19 results about "Laccase activity" patented technology

The invention discloses an Hg < 2 + > detection method for enhancing Hg < 2 + > intrinsic laccase-like activity based on ZIF-8-Au. The invention finds that the mercury ions have laccase-like activity, the enzyme activity of the mercury ions is obviously enhanced under the action of ZIF-8-Au, and the color of the reaction catalyzed by the mercury ions is obviously changed along with the increase of the concentration of Hg < 2 + >, so that a colorimetric analysis method for detecting the mercury ions is developed on the basis, the Turn-On type visual analysis is realized, and the application prospect is wide. The method realizes simple, rapid, sensitive and high-selectivity detection of Hg < 2 + > residues in water and food. The invention provides a new method and principle for the fields of Hg < 2 + > environment monitoring and food safety, and provides a new direction for the development of a heavy metal ion detection technology.

The invention provides a laccase gene LAC18 screened from apples and aphid resistance application of the laccase gene LAC18 in catalytic synthesis of plant lignin, the nucleotide sequence of the gene is SEQ ID NO: 1, and the amino acid sequence of encoded protein of the gene is SEQ ID NO: 2. According to the method, the aphid resistance of the transgenic tobacco is comprehensively evaluated by inoculating aphids on leaves of the transgenic laccase gene tobacco and observing indexes such as the survival rate and the aphid yield. The result shows that the laccase activity and the lignin content of the transgenic laccase tobacco are remarkably improved, the lignin of cell walls is thickened, and the lignification degree is remarkably improved. The translaccase gene tobacco not only can effectively reduce the survival rate of myzus persicae, but also has a remarkable inhibition effect on the average reproductive capacity of the myzus persicae, and the aphid resistance of plants is greatly improved.

The invention provides an efficient microbial fermentation inoculant for straws and a preparation method thereof, and relates to the technical field of biodegradation. The efficient microbial fermentation inoculant for the straw is formed by compounding four strains including trichoderma reesei, streptomycete, lactobacillus plantarum and bacillus amyloliquefaciens according to the mass ratio, the ratio of the viable count of the four strains is that the ratio of the viable count of the trichoderma reesei to the viable count of the streptomycete to the viable count of the lactobacillus plantarum to the viable count of the bacillus amyloliquefaciens is 3: 2: 2: 1.5, the total viable count of the inoculant is larger than or equal to 1.3 * 10 CFU / g, and the cellulase activity is larger than or equal to 85 U / g. The laccase activity is greater than or equal to 42U / g. The invention can effectively solve the industrial pain points of difficult degradation of straws, poor quality and weak stability, and in agricultural production, the microbial inoculum can increase the content of organic matters in soil, can reduce the feed cost in the feed field, and can be used for production of straw-based organic fertilizers in the environmental protection field, and can reduce the use amount of chemical fertilizers.

The present application provides a kind of marine bacteria capable of degrading lignin and removing nitrite, which is a deep-sea seabed sulfide source, and has the function of degrading lignin and removing nitrite.The strain of Halomonas sp.has a preservation number of CGMCC No.34690.The strain screened in the present application can grow and reproduce in seawater, can utilize guaiacol as a carbon source, and can remove nitrite.The strain of the present application has laccase activity, has laccase gene and nitrite reductase gene.The experimental results show that the cumulative removal rate of guaiacol after 2 days of culture is 56%, and the removal rate of nitrite after 4 days of culture is close to 70%, which has great application potential in the marine aquaculture industry.

This invention discloses a laccase derived from *Coprinus gracilis*, its recombinant expression strain, and a highly efficient expression method, belonging to the fields of microbiology and bioengineering technology. Using *Aspergillus niger* MA70.15 as the experimental strain, this invention employs a random integration strategy to achieve pC3-P... citA -SP GlaA - lcc9‑ T trpC ‑pyrG The expression vector was integrated into the upstream region of the promoter of the host bacterium citrate synthase in the form of nine consecutive copies. To investigate the effects of microparticles and osmotic regulators in the fermentation medium on laccase production by recombinant Aspergillus niger, this invention added different types and concentrations of microparticles and osmotic regulators, resulting in a laccase activity of 1566.7 U / L in shake-flask fermentation of recombinant strain AnRcgL1 and 1961 U / L in a 1 L fermenter, successfully achieving efficient recombinant expression of laccase Lcc9 in Aspergillus niger.

This invention discloses a method for detecting octopamine and tyramine using a laccase-like Schiff base Cu-MOF nanozyme. The method uses a Schiff base formed from glutaraldehyde and 2-aminoterephthalic acid as starting reagents as ligands to synthesize a flower-like Cu-MOF nanozyme. This Cu-MOF exhibits near-infrared light-triggered laccase-like activity. Using octopamine and tyramine as substrates, Cu-MOF catalyzes the oxidation of octopamine and tyramine, conjugating 4-aminoantipyrine to form a red coupling product. This product exhibits a high absorption spectrum at 505 nm, demonstrating high detection efficiency with detection limits of 0.18 μg / mL and 0.60 μg / mL, respectively. X-ray photoelectron spectroscopy analysis shows that the Cu(I) / Cu(II) redox reaction participates in the catalytic process. This method is characterized by high sensitivity, strong specificity, simple operation, and rapid response.

Provided is a new CueO mutant with improved activity compared with wild-type CueO. The protein according to one or more embodiments of the present invention contains an amino acid sequence [1] or [2] and has laccase activity: [1] an amino acid sequence containing at least a region of positions 29-516 in SEQ ID NO: 14 with mutations (a) and (b): (a) a substitution of D360 with an amino acid other than D; and (b) one or more selected from a substitution of G304 with an amino acid other than G, a substitution of D373 with an amino acid other than D, and a substitution of Q374 with an amino acid other than Q; or [2] an amino acid sequence 90% or more identical to the sequence [1], and having residues corresponding to positions 360, 304, 373, and 374 of SEQ ID NO: 14 identical to those of the sequence [1].

The invention provides a CeMOF-on-CuMOF nano enzyme, a preparation method thereof and application of the CeMOF-on-CuMOF nano enzyme in alpha-glucosidase detection, and belongs to the technical field of alpha-glucosidase detection. The MOF-on-MOF nano-enzyme (CeMOF-on-CuMOF) with double-enzyme activity is successfully synthesized, oxidase-like activity and laccase-like activity of the MOF-on-MOF nano-enzyme are both synergistically improved, a fluorescence and colorimetric dual-mode sensing method is established based on the enhanced double-enzyme activity, high-sensitivity detection of alpha-glucosidase is realized, and the detection limits are respectively as low as 0.35 U / L and 0.16 U / L. The dual-mode detection has a built-in self-correction function, so that the dual-mode detection is more reliable than the single-mode detection; and the dual-mode sensing technology based on the multifunctional MOF has a wide development prospect by virtue of the synergistic effect, the convenient multifunctional MOF synthesis method and the flexible multi-mode sensing design.

The application belongs to the technical field of microorganisms, and particularly relates to a laccase-producing Serratia marcescens and application thereof. Specifically, the application provides a high-yield laccase-producing Serratia marcescens ZH-5. It is verified through experiments that the Serratia marcescens obtained in the application has significantly improved laccase activity, reaching 16822 U / L, in a LB culture medium added with glycerol. Meanwhile, the strain has good salt tolerance and acid and alkali tolerance, heavy metal tolerance, and the laccase produced by the strain still has certain enzyme activity at 80 DEG C, and has good enzyme activity in a strong acidic environment, thus having good practical application value.

The invention discloses a nano-enzyme with laccase activity and coexistence of Cu single atoms and Cu nano-particles. The nano-enzyme is used for degrading aflatoxin B1. Cu nanoparticles are loaded on Cu single atoms through a one-step pyrolysis method, CuSAC and CuNPs are successfully synthesized, under the low concentration of the material, the CuSAC and CuNPs can rapidly generate free radicals to oxidize AFB1, the degradation rate of aflatoxin B1 within 30 min can reach 90% or above, meanwhile, the material has good anti-interference performance and stability, and experiments show that the CuSAC and CuNPs nano-enzyme has huge potential in the aspect of degrading aflatoxin B1.

This invention discloses a bimetallic co-doped carbon-based nanozyme, its preparation method, and its applications, belonging to the fields of nanomaterials and biomimetic enzyme technology. Using tannic acid and melamine as carbon and nitrogen sources, and introducing iron and manganese salts, this invention successfully prepared an iron-manganese bimetallic co-doped carbon-based nanozyme through a simple mixing, evaporation, and high-temperature calcination method. The resulting nanozyme exhibits an ultrathin nanosheet structure, with Fe and Mn elements uniformly dispersed within the carbon framework. This nanozyme demonstrates significantly enhanced laccase-like activity, with a specific activity reaching 3.4 U / mg, 6.8 times that of natural laccase from Trametes versicolor, and exhibits excellent pH and temperature stability as well as high substrate affinity. The preparation method of this invention is simple, low-cost, and easily scalable. This bimetallic co-doped carbon-based nanozyme has broad application prospects in the fields of catalytic degradation and colorimetric detection and analysis of organic pollutants.

The invention discloses a method for improving enzyme activity of laccase produced by ganoderma lucidum, aims to improve laccase production capacity of ganoderma lucidum, and belongs to the technical field of microbial ferment.The method includes the steps that dominant strains are selected in the mode that strains are screened from all stages for fermentation enzyme production, so that the enzyme activity of laccase used for follow-up production is improved, and the yield of laccase is improved. The method mainly comprises the following steps: (1) screening preservation bacteria; (2) strain recovery and screening; (3) strain amplification culture and screening; and (4) screening strain fermentation enzyme production seed liquid. According to the method, the ganoderma lucidum is screened in different stages, so that the ganoderma lucidum in each stage has the best performance, and the final laccase activity is improved. The enzyme activity of the ganoderma lucidum laccase is improved, the stability of the ganoderma lucidum laccase can be improved, and it is ensured that the enzyme activity of each batch can range from 140000 u / L to 160000 u / L.

The application belongs to the technical field of analysis and detection, and particularly relates to a high-activity nano-enzyme for simultaneously detecting various chlorophenols, a preparation method and application thereof. The nano-enzyme is a composite material formed by in-situ chelation of copper nitrate, adenine and hierarchical porous cerium metal organic framework HM UIO-66(Ce). The copper-adenine formed by coordination of copper nitrate and adenine is uniformly loaded on the surface or pore interface of the hierarchical porous cerium metal organic framework HM UIO-66(Ce) and forms a stable combined structure. The high-activity nano-enzyme has excellent laccase activity. Based on the difference in catalytic reaction kinetics of different chlorophenols, a colorimetric sensing array for detecting various chlorophenols is constructed, so that the recognition and analysis of various target substances are realized. The method does not need to rely on a complex electrode system or various buffer conditions, and has the characteristics of stable structure, simple operation and suitability for rapid detection.

This invention discloses a high-performance laccase mutant constructed based on multi-source gene recombination and its applications. Using BspLac from Bacillus sp. SL-1 and BLTCLac from Bacillus licheniformis TCCC111219 as templates, a mutant library DS was constructed using DNA shuffling technology. Two high-performance laccase mutants, DS2 and DS5, were obtained through screening. Dynamic enzyme production analysis showed that the laccase activity of DS2 peaked at 1922 U / L after 24 hours, equivalent to twice that of the original strain; the laccase activity of DS5 peaked at 1337 U / L after 24 hours, equivalent to 1.4 times that of the original strain. Simultaneously, experimental verification showed that DS2 and DS5 achieved degradation rates of 83% and 89% for malachite green, respectively. This laccase mutant significantly improved the detoxification efficiency of synthetic dyes and possesses good potential for industrial application.

The invention provides preparation of an iron-copper bimetallic nano-enzyme and application of the iron-copper bimetallic nano-enzyme in detection of tetracycline antibiotics in food. The nano enzyme is synthesized by a simple coordination-assisted polymerization assembly method, and has excellent colorimetric performance (peroxidase-like and laccase-like activity) and fluorescence performance. The three-channel colorimetric fluorescent sensing array constructed on the basis of the performance can realize accurate recognition of five tetracycline antibiotics (tetracycline, oxytetracycline, doxycycline, minocycline and metacycline), and can efficiently distinguish binary and ternary mixed tetracycline antibiotics in different proportions at the same time. In order to break through equipment and cost limitations of a traditional detection method, the invention also develops a portable detection device with a built-in test paper sheet, and realizes rapid and field detection of tetracycline antibiotics in actual samples such as milk, chicken farm sewage and the like in combination with smartphone photographing and Image J software analysis, and has a good actual application prospect.

The application of a copper-based nanomaterial with laccase-like activity in aflatoxin B1 degradation, the particle size of Cu-NADH nanoparticles is 10-50 nm, copper ions and NADH form the basic structural unit of nanoparticles through Cu-N coordination, and extend through Cu-N-P coordination to form a chain structure with a length of more than 1 mu m, and the whole presents a loose and porous network structure, which can provide a larger specific surface area for enzymatic reaction. The copper-based nanomaterial with laccase-like activity is applied in aflatoxin B1 degradation; the application has the characteristics of high degradation efficiency and low cost.

The invention discloses a method for detecting octopamine and tyramine by using laccase-like active Schiff base Cu-MOF (Metal Organic Framework) nano-enzyme, which comprises the following steps of: synthesizing the Cu-MOF nano-enzyme with flower-like morphology by using Schiff base formed by using glutaraldehyde and 2-aminoterephthalic acid as initial reagents as a ligand; the Cu-MOF shows laccase-like activity triggered by near-infrared light, octopamine and tyramine are taken as substrates of laccase, the Cu-MOF catalyzes and oxidizes the octopamine and tyramine, 4-aminoantipyrine is combined, a red coupling product is formed through coupling, a high absorption spectrum is shown at 505 nm, high detection efficiency is shown, and the detection limits are 0.18 mu g / mL and 0.60 mu g / mL respectively; x-ray photoelectron spectroscopy analysis shows that the oxidation-reduction reaction of Cu (I) / Cu (II) participates in the catalytic process, and the method has the characteristics of high sensitivity, strong specificity, simplicity and rapidness in operation and the like.

The invention relates to the technical field of nano-enzyme preparation, in particular to Mn-MOF with laccase-like activity and a preparation method and application thereof. The limitation of a copper-based laccase simulant is broken through. Compared with Cu < + >, manganese has a partially-filled d orbit structure ([Ar] 3d54s2), and can more effectively accept and contribute electrons in the catalytic cycle process. Meanwhile, manganese serves as hard acid and forms a stable coordination compound with a [MnO6] octahedral structure with hard alkali, so that the possibility of dissociation or structural deformation of the catalyst in the catalysis process is greatly reduced, and the stability of active sites is kept. In addition, the cost of manganese is lower than that of copper, so that Mn-MOF becomes an ideal choice for designing a high-efficiency laccase simulant. Experiments prove that Mn-MOF has excellent laccase-like catalytic activity which is 75.87 times of that of Cu-MOF and 11.97 times of that of natural laccase. Moreover, in the process of catalytically degrading phenol substrates, the main reduction product of O2 is H2O, the generation amount of a by-product H2O2 is extremely small (1.7%), and the high efficiency and environmental friendliness of the reaction process are ensured.

This invention discloses a colorimetric detection method for histamine and spermine based on Pro-Ag nanozyme-mimicking laccase activity. The method involves first plotting standard absorbance curves for histamine and spermine, then constructing linear regression equations to determine the relationship between the concentrations of histamine and spermine and their absorbance values. The concentrations of histamine and spermine in the sample are then determined using these linear regression equations. This invention is the first to apply the laccase-mimicking activity of Pro-Ag nanozymes to the detection of biogenic amines. In HEPES buffer solution, histamine and spermine can inhibit the laccase activity of Pro-Ag nanozymes, causing the reaction solution to appear light pink, thus enabling rapid detection.