Glucosidases are an indispensable class of enzymes in the sugar metabolism of organisms. To investigate the biological functions and expression patterns of α-glucosidases (AGLUs) and β-glucosidases (BGLUs), we identified the two family members in the genome of melon (Cucumis melo). The number, location on chromosomes, gene structure, subcellular localization, conserved motifs, and phylogenetic relationship of the two family members were analyzed. Based on the cis-acting elements in the promoter region and protein interaction models, their functions were preliminarily predicted. Furthermore, the gene expression of the two family members was determined by qRT-PCR. The results showed that the melon genome contained five AGLU family members on five chromosomes, and all of the five members were located in the extracellular matrix, with the amino acid sequence lengths ranging from 899 aa to 1 060 aa. The melon genome carried 18 BGLU family members on 8 chromosomes, and all the members were located in the cell membrane or cytoplasm, with the amino acid lengths ranging from 151 aa to 576 aa. The qRT-PCR results showed that the expression of about 50% of the genes was down-regulated upon cold stress. CmAGLU5 and CmBGLU7 may be key members of the two families, respectively, in response to cold stress. The expression of all members of the two families was up-regulated under abscisic acid (ABA), high salt, and drought stress. In the AGLU family, CmAGLU3 was the key gene in response to ABA and high salt stress, while CmAGLU4 was the key gene in response to drought stress. In the BGLU family, CmBGLU18 was the key gene in response to ABA, while CmBGLU6 was the key gene in response to high salt and drought stress.
beta-Glucosidase/metabolism* ; Phylogeny ; alpha-Glucosidases/metabolism* ; Gene Expression Regulation, Plant ; Cucurbitaceae/enzymology* ; Multigene Family ; Cucumis melo/enzymology* ; Stress, Physiological

Sugarcane (Saccharum spp.) is an important sugar crop. Biotic and abiotic stresses such as diseases, cold, and drought are major factors limiting sugarcane production. β-1,3-glucanase (EC 3.2.1.39), a member of the pathogenesis-related protein family, plays an essential role not only in the plant defenses against pathogens but also in plant growth, development, and abiotic stress responses. To systematically investigate the sugarcane β-1,3-glucanase gene family, 132 glycoside hydrolase (GH) 17 family members were identified in the genomes of the sugarcane wild species Saccharum spontaneum 'Np-X', the tropical species S. officinarum 'LA-Purple', and the Saccharum spp. hybrid cultivar 'R570'. The results of the phylogenetic analysis categorized them into four subfamilies, of which subfamily Ⅳ had the largest proportion of members (102). The members of the sugarcane GH17 gene family contained five conserved motifs and 0-16 introns. The majority of the GH17 genes exhibited a genome-wide replication pattern, with 89.50% originating from S. spontaneum 'Np-X' and S. officinarum 'LA-Purple', while 58.10% of them in the Saccharum spp. hybrid cultivar 'R570' belonged to the discrete replication type. Four major classes of cis-acting elements were identified in the promoters, including the elements related to plant growth, development, and tissue-specific expression (14.21%), light-responsive elements (38.24%), biotic or abiotic stress-responsive elements (9.18%), and hormone-responsive elements (38.37%), which suggested that this gene family was involved in plant growth, development, hormone responses, and stress responses. Transcriptome and quantitative real-time PCR (RT-qPCR) analyses showed that the sugarcane GH17 genes exhibited tissue-specific expression and were differentially expressed under low temperature, drought, and hormone treatments, as well as during the interactions between different sugarcane genotypes and Sporisorium scitamineum, suggesting their potential roles in plant defenses. In addition, some SsGlu genes (SsGlu5, SsGlu20, SsGlu21, SsGlu25, SsGlu28, and SsGlu39) were expected to serve as candidate stress-related genes. This study lays a foundation for further revealing the molecular mechanisms of the stress resistance of sugarcane via β-1,3-glucanase genes.
Saccharum/physiology* ; Stress, Physiological/genetics* ; Glucan 1,3-beta-Glucosidase/metabolism* ; Multigene Family ; Phylogeny ; Gene Expression Regulation, Plant ; Plant Proteins/genetics*

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

The hydrolysis of xylo-oligosaccharides catalyzed by β-xylosidase plays an important role in the degradation of lignocellulose. However, the enzyme is easily inhibited by its catalytic product xylose, which severely limits its application. Based on molecular docking, this paper studied the xylose affinity of Aspergillus niger β-xylosidase An-xyl, which was significantly differentially expressed in the fermentation medium of tea stalks, through cloning, expression and characterization. The synergistic degradation effect of this enzyme and cellulase on lignocellulose in tea stems was investigated. Molecular docking showed that the affinity of An-xyl to xylose was lower than that of Aspergillus oryzae β-xylosidase with poor xylose tolerance. The K_i value of xylose inhibition constant of recombinant-expressed An-xyl was 433.2 mmol/L, higher than that of most β-xylosidases of the GH3 family. The K_m and V_max towards pNPX were 3.6 mmol/L and 10 000 μmol/(min·mL), respectively. The optimum temperature of An-xyl was 65 ℃, the optimum pH was 4.0, 61% of the An-xyl activity could be retained upon treatment at 65 ℃ for 300 min, and 80% of the An-xyl activity could be retained upon treatment at pH 2.0-8.0 for 24 h. The hydrolysis of tea stem by An-xyl and cellulase produced 19.3% and 38.6% higher reducing sugar content at 2 h and 4 h, respectively, than that of using cellulase alone. This study showed that the An-xyl mined from differential expression exhibited high xylose tolerance and higher catalytic activity and stability, and could hydrolyze tea stem lignocellulose synergistically, which enriched the resource of β-xylosidase with high xylose tolerance, thus may facilitate the advanced experimental research and its application.
Aspergillus niger/genetics* ; Xylose/metabolism* ; Molecular Docking Simulation ; Xylosidases/genetics* ; Cellulases ; Tea ; Hydrogen-Ion Concentration ; Substrate Specificity

β-glucosidase has important applications in food, pharmaceutics, biomass conversion and other fields, exploring β-glucosidase with strong adaptability and excellent properties thus has received extensive interest. In this study, a novel glucosidase from the GH1 family derived from Cuniculiplasma divulgatum was cloned, expressed, and characterized, aiming to find a better β-glucosidase. The amino acid sequences of GH1 family glucosidase derived from C. divulgatum were obtained from the NCBI database, and a recombinant plasmid pET-30a(+)-CdBglA was constructed. The recombinant protein was induced to express in Escherichia coli BL21(DE3). The enzymatic properties of the purified CdBglA were studied. The molecular weight of the recombinant CdBglA was 56.0 kDa. The optimum pH and temperature were 5.5 and 55 ℃, respectively. The enzyme showed good pH stability, 92.33% of the initial activity could be retained when treated under pH 5.5-11.0 for 1 h. When pNPG was used as a substrate, the kinetic parameters K_m, V_max and K_cat/K_m were 0.81 mmol, 291.99 μmol/(mg·min), and 387.50 s^-1 mmol^-1, respectively. 90.33% of the initial enzyme activity could be retained when CdBglA was placed with various heavy metal ions at a final concentration of 5 mmol/L. The enzyme activity was increased by 28.67% under 15% ethanol solution, remained unchanged under 20% ethanol, and 43.68% of the enzyme activity could still be retained under 30% ethanol. The enzyme has an obvious activation effect at 0-1.5 mol/L NaCl and can tolerate 0.8 mol/L glucose. In conclusion, CdBglA is an acidic and mesophilic enzyme with broad pH stability and strong tolerance to most metal ions, organic solvents, NaCl and glucose. These characteristics may facilitate future theoretical research and industrial production.
beta-Glucosidase ; Sodium Chloride ; Temperature ; Glucose ; Ethanol/chemistry* ; Ions ; Hydrogen-Ion Concentration ; Enzyme Stability ; Substrate Specificity

In order to investigate the enzyme production mechanism of yak rumen-derived anaerobic fungus Orpinomyces sp. YF3 under the induction of different carbon sources, anaerobic culture tubes were used for in vitro fermentation. 8 g/L of glucose (Glu), filter paper (Flp) and avicel (Avi) were respectively added to 10 mL of basic culture medium as the sole carbon source. The activity of fiber-degrading enzyme and the concentration of volatile fatty acid in the fermentation liquid were detected, and the enzyme producing mechanism of Orpinomyces sp. YF3 was explored by transcriptomics. It was found that, in glucose-induced fermentation solution, the activities of carboxymethyl cellulase, microcrystalline cellulase, filter paper enzyme, xylanase and the proportion of acetate were significantly increased (P < 0.05), the proportion of propionate, butyrate, isobutyrate were significantly decreased (P < 0.05). The results of transcriptome analysis showed that there were 5 949 differentially expressed genes (DEGs) between the Glu group and the Flp group, 10 970 DEGs between the Glu group and the Avi group, and 6 057 DEGs between the Flp group and the Avi group. It was found that the DEGs associated with fiber degrading enzymes were significantly up-regulated in the Glu group. Gene ontology (GO) function enrichment analysis identified that DEGs were mainly associated with the xylan catabolic process, hemicellulose metabolic process, β-glucan metabolic process, cellulase activity, endo-1,4-β-xylanase activity, cell wall polysaccharide metabolic process, carbohydrate catabolic process, glucan catabolic process and carbohydrate metabolic process. Moreover, the differentially expressed pathways associated with fiber degrading enzymes enriched by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were mainly starch and sucrose metabolic pathways and other glycan degradation pathways. In conclusion, Orpinomyces sp. YF3 with glucose as carbon source substrate significantly increased the activity of cellulose degrading enzyme and the proportion of acetate, decreased the proportion of propionate, butyrate and isobutyrate. Furthermore, the degradation ability and energy utilization efficiency of fungus in the presence of glucose were improved by means of regulating the expression of cellulose degrading enzyme gene and participating in starch and sucrose metabolism pathway, and other glycan degradation pathways, which provides a theoretical basis for the application of Orpinomyces sp. YF3 in practical production and facilitates the application of Orpinomyces sp. YF3 in the future.
Animals ; Cattle ; Neocallimastigales/metabolism* ; Anaerobiosis ; Rumen/microbiology* ; Propionates/metabolism* ; Isobutyrates/metabolism* ; Cellulose/metabolism* ; Fungi ; Starch/metabolism* ; Glucose/metabolism* ; Acetates ; Sucrose/metabolism* ; Cellulases ; Cellulase

Scopoletin is a coumarin compound with various biological activities including detumescence and analgesic, insecticidal, antibacterial and acaricidal effects. However, interference with scopolin and other components often leads to difficulties in purification of scopoletin with low extraction rates from plant resource. In this paper, heterologous expression of the gene encoding β-glucosidase An-bgl3 derived from Aspergillus niger were carried out. The expression product was purified and characterized with further structure-activity relationship between it and β-glucosidase analyzed. Subsequently, its ability for transforming scopolin from plant extract was studied. The results showed that the specific activity of the purified β-glucosidase An-bgl3 was 15.22 IU/mg, the apparent molecular weight was about 120 kDa. The optimum reaction temperature and pH were 55 ℃ and 4.0, respectively. Moreover, 10 mmol/L metal ions Fe²⁺ and Mn²⁺ increased the enzyme activity by 1.74-fold and 1.20-fold, respectively. A 10 mmol/L solution containing Tween-20, Tween-80 and Triton X-100 all inhibited the enzyme activity by 30%. The enzyme showed affinity towards scopolin and tolerated 10% methanol and 10% ethanol solution, respectively. The enzyme specifically hydrolyzed scopolin into scopoletin from the extract of Erycibe obtusifolia Benth with a 47.8% increase of scopoletin. This demonstrated that the β-glucosidase An-bgl3 from A. niger shows specificity on scopolin with good activities, thus providing an alternative method for increasing the extraction efficiency of scopoletin from plant material.
Aspergillus niger/genetics* ; beta-Glucosidase/chemistry* ; Scopoletin ; Polysorbates ; Coumarins

OBJECTIVE: To investigate the inhibitory effects of levofloxacin (LEV) combined with cellulase against bacille CalmetteGuerin (BCG) biofilms in vitro. METHODS: The mature growth cycle of BCG biofilms was determined using the XTT method and crystal violet staining. BCG planktonic bacteria and BCG biofilms were treated with different concentrations of LEV and cellulose alone or jointly, and the changes in biofilm biomass were quantified with crystal violet staining. The mature BCG biofilm was then treated with cellulase alone for 24 h, and after staining with SYTO 9 and Calcofluor White Stain, the number of viable bacteria and the change in cellulose content in the biofilm were observed with confocal laser scanning microscopy. The structural changes of the treated biofilm were observed under scanning electron microscopy. RESULTS: The MIC, MBC and MBEC values of LEV determined by broth microdilution method were 4 μg/mL, 8 μg/mL and 1024 μg/mL, respectively. The combined treatment with 1/4×MIC LEV and 2.56, 5.12 or 10.24 U/mL cellulase resulted in a significant reduction in biofilm biomass (P < 0.001). Cellulase treatments at the concentrations of 10.24, 5.12 and 2.56 U/mL all produced significant dispersion effects on mature BCG biofilms (P < 0.001). CONCLUSION LEV combined with cellulose can effectively eradicate BCG biofilm infections, suggesting the potential of glycoside hydrolase therapy for improving the efficacy of antibiotics against biofilmassociated infections caused by Mycobacterium tuberculosis.
Levofloxacin/pharmacology* ; Gentian Violet/pharmacology* ; BCG Vaccine/pharmacology* ; Anti-Bacterial Agents/pharmacology* ; Biofilms ; Cellulases/pharmacology* ; Microbial Sensitivity Tests

This study aims to explore the resource utilization of used fungus-growing materials produced in the cultivation of Gastrodia elata. To be specific, based on the production practice, this study investigated the recycling mechanism of used fungus-growing materials of G. elata by Phallus inpudicus. To screen edible fungi with wide adaptability, this study examined the allelopathic effects of Armillaria mellea secretions on P. impudicus and 6 kinds of large edible fungi and the activities of enzymes related to degradation of the used fungus-growing materials of G. elata. The results showed that P. impudicus can effectively degrade cellulose, hemicellulose, and lignin in used fungus-growing materials of G. elata. The cellulase activity of A. mellea was significantly higher than that of P. impudicus, and the activities of lignin peroxidase, polyphenol oxidase, and xylanase of P. impudicus were significantly higher than those of A. mellea, which was the important reason why A. mellea and P. impudicus used different parts and components of the used fungus-growing materials to absorb carbon sources and develop ecological niche differences. The growth of P. impudicus was significantly inhibited on the used fungus-growing materials of G. elata. The secretions of A. mellea had allelopathic effects on P. impudicus and other edible fungi, and the allelopathic effects were related to the concentration of allelopathy substances. The screening result showed that the growth and development of L. edodes and A. auricular were not significantly affected by 30% of A. mellea liquid, indicating that they had high resistance to the allelopathy of A. mellea. The results showed that the activities of extracellular lignin peroxidase, polyphenol oxidase, and xylanase of the two edible fungi were similar to those of P. impudicus, and the cellulase activity was higher than that of P. impudicus. This experiment can be further verified by small-scale production tests.
Agaricales ; Ascomycota ; Basidiomycota ; Catechol Oxidase ; Cellulases ; Gastrodia

β-glucosidase has important applications in food, medicine, biomass conversion and other fields. Therefore, exploring β-glucosidase with strong stability and excellent properties is a research hotspot. In this study, a GH3 family β-glucosidase gene named Iubgl3 was successfully cloned from Infirmifilum uzonense. Sequence analysis showed that the full length of Iubgl3 was 2 106 bp, encoding 702 amino acids, with a theoretical molecular weight of 77.0 kDa. The gene was cloned and expressed in E. coli and the enzymatic properties of purified IuBgl3 were studied. The results showed that the optimal pH and temperature for pNPG hydrolysis were 5.0 and 85 ℃, respectively. The enzyme has good thermal stability, and more than 85% of enzyme activity can be retained after being treated at 80 ℃ for2 h. This enzyme has good pH stability and more than 85% of its activity can be retained after being treated at pH 4.0-11.0 for 1 h. It was found that the enzyme had high hydrolysis ability to p-nitrophenyl β-d-glucoside (pNPG) and p-nitrophenyl β-d-xylopyranoside (pNPX). When pNPG was used as the substrate, the kinetic parameters K_m and V_max were 0.38 mmol and 248.55 μmol/(mg·min), respectively, and the catalytic efficiency k_cat/K_m was 6 149.20 s^-1mmol^-1. Most metal ions had no significant effect on the enzyme activity of IuBgl3. SDS completely inactivated the enzyme, while EDTA increased the enzyme activity by 30%. This study expanded the β-glucosidase gene diversity of the thermophilic archaea GH3 family and obtained a thermostable acid bifunctional enzyme with good industrial application potential.
beta-Glucosidase/chemistry* ; Archaea/metabolism* ; Escherichia coli/metabolism* ; Hydrogen-Ion Concentration ; Temperature ; Glucosides ; Enzyme Stability ; Substrate Specificity ; Kinetics