397 results about "Urease" patented technology

The invention relates to the technical field of rock and soil reinforcement, in particular to a method for curing sandy soil by inducing calcium carbonate precipitation through urease. The preparation method comprises the following steps: crushing urease-containing plant seeds to obtain urease-containing powder; the urease-containing powder is mixed with sandy soil, and mixed sandy soil is obtained; the cementing liquid is poured into the mixed sandy soil to form calcium carbonate, and sandy soil solidification is achieved; the cementing liquid is an aqueous solution containing urea and calcium ions. The method provided by the invention not only can solve the problem that urease is difficult to extract and store, but also can increase the thickness of a curing layer and improve the mechanical property, and the method is simple and easy to implement, low in cost and free of risk.

The invention relates to the field of microorganisms, and discloses lactobacillus plantarum with an antibacterial effect and application of the lactobacillus plantarum, and the preservation number of the lactobacillus plantarum is CGMCC (China General Microbiological Culture Collection Center) No.33151. The strain provided by the invention has relatively strong cholate resistance, gastric acid resistance, acid production and H2O2 production capabilities, and has a relatively strong bacteriostatic effect on common pathogenic bacteria such as staphylococcus aureus, candida albicans, escherichia coli, salmonella and helicobacter pylori; the compound can inhibit the activity of urease, interfere helicobacter pylori colonization and the like to inhibit helicobacter pylori infection or reduce the symptoms of helicobacter pylori infection and reduce the disease degree of mice with colitis, can be used for preparing microbial preparations, and has the potential of preparing drugs for preventing and / or treating diseases caused by helicobacter pylori infection.

The invention relates to a coral sand soil multi-dimensional ecological low-carbon reinforcement method which comprises the following steps: S1, a urease solution is sprayed on a coral sand single-particle soil layer, a cementing liquid A is sprayed after standing, the urease solution is extracted from legume plants, and the cementing liquid A is obtained by mixing a urea solution and a calcium chloride solution; s2, on the basis of treatment in the step S1, a sporosarcina pasteurii bacterial solution is firstly sprayed, after standing, a cementing solution B is sprayed, the cementing solution B is alternately and circularly sprayed for multiple times, and the cementing solution B is obtained by mixing a urea solution and a calcium chloride solution; s3, a 3D printing geosynthetic material is laid on the basis treated in the step S2; and S4, laying a coral sand single-particle soil layer on the basis of treatment in the step S3, and repeating the steps S1 to S3. According to the method, a single particle size-foundation unit size-engineering size reinforcing system is constructed, comprehensive reinforcing from a microscopic single particle to a macrostructure can be achieved, and the reinforcing effect and efficiency are effectively improved.

The invention relates to the technical field of biomineralization, and particularly discloses an alkali-resistant urease-producing microbial flora for biomineralization of construction joints and a preparation method of the alkali-resistant urease-producing microbial flora. The microbial flora disclosed by the invention is prepared from the following strains with relative abundance: 4.4 to 5.2 percent of bacillus, 0.39 to 0.46 percent of enterococcus, 4.8 to 5.7 percent of alcaligenes, 0.50 to 0.58 percent of cellulomonas, 22.4 to 24.2 percent of lysobacter, 1.7 to 2.4 percent of pseudomonas, 10.8 to 11.9 percent of Savagea, 15.1 to 16.2 percent of sarcina, 30.8 to 32.2 percent of chloridomonas and 0.41 to 0.48 percent of bacillus. The alkali-resistant microbial compound flora with high urease activity in the limited oxygen and normal environment can effectively overcome the defects that urease microorganisms are low in mineralization efficiency under the anoxic condition, and the strength of an obtained consolidated body is not high.

The invention provides a plant lactobacillus KSFY202408 strain and application thereof, and belongs to the technical field of microorganisms. The preservation number of the plant lactobacillus KSFY202408 provided by the invention is CGMCC (China General Microbiological Culture Collection Center) No. 31102. The survival rate of the strain in artificial gastric juice with the pH value of 3.0 can reach 55.2%, the survival rate of the strain in artificial gastric juice with the pH value of 2.5 can reach 33.2%, the activity of a helicobacter pylori strain can be remarkably inhibited, formation of a helicobacter pylori thallus biological membrane can be inhibited, and the activity of helicobacter pylori metabolite urease can be reduced. Meanwhile, the bacterial strain can remarkably protect cell membrane integrity and cell viability of gastric mucosa epithelial cells, and has important significance on prevention or treatment of gastritis, gastric ulcer and other digestive tract diseases caused by helicobacter pylori.

The invention discloses a method for restoring soil heavy metal pollution by coupling soybean urease with a charcoal cementing agent, and relates to the technical field of soil heavy metal pollution restoration, and the method comprises the following steps: dynamic microbiome regulation and control: introducing photosensitive protein into soil functional bacteria; the acyl homoserine lactone analogue is synthesized and applied to soil, and is competitively combined with a microbial quorum sensing receptor to block an inhibitor to secrete a signal channel; according to the method, microbial urease secretion is regulated and controlled through optogenetics, an inhibitor signal is blocked through quorum sensing interference, and a microbiome is precisely regulated and controlled; the pH-responsive nanocapsule releases an inhibitor in a targeted manner, and the magnetic-responsive nanochain dynamically captures interfering bacteria, so that the limitation of passive adsorption is broken through; the gene editing plant releases coumarin to inhibit fungal metabolism, and the engineering mycorrhizal fungi physically shields an inhibitor to construct cross-biosphere cooperative defense; the urease activity and the heavy metal removal rate are remarkably improved, meanwhile, the soil microbial diversity is maintained, and the soil specificity interference problem is solved.

The present invention relates to the technical field of rock and soil reinforcement, and in particular to a method for urease-induced calcium carbonate precipitation and solidification of sandy soil. The present invention crushes plant seeds containing urease to obtain urease-containing powder; mixes the urease-containing powder with sandy soil to obtain mixed sandy soil; injects a binder into the mixed sandy soil to form calcium carbonate to solidify the sandy soil; the binder is an aqueous solution containing urea and calcium ions. The method provided by the present invention can not only solve the problems of difficult extraction and storage of urease, but also increase the thickness of the solidified layer and improve the mechanical properties, and the method is simple and easy to implement, low cost and risk-free.

The invention discloses a test device and method for blocking rock fractures by a soybean urease induced calcium carbonate deposition technology, the test device comprises a sample, a fracture simulation assembly and a slurry sealing assembly, the sample is composed of an upper rock test block and a lower rock test block; the fracture simulation assembly can simulate two kinds of rock fracture surfaces with different opening degrees. The test sample adopts an upper rock test block made of a transparent material to realize visualization in a test process; the upper shear box and the lower shear box are used for simulating a tension type fracture and a shear fracture surface of a rock, so that the condition that soybean urease induces calcium carbonate to deposit in different rock fracture generation mechanisms to block and reduce permeability of the rock fracture is better tested; when the lower shear box horizontally moves, the lower shear box is sealed through the slurry sealing assembly, and the sealing state can be kept in the shear dislocation of the crack; the device can test the relationship between the soybean urease induced calcium carbonate deposition plugging and permeation reducing effect and the rock fracture type and fracture parameters.

The invention relates to the technical field of civil engineering preparation, and particularly discloses microorganism synergistic fiber solidified soil and a preparation method thereof. The microorganism synergistic fiber solidified soil is prepared from the following components: sandy soil, modified PE fibers, magnesium oxide, urease bacterium liquid and cementing liquid, the preparation method of the modified PE fiber comprises the following steps: soaking the PE fiber in a solution A; taking out the PE fiber, soaking in the solution B, and drying to obtain the PE fiber. The solution A is composed of 12-18 mmol / L of catechol and 4-6 mmol / L of tetraethylenepentamine, and a solvent is a hydroxymethyl aminomethane aqueous solution; the solution B is prepared from 8 to 12 mmol / L of KH-550 silane coupling agent and 16 to 24 mmol / L of EOS tetraethyl silicate, and the solvent is ethanol. According to the microorganism synergistic fiber solidified soil provided by the invention, an MICP-based soil body solidification effect enhancing technology is perfected, so that the mechanical property and the anti-permeability performance of the solidified soil are improved.

The invention discloses a concrete repairing agent with a bacterium-enzyme synergistic mineralization effect and a preparation method of the concrete repairing agent. The preparation method comprises the following steps: culturing urealytic bacteria to obtain a spore bacterium suspension, and mixing the spore bacterium suspension with a urease extracting solution to obtain a mixed solution; mixing the soluble calcium salt solution and the urea solution to obtain a cementing solution; the concrete repairing agent with the bacterium-enzyme synergistic mineralization effect is obtained after the mixed solution and the cementing solution are mixed, and the concrete repairing agent with the bacterium-enzyme synergistic mineralization effect is applied to crack repairing of concrete to generate multiple effects of regulating and controlling crystal forms and enhancing the crack filling compactness and the adhesion effect.

The invention discloses a comprehensive prevention and control method for tobacco root knot nematode disease containing a biological agent. The method comprises the steps of crop rotation of tobacco and buckwheat / quinoa, host resistance induction of the microbial agent in the seedling raising period, tobacco planting soil quality improvement in the transplanting period and the like. The agronomic characters of tobacco seedlings are effectively improved, and the physical characters of soil are improved; the chemical properties of soil pH, alkali-hydrolyzable nitrogen, available phosphorus, quick-acting potassium, exchangeable calcium, exchangeable magnesium and the like are improved; the activity of soil urease, sucrase, acid phosphatase, catalase and peroxidase is improved; the content of water-soluble phenols, compound phenols and total phenols in soil is reduced; the disease index of the tobacco root knot nematode disease can be remarkably reduced, the survival rate of tobacco is increased, the application amount of chemical agents is reduced, and the healthy and sustainable development of the tobacco industry is promoted.

The invention discloses test paper and a kit for detecting urea in body fluid, and the test paper comprises a base layer which comprises a near end and a far end transversely extending from the near end; the sampling area is arranged at the far end of the base layer and is used for absorbing body fluid to be detected; the reaction area is arranged on the base layer and is used for absorbing the body fluid in the sampling area so as to react by utilizing urease in the reaction area; the diffusion area is arranged on the base layer, is connected with the reaction area and is used for performing lateral chromatography on reactants generated in the reaction area from the far end to the near end; the color development area is arranged on the base layer, is isolated from the reaction area through the diffusion area and is used for absorbing reactants subjected to lateral chromatography by the diffusion area so as to carry out color development reaction by utilizing color development substances in the color development area, so that a detection result of the urea in the body fluid is displayed.

The invention provides a preparation method of dark isolated endophytic fungus inoculant vegetation concrete. The preparation method of the inoculant comprises the following steps: carrying out fermentation culture on glucose, corn steep liquor dry powder and soybean cake powder, and preparing into the inoculant by using a freeze spray drying method. The method for improving the drought resistance of the plants in ecological restoration of the vegetation concrete comprises the following steps: layering the vegetation concrete: increasing the cement proportion in the base material proportion of a bottom layer, additionally adding urea, calcium chloride and urease, and inducing the urea and the calcium chloride to generate calcium carbonate precipitate through the urease to play a reinforcing role; additives such as lignocellulose, biochar and ceramsite are additionally added to the middle layer, so that the water-retaining property, porosity and fertility of soil can be improved, and the effect of enhancing plant rooting and branching is achieved; the fungicide and the plant seeds are added into the surface layer, and the fungicide can promote seed germination and plant growth.

The invention discloses application of a mineralized carbon sequestration strain, the mineralized carbon sequestration strain is classified and named as Halomonas sulfidaeresis. ZN2 #, the mineralized carbon sequestration strain is preserved in the China General Microbiological Culture Collection Center (CGMCC), and the preservation number is CGMCC No.32033. The invention further discloses a preparation method of the mineralized carbon sequestration strain. The mineralization carbon sequestration strain can metabolize to generate urease and carbonic anhydrase at the same time, the two enzymes are subjected to a dual mineralization reaction in combination with a microorganism-induced calcium carbonate precipitation technology, the crystal form of a mineralization product is improved, the mineralization strength is improved, meanwhile, carbonic anhydrase can absorb carbon dioxide in the environment, high-strength soil reinforcement is achieved, meanwhile, carbon dioxide emission is reduced, and the soil quality is improved. Therefore, the dual effects of biomineralization remediation and improvement and carbon sequestration and emission reduction of the soil are achieved, and sustainable development of a soil bioremediation and improvement technology is achieved.

The invention discloses a continuous cropping Chinese cabbage planting method based on a microbial agent and application, and belongs to the technical field of crop cultivation. According to the planting method, Chinese cabbage and garlic are intercropped according to the ratio of 1: 1, and a trichoderma harzianum agent is applied. Results show that the planting method can significantly increase the growth indexes such as the plant height, the root length, the leaf chlorophyll content and the soluble sugar content of the Chinese cabbage; the soluble protein content, the peroxidase activity, the superoxide dismutase activity and the malondialdehyde content of the Chinese cabbage leaves are obviously reduced. Meanwhile, the content of rapidly available phosphorus, rapidly available potassium, effective calcium and other substances in the soil can be increased; the activities of urease, catalase and alkaline phosphatase in the soil are also obviously improved. In addition, the number of fungi, bacteria and actinomycetes in the soil is also remarkably increased. Therefore, according to the planting method, the quality of continuous cropping soil can be improved, Chinese cabbage growth is promoted, and theoretical support is provided for healthy and sustainable development of the Chinese cabbage industry.

The invention discloses a novel application of bacillus subtilis WJL-2, and relates to the technical field of microorganisms. The invention discloses a novel application of bacillus subtilis WJL-2. The preservation number of the bacillus subtilis WJL-2 is GDMCC65111, and the preservation number of the bacillus subtilis WJL-2 is GDMCC65111. The new application specifically comprises the following steps: improving soil, regulating and controlling the content of total nitrogen and organic carbon in the soil, regulating and controlling the activity of amylase / urease / cellulase in the soil, regulating and controlling the content of ammonium nitrate nitrogen in the soil, regulating and controlling the mineralization rate of the soil, regulating and controlling the nitration rate of the soil and regulating and controlling the ammoniation rate of the soil. After the strain WJL-2 is inoculated into the soil, the total nitrogen and organic carbon content of the soil is reduced, and the C / N is reduced; the activity of soil amylase is reduced, and the activity of urease and cellulase is increased; the content of ammonium nitrogen in the soil is in a trend of firstly increasing and then decreasing, and the content of nitrate nitrogen is continuously increased; the mineralization rate of soil organic nitrogen is accelerated, the ammoniation rate is in a trend of increasing first and then decreasing, and the nitration rate is in a trend of decreasing first and then increasing.

The invention relates to a composite microbial inoculant for soil improvement, the composite microbial inoculant for soil improvement is composed of PGPR (Pseudomonas tianjinensis) and AMF (Amplified Macrophage Fungi), the PGPR is Pseudomonas tianjinensis and Pseudomonas oryzae, and the AMF is rhizophagus clarus. The composite microbial inoculant for soil improvement is characterized in that the PGPR is Pseudomonas tianjinensis and Pseudomonas oryzae, and the AMF is Pseudomonas oryzae, the PGPR is Pseudomonas tianjinensis and Pseudomonas oryzae. According to the invention, the Pseudomonas tianjinensis, Pseudomonas oryzae and AMF are compounded, so that a synergistic effect is exerted, an obvious growth promoting effect on the ryegrass in the saline-alkali soil is achieved, the content of photosynthetic pigments in the ryegrass is increased, the contents of soluble sugar, soluble protein, proline and malondialdehyde in the ryegrass are further increased, and the CAT enzyme activity is improved. In addition, the complex microbial inoculant is combined with ryegrass planting, a plant-microorganism synergistic system is formed, salinized soil is effectively improved, the conductivity and pH of the soil are reduced, the content of nitrogen, phosphorus and potassium in the soil and the content of rapidly available phosphorus and rapidly available potassium are increased, and meanwhile the activity of urease and phosphatase is improved.

The invention discloses a dialysate regeneration system and dialysis equipment, the dialysate regeneration system comprises a waste liquid passage, a slow flow box, an electromagnetic valve, a reactor and an adsorption mechanism, the waste liquid passage is in through connection with the slow flow box, the slow flow box is connected with the reactor through a pipeline, and the pipeline is provided with the electromagnetic valve. The fixing amount of a urease layer is increased through the treatment film with the three cambered surfaces, the urea decomposition efficiency is improved, the diffusion path of toxins on the treatment film is shortened, meanwhile, the treatment film with the cambered surface structure can guide dialysis waste liquid entering the reactor to generate local turbulence, and the toxins are prevented from being accumulated on the surface of the treatment film; the dialyzer is arranged, the micro horse is started to drive the hollow fiber to rotate, the material exchange efficiency of blood and dialysate is improved, and the situation that protein and cells are deposited on the surface of the hollow fiber, and the service life of the hollow fiber is shortened is avoided.

The present invention discloses a method for solidifying dredged sludge by using biological carbonization activated magnesium oxide technology, and belongs to the technical field of soil solidification. In the present invention, urease-producing bacteria are first used to prepare a pre-hydrolyzed urea solution, and then the pre-hydrolyzed urea solution and an activated magnesium oxide solidifying agent are separately and evenly mixed into dredged sludge with a certain water content according to a certain dosage, stirred to form a slurry, and the slurry is filled in a designated site or model and fully maintained. The present invention greatly reduces the construction cost and improves the feasibility and efficiency of solidification treatment of dredged sludge with high water content by introducing the technology of carbonization of urea solution pre-hydrolyzed by urease-producing microorganisms and activated magnesium oxide solidifying agent.

The invention relates to an integrated grouting device and an offshore wind power single pile foundation anti-scour construction method based on an indigenous microorganism precuring seabed, and the method comprises the following steps: prefabricating a special integrated grouting device according to the installation condition of an offshore wind power single pile foundation; an integrated grouting device is installed on the seabed of the to-be-constructed area through a hammering method and a negative pressure method; urease microorganisms are enriched and cultivated in in-situ seabed soil through an integrated grouting device, the microorganisms are induced to generate calcium carbonate gelatinization crystals so as to bond sandy soil particles, and the overall strength of a surface seabed is improved; and a single-pile foundation is installed on the microorganism solidification seabed. Before pile sinking construction, the surface seabed of the to-be-constructed area is intensified in advance through in-situ enrichment cultivation of indigenous urease microorganisms and induction of mineralization and crystallization of the microorganisms, scouring protection of the single pile foundation in the whole service cycle is achieved, and then the local scouring problem in the pile sinking process is solved.

The invention provides a method for increasing the compression resistance of a geopolymer based on urease induced calcium carbonate precipitation. The method comprises the following steps: S1, preparing a urease solution; s2, preparing a cementing liquid; s3, preparing a fly ash-based geopolymer; and S4, carrying out normal-temperature maintenance on the fly ash-based geopolymer. According to the method for increasing the compression resistance of the geopolymer based on the urease-induced calcium carbonate precipitation, the compression resistance of the fly ash-based geopolymer is improved through the urease-induced calcium carbonate precipitation technology, tedious and complex pretreatment steps are not needed, operation is easy and convenient, and compared with a traditional enhancement method, the method is more efficient and convenient.

The invention provides an application of a lactobacillus paracasei IOB413 metagen in prevention of helicobacter pylori infection, and relates to the technical field of microorganisms. The lactobacillus paracasei IOB413 metaplasm can competitively occupy gastric epithelial cell adhesion sites to directly block the initial colonization of helicobacter pylori, so that infection preposed interception is realized, and the lactobacillus paracasei IOB413 metaplasm is suitable for early prevention of high-incidence people. The compound has dual mechanisms of site blocking and urease inhibition, and can cooperate with antibiotics to improve the eradication rate and reduce the drug resistance. Animal experiments show that the traditional Chinese medicine composition can reduce gastric mucosa proinflammatory factors in a dose-dependent manner, improve the activity of antioxidant enzymes, reduce lipid peroxidation products, relieve mucosa lesion, promote repair and reduce the risk of complications; moreover, gastrointestinal hormone disorder can be reversed, the digestive function is maintained, and related discomfort is relieved.

The invention belongs to the technical field of novel biological building materials, and particularly relates to a method for reinforcing sandy soil by utilizing cement hydration and biological cement bonding, which comprises the following steps: inoculating urease bacteria into a culture medium for culturing to obtain a bacteria solution; preparing a cementing liquid matched with the urease bacteria; portland cement and sand are evenly stirred and filled into a mold, and a sand column blank is obtained; and spraying the bacterial liquid and the cementing liquid from the top of the sand column blank in turn to carry out a microbial mineralization reaction so as to obtain the molded sand column. According to the invention, the hydration effect of Portland cement is cooperated with biological cement to fully fill gaps of sand grains, so that a high-strength composite cementing system is formed. According to the method, the compressive strength of the sandy soil is remarkably improved, particularly, the defect that the strength of the sandy soil subjected to cementation treatment through a single biological grouting method is insufficient can be overcome, powerful guarantee is provided for safety and stability in the fields of foundation reinforcement, structural defect repair and the like, and remarkable academic innovation and engineering application value are achieved.

The invention discloses an alcaligenes faecalis UA strain, a product and application thereof, and a method for repairing an acid mine environment by acid-resistant urease-producing bacteria, and belongs to the technical fields of industrial microorganisms, microorganism application materials and environment repairing. The UA strain CGMCC No.33976 is found for the first time to produce the acid-resistant urease, the urease is stably produced in the environment with the optimum acidity of pH 4.5-pH 6.5 and the initial pH of 3.5-pH 7.5, and the enzyme production activity is the highest in the environment with the initial pH of 5.5-pH 6.5. The UA strain can effectively reduce acidity and remove metal ions in water in an acid mine wastewater real water sample, the removal rate of aluminum, manganese, zinc and cadmium exceeds 99%, and the removal rate of calcium, iron and lead is 92%-98%. The UA strain is screened from the acid mine environment, has biological safety, has industrial purposes of AMD in-situ direct treatment and acid mine environment in-situ remediation, does not need to add chemical agents to adjust the pH value of the environment, and has ecological safety and environmental sustainability.

The invention discloses a self-filling high-strength earth and rockfill dam water plugging material and a preparation method thereof. The preparation method specifically comprises the following steps: adding active strain particles and bentonite into an earth and rockfill material, mixing to obtain a premix, adding a gelling agent, and carrying out ball milling and mixing to obtain aggregate particles; the aggregate particles are placed on a stirrer to be stirred, an organic solution is sprayed to the aggregate particles for hydrophobic modification, modified aggregate is obtained and dried, the modified aggregate and urea are mixed and stirred, and the self-filling high-strength earth and rockfill dam water plugging material is obtained. According to the method, urease of bacteria and microorganisms of urea are used for inducing calcium carbonate precipitation MICP reaction to form calcium carbonate precipitation, the pore structure in traditional earth and stone materials is filled, the porosity and the pore size are reduced, the overall water seepage resistance of the dam body can be improved, meanwhile, the overall dam body is more compact due to the reduction of the porosity, and the dam body is better in water seepage resistance. And after the strength is improved, the external water pressure resistance is improved.

The invention discloses high-urease microbial gel, a preparation method and a method for repairing uranium-polluted soil by using the high-urease microbial gel, and belongs to the technical field of environmental pollution microbial treatment. The preparation method comprises the following steps: 1) mixing sodium alginate, urea and a water-retaining agent to obtain a carrier solution; 2) uniformly mixing the high urease bacteria solution in the logarithmic phase with the carrier solution according to a volume ratio of 5-25% to obtain a bacteria solution mixture; and (3) dropwise adding the bacterial liquid mixture into a cross-linking agent which is stirred at a constant speed for cross-linking and curing, and freeze-drying to obtain the high-urease microbial gel. The high-urease microbial gel is applied to the periphery of a root system of a uranium-enriched plant planted in uranium-contaminated soil to be repaired, and uranium-contaminated soil is repaired through combination of microorganisms and plants. Urease-producing bacteria in the high-urease microbial gel induce decomposition of urea to generate carbonate, uranyl ions in the soil are activated, the mobility of uranium in the soil is improved, and extraction of uranium in the soil by uranium-enriched plants is promoted.

The invention provides an EICP-based sandy soil curing agent, a sandy soil curing method and application thereof, and relates to the technical field of rock and soil reinforcement. The sandy soil curing agent comprises a urease solution, a cementing fluid and a hydrophobic polymer, wherein the urease solution is prepared by salting out a urease crude extract and then carrying out solid-liquid separation; the cementing liquid comprises calcium salt, magnesium salt and urea. The curing agent is convenient to use, the solidified soil body is stable in structure, and the curing agent has excellent disintegration resistance. The invention further provides a sandy soil curing method and application of the sandy soil curing agent or the sandy soil curing method.

The invention discloses a urease-producing microorganism induced calcium carbonate deposition solution for foundation reinforcement and a preparation method and application thereof, and belongs to the technical field of foundation reinforcement. The urease-producing microorganism induced calcium carbonate deposition solution comprises a bacterial solution, a cementing solution and a sodium citrate solution, the bacterial liquid comprises bacteria capable of generating urease and citrobacter freundii. Sodium citrate in the urease-producing microorganism induced calcium carbonate deposition solution can chelate free calcium ions in advance, the concentration of the free calcium ions is reduced, the risk of precipitation at an injection port in the single-phase injection process is eliminated, and the solution can smoothly permeate into a deep layer; citrobacter freundii produces acid through metabolism and utilizes citric acid radicals through metabolism to ensure gradual release of calcium ions, so that uniform deposition of calcium carbonate is triggered. Through the synergistic effect of sodium citrate chelated calcium ions and citrobacter freundii metabolism, the solution can be uniformly distributed in the soil sample, and the problem of uniformity of single-phase perfusion is successfully solved.

The invention discloses a compound microbial agent and application thereof in quality improvement of liquorice in saline-alkali soil in an arid region, and belongs to the field of microbial technology and agricultural planting. The compound microbial agent is prepared from arthrobacter globiforme, filamentous pseudomonas, sinorhizobium meliloti bacillus and bacillus subtilis; the viable count concentration of the compound microbial agent is (1-2) * 10 < 10 > CFU / mL. The compound microbial agent can remarkably improve the yield and quality of liquorice, and meanwhile, the compound microbial agent can improve the fertility of saline-alkali soil by activating soil phosphorus and potassium and improving the activity of urease and alkaline phosphatase. The invention solves the problems of weak glycyrrhiza rhizosphere colonization ability and low component conversion rate of the existing fungicide, and provides an innovative technical scheme for efficient glycyrrhiza planting in the saline-alkali soil in the arid region.

To provide a soil improvement method utilizing urea and urease, allowing reduction of ammonia generated in the course of soil improvement.SOLUTION: The present invention provides a soil improvement method in which calcium carbonate is generated from carbon dioxide produced through urea and urease to solidify soil, the method characterized by further adding a phosphorus compound and a magnesium compound to produce magnesium ammonium phosphate from at least a part of the ammonia generated through urea and urease.SELECTED DRAWING: None