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Polyethylene terephthalate (PET) is a widely utilized synthetic polymer, favored in various applications for its desirable physicochemical characteristics and widespread accessibility. However, its extensive utilization, coupled with improper waste disposal, has led to the alarming pollution of the environment. Thus, recycling PET products is essential for diminishing global pollution and turning waste into meaningful materials. Therefore, this study proposes the fabrication of electrospun membranes made of recycled PET nanofibers as a cost-effective valorization method for PET waste. ZnO nanoparticles were coated onto polymeric materials to enhance the antimicrobial properties of the PET fibers. Morphostructural investigations revealed the formation of fibrillar membranes made of unordered nanofibers (i.e., 40–100 nm in diameter), on the surface of which zinc oxide nanoparticles of 10–20 nm were attached. PET@ZnO membranes demonstrated effective antimicrobial and antibiofilm activity against Gram-positive and Gram-negative bacteria, yeasts, and molds, while imparting no toxicity to amniotic fluid stem cells. In vivo tests confirmed the materials' biocompatibility, as no side effects were observed in mice following membrane implantation. Altogether, these findings highlight the potential of integrating ZnO nanoparticles into recycled PET to develop multifunctional materials suitable for healthcare facilities (such as antimicrobial textiles) and biomedical devices, including applications such as textiles, meshes, and sutures. [ABSTRACT FROM AUTHOR]

Domestic cats (Felis Catus) are often exposed to stimuli that have the potential to negatively impact their welfare. These can include situations such as veterinary visits, travel, changes to their home environment, and interactions with unfamiliar people or pets. Cannabidiol (CBD)-infused pet products have grown in popularity in recent years, as pet owners search for ways to calm and relax their pets. However, research into the pharmacokinetic properties of CBD in cats is limited and investigations into its efficacy are in their infancy. The present study aimed to explore the effect of a single 4 mg/kg bodyweight dose of a THC-free CBD distillate on measures of stress in cats when experiencing a composite stress-paradigm, consisting of cat carrier travel and exposure to a novel person within an unfamiliar environment. Physiological and behavioural indicators of stress were collected pre-, during, and post-testing. No significant effect of CBD was observed on serum cortisol, IgA, or glucose, either before or immediately after the stress-paradigm (all p > 0.05). This was true despite cortisol being shown to significantly increase post-test for both treatments (both p < 0.001), suggesting that travel and meeting a novel person successfully induced a stress response within this population of cats. No significant differences in any measures of cat behaviour, including latency to approach the novel person, were observed between treatments (all p > 0.05). Overall, no influence of CBD was observed in cats, suggesting further research into appropriate dosage, delivery matrices, and other conditional factors, such as individual coping styles, should be considered. [ABSTRACT FROM AUTHOR]

Less than 7000 cheetahs (Acinonyx jubatus) persist in Africa. Although human–wildlife conflict, habitat degradation, and loss of prey are major threats to cheetah populations, illegal trade in live cubs for pets may have the most significant impact on populations in the Horn of Africa. We developed a novel, stepwise decision support tool to predict probable trafficking routes by leveraging the power of distinct modeling approaches. First, we created a cheetah habitat suitability index (HSI) to determine where source cheetah populations may occur. We then created a trafficking network model linking known and predicted cheetah populations with documented destinations in the Arabian Peninsula. A significant area in Eastern Ethiopia and Northern Somalia was estimated to harbor undocumented cheetahs. When these predicted populations were used as a supply source, the trafficking network model showed multiple routes passing through Somaliland and across the Gulf of Aden to Yemen, supporting the notion that undocumented cheetahs may be supplying pet market demands. Though we demonstrate how our decision support tool can inform law enforcement, conservation strategies, and community engagement, we caution that our results are not fully validated due to limited accessibility, alternative trafficking routes, and the cryptic nature of illegal wildlife trade. [ABSTRACT FROM AUTHOR]

The recycling of PET trays is highly challenging. The aim of this paper was to investigate the issues related to the mechanical recycling process and, the correlation between feedstock composition and the quality of the produced rPET. Four feedstocks with different degrees of impurity were mechanically recycled at a laboratory pilot scale. The optical and thermal properties of the rPET products were examined to determine the quality and to seek relations with the starting level of impurities. The final products of the PET trays' mechanical recycling were found to be affected by the presence of impurities (organics) and multi-material (non-PET) elements in the feedstocks. The rPET products crystallised faster for contaminated feedstocks showed lower molecular mass and higher yellow index values due to thermal degradation. Yellowing is a crucial parameter in assessing the thermal degradation of rPET. Injection moulded samples corresponding to higher contamination levels, reported values of Yellow Index equal to 179 and 177 compared to 15 of mono-PET sample. The intrinsic viscosity decreased from 0.60 dL/g to just above 0.30 dL/g, and losses were more significant for soiled or multi-material feedstocks. A method of improving the final quality would involve the purification of the starting feedstock from impurities. [ABSTRACT FROM AUTHOR]

• 16 different types of PET trays from LWP and SP's samples were characterised. • Composition of PET tray as packaging objects, polymers, contaminants was determined. • Mechanical and chemical recyclability assessment of PET trays was implemented. • A few less common PET trays are suitable to obtain rPET through mechanical process. • For the most common PET trays the more appropriate recycling is depolymerisation. The compositions of Dutch lightweight packaging waste (LWP) and sorted products named "PET (Polyethylene terephthalate) trays" have been determined on object level. Additionally, the PET trays from both waste types were sorted in 16 categories representing their packaging use and material build-up. The material composition of at least 10 representative trays from each category was determined with chemical and thermal analysis, based on which the average material composition per category was established. Based on this data the average material composition of sorted PET tray products was approximated. The recyclability of the various categories of PET trays was assessed based on their material build-up. The most ubiquitous PET trays in Dutch LWP and sorted products were only found to be suitable to produce opaque recycled PET with mechanical recycling processes. Whereas only some more uncommon PET trays can be used to produce transparent recycled PET with mechanical recycling processes. Depolymerisation is deemed to be a more appropriate recycling process that will allow the production of transparent food-grade recycled PET. [ABSTRACT FROM AUTHOR]

Chemical recycling of Polyethylene Terephthalate (PET) has gotten great attention today. Aminolysis, one of the chemical recycling methods, is the degradation of polyesters using primary amines that attack its functional group. It is not much explored as a commercial recycling technique among the chemical recycling methods. This review aims to explain the aminolysis method of PET degradation in terms of reaction operating conditions such as PET to solvent ratio, temperature, degradation time, and catalyst dosage. The primary product of aminolysis of PET is also discussed and their most common application in the preparation of secondary products is presented. Thus, PET-derived primary products can be used to synthesize polymers such as polyurethane and develop enhanced products like paints and coatings. Additionally, nonconventional procedures of PET aminolysis techniques: such as microwave radiation, ultrasound, UV radiation, and sunlight were assessed by comparison. [ABSTRACT FROM AUTHOR]

As an environmentally friendly technology, enzymatic degradation of waste polyethylene terephthalate (PET) has great application potential. Mono (hydroxyethyl) terephthalate (MHET), an intermediate product of PET degradation, accumulates during the degradation process. MHET reduces the activity of PETase and influences further enzymatic degradation. The combined catalysis of MHETase and PETase is an effective strategy to solve this problem. However, the difference in thermostability between MHETase and PETase limits their combination. In our previous study, a PETase of muEst1 exhibited acceptable PET-degradation ability, but the abundant MHET accumulation in its degradation products limited its further application. In this study, MHETases with good thermostability were screened for combination with muEst1 for the cascade reaction of PET degradation, and a two-stage variable-temperature program was developed. The results of this investigation show that this approach results in a PET-degradation rate of 92.71% with a terephthalic acid content above 85.9%. This investigation provides an alternative method for scaled-up enzymatic PET degradation. [ABSTRACT FROM AUTHOR]

Poly(ethylene terephthalate) (PET), extensively employed in bottles, film, and fiber manufacture, has generated persistent environmental contamination due to its non‐degradable nature. The resolution of this issue requires the conversion of waste PET into valuable products, often achieved through depolymerization into monomers. However, the laborious purification procedures involved in the extraction of monomers pose challenges and constraints on the complete utilization of PET. Herein, a strategy is demonstrated for the polymer‐to‐polymer upcycling of waste PET into high‐value biodegradable and programmable materials named PEXT. This process involves reversible transesterifications dependent on ester bonds, wherein commercially available X‐monomers from aliphatic diacids and diols are introduced, utilizing existing industrial equipment for complete PET utilization. PEXT features a programmable molecular structure, delivering tailored mechanical, thermal, and biodegradation performance. Notably, PEXT exhibits superior mechanical performance, with a maximal elongation at break of 3419.2 % and a toughness of 270.79 MJ m−3. These characteristics make PEXT suitable for numerous applications, including shape‐memory materials, transparent films, and fracture‐resistant stretchable components. Significantly, PEXT allows closed‐loop recycling within specific biodegradable analogs by reprograming PET or X‐monomers. This strategy not only offers cost‐effective advantages in large‐scale upcycling of waste PET into advanced materials but also demonstrates its enormous prospect in environmental conservation. [ABSTRACT FROM AUTHOR]

The impact of climate change on the hydrological cycle has spurred extensive research, particularly regarding potential evapotranspiration (PET), a crucial variable linking water, energy, carbon cycles, and ecosystem services. PET estimation usually relies on in situ weather station data, but data scarcity in regions like Nigeria's Ogun-Osun Basin poses challenges. With few in situ ET monitoring stations, researchers have turned to alternative PET sources, such as satellite and reanalysis products. In this study, we evaluated four PET products in the Ogun-Osun Basin: Global Land Evaporation Amsterdam Model (GLEAM), hourly potential evapotranspiration (hPET), amine early warning systems network (NET) Land Data Assimilation System (FLDAS), and Global Land Data Assimilation System (GLDAS). We assessed monthly and annual timescales using statistical indicators such as the Pearson correlation coefficient (PCC/r), mean absolute error (M.A.E.), root mean square error (RMSE), Nash–Sutcliffe efficiency (NSE), and percent bias (PBIAS). The results showed that hPET outperformed other PET datasets at the monthly scale, with the highest correlation, lowest errors, and minimal bias values (P.C.C. = 0.80, RMSE = 25.55, PBIAS = 13.62%). GLDAS dataset showed closer performance to the hPET dataset (P.C.C. = 0.61, RMSE = 94.76, PBIAS = 71.1%) and GLEAM (P.C.C. = 0.12, RMSE = 64.67, PBIAS = 73.52%). Moreover, the FLDAS dataset performed least compared to other assessed PET datasets. hPET's overall better performance was further certified at the annual scale, again outperforming the other products across all performance indicators (PCC = 0.34, M.A.E. = 258.10, RMSE = 263.05). The performance of the other products was quite poor, but the GLEAM product came closest to hPET compared to the other assessed products (P.C.C. = − 0.20, M.A.E. – 711.57, RMSE = 716.97). Overall, the hPET dominated all statistical indicators at both timescales, making it the best PET product among the ones evaluated by this study. The findings indicate that hPET is a reliable alternative source of PET data, which can greatly support future hydrological research and modelling in the Ogun-Osun Basin. [ABSTRACT FROM AUTHOR]

PETase exhibits a high degradation activity for polyethylene terephthalate (PET) plastic under moderate temperatures. However, the effect of non-active site residues in the second shell of PETase on the catalytic performance remains unclear. Herein, we proposed a crystal structure- and sequence-based strategy to identify the key non-active site residue. D186 in the second shell of PETase was found to be capable of modulating the enzyme activity and stability. The most active PETaseD186N improved both the activity and thermostability with an increase in Tm by 8.89 °C. The PET degradation product concentrations were 1.86 and 3.69 times higher than those obtained with PETaseWT at 30 and 40 °C, respectively. The most stable PETaseD186V showed an increase in Tm of 12.91 °C over PETaseWT. Molecular dynamics (MD) simulations revealed that the D186 mutations could elevate the substrate binding free energy and change substrate binding mode, and/or rigidify the flexible Loop 10, and lock Loop 10 and Helix 6 by hydrogen bonding, leading to the enhanced activity and/or thermostability of PETase variants. This work unraveled the contribution of the key second-shell residue in PETase in influencing the enzyme activity and stability, which would benefit in the rational design of efficient and thermostable PETase. [ABSTRACT FROM AUTHOR]

Poly(ethylene terephthalate) (PET) is a very valuable and beneficial material for industrial purposes, with various different applications. Due to the high annual production volume of over 50 million tons worldwide and the indiscriminate disposal by consumers, the polymers accumulate in the environment, causing negative effects on various ecosystems. Biodegradation via suitable enzymes represents a promising approach to combat the plastic waste issue so validated methods are required to measure the efficiency and efficacy of these enzymes. PETase and MHETase from Ideonella sakaiensis are suitable enzymes needed in combination to completely degrade PET into its environmentally friendly monomers. In this project, we compare and combine a previously described bulk absorbance measurement method with a newly established 1H NMR analysis method of the PET degradation products mono(2-hydroxyethyl) terephthalic acid, bis(2-hydroxyethyl) terephthalic acid and terephthalic acid. Both were optimized regarding different solvents, pH values and drying processes. The accuracy of the measurements can be confirmed with sensitivity limits of 2.5–5 µM for the absorption method and 5–10 µM for the 1H NMR analysis. The combination of the described methods therefore allows a quantitative analysis by using bulk absorption coupled with a qualitative analysis through 1H NMR. The methods established in our work can potentially contribute to the development of suitable recycling strategies of PET using recombinant enzymes. [ABSTRACT FROM AUTHOR]

Poly(ethylene terephthalate) (PET) is a major plastic polymer utilized in the single-use and textile industries. The discovery of PET-degrading enzymes (PETases) has led to an increased interest in the biological recycling of PET in addition to mechanical recycling. IsPETase from Ideonella sakaiensis is a candidate catalyst, but little is understood about its structurefunction relationships with regards to PET degradation. To understand the effects of mutations on IsPETase productivity, we develop a directed evolution assay to identify mutations beneficial to PET film degradation at 30 °C. IsPETase also displays enzyme concentration-dependent inhibition effects, and surface crowding has been proposed as a causal phenomenon. Based on total internal reflectance fluorescence microscopy and adsorption experiments, IsPETase is likely experiencing crowded conditions on PET films. Molecular dynamics simulations of IsPETase variants reveal a decrease in active site flexibility in free enzymes and reduced probability of productive active site formation in substrate-bound enzymes under crowding. Hence, we develop a surface crowding model to analyze the biochemical effects of three hit mutations (T116P, S238N, S290P) that enhanced ambient temperature activity and/or thermostability. We find that T116P decreases susceptibility to crowding, resulting in higher PET degradation product accumulation despite no change in intrinsic catalytic rate. In conclusion, we show that a macromolecular crowdingbased biochemical model can be used to analyze the effects of mutations on properties of PETases and that crowding behavior is a major property to be targeted for enzyme engineering for improved PET degradation. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) is a versatile material with a wide range of applications, and the demand for PET products has been steadily increasing in recent years. This has generated large quantities of non-biodegradable PET waste. To reduce environmental pollution, recycling and reuse of waste PET is an economical solution. Different PET products vary greatly in their impurity contents, processing technology, and performance, which poses certain challenges for the recovery, purification, and reuse of PET waste in a high value-added manner. Various recycling and reutilization methods are compared, potential issues with different PET products in the recycling process are analyzed, and viscosity enhancement modification techniques and applications of recycled PET are introduced. This paper provides a reference for the recycling of various waste PET products. [ABSTRACT FROM AUTHOR]

The marketing of dog food influences pet-owners to nurture the 'carnivorous' nature of the dog, keeping animal-based protein central to the industry. Alas, dog food has a significant impact on welfare. Consumers are aware of this impact, shifting the industry towards alternative pet food movements such as Open Farm, the first certified humane food. This article examines the material and discursive practices through which 'humaneness' is constituted as a quality within the humane pet food supply chain and how it reinforces embedded animal hierarchies. By reviewing the marketing and history of commercial dog food production, I show how 'caring' for the carnivorous dog lays the framework for killing. I use Open Farm's transparency tool to trace the value chain and compare it with the imagery, discursive claims, and material practices found within the Global Animal Partnership standards. I argue that instead of questioning animal-based protein, humane certification creates an alternative in which the pet owner could still 'care' for the wildness of their domesticated dog while simultaneously 'caring' for farmed animals. Thus, it reinforces the hierarchies of the industry. Additionally, the validity of the humane claims depends on the animals' charisma and proximity to humans. In other words, marketing in the humane dog food supply chain creates animal–animal positionalities, in which the animals' care or killability is mediated through the humans' supply chain and marketing. However, as I show with interview data, the hierarchies are fragile and must be continuously reinforced, as animals can slip into different positions. Their proximity to humans alters their positionality and their killability. [ABSTRACT FROM AUTHOR]

Currently, many of our living facilities are dependent on poly(ethylene terephthalate) (PET). It is utilized in the production of textiles, beverage bottles, food packaging, implants, and so forth. Although PET has desirable properties, it has to be amended for certain applications that have been modified by different methods. For modifications, aminolysis is used by several investigators, and this report reviews critically the related literature. Amines can be applied to impart the desired properties and produce active sites to be used for further alterations by successive reactions. Amine treatments alone enhance wettability, increase dyeability, and most applicable, produce functionality on the surface. By further reactions with several other chemicals, a spectrum of properties was endowed to PET products, such as flame retarding, anti‐fouling property, highest hygroscopicity, silk‐like character, biocompatibility, and so forth. There are a large number of works, mainly to change the surface properties, but the literature on the in vivo or common everyday evaluation of the amended products is scarce. Most of the modifications of PET products by amines are accompanied by a decrease in some other properties. Then the process of aminolysis and modifications have to be optimized with respect to several production parameters. [ABSTRACT FROM AUTHOR]

A technical approach was proposed to recycle waste PET yarn on site with the aim of building green manufacturing plant with no waste accumulation. In the recycling process, the waste PET yarn with almost infinite aspect ratio was first treated with custom-designed grinder prior to recycling, which breaks the yarn into small pieces and produce powder-like final product (waste yarn/fiber powder, WYP/WFP). Then it could be mixed with PTA and EG to form slurry and fed into manufacturing unit using well-established method rather than be fed as melt by screw-extruder that is known for its high energy intensity. Furthermore, the wetting of WYP by EG during slurry formation facilitates the de-oxygenation process and is beneficial to improve the quality of product, which produces higher quality products with lower cost compared to conventional methods. PET containing 20 wt.% WYP addition using the proposed technical approach could give best balance between performance and profit margin. The properties of the produced PET products (20% WYP addition) were found similar to that of virgin counterparts and meet the specs for various commercial application. With the help of energy benign treatment and feeding processes, the energy intensity and CO2 emission of this method compared to conventional method were reduced by 78.96% and 62.02%, respectively. The method proposed a novel energy efficient and cost-effective approach to reliably recycle waste PET to high quality PET products on site. It partially solves the problems that the industry currently encountered, such as high recycle cost, relatively low product quality, high energy intensity and low economic benefit. It moves one step forward to the greening of the manufacturing process and may help on the sustainable development of the PET industry. [ABSTRACT FROM AUTHOR]

Online consumer reviews (OCRs) significantly influence consumer purchase decisions for new products. Therefore, today's companies actively seek practical approaches for analyzing these OCRs. This study proposes a comprehensive method for OCR analysis using topic modeling and association rule analysis to overcome the current limitations in topic interpretation and topic overlap in text mining. Meanwhile, to examine the development of the high-tech industry and customer interest in the pet care field, this study synthesizes and analyzes reviews from consumers who are using healthcare products in the pet industry. To this end, we first collected 20,820 customer reviews from Amazon.com (accessed on 2 August 2023) for high-tech pet products and categorized them into three distinct product categories. Topic modeling was then conducted on each category, revealing five key topics per category. Subsequently, association rules analysis was performed on the customer reviews associated with the most representative topic. As a result, we were able to demonstrate that 'satisfaction' emerged as the most crucial topic across all three categories of high-tech pet products. Satisfaction is a topic expressing consumers' attitudes after experiencing the product, and they used words to describe their feelings in the product reviews. A diverse range of associated terms was also identified that represented the essence of each product's corresponding representative explanations. By leveraging these approaches, we are confident that pet product companies and market players will gain valuable insights into consumer preferences and behavior. [ABSTRACT FROM AUTHOR]

Simple Summary: Fish and fish by-products are excellent sources of high-quality protein for cats and dogs. However, the handling, processing, and storage of raw materials can increase variation and negatively impact their technological properties. This study aimed to evaluate the use of spray-dried animal plasma (SDAP) as a binder in fish by-products recipes for chunks in gravy. The results showed that the inclusion of SDAP in recipes significantly improved the consistency (hardness), elasticity (springiness), cohesiveness, chewiness, and juiciness of the final wet products. These improvements were observed in a chunk recipe with a 35% content of mixed salmon and tuna by-products, and another recipe with chunks having a final content of a 4% salmon by-product. There was a positive linear effect of increased SDAP inclusion in the recipes for most of the technological parameters measured such as elasticity, flexibility, juiciness, and hardness. Our findings indicate that SDAP is an excellent nutritional binder that can enhance the final technological properties of wet pet food products using high-quality fish recipes and potentially in recipes containing protein-rich fish by-products with low functionality. Spray-dried animal plasma (SDAP) and wheat gluten (WG) are common binders in wet pet food that provide amino acids and energy, as well as texture and cohesiveness due to their gelling strength, water retention and fat emulsion properties. Binder use is a valuable tool especially in recipes based on ingredients with low technological properties such as fish by-products containing spines and scales and soft texture after cooking. Two basal recipes for chunks in gravy were produced to evaluate experimental treatments. One basal recipe used a mixture of salmon and tuna by-products as the only animal protein sources without binders or with a 20 g/kg inclusion of SDAP or WG. The other basal recipe mimicked a more typical commercial recipe containing meat animal ingredients and a 40 g/kg salmon by-product to develop experimental treatments with and 0, 10, 20, 30 or 40 g/kg inclusions of SDAP. Dry matter, protein, and viscosity were evaluated in raw emulsions. After a 1 h retorting at 121 °C, hardness was measured in emulsions and in cooked chunks, juiciness, and Texture Profile Analysis (TPA) were assessed. Results demonstrated the viability of producing quality chunks in gravy containing only fish by-products including 20 g/kg of SDAP, which significantly increased hardness, elasticity, cohesiveness, and juiciness. There was a positive linear correlation of increased SDAP inclusion rate in the commercial recipe for most of the quality parameters evaluated. Based on these results, the inclusion of SDAP in fish recipes can help manufacturers achieve technological quality control targets for commercial wet pet food and may help producers to successfully formulate new recipes for wet pet food products using fish by-products as the sole animal protein source. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) is used in textile and packaging industries. The main source of PET production is fossil fuels with limited capacity. Also, PET products are single use that transform into high volumes of wastes, causing ecosystem problems. Recycling is proposed to confront this challenge. The four major PET recycling techniques are mechanical, chemical, pyrolysis, and enzymatic. Mechanical, pyrolysis, and enzymatic techniques have constrained capabilities to manage PET waste. Chemical recycling is the potential path to expanding recycling PET waste with possibility of upcycling and addressing dirty waste streams. Several chemical methods are introduced and discussed in literature. The five major chemical recycling techniques are glycolysis, alcoholysis, aminolysis, ammonolysis, and hydrolysis. This review describes PET depolymerization via these techniques and introduces hydrolysis as the one that can depolymerize PET in an organic‐free solvent environment. Hydrolysis tolerates PET mixed wastes streams including copolymers. It helps avoid challenges attributed to using organic solvents in reaction systems. Moreover, hydrolysis produces terephthalic acid, PET monomer, which has recently gained attention as the initiative monomer for PET production. The review focuses on three forms of hydrolysis—alkaline, neutral, and acid, by presenting background studies, issued patents, and recent trends on application of hydrolysis. [ABSTRACT FROM AUTHOR]

Electro-oxidation of ethylene glycol (EG) derived from polyethylene terephthalate (PET) into value-added C2 products is essential for the electro-reforming of waste PET. However, achieving high selectivity and stability in the EG oxidation reaction (EGOR) remains a significant challenge. Herein, we successfully fabricated segregation-less Pd1Ag1 alloy nanoparticles (NPs) that can be used for the electro-reforming of waste PET into glycolate C2 products with high selectivity (97%) and long-term stability (>500 h). Electrochemical measurements and in situ Fourier-transform infrared spectroscopy (FTIR) results reveal that the addition of Ag atoms improves glycolate selectivity by reducing its adsorption on Pd active sites. In addition, the surface *OH species generated on Ag sites facilitate the rapid oxidation of toxic carbonyl species, thereby improving the stability of Pd sites. Therefore, the synergistic effects of Pd1Ag1 NPs provide an effective way for practical electro-reforming of real-world waste PET into value-added products with high selectivity and stability. [ABSTRACT FROM AUTHOR]

Biocatalysis is a key technology enabling plastic recycling. However, despite advances done in the development of plastic-degrading enzymes, the molecular mechanisms that govern their catalytic performance are poorly understood, hampering the engineering of more efficient enzyme-based technologies. In this work, we study the hydrolysis of PET-derived diesters and PET trimers catalyzed by the highly promiscuous lipase B from Candida antarctica (CALB) through QM/MM molecular dynamics simulations supported by experimental Michaelis–Menten kinetics. The computational studies reveal the role of the pH on the CALB regioselectivity toward the hydrolysis of bis-(hydroxyethyl) terephthalate (BHET). We exploit this insight to perform a pH-controlled biotransformation that selectively hydrolyzes BHET to either its corresponding diacid or monoesters using both soluble and immobilized CALB. The discoveries presented here can be exploited for the valorization of BHET resulting from the organocatalytic depolymerization of PET. Plastic-degrading enzymes can be utilized for plastic recycling. Here, QM/MM molecular dynamics and experimental Michaelis–Menten kinetics provide insight into PETase/MHTase activities of the lipase B from Candida antartica. [ABSTRACT FROM AUTHOR]

Abstract—The influence of irradiation with accelerated electrons (energy 8.5 MeV, dose 5 kGy) on the physical properties of medical devices made of polyethylene terephthalate (PET) was studied by infrared (IR) spectroscopy. The revealed post-irradiation changes in the IR spectra can be used to justify the choice of the dose of irradiation of PET products with electrons during the radiation sterilization procedure. [ABSTRACT FROM AUTHOR]

Due to the close relationship between pets and humans, pet owners are highly invested in proper diets for their pets. Even though pet food mislabeling is concerning, there are few studies on this topic. This study investigated pet food mislabeling in South Korea's market based on DNA barcoding. In total, 10 pet food products were purchased, and 200 sequences of the partial Cytochrome c oxidase subunit 1 (COI) gene were generated from clones of the samples. The obtained sequences were compared to available public databases to identify species present in the ingredients. The data analyses showed that the labeled species were consistent with species detected by COI sequences in 6 of the products. However, the expected species were not detected in 4 products, revealing possible mislabeling in these samples. Our findings indicated that DNA barcoding might represent a promising tool to detect pet food mislabeling. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) is a prevalent synthetic polymer that is known to contaminate marine and terrestrial environments. Currently, only a limited number of PET-active microorganisms and enzymes (PETases) are known. This is in part linked to the lack of highly sensitive function-based screening assays for PET-active enzymes. Here, we report on the construction of a fluorescent biosensor based on Comamonas thiooxidans strain S23. C. thiooxidans S23 transports and metabolizes TPA, one of the main breakdown products of PET, using a specific tripartite tricarboxylate transporter (TTT) and various mono- and dioxygenases encoded in its genome in a conserved operon ranging from tphC-tphA1. TphR, an IclR-type transcriptional regulator is found upstream of the tphC-tphA1 cluster where TPA induces transcription of tphC-tphA1 up to 88-fold in exponentially growing cells. In the present study, we show that the C. thiooxidans S23 wild-type strain, carrying the sfGFP gene fused to the tphC promoter, senses TPA at concentrations as low as 10 mM. Moreover, a deletion mutant lacking the catabolic genes involved in TPA degradation thphA2-A1 (ΔtphA2A3BA1) is up to 10,000-fold more sensitive and detects TPA concentrations in the nanomolar range. This is, to our knowledge, the most sensitive reporter strain for TPA and we demonstrate that it can be used for the detection of enzymatic PET breakdown products. [ABSTRACT FROM AUTHOR]

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PVC is one of the commonly preferred thermoplastics. Plasticizing additives or plasticizers are added to break interstrand-dipole interaction in PVC and soften PVC in general. Plasticizers have many applications such as electrical connectors, vinyl floorings, vinyl water stops, toys, bottle caps, and medical devices. Although a great majority of plasticizers are phthalates that harm to environment, Dioctyl terephthalate (DOTP) is known as a non-phthalate plasticizer. DOTP, one of the plasticizers preferred in the industry, is an aromatic terephthalate. There are two main production methods of DOTP; direct esterification and transesterification. In this review, different synthesis reactions of DOTP plasticizer were summarized. Studies have generally focused on different catalysts, solvents, reactant ratios, and reaction conditions such as temperature, pressure, and reaction time in literature. Synthesizing DOTP from scrap PET products is an environmentally friendly manufacturing method. Besides, properties of DOTP plasticized PVC, mainly migration, mechanical and thermal properties, have been reviewed. According to the results, DOTP has high compatibility with PVC, and DOTP plasticized PVC shows good migration, mechanical and thermal properties. DOTP is a promising plasticizer due to having good properties, low production cost, and low toxicity. [ABSTRACT FROM AUTHOR]