126 results about "Urease enzyme" patented technology

The invention relates to a low-cost high-stability urease inhibitor and a preparation method and application thereof.The preparation method includes the steps that montmorillonite is modified with inorganic acid to obtain inorganic acid modified montmorillonite, then hydrogen ions in the inorganic acid modified montmorillonite are exchanged with a cationic surface active agent to obtain quaternary ammonium salt surface active agent modified organic montmorillonite, and the quaternary ammonium salt surface active agent modified organic montmorillonite is used for preparing the urease inhibitor. After montmorillonite is subjected to organic modification, the hydrophobicity is greatly improved, and the organic modified montmorillonite has hydrophilicity and hydrophobicity. The organic modified montmorillonite interacts with amino acid residues in a urease flap region due to the hydrophobic effect, so that the amino acid residues are gathered in the organic modified montmorillonite due to the hydrophobic effect, urease conformational change is caused, catalytic activity on urea is lost, and the organic modified montmorillonite has a remarkable urease inhibition effect, is stable in chemical property and non-toxic in material, and can be used for preparing a novel urease inhibitor. The fertilizer is easy to disperse in fertilizer and soil and low in price.

The invention relates to a particulate composition comprising, or substantially consisting of, urea, an inhibitor, preferably a urease inhibitor and / or a nitrification inhibitor, and an additive, wherein the additive comprises components (i), (ii), and optionally (iii): (i) one or more polyhydric alcohols; preferably one or more carbohydrates, preferably selected from monosaccharides, disaccharides, and oligosaccharides; (ii) a first polymer, preferably an amine-containing polymer; more preferably a polyvinylamine or a polyalkyleneimine; and (ii) optionally, a second polymer, preferably a polar polymer; more preferably a water-soluble polar polymer. The invention further relates to a process for producing the particulate composition, an additive for a particulate composition, and the use of the particulate composition as a fertilizer.

The invention discloses a probiotic animal feed and a preparation method thereof, and belongs to the technical field of animal feeds, the probiotic animal feed comprises the following components by mass: 40-55 parts of caragana microphylla powder, 20-30 parts of fermented soybean meal, 3-5 parts of a composite probiotic preparation, 5-10 parts of a medicinal and edible additive, and 2-3 parts of a mineral premix. According to the composite probiotic preparation, bacillus licheniformis, pediococcus pentosaceus and saccharomyces cerevisiae boulardii synergistically improve the fiber decomposition efficiency, inhibit pathogenic bacteria and reduce ammonia nitrogen emission. The medicinal and edible additive is of a multi-layer micro-capsule structure, the outer layer is carboxymethyl chitosan and copper gluconate modified nano zeolite, active substances in the middle layer are rapidly released through rumen pH response, and the middle layer contains a yucca extract, a liquorice extract and other components and can inhibit urease activity and ammonia-producing bacteria; in the inner layer, a nano-selenium-vitamin E compound, curcumin and the like are slowly released through sodium alginate-pectin gel, so that intestinal metabolism is optimized. The process of pretreating caragana microphylla through steam explosion and performing solid-state fermentation on soybean meal through aspergillus oryzae is utilized, so that grain-free production is realized.

The invention discloses a coated defluorination composite material based on a microbial mineralization technology and a preparation method thereof. According to the coated defluorination composite material, urease vaterite calcium carbonate particles are used as a material core part, and the outer surface of the core part is coated with a calcium cross-linked porous composite film to serve as a coating layer of the material; the calcium cross-linked porous composite membrane is a porous membrane material formed by cross-linking calcium ions and a porous matrix, and the porous matrix is selected from any one of chitosan, cellulose, sodium alginate and porous silicon; the urease vaterite calcium carbonate particles are generated in situ after urea hydrolysis is catalyzed by urease and a calcium source is added. The composite material has the advantages of efficient defluorination effect and good stability when used in fluorine-containing wastewater, and the preparation method of the coated defluorination composite material is simple and easy to implement.

The invention discloses a method for preparing a biobrick by using engineering bacteria, and belongs to the technical field of biological building materials. Escherichia coli engineering bacteria capable of generating urease are obtained through engineering modification of escherichia coli, an escherichia coli engineering bacteria solution is mixed with a matching solution containing urea and mineral calcium salt, then sand grains and a hydrogel adhesive are added, and under the appropriate environmental condition, urease generated by the escherichia coli engineering bacteria can catalyze urea decomposition, so that the urea decomposition rate is increased, and the urea decomposition rate is increased. Ammonia and carbonate ions are generated and then react with calcium ions to generate calcium carbonate, so that sand grains are cemented together, and the biobrick with certain strength and biological characteristics is formed. The biobrick not only has good strength, but also has certain self-repairing capability and environmental adaptability, and can be applied to the field of civil engineering as a green and sustainable building material. The preparation method disclosed by the invention is simple, efficient and environment-friendly, has important significance on the national double-carbon strategy, and has a wide application prospect.

The present invention relates to urease inhibitor compositions containing tert-butylhydroquinone and optionally an additive component to enhance the inhibitory properties of tert-butylhydroquinone. Further described are uses of these compositions in agriculture to increase nutrient uptake and inhibit urease enzyme activity.

Fertilizers with urease inhibitors and / or nitrification inhibitors are described. The fertilizer can include an extruded granule containing urea, a polymeric binder, and a nitrification inhibitor and / or an urease inhibitor.

The invention belongs to the technical field of civil engineering and hydraulic engineering, and particularly relates to a concrete crack repairing method. Urease is used for inducing calcium carbonate deposition, chitosan and sodium alginate are combined for repairing, and effective filling and repairing of concrete cracks are achieved. The urease solution can catalyze decomposition of urea to generate ammonia and carbon dioxide, and a necessary alkaline environment and a carbon source are provided for deposition of calcium carbonate; chitosan and sodium alginate are used as natural polymer materials, have good biocompatibility and environmental friendliness, and can enhance the strength and stability of the restoration body and improve the binding power of the restoration body and a concrete matrix, thereby ensuring that the restoration effect is more durable, reliable and stable. The repairing method provided by the invention is remarkable in effect, and the mechanical property of the concrete can be effectively improved. The repairing method provided by the invention is simple and convenient to operate, improves the repairing efficiency of the concrete crack, reduces the construction difficulty and cost, and is environment-friendly.

A method for distinguishing metal ions Cu 2+ and Mn 2+ This method utilizes a pH clock reaction system of "urease-CO(NH2)2-H2SO4" as the distinguishing solution, based on the Cu of the sample to be distinguished. 2+ and Mn 2+ The reactions between Cu and the products of urea hydrolysis catalyzed by urease differ, resulting in different patterns produced by the pH clock system, thus enabling the determination of Cu... 2+ and Mn 2+ Qualitative analysis of Cu involved in this invention. 2+ and Mn 2+ The qualitative analysis method is characterized by high accuracy, ease of operation, and convenience.

The invention relates to a method for producing particles comprising urea and at least one urease inhibitor and / or at least one nitrification inhibitor, and to a suitable apparatus for carrying out the method.

The invention relates to a stabilized fertilizer containing antibacterial peptide and a preparation method thereof, the stabilized fertilizer containing antibacterial peptide is characterized by containing jerusalem artichoke antibacterial peptide; the jerusalem artichoke antibacterial peptide is a product obtained after jerusalem artichoke residues are subjected to enzymolysis. The enzymolysis is protease enzymolysis; the protease is acid protease or alkaline protease. The antibacterial peptide-containing fertilizer prepared by the invention can meet the requirement of a stable fertilizer without additionally adding a nitrification inhibitor or a urease inhibitor.

A method for contamination control when growing yeasts is provided. Bacterial contamination is controlled by using urea as the primary nitrogen source while simultaneously limiting the amount of nickel available to contaminating bacteria. Bacteria require nickel as a cofactor for urease enzymes in order to use urea for growth while yeasts do not require nickel as a cofactor for any enzymes. Nickel is limited by using metals in heat exchangers that do not leach nickel. Ethyl carbamate is limited by using a carbon / nitrogen ratio that consumes all urea during fermentation. After fermentation completes, yeast is recycled using centrifugation, enabling use of high concentrations of yeast to reduce fermentation time from 48 hours to 12 hours and to eliminate bacterial contamination from growth on free amino nitrogen.

A method for stabilizing a reducing slag includes the steps of: subjecting a reducing slag which contains an alkaline earth metal oxide to a drying treatment, so as to obtain a dried reducing slag; mixing a urease-producing bacterium, a fermentation medium, and a nutrient, followed by conducting a fermentation treatment, so as to obtain a fermentation product containing urease; subjecting the fermentation product to a foam fractionation treatment, so as to obtain a foam containing urease; mixing the dried reducing slag, the foam containing urease, and urea, followed by conducting a urea hydrolysis reaction and a precipitation reaction in sequence, so as to obtain a product containing a stabilized reducing slag and a residual liquid; and subjecting the product to a solid-liquid separation treatment, so as to separate the stabilized reducing slag and the residual liquid from the product.

The invention provides an innovative dual-mode detection method based on a dipeptide nano framework (DNPs), which is used for efficiently detecting helicobacter pylori. According to the method, firstly, a DNPs material formed by chelating dipeptide (Trp-Phe) and zinc ions (Zn (II)) is synthesized, and the material is decomposed along with the increase of the pH value in an alkaline environment, so that the Zn (II) is released; then, urea is hydrolyzed under the catalysis of urease to generate ammonia, so that the pH value of the solution is increased, and the decomposition of DNPs and the release of Zn (II) are further promoted. By utilizing an electrochemical detection mode, real-time analysis on urea and urease is realized by monitoring an electrochemical signal of Zn (II); meanwhile, in combination with the fluorescence characteristics of DNPs, the concentration of urea and urease is indirectly and quantitatively analyzed by monitoring the fluorescence intensity change. The dual-mode detection method combines the advantages of electrochemistry and fluorescence detection, has high sensitivity and real-time performance, provides an effective means for accurate detection of helicobacter pylori, and shows a wide application prospect in clinical diagnosis and sensing technologies.

The vertical shaft excavation drilling tool comprises a liquid injection mechanism used for injecting a urease solution and a drill rod, a drill bit is fixedly installed at one end of the drill rod, a groove is formed in the side wall of the drill rod and extends in the length direction of the drill rod, and the liquid injection mechanism is used for injecting the urease solution. A liquid inlet hole and a plurality of liquid outlet holes which are communicated with the groove are formed in the side wall of the drill rod, the liquid inlet hole is located at the end, away from the drill bit, of the drill rod, the liquid outlet holes are distributed in the length direction of the groove and located at the end, close to the drill bit, of the drill rod, and the liquid injection mechanism is communicated with the liquid inlet hole. The utility model aims to solve the problems that in the prior art, cement slurry materials or cement-water glass mixed slurry is mostly adopted to block cracks after water leakage of the side wall of a vertical shaft, but the cement slurry materials can shrink after being hardened, small cracks are easily generated, the cracks are gradually enlarged under hydraulic scouring, and the water blocking effect is poor. And the construction difficulty of plugging the crack after water leakage is high.

The invention discloses a urease activity detection method based on a non-reversible reaction of dopamine and resorcinol. The urease activity detection method comprises the following steps: mixing a sample to be detected, a buffer solution with the pH value of 7.0 and a urea solution with a certain concentration; adding a certain amount of dopamine and resorcinol into the mixed solution, under the condition of 25-45 DEG C, catalyzing urea hydrolysis by urease, causing the pH value of the surrounding area of the urease to rise so as to form a local alkaline environment, further inducing the reaction of the dopamine and the resorcinol to generate a blue fluorescent substance, and adding excessive hydrochloric acid to terminate the reaction after the reaction is carried out for 40-120 minutes; and detecting the fluorescence intensity of the reaction liquid by using a fluorospectro photometer, and calculating the urease activity in the sample according to a fluorescence intensity-urease concentration standard curve. The urease activity detection method based on the reaction of dopamine and resorcinol has the advantages of high detection speed, high sensitivity, good selectivity and the like.

The invention discloses a urea detection method based on urease-ion chromatography combination, a urease protective agent and application of the urease protective agent, and belongs to the technical field of urea detection. The method specifically comprises the following steps: (1) adding a urease protective agent into a urea solution to be detected, shaking and uniformly mixing, and filtering; (2) adding a urease solution into the solution treated in the step (1), uniformly mixing, and then reacting under a water bath condition to decompose urea; and (3) detecting the solution obtained in the step (2) and the standard solution by using an ion chromatograph, and then calculating the content of urea. Through combination of multiple technologies, the detection operation process is remarkably simplified, meanwhile, the quantitative detection limit is reduced, and the sensitivity and accuracy of urea detection are greatly improved; besides, by adding the urease protective agent, the influence of interference substances such as metal ions and nitrogen-containing compounds is effectively eliminated, and the anti-interference capability of the method is remarkably enhanced.

The invention discloses a catecholamine substance multicolor visual detection kit and detection method based on synergistic catalytic reaction induction, and the method comprises the following steps: firstly, enabling catecholamine and AgNPLs to be subjected to a sufficient chemical adsorption reaction, and then adding hydrogen peroxide, so that the Ag NPLs are etched to different degrees and show different colors. According to the reaction of silver ions and urease and the cascade urease catalytic reaction, the color of pH indicator phenol red is changed, so that the colors of Ag NPLs and phenol red are compounded, the color recognition degree after the etching reaction is enhanced, and catecholamine substances are detected according to different colors. The method is simple, convenient, efficient, sensitive and high in naked eye recognition degree, and can be used for detecting diseases such as depression.

The application discloses a water-retaining agent with salt resistance and urease inhibition, and a preparation method and application thereof, and belongs to the technical field of water-retaining in agriculture and forestry. The water-retaining agent is prepared from the following raw materials in mass parts: 100 parts of monomers, 3-10 parts of anionic natural polymer derivatives, 0.1-0.5 parts of cross-linking agents, 5-15 parts of modified lithium saponite or modified bentonite, and 0.1-1 parts of initiators; wherein the monomers are one or more of acrylic acid, acrylic acid salt or acrylamide; and the modified lithium saponite or modified bentonite is obtained by modifying lithium saponite or bentonite by quaternary ammonium salt natural polymer derivatives. The water-retaining agent has high water absorption ratio and salt water absorption ratio, can maintain stable water absorption and water retention performance in a high-salt environment, can delay the urea hydrolysis rate and reduce nitrogen loss, can realize synchronous application of the water-retaining agent and fertilizer, and can simplify farm operations.

Disclosed is a dual functional urease and nitrification inhibitor composition and method for inhibiting the hydrolysis of urea and nitrification of ammonia in soil. Methods of making the dual functional urease and nitrification inhibitor and / or a composition containing the dual functional urease and nitrification inhibitor are also disclosed.

Preventing the flow of soil grains into oil and gas wells is highly desirable for the protection of hydrocarbon production. Geotechnical engineering solutions addressing this issue may utilize enzyme-induced precipitation methods to consolidate and increase shear strength. Methods may comprise: providing a mixture comprising urea, a urease enzyme, calcium chloride, magnesium chloride, and a cellulose; contacting at least a portion of the mixture with at least a portion of a subterranean formation; and forming a biomineral precipitate within the subterranean formation. The biomineral precipitate, comprised of a carbonate mineral and an evaporite mineral, may consolidate particles within the subterranean formation to form a consolidated body.

The invention relates to the field of compound fertilizer production, and particularly discloses a high-activity urea-based compound fertilizer preparation method, which specifically comprises: 1, melting urea, and uniformly mixing with other components to obtain a mixed slurry; 2, granulating the mixed slurry, and cooling to obtain a fertilizer; step 3, spraying the fertilizer with an anti-blocking agent to obtain a product; the high-activity urea-based compound fertilizer comprises the following components: urea, vermiculite powder, monoammonium phosphate, potassium sulfate, humic acid, a urease inhibitor, a phosphorus activator, an agricultural selenium fertilizer, zinc sulfate, borax and a nitrification inhibitor. Due to the addition of the anti-blocking agent, the compound fertilizer is not easy to block due to moisture absorption, so that the purpose that the urea-based compound fertilizer is not easy to harden is achieved.

The application discloses a kind of biological hybrid micro machine population oral delivery system of imitating Helicobacter pylori survival mechanism, belong to oral stomach medicine delivery technical field.The system is by active power module (flagellum driven chlamydomonas reinhardtii), environmental regulation module (acid urease modified on algal surface) and multifunctional load module (macrophage membrane wrapped drug-loaded nanoparticles) synergistic assembly through polydopamine (PDA) spatial conformation control layer is formed.Active power module utilizes self-movement ability to penetrate mucus barrier and extend intracavity retention time to 12 hours or more;Environmental regulation module produces local alkalization effect by catalyzing urea hydrolysis, provides chemical shield for system in extremely acid environment of pH 1.0-3.0, protects active power module from gastric acid inactivation;Multifunctional load module is accurately delivered to gastric epithelial cells by inflammation targeting effect, such as CRISPR / Cas9 biological macromolecule, and realizes up to 31.8% in-vivo gene editing efficiency.The application provides a non-invasive, modular active delivery platform for the precise treatment of gastric diseases such as gastritis through the synergistic effect of physical penetration, metabolic reprogramming and gene intervention.

The present application relates to the field of solidifying agent, and more particularly to a kind of composite solidifying agent for construction waste recycled material flow state solidified soil and preparation method thereof, comprising the following raw materials: sulphoaluminate cement 20-30 parts, slag powder 15-25 parts, recycled brick powder 10-15 parts, amino-terminated hyperbranched polymer 4-7 parts, silane coupling agent 2-4 parts, urease composite material 2-3 parts, urea microspheres 1-3 parts, calcium chloride 0.5-2 parts, construction waste recycled micro powder 10-18 parts, fly ash 5-10 parts.The solidifying agent solves the technical problems of weak interface in construction waste recycled material flow state solidified soil, enzyme activity easy deactivation, large strength fluctuation, serious shrinkage and cracking and the like through multi-component synergistic effect.

The invention provides a fertilizer synergist. The fertilizer synergist comprises a urease inhibitor, glutamic acid, organic silicon and a load carrier, the invention further provides a preparation method of the fertilizer and application of the fertilizer in improving the fertilizer utilization rate in the dry-farming potato planting process. According to the invention, the space-time synergistic effect of NBPT and L-glutamic acid discovered for the first time is taken as a basic mechanism; nBPT delays urea hydrolysis, and creates a time window for L-glutamic acid to activate root nitrogen transporter; l-glutamic acid is combined with soil particles through carboxyl of L-glutamic acid to form a slow-release microenvironment, meanwhile, root systems are promoted to secrete organic acid, and nitrogen absorption is enhanced; the organic silicon can change the soil agglomeration structure, increase the water holding capacity of the soil and reduce water infiltration and evaporation; through the synergistic effect of the three, the effective retention time of the nitrogen fertilizer in a root zone is remarkably prolonged, and the nitrogen utilization rate and the water utilization efficiency are improved.

A method for contamination control when growing yeasts is provided. Bacterial contamination is controlled by using urea as the primary nitrogen source while simultaneously limiting the amount of nickel available to contaminating bacteria. Bacteria require nickel as a cofactor for urease enzymes in order to use urea for growth while yeasts do not require nickel as a cofactor for any enzymes. Nickel is limited by using titanium in plate heat exchangers instead of stainless steel. Ethyl carbamate is limited by using a carbon / nitrogen ratio that consumes all urea during fermentation and by separating co-products after fermentation and before distillation. Yeast recycling is performed by using either single-step or two-step centrifugation, without acid washing. This method enables yeast recycling with sugarcane ethanol and sugar beet ethanol production. This method also enables yeast recycling with corn ethanol and grain ethanol production with coproduct recovery after fermentation and before distillation.

The invention relates to a self-repairing anti-scaling polyurea-cellulose nanocrystalline coating as well as a preparation method and application thereof, and belongs to the technical field of chemistry and chemical engineering. The coating comprises an aqueous polyurea-disulfide bond dynamic matrix, cellulose nanocrystals, a urease / urea microcapsule self-repairing agent and an auxiliary agent, and the urease / urea microcapsule self-repairing agent comprises urease, urea, first isocyanate, polyether amine and an emulsifier. The main structure of the coating is a dynamic polyurea network containing disulfide bonds, and the network is filled with nanoscale coarse structure cellulose nanocrystals and a urease / urea microcapsule self-repairing agent. Wherein the disulfide bond dynamic polyurea network structure improves the structural stability and durability of the coating in high-temperature, high-speed sand-containing washing and strong acid / weak acid environments, and the urease / urea microcapsule self-repairing agent endows the coating with the capability of quickly repairing damage in a high-humidity environment.

The invention relates to an application of a ruminant non-protein nitrogen feed synergist N-methylglycine and salts thereof as a rumen urease inhibitor in ruminant feeding. The N-methylglycine and the salts thereof have an efficient inhibition effect on rumen urease, and can be used as a novel non-protein nitrogen feed synergist to be combined with urea to replace soybean meal feed to be applied to ruminant feeding.

Provided in the invention is a stabilized fertilizer composition (I) suitable for use in fertilizers and comprising: Urea (a), One or more compounds (b), One or more urease inhibitors (c1) and / or one or more nitrification inhibitors (c2), optionally provided in one or more carriers (d), said compounds (c) being different from compounds (b), Optionally one or more additives (e) different from any of the above, and Water (f) in an amount less than about 10 wt % and preferably less than about 5 wt %; wherein compounds (b) are selected from thiosulfates (b1) and / or from polysulfides (b2) and / or from (bi)sulfites (b3); and wherein the ratio of urea (a) to compounds (b) is from 1:99 to 99:1, preferably from 2:98 to 98:2. Products of the invention can be made in various forms and in different ways. All of the materials of the invention are suitable for use in fertilizers and blend well with solid and liquid fertilizers standardly used. They have excellent shelf life and provide good urea-N protection.