil, generated through the pyrolysis of plastic without oxygen, known as plastic-to-fuel conversion, stands as a promising alternative fuel. This research employs bibliometric analysis, a quantitative method, to comprehensively assess publications in the domain of waste plastic oil integration within reactivity-controlled compression ignition engines. Utilizing Scopus as the primary repository post-2017, the study categorizes information into pivotal aspects, including influential journals, countries, authors, affiliations, document types, thematic areas, sponsors and keywords. The analysis reveals significant contributions from diverse nations, prominently India, China, Turkey and Malaysia. Noteworthy is the prevalence of Energy, Engineering and Chemical Engineering as thematic focal points, with the journal Fuel leading the count followed by the journal Energy emerging as a prominent conduit. Institutional contributions are prolific, led by Gandhi Institute of Technology and Management University and Vellore Institute of Technology. Renowned authors 'Gugulothu S.K' and 'He Z' play a pivotal role in shaping the discourse. The National Natural Science Foundation of China stands out as a primary patron. This bibliometric analysis provides a structured understanding of waste plastic oil integration in reactivity-controlled compression ignition engines, laying the groundwork for future research avenues. The study identifies potential research platforms beyond Scopus, including Web of Science, CrossRef, Science Direct and Google Scholar, as valuable repositories for further exploration. Moreover, after careful observation of the research articles published by the top 10 authors as found in the study, it was found that the authors share a few common characteristics that helped them in advancing the understanding and application of waste plastic oil in reactivity-controlled compression ignition engines. These are also summarized in the present study with supporting data. [ABSTRACT FROM AUTHOR]

This document discusses the importance of sustainable food packaging in reducing waste and protecting the environment. It highlights various types of biobased polymers that can be used in packaging materials, as well as different methods for film formation. The document also provides an overview of six articles that focus on the effects and applications of sustainable food packaging in different types of foods. These articles cover topics such as the use of surfactants in sodium alginate coatings, pH-responsive films for monitoring pork freshness, substitute materials in food contact materials, intelligent packaging for food freshness detection, gas-regulating packaging for fruit preservation, and the use of waste materials for sustainable packaging films. The document concludes by discussing future trends and challenges in sustainable food packaging, including the need for innovative packaging technologies and the demand for multi-functional packaging. [Extracted from the article]

Polyhydroxyalkanoates (PHA) are a promising bio-based alternative to traditional plastics derived from petroleum. Cyanobacteria are photosynthetic organisms that produce PHA from CO2 and sunlight, which can potentially reduce production costs and environmental footprint in comparison to heterotrophic bacteria cultures because (1) they utilize inorganic carbon sources for growth and (2) they do not require intensive aeration for oxygenation. Moreover, supplementing precursors such as propionate, acetate, valerate, etc., can be used to obtain various copolymers with plastic customizable properties in comparison to the classical homopolymers, such as polyhydroxybutyrate, PHB. This critical review covers the latest advances in PHA production, including recent discoveries in the metabolism interplay between PHA and glycogen production, and new insights into cultivation strategies that enhance PHA accumulation, and purification processes. This review also addresses the challenges and suggests potential solutions for a viable industrial PHAs production process. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) is one of the most marketed aromatic polyesters in the world with an annual demand in 2022 of approximately 29 million metric tons, expected to increase by 40% by 2030. The escalating volume of PET waste and the current inadequacy of recycling methods have led to an accumulation of PET in the terrestrial ecosystem, thereby posing significant global health risks. The pressing global energy and environmental issues associated with PET underscore the urgent need for "upcycling" technologies. These technologies aim to transform reclaimed PET into higher-value products, addressing both energy concerns and environmental sustainability. Enzyme-mediated biocatalytic depolymerization has emerged as a potentially bio-sustainable method for treating and recycling plastics. Numerous plastic-degrading enzymes have been identified from microbial origins, and advancements in protein engineering have been employed to modify and enhance these enzymes. Microbial metabolic engineering allows for the development of modified microbial chassis capable of degrading PET substrates and converting their derived monomers into industrial relevant products. In this review, we describe several engineering approaches aiming at enhancing the performances of PET-degrading enzymes and we present the current metabolic engineering strategies adopted to bio-upcycle PET into high-value molecules. [ABSTRACT FROM AUTHOR]

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This comprehensive review delves into the complex issue of plastic pollution, focusing on the emergence of biodegradable plastics (BDPs) as a potential alternative to traditional plastics. While BDPs seem promising, recent findings reveal that a large number of BDPs do not fully degrade in certain natural conditions, and they often break down into microplastics (MPs) even faster than conventional plastics. Surprisingly, research suggests that biodegradable microplastics (BDMPs) could have more significant and long-lasting effects than petroleum-based MPs in certain environments. Thus, it is crucial to carefully assess the ecological consequences of BDPs before widely adopting them commercially. This review thoroughly examines the formation of MPs from prominent BDPs, their impacts on the environment, and adsorption capacities. Additionally, it explores how BDMPs affect different species, such as plants and animals within a particular ecosystem. Overall, these discussions highlight potential ecological threats posed by BDMPs and emphasize the need for further scientific investigation before considering BDPs as a perfect solution to plastic pollution. [ABSTRACT FROM AUTHOR]

The escalating demand for sustainable alternatives to conventional plastics has inspired extensive research into bioplastic production. This study aims to help meet the demand for eco-friendly materials by exploring the potential of pear waste biomass as a valuable resource for polyhydroxyalkanoates (PHA) production in biorefineries. To meet the growing demand for bioplastics, it is crucial to develop novel PHA materials with desirable product quality from cost-effective waste-carbon substrates. Bioplastics, known for their biodegradability and ease of decomposition, offer a promising solution for alleviating the burden on municipal and industrial waste management. However, the bottleneck in industrial PHA production lies in the high cost of carbon substrates and the complexity of downstream processes. Bacterial PHA production has emerged as a promising approach because it utilizes agricultural and industrial waste as renewable carbon substrates, thereby eliminating waste management challenges. This process not only addresses the issues associated with synthetic plastics but also contributes to a more sustainable future. Specifically, agro-industrial waste from the pear fruit industry, including pear residues, pear twigs, and discarded paper bags, represents a promising feedstock for PHA production due to its abundant availability and potential to mitigate waste disposal issues. This review comprehensively examines state-of-the-art approaches, challenges, and opportunities in producing PHA from pear waste materials. Moreover, it highlights the potential of pear waste biomass as a resource for PHA production in biorefineries, emphasizing its role in addressing waste management challenges and contributing to the development of eco-friendly materials. [ABSTRACT FROM AUTHOR]