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Phoenix Dancong tea essential oil possesses unique aroma characteristics and bioactivities, offering broad application potential in the food, pharmaceutical, and daily chemical fields. To achieve efficient extraction and expand its use in functional textiles, supercritical CO[sub.2] (SC-CO[sub.2]) extraction was employed to optimize the extraction process of Phoenix Dancong tea essential oil. Based on single-factor experiments, the optimal extraction conditions were determined as follows: pressure of 25 MPa, temperature of 50 °C, CO[sub.2] flow rate of 8 L/h, and extraction time of 3 h, resulting in an essential oil yield of 1.12%. Response surface methodology (RSM) revealed that the experimental data fit the regression model well (R[sup.2] = 95.49%, R[sup.2]Adj = 89.69%). Furthermore, the extracted essential oil was blade-coating to cotton, nylon, polyester, and wool fabrics to evaluate its aroma retention performance. Results indicated that cotton fibers exhibited the best absorption and sustained fragrance retention, maintaining a high odor grade even after 8 weeks. This study provides a theoretical basis and practical reference for the green extraction of Phoenix Dancong tea essential oil and its application in smart aromatic textiles.

Successes in biocatalytic polyester recycling have raised the possibility of deconstructing alternative polymers enzymatically, with polyamide (PA) being a logical target due to the array of amide-cleaving enzymes present in nature. Here, we screen 40 potential natural and engineered nylon-hydrolyzing enzymes (nylonases), using mass spectrometry to quantify eight compounds resulting from enzymatic nylon-6 (PA6) hydrolysis. Comparative time-course reactions incubated at 40-70 °C showcase enzyme-dependent variations in product distributions and extent of PA6 film depolymerization, with significant nylon deconstruction activity appearing rare. The most active nylonase, a NylC K variant we rationally thermostabilized (an N-terminal nucleophile (Ntn) hydrolase, NylC K -TS, T m  = 87.4 °C, 16.4 °C higher than the wild-type), hydrolyzes 0.67 wt% of a PA6 film. Reactions fail to restart after fresh enzyme addition, indicating that substrate-based limitations, such as restricted enzyme access to hydrolysable bonds, prohibit more extensive deconstruction. Overall, this study expands our understanding of nylonase activity distribution, indicates that Ntn hydrolases may have the greatest potential for further development, and identifies key targets for progressing PA6 enzymatic depolymerization, including improving enzyme activity, product selectivity, and enhancing polymer accessibility. Polyamides (PAs) or nylons are types of plastics with wide applications, but due to their accumulation in the environment, strategies for their deconstruction are of interest. Here, the authors screen 40 potential nylon-hydrolyzing enzymes (nylonases) using a mass spectrometry-based approach and identify a thermostabilized N-terminal nucleophile hydrolase as the most promising for further development, as well as crucial targets for progressing PA6 enzymatic depolymerization.

Comfort properties of clothing are one of the main indicators of clothing quality and have been widely investigated in the past decades. This research concentrates on the water vapour permeability of nylon pantyhose, by examining behaviours in the relaxed state, as well as under extension of knits of 100%, comparative to wear conditions and above 100%. Permetest apparatus was used to measure the water vapour permeability according to the standard ISO 11092. The results indicate that for very fine fabrics permeability stays constant under extension, while for fabrics above 44 dtex the water vapour permeability changes significantly with extension. Keywords: comfort; biaxial extension; knitted fabric. Svojstva komfora odece, kao što su sposobnost prenosa toplote, vazduha i vodene pare, predstavljaju neke od glavnih indikatora njenog kvaliteta, te su stoga bila predmet veceg broja istraživanja poslednjih decenija. U okviru ovog istraživanja ispitivana je propustljivost vodene pare ženskih najlon hulahop carapa, u njihovom relaksiranom stanju, kao i prilikom istezanja pletenine od 100% (što odgovara uslovima nošenja) i više (121 i 144%). Za merenje propustljivosti vodene pare korišcena je aparatura \"Permetest\" prema standardu ISO 11092. Rezultati pokazuju da kod vrlo finih pletenina (izradenih od tankih filamenata) nema promena u propustljivosti vodene pare prilikom njihovog istezanja, dok kod pletenina izradjenih od filamenta finoce iznad 44 dtex propustljivost vodene pare raste proporcionalno sa istezanjem. Kljucne reci: komfor, dvoaksijalno istezanje, pletenina

Nylon 5 and nylon 6,5 are recently explored as new commercial polyamides, of which the monomer includes δ-valerolactam. In this study, a novel catalytic activity of lysine 2-monooxygenase (DavB) was explored to produce δ-valerolactam from l-pipecolic acid (L-PA), functioning as oxidative decarboxylase on a cyclic compound. Recombinant Escherichia coli BS01 strain expressing DavB from Pseudomonas putida could synthesize δ-valerolactam from l-pipecolic acid with a concentration of 90.3 mg/L. Through the co-expression of recombinant apoptosis-inducing protein (rAIP) from Scomber japonicus, glucose dehydrogenase (GDH) from Bacillus subtilis, Δ1-piperideine-2-carboxylae reductase (DpkA) from P. putida and lysine permease (LysP) from E. coli with DavB, δ-valerolactam was produced with the highest concentration of 242 mg/L. α-Dioxygenases (αDox) from Oryza sativa could act as a similar catalyst on l-pipecolic acid. A novel δ-valerolactam synthesis pathway was constructed entirely via microbial conversion from feedstock lysine in this study. Our system has great potential in the development of a bio-nylon production process.Key points• DavB performs as an oxidative decarboxylase on L-PA with substrate promiscuity.• Strain with rAIP, GDH, DpkA, LysP, and DavB coexpression could produce δ-valerolactam.• This is the first time to obtain valerolactam entirely via biosynthesis from lysine.

Nylons, derived from fossil fuels, are widely used for their toughness and flexibility, but they pose environmental concerns due to their low biodegradability. This study explored an efficient method for the monomerization of polymeric nylons, specifically nylon-6 and nylon-6,6, through a combination of chemical pretreatment and enzymatic hydrolysis using two kinds of nylon hydrolases, NylB and NylC (Nyl series enzymes). To break down the strong intermolecular hydrogen bonding between polymer chains of nylon, two pretreatment methods were investigated: homogeneous dispersion and soluble oligomerization induced by acid treatment. Homogeneous dispersion enhances water solubility, while soluble oligomerization reduces the molecular weight. These pretreatments significantly increased the enzyme sensitivity of the nylons, resulting in nearly complete conversion into monomers by Nyl series. Finally the convincing monomerization toward market products such as used fishing nets was also achieved. This study highlights the potential of this methodology for chemical recycling, offering a promising solution for reducing environmental impacts and achieving a circular economy for nylon products.

Nylon 12 is valued for its exceptional properties and diverse industrial applications. Traditional chemical synthesis of nylon 12 faces significant technical challenges and environmental concerns, while bioproduction from plant-extracted decanoic acid (DDA) raises issues related to deforestation and biodiversity loss. Here, we show the development of an engineered Escherichia coli cell factory capable of biosynthesizing the nylon 12 monomer, ω-aminododecanoic acid (ω-AmDDA), from glucose. We enable de novo biosynthesis of ω-AmDDA by introducing a thioesterase specific to C12 acyl-ACP and a multi-enzyme cascade converting DDA to ω-AmDDA. Through modular pathway engineering, redesign and dimerization enhancement of the rate-limiting P450, reconstruction of redox and energy homeostasis, and enhancement of oxidative stress tolerance, we achieve a production level of 471.5 mg/L ω-AmDDA from glucose in shake flasks. This work paves the way for sustainable nylon 12 production and offers insights for bioproduction of other fatty acid-derived products. Nylon-12 monomers are traditionally produced through chemical synthesis and more recently by bioconversion of plant-derived lauric acid. Here, the authors report the construction of E. coli cell factory to enable de novo biosynthesis of the nylon 12 monomer ω-aminolauric acid from glucose.

Cyclohexanone oxime, an important nylon-6 precursor, is conventionally synthesized through cyclohexanone-hydroxylamine (NH 2 OH) and cyclohexanone ammoxidation methodologies. These strategies require complicated procedures, high temperatures, noble metal catalysts, and toxic SO 2 or H 2 O 2 usage. Here, we report a one-step electrochemical strategy to synthesize cyclohexanone oxime from nitrite (NO 2 − ) and cyclohexanone under ambient conditions using a low-cost Cu-S catalyst, avoiding complex procedures, noble metal catalysts and H 2 SO 4 /H 2 O 2 usage. This strategy produces 92% yield and 99% selectivity of cyclohexanone oxime, comparable to the industrial route. The reaction undergoes a NO 2 −  → NH 2 OH→oxime reaction pathway. This electrocatalytic strategy is suitable for the production of other oximes, highlighting the methodology universality. The amplified electrolysis experiment and techno-economic analysis confirm its practical potential. This study opens a mild, economical, and sustainable way for the alternative production of cyclohexanone oxime. The sustainable synthesis of cyclohexanone oxime, the precursor of nylon-6, without toxic SO 2 or H 2 O 2 usage is desirable. Here, the electrosynthesis of cyclohexanone oxime from nitrite and cyclohexanone under ambient conditions is reported.

Nylon powders are a type of microplastic (MP) used in personal care products such as cosmetics and sunscreens. To determine the effects of nylon polymers on freshwater microalgae, we investigated the effects of two types of micrometer-sized nylon polymers, i.e., powdered nylon 6 (Ny6-P) and nylon 12 (Ny12), and four other micrometer-sized MPs, i.e., low-density polyethylene, polyethylene terephthalate, polystyrene, and ultra-high-molecular-weight polyethylene, on the microalga Raphidocelis subcapitata . The results showed that Ny6-P inhibited R. subcapitata growth more than the other MPs; R. subcapitata growth was inhibited by 54.2% with 6.25 mg/L Ny6-P compared with the control. Ny6-P in the culture media adhered to R. subcapitata cells electrostatically, which may have disrupted growth and photosynthetic activity. Metabolomic analysis revealed that many metabolites related to the amino acid catabolic pathway and γ-glutamyl cycle were induced, which might trigger responses to avoid starvation and oxidative stress. Our study provides important information on the effects of Ny6-P on algae in freshwater environments.