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Quorum sensing (QS) is a cellular communication mechanism in which bacteria secrete and recognize signaling molecules to regulate group behavior. Lipases provide energy for bacterial cell growth but it is unknown whether they influence nutrient-dependent QS by hydrolyzing substrate. A high-yield lipase-producing strain, Burkholderia pyrrocinia WZ10-3, was previously identified in our laboratory, but the composition of its crude enzymes was not elucidated. Here, we identified a key extracellular lipase, Lip1728, in WZ10-3, which accounts for 99 % of the extracellular lipase activity. Lip1728 prefers to hydrolyze triglycerides at sn-1,3 positions, with pNP-C16 being its optimal substrate. Lip1728 exhibited activity at pH 5.0-10.0 and regardless of the presence of metal ions. It had strong resistance to sodium dodecyl sulfate and short-chain alcohols and was activated by phenylmethanesulfonylfluoride (PMSF). Lip1728 knockout significantly affected lipid metabolism and biofilm formation in the presence of olive oil. Finally, oleic acid, a hydrolysate of Lip1728, influenced the production of the signal molecule N-acyl homoserine lactone (AHL) and biofilm formation by downregulating the AHL synthetase gene pyrI. In conclusion, Lip1728, as a key extracellular lipase in B. pyrrocinia WZ10-3, exhibits superior properties that make it suitable for biodiesel production and plays a crucial role in QS.

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Vibrio parahaemolyticus, a prevalent foodborne pathogen found in both water and seafood, poses substantial risks to public health. The conventional countermeasure, antibiotics, has exacerbated the issue of antibiotic resistance, increasing the difficulty of controlling this bacterium. Phage lysins, as naturally occurring active proteins, offer a safe and reliable strategy to mitigate the impact of V. parahaemolyticus on public health. However, there is currently a research gap concerning bacteriophage lysins specific to Vibrio species. To address this, our study innovatively and systematically evaluates 37 phage lysins sourced from the NCBI database, revealing a diverse array of conserved domains and notable variations in similarity among Vibrio phage lysins. Three lysins, including Lyz_V_pgrp, Lyz_V_prgp60, and Lyz_V_zlis, were successfully expressed and purified. Optimal enzymatic activity was observed at 45℃, 800 mM NaCl, and pH 8-10, with significant enhancements noted in the presence of 1 mM membrane permeabilizers such as EDTA or organic acids. These lysins demonstrated effective inhibition against 63 V. parahaemolyticus isolates from clinical, food, and environmental sources, including the reversal of partial resistance, synergistic interactions with antibiotics, and disruption of biofilms. Flow cytometry analyses revealed that the combination of Lyz_V_pgp60 and gentamicin markedly increased bacterial killing rates. Notably, Lyz_V_pgrp, Lyz_V_pgp60, and Lyz_V_zlis exhibited highly efficient biofilm hydrolysis, clearing over 90 % of preformed V. parahaemolyticus biofilms within 48 h. Moreover, these lysins significantly reduced bacterial loads in various food samples and environmental sources, with reductions averaging between 1.06 and 1.29 Log CFU/cm2 on surfaces such as stainless-steel and bamboo cutting boards and approximately 0.87 CFU/mL in lake water and sediment samples. These findings underscore the exceptional efficacy and versatile application potential of phage lysins, offering a promising avenue for controlling V. parahaemolyticus contamination in both food and environmental contexts.

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The limited availability of phospholipase A1 (PLA1) has posed significant challenges in enzymatic degumming. In this study, a novel PLA1 (UM2) was introduced to address this limitation, which had a unique thermo-responsive ability to switch phospholipase and lipase activities in response to temperature variations. Remarkably, UM2 displayed an unprecedented selectivity under optimized conditions, preferentially hydrolyzing phospholipids over triacylglycerols-a specificity superior to that of commercial PLA1. Moreover, UM2 demonstrated high efficiency in hydrolyzing phospholipids with a predilection for phosphatidylcholine (PC) and phosphatidylethanolamine (PE). A practical application of UM2 on crude flaxseed oil led to a dramatic reduction in phosphorus content, plummeting from an initial 384.06 mg/kg to 4.38 mg/kg. Broadening its industrial applicability, UM2 effectively performed enzymatic degumming for other distinct crude vegetable oils with a unique phospholipid composition. Collectively, these results highlighted the promising application of UM2 in the field of oil degumming.

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Microbial pectinolytic enzymes are important in various industries, particularly food processing. This study focuses on uncovering insights into a novel pectin lyase, BvPelB, from Bacillus velezensis 16B, with the aim of enhancing fruit juice processing. The study examines the structural and functional characteristics of pectinolytic enzyme, underscoring the critical nature of substrate specificity and enzymatic reaction mechanisms. BvPelB was successfully expressed and purified, exhibiting robust activity under alkaline conditions and thermal stability. Structural analysis revealed similarities with other pectin lyases, despite limited sequence identity. Biochemical characterization showed BvPelB's preference for highly methylated pectins and its endo-acting mode of cleavage. Treatment with BvPelB significantly increased juice yield and clarity without generating excessive methanol, making it a promising candidate for fruit juice processing. Overall, this study provides valuable insights into the enzymatic properties of BvPelB and its potential industrial applications in improving fruit juice processing efficiency and quality.

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λ-carrageenan oligosaccharides can be widely applied in the food, pharmaceutical, medicine and cosmetic industries due to their abundant bioactivities, and they are important products for the high-value utilization of λ-carrageenan. However, oligosaccharides with different degrees of polymerization have different properties, and the final products of λ-carrageenase reported so far are mainly λ-neocarrabiose, λ-neocarratetraose and λ-neocarrahexaose without longer-chain oligosaccharides. Further research is consequently required. Herein, a mutant λ-carrageenase was constructed by deleting the pyrroloquinoline quinone-like domain of OUC-CglA derived from Maribacter vaceletii. Interestingly, it was discovered that the majority of final products of the mutant OUC-CglA-DPQQ were long-chain oligosaccharides with a polymerization degree of 10-20, which underwent significant changes compared to that of OUC-CglA. Additionally, without the pyrroloquinoline quinone-like domain, fewer inclusion bodies were produced throughout the expression process, and the yield of the λ-carrageenase increased about five-fold. However, compared to its parental enzyme, significant changes were made to its enzymatic properties. Its optimal temperature and pH were 15 °C and pH 7.0, and its specific activity was 51.59 U/mg. The stability of the enzyme decreased. Thus, it was found that the deleting domain was related to the formation of inclusion bodies, the stability of the enzyme, the activity of the enzyme and the composition of the products.

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BACKGROUND: Citrus products often suffer from delayed bitterness, which is generated from the conversion of non-bitter precursors (limonoate A-ring lactone, LARL) to limonin under the catalysis of limonin D-ring lactone hydrolase (LDLH). In this study, LDLH was isolated and purified from sweet orange seeds, and a rapid and accurate high-performance liquid chromatography method to quantify LARL was developed and applied to analyze the activity and enzymatic properties of purified LDLH. RESULTS: Purified LDLH (25.22 U mg-1) showed bands of 245 kDa and 17.5 kDa molecular weights in native polyacrylamide gel electrophoresis (PAGE) and sodium dodecyl sulfate PAGE analysis respectively. After a 24 h incubation under strongly acidic (pH 3) or strongly alkaline (pH 9) conditions, LDLH still retained approximately 100% activity. Moreover, LDLH activity was not impaired by thermal treatment at 50 °C for 120 min. Enzyme inhibition assays showed that LDLH was inactivated only after ethylenediaminetetraacetic acid treatment, and other enzyme inhibitors showed no significant effect on its activity. In addition, the LDLH activity of calcium ion (Ca2+) intervention was 108% of that in the blank group, and that of zinc ion (Zn2+) intervention was 71%. CONCLUSION: LDLH purified in this study was a multimer containing 17.5 kDa monomer with a wide pH tolerance range (pH 3-9) and excellent thermal stability. Moreover, LDLH might be a metallopeptidase, and its activity was stimulated by Ca2+ and significantly inhibited by Zn2+. These findings improve our understanding of LDLH and provide some important implications for reducing the bitterness in citrus products in the future. © 2024 Society of Chemical Industry.

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Arginine deiminase (ADI) has garnered significant interest because of its ability to objectively eradicate cancer cells and produce L-citrulline. To meet the production demands, this study focused on enhancing the enzyme activity and thermal stability of ADI. In this study, 24 ADI mutants were obtained through computer aid site-specific mutation in the ADI of Enterobacter faecalis. Notably, the specific enzyme activities of F44W, N163P, E220I, E220L, N318E, A336G, T340I, and N382F increased, reaching 1.33-2.53 times that of the original enzyme. This study confirmed that site-specific mutations are critical for optimizing enzyme function. Additionally, the F44W, N163P, E220I, T340I, and A336G mutants demonstrated good thermal stability. The optimal pH for mutant F44W increased to 8, whereas mutants E220I, I244V, A336G, T340I, and N328F maintained an optimal pH of 7.5. Conversely, the M109L, N163P, E220L, I244L, and N318E mutants shad an optimal pH of 7. This study revealed that mutant enzymes with increased activity were more likely to contain mutation sites situated near the four loops associated with catalytic residues, whereas mutations at the dimer junction sites had a higher tendency to enhance enzyme stability. These findings contribute to the development of ADI industrial applications and its modifications.

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κ-Carrageenase plays a crucial role in the high-value utilization of carrageenan. Heat resistance is a key factor in the practical application of κ-carrageenase, as carrageenan exhibits gel-like properties. Previous studies have shown that the C-terminal noncatalytic domains (nonCDs) can affect the thermostability of κ-carrageenases. In this study, we expressed and characterized a κ-carrageenase, MtKC16A, which contains three nonCDs, from Microbulbifer thermotolerans. MtKC16A has the highest activity at 80 °C and pH 7.0. Surprisingly, it exhibits excellent heat resistance, with 71.58% relative activity at 100 °C and still retains over 50% residual activity after incubation at 100 °C for 60 min. Additionally, MtKC16A has been shown to have a dual substrate hydrolysis activity. It can degrade κ-carrageenan to produce highly single Nκ4 and degrade ß/κ-carrageenan to produce Nκ2 and desulfated Nκ4 DA-G-DA-G4S, suggesting its potential in producing κ- and ß/κ-hybrid oligosaccharides. Furthermore, we found that the unknown function domain (UNFD) in MtKC16A plays the most vital role among the three nonCDs. When this UNFD is truncated, the resulting mutants completely lose their catalytic ability at 100 °C. Finally, by introducing this UNFD to the C-terminal of another κ-carrageenase CaKC16B, we were able to improve its heat resistance at 100 °C.

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Polymerized guluronates (polyG)-specific alginate lyase with lower polymerized mannuronates (polyM)-degrading activity, superior stability, and clear action mode is a powerful biotechnology tool for the preparation of AOSs rich in M blocks. In this study, we expressed and characterized a polyG-specific alginate lyase OUC-FaAly7 from Formosa agariphila KMM3901. OUC-FaAly7 belonging to polysaccharide lyase (PL) family 7 had highest activity (2743.7 ± 20.3 U/µmol) at 45 °C and pH 6.0. Surprisingly, its specific activity against polyG reached 8560.2 ± 76.7 U/µmol, whereas its polyM-degrading activity was nearly 0 within 10 min reaction. Suggesting that OUC-FaAly7 was a strict polyG-specific alginate lyase. Importantly, OUC-FaAly7 showed a wide range of temperature adaptations and remarkable temperature and pH stability. Its relative activity between 20 °C and 45 °C reached >90 % of the maximum activity. The minimum identifiable substrate of OUC-FaAly7 was guluronate tetrasaccharide (G4). Action process and mode showed that it was a novel alginate lyase digesting guluronate hexaose (G6), guluronate heptaose (G7), and polymerized guluronates, with the preferential generation of unsaturated guluronate pentasaccharide (UG5), although which could be further degraded into unsaturated guluronate disaccharide (UG3) and trisaccharide (UG2). This study contributes to illustrating the catalytic properties, substrate recognition, and action mode of novel polyG-specific alginate lyases.

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Histamine, found abundantly in salt-fermented foods, poses a risk of food poisoning. Natronobeatus ordinarius, a halophilic archaeon isolated from a salt lake, displayed a strong histamine degradation ability. Its histamine oxidase (HOD) gene was identified (hodNbs). This is the first report of an archaeal HOD. The HODNbs protein was determined to be a tetramer with a molecular weight of 307 kDa. HODNbs displayed optimum activity at 60-65 °C, 1.5-2.0 M NaCl, and pH 6.5. Notably, within the broad NaCl range between 0.5 and 2.5 M, HODNbs retained above 50% of its maximum activity. HODNbs exhibited good thermal stability, pH stability, and salinity tolerance. HODNbs was able to degrade various biogenic amines. The Vmax of HODNbs for histamine was 0.29 µmol/min/mg, and the Km was 0.56 mM. HODNbs exhibited high efficiency in histamine removal from fish sauce, namely, 100 µg of HODNbs degraded 5.63 mg of histamine (37.9%) in 10 g of fish sauce within 24 h at 50 °C. This study showed that HODNbs with excellent enzymatic properties has promising application potentials to degrade histamine in high-salt foods.

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With the industrialization and development of modern science, the application of enzymes as green and environmentally friendly biocatalysts in industry has been increased widely. Among them, lipase (EC. 3.1.1.3) is a very prominent biocatalyst, which has the ability to catalyze the hydrolysis and synthesis of ester compounds. Many lipases have been isolated from various sources, such as animals, plants and microorganisms, among which microbial lipase is the enzyme with the most diverse enzymatic properties and great industrial application potential. It therefore has promising applications in many industries, such as food and beverages, waste treatment, biofuels, leather, textiles, detergent formulations, ester synthesis, pharmaceuticals and medicine. Although many microbial lipases have been isolated and characterized, only some of them have been commercially exploited. In order to cope with the growing industrial demands and overcome these shortcomings to replace traditional chemical catalysts, the preparation of new lipases with thermal/acid-base stability, regioselectivity, organic solvent tolerance, high activity and yield, and reusability through excavation and modification has become a hot research topic.

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Polysaccharides have attracted immense attention as the largest source of bioactive compounds. Its bioavailability and bioactivity can be improved by utilizing degradation enzymes to reduce their molecular weight and viscosity. In this study, a 654 bp gene encoding xylanase was screened from the genome of Bacillus altitudinis JYY-02 and overexpressed in Escherichia coli Rosetta (DE3). The recombinant xylanase with a molecular weight of 27.98 kDa was purified (11.7-fold) using Ni-NTA affinity chromatography, with a 43.6% final yield. Through molecular docking, Glu, Arg, Tyr, and Trp were found to be the main amino acids involved in the interaction between xylanase and xylobiose. The effects of pH, temperature, metal ions, and substrates on xylanase activity were determined, and the results showed that the highest catalytic activity was displayed at pH 6.5, 50 °C temperature, with Cu2+ as an activator and xylan as the substrate. The Km (substrate concentration that yields a half-maximal velocity) and Vmax (maximum velocity) of recombinant xylanase were 6.876 mg/mL and 10984.183 µmol/mg∙pr/min, respectively. The recombinant xylanase was thermostable, with 85% and 39% of the enzymatic activity retained after 1 h at 60 °C and 1 h at 90 °C, respectively. The recombinant xylanase demonstrated a significant clarifying effect on fruit juices.

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Chitin deacetylase (CDA) can catalyze the deacetylation of chitin to produce chitosan. In this study, we identified and characterized a chitin deacetylase gene from Euphausia superba (EsCDA-9k), and a soluble recombinant protein chitin deacetylase from Euphausia superba of molecular weight 45 kDa was cloned, expressed, and purified. The full-length cDNA sequence of EsCDA-9k was 1068 bp long and encoded 355 amino acid residues that contained the typical domain structure of carbohydrate esterase family 4. The predicted three-dimensional structure of EsCDA-9k showed a 67.32% homology with Penaeus monodon. Recombinant chitin deacetylase had the highest activity at 40 °C and pH 8.0 in Tris-HCl buffer. The enzyme activity was enhanced by metal ions Co2+, Fe3+, Ca2+, and Na+, while it was inhibited by Zn2+, Ba2+, Mg2+, and EDTA. Molecular simulation of EsCDA-9k was conducted based on sequence alignment and homology modeling. The EsCDA-9k F18G mutant showed a 1.6-fold higher activity than the wild-type enzyme. In summary, this is the first report of the cloning and heterologous expression of the chitin deacetylase gene in Euphausia superba. The characterization and function study of EsCDA-9k will serve as an important reference point for future application.

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Bioluminescence in beetles has long fascinated biologists, with diverse applications in biotechnology. To date, however, our understanding of its evolutionary origin and functional variation mechanisms remains poor. To address these questions, we obtained high-quality reference genomes of luminous and nonluminous beetles in 6 Elateroidea families. We then reconstructed a robust phylogenetic relationship for all luminous families and related nonluminous families. Comparative genomic analyses and biochemical functional experiments suggested that gene evolution within Elateroidea played a crucial role in the origin of bioluminescence, with multiple parallel origins observed in the luminous beetle families. While most luciferase-like proteins exhibited a conserved nonluminous amino acid pattern (TLA346 to 348) in the luciferin-binding sites, luciferases in the different luminous beetle families showed divergent luminous patterns at these sites (TSA/CCA/CSA/LVA). Comparisons of the structural and enzymatic properties of ancestral, extant, and site-directed mutant luciferases further reinforced the important role of these sites in the trade-off between acyl-CoA synthetase and luciferase activities. Furthermore, the evolution of bioluminescent color demonstrated a tendency toward hypsochromic shifts and variations among the luminous families. Taken together, our results revealed multiple parallel origins of bioluminescence and functional divergence within the beetle bioluminescent system.

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Arabinoxylans (AXs) are hemicellulosic polysaccharides consisting of a linear backbone of ß-1,4-linked xylose residues branched by high content of α-L-arabinofuranosyl (Araf) residues along with other side-chain substituents, and are abundantly found in various agricultural crops especially cereals. The efficient bioconversion of AXs into monosaccharides, oligosaccharides and/or other chemicals depends on the synergism of main-chain enzymes and de-branching enzymes. Exo-α-L-arabinofuranosidases (ABFs) catalyze the hydrolysis of terminal non-reducing α-1,2-, α-1,3- or α-1,5- linked α-L-Araf residues from arabinose-substituted polysaccharides or oligosaccharides. ABFs are critically de-branching enzymes in bioconversion of agricultural biomass, and have received special attention due to their application potentials in biotechnological industries. In recent years, the researches on microbial ABFs have developed quickly in the aspects of the gene mining, properties of novel members, catalytic mechanisms, methodologies, and application technologies. In this review, we systematically summarize the latest advances in microbial ABFs, and discuss the future perspectives of the enzyme research.

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BACKGROUND: Corn poppy (Papaver rhoeas) is the most damaging broadleaf weed in France. Massively parallel amplicon sequencing was used to investigate the prevalence, mode of evolution and spread of resistance-endowing ALS alleles in 422 populations randomly sampled throughout poppy's range in France. Bioassays were used to detect resistance to the synthetic auxin 2,4-D in 43 of these populations. RESULTS: A total of 21 100 plants were analysed and 24 mutant ALS alleles carrying an amino-acid substitution involved or potentially involved in resistance were identified. The vast majority (97.6%) of the substitutions occurred at codon Pro197, where all six possible single-nucleotide non-synonymous substitutions plus four double-nucleotide substitutions were identified. Changes observed in the enzymatic properties of the mutant ALS isoforms could not explain the differences in prevalence among the corresponding alleles. Sequence read analysis showed that mutant ALS alleles had multiple, independent evolutionary origins, and could have evolved several times independently within an area of a few kilometres. Finally, 2,4-D resistance was associated with mutant ALS alleles in individual plants in one third of the populations assayed. CONCLUSION: The intricate geographical mosaic of mutant ALS alleles observed is the likely result of the combination of huge population sizes, multiple independent mutation events and human-mediated spread of resistance. Our work highlights the ability of poppy populations and individual plants to accumulate different ALS alleles and as yet unknown mechanisms conferring resistance to synthetic auxins. This does not bode well for the continued use of chemical herbicides to control poppy. © 2023 Society of Chemical Industry.

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AIM To study the extraction process,enzymatic properties and practical application of glucuronic hydrolase in Scutellaria baicalensis stems and leaves(sbsl GUS).METHODS With granularity,water consumption,extraction time and extraction frequency as influencing factors,enzymatic activity as an evaluation index,the extraction process was optimized by orthogonal test on the basis of single factor test.The relationship between substrate(baicalin)concentration and enzymolysis rate,after which Vmax and Km were calculated,the effects of pH value,temperature and metal ion on enzymatic activity were investigated,pH stability and heat stability were evaluated.sbsl GUS was adotped in the enzymolysis of baicalin to prepare baicalein,then the effects of pH value,temperature,reaction time,initial substrate concentration and enzyme addition on transfer rate were investigated.RESULTS The optimal extraction process was determined to be 40 mesh for granularity,10 times for water consumption,15 min for extraction time,and 3 times for extraction frequency.The enzymolysis accorded with the kinetics of enzymatic reaction,Km was 0.006 3 mol/L,Vmax was 70.42 μmol/h,the strongest enzymatic activity was found at the pH value of 6.0,temperature of 45℃and metal ion of 100 mmol/L Cu2+,sbsl GUS demonstrated good stability at the ranges of 4.0-7.0 for pH value and 4-30℃for temperature.The optimal preparation process was determined to be 6.0 for pH value,45℃for temperature,more than 12 h for reaction time,67.2 mmol/L for initial substrate concentration,and 1 mL/0.269 mmol baicalin for enzyme addition,the transfer rate was 97.83%.CONCLUSION sbsl GUS enzymolysis exhibits high efficiency and mild condition,which can provide a simple preparation method for obtaining baicalein,and expand the application path of Scutellaria baicalensis stems and leaves.

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In this study, the wild-type Bacillus cereus ATA179 was mutagenized by random UV mutagenesis to increase lipase production. The mutant with maximum lipolytic activity was named Bacillus cereus EV4. The mutant strain (10.6 U/mL at 24 h) produced 60% more enzyme than the wild strain (6.6 U/mL at 48 h). Nutritional factors on lipase production were investigated. Sucrose was the best carbon source, (NH4)2HPO4 was the best nitrogen source and CuSO4 was the best metal ion source. Mutant EV4 showed a 32% increase in lipase production in the modified medium. The optimum temperature and pH were found to be 60 °C and 7.0, respectively. CuSO4, CaCl2, LiSO4, KCl, BaCl2, and Tween 20 had an activating effect on the enzyme. Vmax and Km values were found to be 17.36 U/mL and 0.036 mM, respectively. The molecular weight was determined as 28.2 kDa. The activity of lipase was found to be stable up to 60 days at 20 °C, 75 days at 4 °C, and 90 days at -20 °C. The potential of lipase in the detergent industry was investigated. The enzyme was not affected by detergent additives but was effective in removing stains in fabrics contaminated with oily substances.

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ß-glucosidase has important applications in food, pharmaceutics, biomass conversion and other fields, exploring ß-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 ß-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 Km, Vmax and Kcat/Km 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.

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At presently, the catalytic activity of xylanase is sub-optimal, and the required reaction conditions are harsh. To improve its catalytic activity and stability, xylanase (XY) was chemically modified with maleic anhydride (MA). The enzymatic properties of this maleic anhydride-modified xylanase (MA-XY) were then evaluated and analyzed spectroscopically. The results showed that the thermal stability, use of organic solvents, storage stability and the pH range of 3.0 to 9.0 for MA-XY were better than that for XY alone. The kinetic parameters of the enzyme (Km values) decreased from 40.63 to 30.23 mg/mL. Spectroscopic analysis showed that XY had been modified by the acylation reaction to become a tertiary structure. An assay based on clarifying fruit juices showed that the clarification capacity and reducing sugar content using MA-XY increased compared with those using XY. Overall, this study provides a theoretical basis for improving the application of XY in the food industry.