1.Enzymatic depolymerization of polyester-cotton textiles for the recovery of terephthalic acid.
Hongzhao WANG ; Yuntao CUN ; Minxuan WANG ; Zhenwu YANG ; Hao HE ; Yushan ZHU
Chinese Journal of Biotechnology 2025;41(9):3553-3566
Polyethylene terephthalate (PET) fibers are characterized by exceptional mechanical strength, and textiles blended with cotton fibers combine both comfort and durability, showcasing widespread use in daily applications. However, improper disposal of discarded polyester-cotton textiles has resulted in severe environmental pollution, necessitating urgent and effective mitigation strategies. Enzymatic recycling of textiles offers superior environmental benefits and holds greater potential for industrial applications than alternative recycling methods. This study aims to explore a large-scale solution for the treatment of waste textiles, particularly addressing the challenge of resource recovery from polyester-cotton blended fabrics. An innovative enzymatic depolymerization process has been developed to achieve the recovery of high-purity terephthalic acid monomers. Experiments were conducted on three different textile blends with polyester-to-cotton ratios of 65/35, 70/30, and 80/20, and the influences of different colors on the process were investigated. Initially, the textiles were pretreated through mechanical grinding, which was followed by depolymerization of cotton fibers with commercial cellulase. The crystallinity of PET in the textiles was reduced through a rapid heating and cooling process. Subsequently, the PET was depolymerized by the engineered PET hydrolase. The results demonstrated that after decolorization and separation of terephthalic acid (TPA) from the reaction system, the monomer recovery rates for the three textile blends (65/35, 70/30, and 80/20) reached 90%, 91%, and 92%, respectively. Characterization analysis by nuclear magnetic resonance (NMR) confirmed that the purity of the recovered TPA was greater than 99%. In conclusion, the fully enzymatic recycling process developed in this study shows considerable promise for large-scale industrial applications and is anticipated to significantly advance the adoption and development of enzymatic recycling technologies for PET in industrial processes.
Phthalic Acids/chemistry*
;
Polyesters/chemistry*
;
Textiles
;
Cotton Fiber
;
Polyethylene Terephthalates/chemistry*
;
Cellulase/chemistry*
;
Recycling/methods*
;
Polymerization
2.A new biosynthesis route for production of 5-aminovalanoic acid, a biobased plastic monomer.
Yaqi KANG ; Ruoshi LUO ; Fanzhen LIN ; Jie CHENG ; Zhen ZHOU ; Dan WANG
Chinese Journal of Biotechnology 2023;39(5):2070-2080
5-aminovalanoic acid (5AVA) can be used as the precursor of new plastics nylon 5 and nylon 56, and is a promising platform compound for the synthesis of polyimides. At present, the biosynthesis of 5-aminovalanoic acid generally is of low yield, complex synthesis process and high cost, which hampers large-scale industrial production. In order to achieve efficient biosynthesis of 5AVA, we developed a new pathway mediated by 2-keto-6-aminohexanoate. By combinatory expression of L-lysine α-oxidase from Scomber japonicus, α-ketoacid decarcarboxylase from Lactococcus lactis and aldehyde dehydrogenase from Escherichia coli, the synthesis of 5AVA from L-lysine in Escherichia coli was achieved. Under the initial conditions of glucose concentration of 55 g/L and lysine hydrochloride of 40 g/L, the final consumption of 158 g/L glucose and 144 g/L lysine hydrochloride, feeding batch fermentation to produce 57.52 g/L of 5AVA, and the molar yield is 0.62 mol/mol. The new 5AVA biosynthetic pathway does not require ethanol and H2O2, and achieved a higher production efficiency as compared to the previously reported Bio-Chem hybrid pathway mediated by 2-keto-6-aminohexanoate.
Nylons
;
Lysine/metabolism*
;
Hydrogen Peroxide/metabolism*
;
Metabolic Engineering
;
Plastics/metabolism*
;
Fermentation
;
Escherichia coli/metabolism*
;
Aminocaproates/metabolism*
3.Proteomics-based screening of differentially expressed proteins in skin of Chinese merino fine sheep (JunKen type) of different gender.
Yiyuan ZHANG ; Yanhua GUO ; Hong TANG ; Xinhua WANG ; Limin WANG ; Ping ZHOU
Chinese Journal of Biotechnology 2022;38(10):3925-3939
The purpose of this study was to understand the effect of gender on the traits of wool. One-year-old male and female Chinese merino sheep (JunKen type) were used to screen differentially expressed proteins in skin tissues by quantitative proteomics using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and data independent acquisition (DIA) strategy. This was followed by GO function annotation, KEGG metabolic pathway and protein network interaction analysis on the differential proteins obtained. The result showed that there were 674 differentially expressed proteins between male and female groups, whereas 280 proteins were up-regulated and 394 proteins were down-regulated in the male group. Through further comparison and analysis, there were 43 differentially expressed proteins related to skin hair follicle development and wool phenotype, 30 up-regulated and 13 down-regulated. The GO annotation analysis of differentially expressed proteins were mainly enriched in 37 processes of molecular function such as oxygen binding, chondroitin sulfate binding, heme binding, glutathione peroxidase activity and glutathione transferase activity; 120 biological processes such as cellular oxidant detoxification, regulation of muscle contraction, notch signaling pathway, calcium ion transmembrane transport and glutathione metabolism; and 31 processes related to cellular components such as mast cell granule, nucleus, sarcoplasmic reticulum and endoplasmic reticulum lumen. KEGG analysis showed that the differentially expressed proteins were involved sixteen signaling pathways, among which MAPK and p53 signaling pathways were closely related to wool growth and development. The protein network interaction analysis discovered that COL1A1 was closely related to MMP2, SPARC, THBS1 and other differentially expressed proteins, which might play a key role in wool growth and development. Thus, this study obtained basic data for revealing the molecular mechanism of sheep wool traits of different gender.
Animals
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Male
;
Female
;
Proteomics
;
Chromatography, Liquid/methods*
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Tandem Mass Spectrometry/methods*
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Wool
;
China
5.Isolation of Penicillium expansum WH-3 for the production of L(+)-tartaric acid.
Wen-Na BAO ; Yi CHEN ; Hong-Xiu LIAO ; Hang CHEN ; Shi-Wang LIU ; Yong LIU
Journal of Zhejiang University. Science. B 2020;21(10):835-840
The L(+)-form of tartaric acid (L(+)-TA) exists extensively in nature, and is widely used in the food, chemical, textile, building, and pharmaceutical industries (Su et al., 2001). The main method for L(+)-TA production is microbial transformation by cis-epoxysuccinate hydrolase (CESH), which can catalyze the asymmetric hydrolysis of cis-epoxysuccinic acid or its salts to TA or tartrate (Bao et al., 2019). Seventeen species containing CESH have been isolated so far. However, most species for L(+)-TA production have been reported from bacteria (Xuan and Feng, 2019). The only fungus isolated from soil by our lab recently, that could be used as catalyst for the process under acidic condition, is Aspergillus niger WH-2 (Bao et al., 2020). In order to find strains with new characteristics, this study attempted to isolate a new CESH source from fungi and investigate its application value.
Aspergillus niger/metabolism*
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Biomass
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Catalysis
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Fermentation
;
Hydrogen-Ion Concentration
;
Hydrolases/chemistry*
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Hydrolysis
;
Industrial Microbiology
;
Magnetic Resonance Spectroscopy
;
Penicillium/metabolism*
;
Phylogeny
;
Soil
;
Species Specificity
;
Stereoisomerism
;
Tartrates/chemistry*
;
Temperature
;
Textiles
7.Research progress on the biomimetic remineralization of hard tooth tissues based on polyamide-amine dendrimer.
Ke-Zhen XIANG ; Liang CHEN ; De-Qin YANG
West China Journal of Stomatology 2020;38(6):692-696
Polyamide-amine (PAMAM) dendrimer, a new hyperbranched macromolecular polymer, is considered an "artificial protein" by many scholars on account of its excellent chemical and biological characteristics. PAMAM has internal cavities and a large number of reactive terminal groups. These structures allow the polymer to be used as a bionic macromoleculethat could simulate the biomimetic mineralization of the natural organic matrix on the surface of tooth tissue. Specifically, PAMAM can beused as an organic template to regulate mineral nucleation and crystal growth; thus, the polymerisa more ideal dental restoration material than traditional allogenic materials. This article reviews research progress on thePAMAM-induced biomimetic mineralization of hard tooth tissues.
Amines
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Biomimetics
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Dendrimers
;
Humans
;
Nylons
;
Tooth Remineralization
8.Transperitoneal para-aortic lymphadenectomy by robot assisted laparoscopy in 10 steps
Mellie HEINEMANN ; Isabelle MASQUIN ; Guillaume BLACHE ; Laura SABIANI ; Camille JAUFFRET ; Gilles HOUVENAEGHEL ; Eric LAMBAUDIE
Journal of Gynecologic Oncology 2019;30(5):e74-
OBJECTIVE: Para-aortic lymphadenectomy was the cornerstone of gynecologic oncology surgery. In endometrial cancer, the quality of para-aortic lymphadenectomy had direct impact on survival of patient. The launch of robot assisted laparoscopy started in 2005 in France, and in 2008 a transperitoneal para-aortic lymphadenectomy was described [1]. With the increase of robots, the robot assisted laparoscopy became more and more popular, hence the need of video tutorial to help less experienced surgeon in this surgical procedure [2]. METHODS: We proposed a description in 10 key steps, of a transperitoneal para-aortic lymphadenectomy by robot assisted laparoscopy (Da Vinci® Si or Xi Robot Surgical System; Intuitive Surgical Inc., Sunnyvale, CA, USA), without other surgical procedure. RESULTS: The 10 steps are: Step 1: port placement and Da Vinci robot positioning Step 2: identification of the right ureter Step 3: identification of the left renal vein Step 4: latero-caval and aorto-caval lymph nodes dissection Step 5: identification of the left ureter Step 6: creation of peritoneal tent Step 7: identification of the inferior mesenteric artery Step 8: latero-aortal lymph nodes dissection Step 9: pre-sacral lymph nodes dissection Step 10: extraction of bags with specimen and surgical textile CONCLUSION: A standardization of transperitoneal para-aortic lymphadenectomy by robot-assisted laparoscopy is the basis of teaching and learning process. Also it increases the quality of surgery, and consequently decreases the risk of complications.
Endometrial Neoplasms
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Female
;
France
;
Humans
;
Laparoscopy
;
Learning
;
Lymph Node Excision
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Lymph Nodes
;
Mesenteric Artery, Inferior
;
Renal Veins
;
Textiles
;
Ureter
9.Surface alterations following instrumentation with a nylon or metal brush evaluated with confocal microscopy
Young Sung KIM ; Jun Beom PARK ; Youngkyung KO
Journal of Periodontal & Implant Science 2019;49(5):310-318
PURPOSE: Surface alterations of titanium discs following instrumentation with either a nylon brush or a metal brush were evaluated. METHODS: A total of 27 titanium discs with 3 surface types (9 discs for each type), including machined (M) surfaces, sandblasted and acid-etched (SA) surfaces, and surfaces treated by resorbable blast media (RBM), were used. Three discs were instrumented with a nylon brush, another 3 discs were instrumented with a metal brush, and the remaining 3 discs were used as controls for each surface type. Surface properties including the arithmetic mean value of a linear profile (Ra), maximum height of a linear profile (Rz), skewness of the assessed linear profile (Rsk), arithmetic mean height of a surface (Sa), maximum height of a surface (Sz), developed interfacial area ratio (Sdr), skewness of a surface profile (Ssk), and kurtosis of a surface profile (Sku) were measured using confocal microscopy. RESULTS: Instrumentation with the nylon brush increased the Ra, Sa, and Sdr of the M surfaces. On the SA surfaces, Ra, Sa and Sdr decreased after nylon brush use. Meanwhile, the roughness of the RBM surface was not affected by the nylon brush. The use of the metal brush also increased the Ra, Sa, and Sdr of the M surface; however, the increase in Sdr was not statistically significant (P=0.119). The decreases in the Rz, Sz, Ra, Sa, and Sdr of the SA surfaces were remarkable. On the RBM surfaces, the use of the metal brush did not cause changes in Ra and Sa, whereas Rz, Sz, and Sdr were reduced. CONCLUSIONS: Titanium surfaces were altered when instrumented either with a nylon brush or a metal brush. Hence, it is recommended that nylon or metal brushes be used with caution in order to avoid damaging the implant fixture/abutment surface.
Dental Implants
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Microscopy, Confocal
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Nylons
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Peri-Implantitis
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Surface Properties
;
Titanium
10.Utilizing a Previous Silicone Band Track in Recurred Retinal Detachment
Journal of the Korean Ophthalmological Society 2019;60(7):696-700
PURPOSE: We report a case of utilizing a previous silicone band track in the reoperation of scleral encircling. CASE SUMMARY: An 8-year-old male presented with rhegmatogenous retinal detachment in the right eye. Five days after this diagnosis, he received scleral buckling surgery and cryopexy to seal the retinal tear. One month after surgery, a fundus examination showed subretinal fluid at the inferior site of the scleral buckle. He underwent scleral encircling surgery and a cryopexy procedure. The patient has had an uneventful postoperative course, and the retina has remained attached over a follow-up period of 9 months. However, exotropia and hypotropia developed in the right eye. Diagnosis of restrictive strabismus due to tissue adhesion around the silicone band was made. The encircling band was therefore removed and laser photocoagulation was performed 360° around the retina. Twenty-four hours after surgery, a fundus examination showed subretinal fluid. He received 360° scleral encircling surgery not using the 360° conjunctival peritomy. After confirming a previous encircling tract using #0-0 polydioxanone as a guide, #5-0 Nylon was tied to the end of the guide and inserted through the encircling tract with the end sutured with the silicone band. The silicone band was inserted into the encircling tract by pulling the #5-0 Nylon as a guide. Ophthalmoscopy revealed an attached retina with indentation of the scleral buckle at 360°. CONCLUSIONS: For reoperation in patients who previously underwent scleral encircling surgery, using the previous scleral encircling tract may be effective in cases with conjunctival and tissue adhesion.
Child
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Diagnosis
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Exotropia
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Follow-Up Studies
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Humans
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Light Coagulation
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Male
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Nylons
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Ophthalmoscopy
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Polydioxanone
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Reoperation
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Retina
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Retinal Detachment
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Retinal Perforations
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Retinaldehyde
;
Scleral Buckling
;
Silicon
;
Silicones
;
Strabismus
;
Subretinal Fluid
;
Tissue Adhesions

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