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 simplified and miniaturized glucometer-based assay for the detection of β-glucosidase activity.
Min-Yi JIN ; Tong ZHANG ; Yi-Shun YANG ; Yue DING ; Jun-Song LI ; Gao-Ren ZHONG
Journal of Zhejiang University. Science. B 2019;20(3):264-272
β-Glucosidase activity assays constitute an important indicator for the early diagnosis of neonatal necrotizing enterocolitis and qualitative changes in medicinal plants. The drawbacks of the existing methods are high consumption of both time and reagents, complexity in operation, and requirement of expensive instruments and highly trained personnel. The present study provides a simplified, highly selective, and miniaturized glucometer-based strategy for the detection of β-glucosidase activity. Single-factor experiments showed that optimum β-glucosidase activity was exhibited at 50 °C and pH 5.0 in a citric acid-sodium citrate buffer when reacting with 0.03 g/mL salicin for 30 min. The procedure for detection was simplified without the need of a chromogenic reaction. Validation of the analytical method demonstrated that the accuracy, precision, repeatability, stability, and durability were good. The linear ranges of β-glucosidase in a buffer solution and rat serum were 0.0873-1.5498 U/mL and 0.4076-2.9019 U/mL, respectively. The proposed method was free from interference from β-dextranase, snailase, β-galactosidase, hemicellulase, and glucuronic acid released by baicalin. This demonstrated that the proposed assay had a higher selectivity than the conventional dinitrosalicylic acid (DNS) assay because of the specificity for salicin and unique recognition of glucose by a personal glucose meter. Miniaturization of the method resulted in a microassay for β-glucosidase activity. The easy-to-operate method was successfully used to detect a series of β-glucosidases extracted from bitter almonds and cultured by Aspergillus niger. In addition, the simplified and miniaturized glucometer-based assay has potential application in the point-of-care testing of β-glucosidase in many fields, including medical diagnostics, food safety, and environmental monitoring.
Animals
;
Aspergillus niger
;
Calibration
;
Cellulase/analysis*
;
Chemistry, Clinical/methods*
;
Dextranase/analysis*
;
Enterocolitis, Necrotizing/diagnosis*
;
Equipment Design
;
Flavonoids/analysis*
;
Glucose/analysis*
;
Glucuronic Acid/analysis*
;
Glucuronidase/analysis*
;
Glycoside Hydrolases/analysis*
;
Hydrogen-Ion Concentration
;
Linear Models
;
Multienzyme Complexes/analysis*
;
Plants, Medicinal
;
Polygalacturonase/analysis*
;
Rats
;
Reproducibility of Results
;
beta-Galactosidase/analysis*
;
beta-Glucosidase/analysis*
3.Cause and control of Radix Ophiopogonis browning during storage.
Hui WANG ; Jin QI ; Dong-Qi HAN ; Tian XU ; Ji-Hua LIU ; Min-Jian QIN ; Dan-Ni ZHU ; Bo-Yang YU
Chinese Journal of Natural Medicines (English Ed.) 2015;13(1):73-80
In the storage of Radix Ophiopogonis, browning often happens to cause potential risk with regard to safety. Previously few reports investigate the browning of Radix Ophiopogonis. In this research, the causes and mechanisms of the browning of Radix Ophiopogonis were preliminarily elucidated. Content determination by high-performance liquid chromatography (HPLC) and spectrophotometry, enzyme activity determination by colorimetry, and morphological observation by electron microscopy were performed in the present study. Uniform design and three-dimensional response surfaces were applied to investigate the relationship between browning and storage factors. The cortex cell wall of browned Radix Ophiopogonis was ruptured. Compared with the normal Radix Ophiopogonis, cellulase and polyphenol oxidase enzymes were activated, the levels of 5-hydroxymethylfurfural (5-HMF), total sugars, and reducing sugars were increased, while the levels of polysaccharides and methylophiopogonanone A were decreased in browned Radix Ophiopogonis. The relationship between the storage factors and degree of browning (Y) could be described by following correlation equation: Y = - 0.625 4 + 0.020 84 × X3 + 0.001 514 × X1 × X2 - 0.000 964 4 × X2 × X3. Accompanied with browning under storage conditions, the chemical composition of Radix Ophiopogonis was altered. Following the activation of cellulase, the rupture of the cortex cell wall and the outflow of cell substances flowed out, which caused the Radix Ophiopogonis tissue to become soft and sticky. The main causes of the browning were the production of 5-HMF, the activation of polyphenol oxidase, Maillard reactions and enzymatic browning. Browning could be effectively prevented when the air relative humidity (HR), temperature, and moisture content were under 25% RH, 12 °C and 18%, respectively.
Carbohydrates
;
biosynthesis
;
Catechol Oxidase
;
Cell Wall
;
enzymology
;
Cellulase
;
Chromatography, High Pressure Liquid
;
Food Storage
;
methods
;
Furaldehyde
;
analogs & derivatives
;
chemical synthesis
;
Humidity
;
Maillard Reaction
;
Ophiopogon
;
chemistry
;
enzymology
;
Temperature
4.Preparation and vitality detection of protoplast in Salvia miltiorrhiza Bunge.
Nan ZHU ; Jun LIU ; Xinyu ZHANG ; Juan'e DONG
Chinese Journal of Biotechnology 2014;30(10):1612-1621
We prepared protoplasts from Salvia miltiorrhiza Bunge suspension culture cells. Then, the protoplasts' vitality and functions were tested by fluorescein diacetate staining method and Fluo-3/AM flourescent probe. The optimal condition of protoplast isolation was Cellulase R-10 1.5%, Pectinase Y-23 0.3%, Macerozyme R-10 0.5%, 40 r/min 12 h, 600 r/min 5 min, and the protoplasts yield was 1.1x10(6) cells/g FW, the vitality was more than 95% by using fluorescein diacetate staining method. It has been confirmed that calcium fluorescent probe Fluo-3/AM can be successfully loaded into protoplasts.
Aniline Compounds
;
chemistry
;
Cell Culture Techniques
;
Cellulase
;
chemistry
;
Fluorescent Dyes
;
chemistry
;
Protoplasts
;
chemistry
;
Salvia miltiorrhiza
;
growth & development
;
Xanthenes
;
chemistry
5.Study on preparation of sagittatoside B with epimedin B converted from cellulase.
Feng-Juan XU ; E SUN ; Zhen-Hai ZHANG ; Li CUI ; Xiao-Bin JIA
China Journal of Chinese Materia Medica 2014;39(2):235-239
To prepare sagittatoside B with epimedin B Hydrolyzed from cellulase. With the conversion ratio as the index, the effects of pH value, temperature, reaction time, dosage of enzyme and concentration of substrates on the conversion ratio were detected. L9 (3(4)) orthogonal design was adopted to optimize the preparation process. Hydrolyzed products were identified by MS, 1H-NMR, and 13C-NMR. The results showed that the optimum reaction conditions for the enzymatic hydrolysis were that the temperature was 50 degrees C, the reaction medium was pH 5.6 acetic acid-sodium acetate buffer solution, the concentration of substrates was 20 g x L(-1), the mass ratio between enzyme and substrate was 3: 5, and the relative molecular mass of the reaction product was 646.23. NMR data proved that the product was sagittatoside B. The process is simple and reliable under mild reaction conditions, thus suitable for industrial production.
Cellulase
;
metabolism
;
Drug Compounding
;
methods
;
Flavonoids
;
chemistry
;
Hydrogen-Ion Concentration
;
Hydrolysis
;
Temperature
;
Time Factors
6.Study on different factors affecting the bionic enzymatic hydrolysis of icariin.
Xia GAO ; Yan CHEN ; Ying WANG ; Wen-jie SUN ; Xiao-bin JIA
Acta Pharmaceutica Sinica 2013;48(11):1716-1721
This study aims to observe different factors which affected the bionic enzymatic hydrolysis of icariin into baohuoside I and to optimize the reaction conditions in order to provide research foundation for building a novel bionic enzymolysis drug delivery system. To simulate the environment in vivo, 37 degrees C was set as the temperature and artificial intestinal juice and gastric juice were selected as the buffer solutions. Taking the conversion of baohuoside I as index, the effects of the kinds of enzyme, enzyme activity, substrate concentration, reaction time, pancreatin in artificial intestinal juice and surfactant on the conversion of baohuoside I were investigated. The results showed that cellulase, beta-glucosidase and snailase were all inactive in artificial gastric juice and no baohuoside I generated. Pancreatin in artificial intestinal juice couldn't significantly influence the activity of beta-glucosidase or snailase (P > 0.05), but noticeably decrease the activity of cellulase (P < 0.05). In artificial intestinal juice, the conversion of baohuoside I was highest by using beta-glucosidase, and the optimum reaction conditions were determined as follows: enzyme activity 10 U x mL(-1), substrate concentration 1 mg x mL(-1), 3 g x L(-1) rhamnolipid and reaction time 3 h. Under this condition, the conversion of baohuoside I was 99.8%.
Animals
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Cellulase
;
chemistry
;
Flavonoids
;
biosynthesis
;
metabolism
;
Hydrolases
;
chemistry
;
isolation & purification
;
Hydrolysis
;
Pancreatin
;
chemistry
;
Snails
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enzymology
;
Surface-Active Agents
;
chemistry
;
beta-Glucosidase
;
chemistry
7.Improved extraction of solanesol from tobacco waste by enzymatic cell wall breaking.
Xingmin WANG ; Yuwen ZHANG ; Guizhi ZHANG ; Zhongyi YIN
Chinese Journal of Biotechnology 2013;29(11):1706-1710
To improve the extraction of solanesol from tobacco waste, we developed an enzymatic cell wall-breaking process with combined cellulase and ligninase. The effects of reaction time, temperature, pH and enzyme/substrate ratio were determined. The results show that the catalytic effect was better than either single enzyme when the ratio of cellulase to ligninase was 15:1 (U/U). Under the optimized conditions of 175 U/g (enzymes/substrate), tobacco to water 1:5 (W/W), temperature 40 degrees C and pH 6.0, the concentration of solanesol in the solution could reach 0.33 g/L after 8 h. And the average leaching rate reached 96.53% which was 1.68 times of the extraction methods of chemical reflux. It provides new way for the extraction of solanesol from tobacco waste, and worthwhile to be further explored.
Cell Wall
;
metabolism
;
Cellulase
;
metabolism
;
Oxygenases
;
metabolism
;
Plant Leaves
;
chemistry
;
Terpenes
;
isolation & purification
;
Tobacco
;
chemistry
8.Molecular engineering of cellulase catalytic domain based on glycoside hydrolase family.
Xiaomei ZHANG ; Dandan LI ; Lushan WANG ; Yue ZHAO ; Guanjun CHEN
Chinese Journal of Biotechnology 2013;29(4):422-433
Molecular engineering of cellulases can improve enzymatic activity and efficiency. Recently, the Carbohydrate-Active enZYmes Database (CAZy), including glycoside hydrolase (GH) families, has been established with the development of Omics and structural measurement technologies. Molecular engineering based on GH families can obviously decrease the probing space of target sequences and structures, and increase the odds of experimental success. Besides, the study of cellulase active-site architecture paves the way toward the explanation of catalytic mechanism. This review focuses on the main GH families and the latest progresses in molecular engineering of catalytic domain. Based on the combination of analysis of a large amount of data in the same GH family and their conservative active-site architecture information, rational design will be an important direction for molecular engineering and promote the rapid development of the conversion of biomass.
Catalytic Domain
;
genetics
;
Cellulase
;
chemistry
;
genetics
;
Directed Molecular Evolution
;
methods
;
Evolution, Molecular
;
Glycoside Hydrolases
;
chemistry
;
genetics
;
Protein Engineering
;
methods
9.Optimization of liquid ammonia treatment for enzymatic hydrolysis of Saccharum arundinaceum to fermentable sugars.
Jianjun LIU ; Hehuan PENG ; Xiangjun ZHAO ; Cheng CHENG ; Feng CHEN ; Qianjun SHAO
Chinese Journal of Biotechnology 2013;29(3):333-341
China has abundant available marginal land that can be used for cultivation of lignocellulosic energy plants. Saccharum arundinaceum Retz. is a potential energy crop with both high biomass yield and low soil fertility requirements. It can be planted widely as cellulosic ethanol feedstock in southern China. In the present work Saccharum arundinaceum was pretreated by liquid ammonia treatment (LAT) to overcome biomass recalcitrance, followed by enzymatic hydrolysis. The monosaccharide contents (glucose, xylose, and arabinose) of the enzymatic hydrolysate were determined by high performance liquid chromatography. Experimental results show that the optimal LAT pretreatment conditions were 130 0C, 2:1 (W/W) ammonia to biomass ratio, 80% moisture content (dry weight basis) and 5 min residence time. Approximately 69.34% glucan and 82.60% xylan were converted after 72 h enzymatic hydrolysis at 1% glucan loading using 15 FPU/(g of glucan) of cellulase. The yields of glucose and xylose were 573% and 1 056% higher than those of the untreated biomass, and the LAT-pretreated substrates obtained an 8-fold higher of total monosaccharide yield than untreated substrates. LAT pretreatment was an effective to increase the enzymatic digestibility of Saccharum arundinaceum compared to acid impregnated steam explosion and similar to that of acid treatment and ammonia fiber expansion treatment.
Ammonia
;
chemistry
;
Cellulase
;
metabolism
;
Ethanol
;
metabolism
;
Fermentation
;
Hydrolysis
;
Monosaccharides
;
metabolism
;
Saccharum
;
chemistry
;
metabolism
10.Kinetics of enzymatic hydrolysis of steam-explosion pretreated corn straw.
Shengtao REN ; Keke CHENG ; Andong SONG ; Jian'an ZHANG
Chinese Journal of Biotechnology 2011;27(4):592-597
In order to learn the enzymatic hydrolysis characteristics of steam-explosion pretreated corn straw by cellulase, the effects of substrate concentration, cellulase concentration and temperature were determined. The kinetics of the hydrolysis reaction could be described with the Michealis-Menten equation, and the hydrolysis reaction obeyed the classical first-order reaction rate in the first three hours. In the condition of 45 degrees C and pH 5.0 and the stirring rate 120 r/min, the Michealis constant (Km) and maximum rate (Vm) for 1.2 FPU/mL of cellulase were 11.71 g/L and 1.5 g/(L x h). The kinetic model, including the parameters such as substrate concentration, enzymatic concentration and temperature, was suit for the hydrolysis reaction under the temperature range from 30 degrees C-50 degrees C.
Catalysis
;
Cellulase
;
chemistry
;
Hydrolysis
;
Kinetics
;
Plant Stems
;
Steam
;
Zea mays

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