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*
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Polyesters/chemistry*
;
Textiles
;
Cotton Fiber
;
Polyethylene Terephthalates/chemistry*
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Cellulase/chemistry*
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Recycling/methods*
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Polymerization
2.The deubiquitinating enzyme 13 retards non-alcoholic steatohepatitis via blocking inactive rhomboid protein 2-dependent pathway.
Minxuan XU ; Jun TAN ; Liancai ZHU ; Chenxu GE ; Wei DONG ; Xianling DAI ; Qin KUANG ; Shaoyu ZHONG ; Lili LAI ; Chao YI ; Qiang LI ; Deshuai LOU ; Linfeng HU ; Xi LIU ; Gang KUANG ; Jing LUO ; Jing FENG ; Bochu WANG
Acta Pharmaceutica Sinica B 2023;13(3):1071-1092
Nowadays potential preclinical drugs for the treatment of nonalcoholic steatohepatitis (NASH) have failed to achieve expected therapeutic efficacy because the pathogenic mechanisms are underestimated. Inactive rhomboid protein 2 (IRHOM2), a promising target for treatment of inflammation-related diseases, contributes to deregulated hepatocyte metabolism-associated nonalcoholic steatohepatitis (NASH) progression. However, the molecular mechanism underlying Irhom2 regulation is still not completely understood. In this work, we identify the ubiquitin-specific protease 13 (USP13) as a critical and novel endogenous blocker of IRHOM2, and we also indicate that USP13 is an IRHOM2-interacting protein that catalyzes deubiquitination of Irhom2 in hepatocytes. Hepatocyte-specific loss of the Usp13 disrupts liver metabolic homeostasis, followed by glycometabolic disorder, lipid deposition, increased inflammation, and markedly promotes NASH development. Conversely, transgenic mice with Usp13 overexpression, lentivirus (LV)- or adeno-associated virus (AAV)-driven Usp13 gene therapeutics mitigates NASH in 3 models of rodent. Mechanistically, in response to metabolic stresses, USP13 directly interacts with IRHOM2 and removes its K63-linked ubiquitination induced by ubiquitin-conjugating enzyme E2N (UBC13), a ubiquitin E2 conjugating enzyme, and thus prevents its activation of downstream cascade pathway. USP13 is a potential treatment target for NASH therapy by targeting the Irhom2 signaling pathway.
3.Adulteration detection of tea samples based on plant rbcL gene sequencing.
Chinese Journal of Biotechnology 2018;34(2):275-281
Tea is one of the most popular drinks in the world, but counterfeit or adulterated tea can be found now and then on the tea market. The traditional methods dependent on sensory, physical and chemical tests cannot identify the composition of adulterated plant species accurately. We developed therefore a method for identification of adulterated plants in tea based on qualitative detection of plant rbcL (Ribulose 1,5-bisphosphate carboxylase-oxygenase large subunit) fragments, which involved amplification, sequencing and sequence analyses of rbcL fragments. Seven tea samples were analyzed with the established method. The results showed that Yueyanghuangcha (yellow tea) and Xinyangmaojian (green tea) were pure with only detection of the tea plant Camellia sinensis; Zhengshan Souzhong (black tea), Tieguanyin (oolong tea), Tailaoyinzhen (white tea), Liupao and Pu-erh (dark tea) were, to a certain extent, adulterated with non-Camellia sinensis plants. The method introduced in this study only requires a small amount of tea samples, easy to operate and reliable. It can be used to determine if any tea samples are adulterated.

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