87 results about "Ampicillin" patented technology

The invention discloses a bacteriostatic composition which comprises a synergist and a bacteriostatic agent, the synergist is ethyl phenylacetate or a derivative thereof, and the bacteriostatic agent is selected from hydrogen peroxide, beta-lactam antibiotics, macrolide antibiotics and aminoglycoside antibiotics. The synergist disclosed by the invention is wide in synergistic effect spectrum range, and has a remarkable synergistic bacteriostatic effect when being combined with hydrogen peroxide, amoxicillin, ampicillin, benzylpenicillin potassium, erythromycin, azithromycin and amikacin; the antibacterial effect is weak when the compound is independently used, but the virulence of staphylococcus aureus can be remarkably reduced, the formation of hemolysin, staphylococcus flavin, enterotoxin and a biofilm can be inhibited, and meanwhile, the selective pressure on bacteria is favorably reduced due to the relatively low antibacterial activity, so that the occurrence of drug resistance is delayed; the method is suitable for various application scenes such as food processing industry.

The present invention belongs to the field of biotechnology, and specifically relates to the use of the CD630_27900 gene in reducing the tolerance of Clostridium difficile. Knocking out the CD630_27900 gene can reduce the tolerance of Clostridium difficile to acidic environments and antibiotics and reduce its cytotoxicity; the sequence of the CD630_27900 gene is shown in SEQ ID NO.1; the antibiotics include ampicillin, metronidazole, amoxicillin, vancomycin, norfloxacin, cefoxitin, clindamycin and kanamycin. The research results of the present invention suggest that the CD630_27900 gene can be used as a target for inhibiting the drug resistance and reducing the toxicity of Clostridium difficile, providing a new idea for the treatment of Clostridium difficile infection (CDI).

The invention discloses a prebiotic composition capable of proliferating intestinal beneficial flora and a preparation method thereof, and the prebiotic composition comprises the following raw materials in parts by weight: 35-45 parts of partially hydrolyzed complex gum, 30-40 parts of green banana resistant starch, 15-25 parts of enzymolysis okra polysaccharide and 3-5 parts of tea polyphenol. According to the composition, the partially hydrolyzed complex gum with specific molecular weight, the green banana resistant starch, the enzymolysis okra polysaccharide and the tea polyphenol are scientifically compounded, so that efficient proliferation of intestinal effective microbial communities and comprehensive and positive regulation and control of intestinal microenvironment are realized, and the composition is prepared by utilizing four components with complementary functions and different effects. The bacillus amyloliquefaciens can effectively proliferate traditional beneficial bacteria such as bifidobacteria and lactobacillus, can effectively nourish butyric acid producing bacteria such as clostridium praeparatum and inhibit growth of harmful bacteria, so that the bacillus amyloliquefaciens has the function of remarkably improving intestinal flora disorder caused by ampicillin, and has the functions of promoting generation of short-chain fatty acid and maintaining intestinal barriers.

The invention discloses a Weissella virida 38-3 strain and an application thereof. Relates to the technical field of microorganisms. The invention provides a strain and application thereof. The strain is safe in separation source, high in growth speed and excellent in fermentation performance; the strain has the advantages of good biological safety, no hemolytic activity and no generation of bioamine, is sensitive to antibiotics such as ampicillin, erythromycin, kanamycin, streptomycin, tetracycline, vancomycin, chloramphenicol, gentamicin, clindamycin, ciprofloxacin, cefixime and the like, has good probiotic performance, has good gastric juice and intestinal juice tolerance and strong cell surface adhesion, and can be used for preparing antibiotics. Good pathogenic bacterium inhibiting and cholesterol lowering capabilities are realized. The strain disclosed by the invention can be used as a probiotic to prepare a food leavening agent, multifunctional medicines, functional foods or health-care foods, and has wide market prospects and application values.

The invention discloses a high-specific-activity glucose oxidase mutant as well as a construction method and antibacterial application thereof, and belongs to the technical field of bioengineering. Glucose oxidase GODY is used as a female parent, Ala143 is mutated into Leu143, then a mutant A143L is obtained, and the specific activity of the mutant A143L is improved by 3.1 times compared with that of a wild type; in the aspect of thermal stability, the T50 value and the half-life period at 75 DEG C of the mutant A143L are respectively increased by 6 DEG C and 9 minutes compared with those of the wild mutant A143L; in the aspect of antibacterial performance, the IC50 value of the mutant A143L to staphylococcus aureus is 19.2 mg / L, and the antibacterial performance of the mutant A143L is obviously superior to that of a wild type and is equivalent to that of ampicillin. The acquisition of the mutant with high catalytic activity provides theoretical reference for the improvement of the catalytic performance of enzyme, and the mutant A143L with strong antibacterial performance shows huge application prospects in antibiotic substitution.

The invention discloses recombinant escherichia coli for efficiently producing gamma-aminobutyric acid as well as a construction method and application of the recombinant escherichia coli, and belongs to the technical field of gene engineering or biology. The recombinant escherichia coli capable of efficiently producing gamma-aminobutyric acid is obtained by heterologous expression of a mutant glutamate decarboxylase gene gadB C11 in E.coli BL21 (DE3) and heterologous expression of a GABA / Glu reverse transport channel gene gadC C41 connected in series with weak RBS and a pyridoxal phosphokinase gene pdxY connected in series with strong RBS under the action of an araBAD promoter. The gamma-aminobutyric acid is inoculated into an LB liquid culture medium containing kanamycin and ampicillin to be cultured until OD600 is equal to 0.6, and IPTG, 1-arabinose and 1-glutamic acid are added for conversion, so that the gamma-aminobutyric acid can be obtained. According to the method, the pH value does not need to be adjusted, the gamma-aminobutyric acid can be synthesized by constructing a reverse transport path and an endogenous PLP refilling path in escherichia coli and directionally modifying a rate-limiting enzyme, and the problems that the GABA production cost is high, the enzyme activity is low, and the optimal pH value of GAD is incompatible with one-step production of GABA are solved.

The invention relates to a recombinant engineering bacterium for expressing pure iron nitrogenase as well as a construction method and application of the recombinant engineering bacterium, and belongs to the field of biotechnology and bioengineering. Key gene clusters of rhodopseudomonas and Vilnelande nitrogen-fixing bacteria are amplified and cloned into an expression vector, escherichia coli is converted to obtain recombinant engineering bacteria for expressing pure iron nitrogenase, and the pure iron nitrogenase expressed by the recombinant engineering bacteria can reduce carbon dioxide (CO2) into methane (CH4); the recombinant engineering bacteria are cultured in an LB culture medium added with ferric chloride, ampicillin and spectinomycin, oxygen exposure is reduced as much as possible under the optimized semi-anaerobic condition, the enzyme activity can be improved to the maximum extent, and compared with a traditional system, the methane yield is remarkably increased; by providing a novel methane production scheme, the technical defects of low efficiency and oxygen sensitivity of the traditional nitrogenase process are improved; the process of the present invention contributes to carbon capture and utilization by converting waste carbon dioxide into valuable methane.

The invention relates to the technical field of chemical synthesis, in particular to a dihydropyrazole derivative, a preparation method thereof and application of the dihydropyrazole derivative in preparation of antibacterial drugs. The dihydropyrazole derivative is prepared from corresponding raw materials through aldol condensation, Michael addition and acylation reaction, the reaction conditions are mild, the steps are simple, and the raw materials are low in cost and easy to obtain. The compound has excellent activity of resisting staphylococcus aureus, methicillin-resistant staphylococcus aureus, ampicillin-resistant staphylococcus aureus, pseudomonas aeruginosa and bacillus subtilis. The invention is of great significance to development and research of new antibacterial drugs.

The invention belongs to the field of microbial technology, and specifically relates to a strain of acid fish lactobacillus PKC6 and an application thereof. The acid fish lactobacillus PKC6 is deposited in the General Microbiological Center of the China Microbiological Culture Collection Administration Committee, and the deposit number is CGMCC NO. 27201. The new strain of acid fish lactobacillus PKC6 screened by the invention is resistant to gentamicin, polymyxin B, vancomycin, kanamycin and norfloxacin, sensitive to ampicillin, penicillin, cephalexin and doxycycline, and has a good inhibitory effect on Escherichia coli and Staphylococcus aureus; the strain screened by the invention, after being compounded with a composite enzyme and co-fermented with palm meal, can greatly increase the content of nutrients in the fermentation product, and has a more obvious promoting effect on the intestinal development of raised animals, thereby achieving the purpose of improving the palatability of feed and promoting intestinal development.

The invention discloses a 4-hydroxyphenylacetic acid 3-hydroxylase mutant, a coding gene of the 4-hydroxyphenylacetic acid 3-hydroxylase mutant and application of the 4-hydroxyphenylacetic acid 3-hydroxylase mutant and the coding gene of the 4-hydroxyphenylacetic acid 3-hydroxylase mutant. The 4-hydroxyphenylacetic acid 3-hydroxylase mutant is one of the following: glutamine at the 212th site of an amino acid sequence as shown in SEQ ID NO.1 is mutated into alanine, as shown in SEQ ID NO.3; the glutamic acid at the 216th site of the amino acid sequence as shown in SEQ ID NO.1 is mutated into alanine, as shown in SEQ ID NO.4; after the genetically engineered bacteria (Q212A and E216A) are subjected to shake flask fermentation in an M9Y culture medium containing 100 [mu] g / mL of ampicillin for 24 h, the tanshinol yield reaches 757.18 mg / L, and the tanshinol yield reaches 744.36 mg / L. The genetically engineered bacteria are good in substrate specificity in tanshinol biosynthesis, high in catalytic efficiency, simple in process and environmentally friendly.

The invention provides a method for synthesizing piperacillin with high selectivity. The method comprises the following steps: taking ampicillin as an initial raw material, under anhydrous and alkaline conditions, carrying out selective reaction on side chain amino of ampicillin and triphosgene to generate an isocyanate intermediate, and then coupling the intermediate with N-ethyl-2, 3-diketopiperazine to directly obtain piperacillin. The key point of the invention is that the generation of by-products such as self-coupling urea is effectively inhibited by utilizing the characteristics of moderate reaction activity and high selectivity of the isocyanate intermediate. The method has the advantages of simple route, high selectivity, few byproducts, high yield and the like, and provides a more economical and efficient way for industrial production of piperacillin.

This invention discloses a method for preparing amorphous Cu-MOFs and their applications, relating to the field of metal-organic framework materials technology. The key technical points are: CuCl2 is used as the copper source and 4,4′-bipyridine as the ligand, and Cu-MOFs are synthesized via a solvothermal method. Transmission electron microscopy shows that the obtained material exhibits a typical micron-scale sheet-like morphology. After etching with ammonia, the sample morphology transforms into rough-surfaced nanospheres with a significantly increased pore size, indicating a local rearrangement of its framework structure. X-ray diffraction analysis shows that the original Cu-MOF has high crystallinity, while the diffraction peaks of the etched aCu-MOF essentially disappear, exhibiting amorphous characteristics. As a signal conversion element in a colorimetric sensor, aCu-MOF can achieve reliable detection of ampicillin under neutral conditions. Using thiram as a cofactor, a highly selective thiram colorimetric sensing system can be constructed.

The application discloses application of tegaserod maleate in preparation of an antibacterial drug synergist, and proves that the tegaserod maleate can produce a synergistic antibacterial effect with a plurality of commonly used antibacterial drugs (including tylosin, tetracycline, enrofloxacin, ampicillin and the like), can significantly enhance the antibacterial activity of the antibacterial drugs on gram-negative bacteria, and reduce the drug resistance of bacteria to the antibacterial drugs; the antibacterial composition composed of the tegaserod maleate and the antibacterial drugs can be used for preparing a drug for treating escherichia coli infection, and the synergistic antibacterial mechanism is mainly to destroy the inner and outer membrane permeability of bacteria, regulate the proton motive force of bacteria, inhibit the activity of bacterial efflux pumps, interfere with the energy metabolism homeostasis of bacteria and induce the bacteria to produce oxidative stress. The application provides a new technical strategy for the treatment of clinical escherichia coli infection, and has important clinical application value and industrialization potential.

The invention relates to the technical field of pharmaceutical preparations, in particular to an ampicillin tablet and a preparation method thereof.The method comprises the steps that medicine raw materials of the ampicillin tablet are mixed, granulated, tableted and coated, the medicine raw material mixture is tableted based on initial pressure, the porosity and aperture uniformity are detected to obtain the actual tableting compactness, and the actual tableting compactness is obtained. Determining whether tabletting and coating are carried out based on the actual tabletting compactness to obtain the ampicillin tablet; determining a coating thickness adjustment value based on a comparison result between the dissolution rate of the actual region and the overall standard dissolution rate interval of the ampicillin tablet, and determining atomization pressure and a spraying angle based on the coating thickness adjustment value and an adjustment value difference value; the adjustment initial pressure is determined based on a comparison result of the verification actual dissolution rate and the overall standard dissolution rate intermediate value. According to the method, the actual dissolution rate of the ampicillin tablet is accurately controlled by adjusting the atomization parameters and the initial pressure according to the detection result of the regional dissolution rate, so that the drug effect is uniformly released, and the drug effect exerting reliability is improved.

The invention discloses an agrobacterium tumefaciens-mediated genetic transformation method of Archeustochytrium cidebbufense, which comprises the following steps: firstly, inducing and collecting zoospore of Archeustochytrium cidebbufense; secondly, preparing agrobacterium tumefaciens containing a hygromycin resistance gene and a target gene plasmid; then, activating and inducing agrobacterium tumefaciens; creating a groove area on an induction culture medium plate, and co-culturing the zoospore and the induced agrobacterium tumefaciens in a groove; and finally, screening the Arteustochytrium limacinum transformant on a selective culture medium containing 25 mg / L of hygromycin, 200 mg / L of tiaculosporin and 300 mg / L of ampicillin. According to the invention, the efficient genetic transformation method of the Arteustochytrids cidebbuki is established for the first time, the method has the advantages of high transformation rate, stable inheritance and the like, an important technical means is provided for deeply researching the pathogenesis of the Arteustochytrids cidebbuki, and meanwhile, a foundation is laid for developing a new strategy for preventing and controlling microalgae diseases.

The present invention relates to the technical field of intelligent detection instruments, specifically a high-frequency oscillator for a freeze-dried powder injection vial, comprising a shell and a vibration mechanism; a cover plate is hingedly connected to the upper end of the rear side surface of the shell by a hinge, a placement tube is placed in the upper end opening of the shell, a vial is placed inside the placement tube, a partition is provided at the inner bottom end of the shell, a rotating sleeve is rotatably connected in the circular holes symmetrically arranged in the middle of the partition, a rotating mechanism cooperating with the rotating sleeve is provided on the outer side surface of the placement tube, both rotating sleeves are rotatably connected to a connecting frame, a high-frequency vibrator is provided on the rubber pad inside the connecting frame, a convex shaft is provided at the upper end of the high-frequency vibrator, and a vibration plate is rotatably connected to the upper end of the convex shaft through a plane bearing. The present application facilitates the fixed installation of the vial, can automatically oscillate the vial, the oscillation of the vial is more uniform and comprehensive, the oscillation efficiency is higher, and the freeze-dried powder injection inside the vial can be fully contacted with the rubber stopper at the lower end of the vial.

The application discloses a fermentation method for producing thiamine pyrophosphokinase and belongs to the technical field of bioengineering. The BL21 recombinant engineering bacteria containing pET28a-TPK, pET28a-ProS2-TPK or pET28a-SUMO-TPK are constructed, the seed liquid is prepared, the isopropyl-beta-D-thiogalactoside is used for inducing expression, the bacteria are collected, the cells are broken and the supernatant is collected to obtain the TPK crude enzyme liquid. In the fermentation, the LB / TB culture medium containing 50 μg / mL kanamycin or 100 μg / mL ampicillin is used. The SUMO label is introduced to guide the correct folding of the TPK, so that the soluble expression ratio of the TPK is more than 85%, the ratio is improved by 2 times compared with the common system, the inclusion body ratio is greatly reduced, the process is stable and has good repeatability, and an effective scheme is provided for the industrialized large-scale preparation of the TPK.

The invention discloses a nano-enzyme antibiotic adjuvant as well as a preparation method and application thereof, and belongs to the technical field of nano-drug delivery system antibiosis. The method comprises the following steps: dispersing bovine serum albumin and heme in water, and carrying out ultrasonic oscillation; injecting absolute ethyl alcohol, adding glutaraldehyde, continuing the reaction, centrifuging after the reaction is finished, and collecting a reaction product; and washing the reaction product, carrying out first freeze drying, mixing the product obtained by freeze drying with ampicillin antibiotic, carrying out ultrasonic oscillation, centrifuging, and carrying out second freeze drying to obtain the bovine serum albumin-heme-ampicillin nano-composite. According to the invention, the bovine serum albumin coated heme nano-composite is obtained by a solvent removal method and is embedded with the ampicillin antibiotic, so that good biocompatibility is achieved, and the sterilization efficiency of the ampicillin antibiotic on drug-resistant bacteria is improved.

The application discloses an application of near-infrared controllable Fe, Zn doped tea polyphenol based carbon dot nanometer enzyme in fruit preservation, and belongs to the technical field of agricultural product preservation.The application takes tea polyphenol as a precursor, and prepares Fe, Zn doped carbon dots (Fe, Zn@GTP) nanometer enzyme with excellent antioxidant and antibacterial activity through a microwave assisted method.The Fe, Zn@GTP nanometer enzyme exhibits near-infrared light enhanced peroxidase, superoxide dismutase and catalase catalytic activity and photo-thermal performance.The Fe, Zn@GTP has antibacterial effects on escherichia coli, staphylococcus aureus, methicillin-resistant staphylococcus aureus, ampicillin-resistant escherichia coli and penicillium expansum, and the inhibition rate of the bacterial biofilm treated by the Fe, Zn@GTP is more than 90%.In the preservation experiment, the PVA / Fe, Zn@GTP film can effectively prolong the preservation period of fruits, significantly reduce the occurrence rate of fruit mold and browning, and the deterioration degree of quality indexes.

This invention belongs to the field of pharmaceutical technology, specifically relating to the application of glutamine in the preparation of drugs that inhibit gene mutations in *E. coli*. This application combines glutamine and ampicillin, and after multiple passages, it can inhibit drug-resistance gene mutations in *E. coli*, significantly reducing the mutation probability of drug-resistance genes, decreasing the fold increase in the minimum inhibitory concentration (MIC) of ampicillin after passage, and lowering the survival rate. Animal experiments have also demonstrated that passaged bacteria with added glutamine and ampicillin are more easily cleared by the body, achieving the effect of slowing down the formation of drug-resistance gene mutations in *E. coli* to ampicillin.

The present invention belongs to the field of microorganisms, and specifically relates to a strain of Pediococcus pentosaceus PKC10 and its application. The Pediococcus pentosaceus PKC10 is deposited in the General Microbiological Center of the China Microbiological Culture Collection Administration Committee, and the deposit number is CGMCC NO.27203. The new strain Pediococcus pentosaceus PKC10 screened by the present invention is resistant to gentamicin, polymyxin B, vancomycin, kanamycin and norfloxacin, sensitive to ampicillin, penicillin, cephalexin and doxycycline, and has a good inhibitory effect on Escherichia coli and Staphylococcus aureus; the screening method provided by the present invention is simple and efficient; the screened strain has good application prospects in preparing fermentation agents, further preparing feeds, etc., turning agricultural and sideline products into treasures, broadening the source of feeds, reducing breeding costs, alleviating the contradiction of insufficient feed supply, and being conducive to the development of animal husbandry.

The application discloses a glucose oxidase mutant with simultaneously improved thermal stability and acid resistance and antibacterial application thereof, and belongs to the field of genetic engineering and protein engineering. The application takes glucose oxidase AiGODL as a mother to obtain a mutant AiGODL_E148K / F283Y by respectively mutating Glu148 and Phe283 into Lys148 and Tyr283. It is found through experiments that, compared with wild-type glucose oxidase AiGODL, the mutant AiGODL_E148K / F283Y has improved heat resistance and acid resistance, and has the same level of specific activity and catalytic efficiency as AiGODL and the same antibacterial performance as ampicillin. The mutant AiGODL_E148K / F283Y provided by the application has great application prospect in antibacterial and antibiotic substitution.

The application discloses a pSY1A plasmid vector for a wheat germ cell-free expression system, which is constructed by introducing an ampicillin resistance gene, an Ori replicon, a T7 promoter, a translation enhancer, a MCS (multiple cloning site), a 3'-UTR sequence and a T7 terminator sequence on the basis of part of a sequence of an E. coli plasmid pUC19. The pSY1A plasmid vector has a MCS into which an exogenous gene can be inserted, and the MCS and a transcription assembly constitute a transcription module, so that the transcription module can be preserved by preserving the plasmid, and in-vitro transcription of the wheat germ cell-free expression system becomes more convenient and faster.

This invention discloses the application of inulin in enhancing the efficacy of ampicillin against drug-resistant Salmonella, belonging to the field of pharmaceutical biotechnology. The research of this invention shows that inulin itself does not have an inhibitory effect on Salmonella, but when used in combination with ampicillin, it can significantly enhance the inhibitory effect of ampicillin on Salmonella. Both in vitro and in vivo experiments of this invention have yielded the same conclusion. This invention can reduce the use of antibiotics and provides a new research direction for the prevention and control of Salmonella.

In the present invention, the influence by flora of the skin on dermatitis is examined by analyzing Tmem79-knockout model mice, and a bacterium having a suppressive effect on dermatitis is identified, and the present invention relates to a pharmaceutical composition derived from such a bacterium, containing as active components one or more substances selected from: (a) a bacterial cell of an ampicillin-sensitive bacterium, or a constituent component of the bacterium; (b) a culture supernatant of an ampicillin-sensitive bacterium, or a purified product from the culture supernatant; (c) an extract of an ampicillin-sensitive bacterium; and (d) a metabolite of an ampicillin-sensitive bacterium.

The invention belongs to the technical field of biology, and particularly relates to a bifidobacterium longum subsp. Longum FMBL B241768LS, a microbial inoculum and application of the microbial inoculum in hypoglycemic products, the bifidobacterium longum subsp. Longum FMBL B241768LS is preserved in China Center for Type Culture Collection on October 14, 2024, and the preservation number is CCTCC NO: M 20242173; the inhibitory activity of the compound on dipeptidyl peptidase IV is as high as 79.17%; the compound has a relatively good inhibition effect on the activity of alpha-glucosidase and alpha-amylase; the compound shows drug resistance to ciprofloxacin, ampicillin, penicillin G, clindamycin, kanamycin and polymyxin B; a good inhibition effect is achieved on pathogenic bacteria; the strain can be used for preparing medicines, fermented foods, health-care products and food additives for reducing blood sugar and inhibiting pathogenic bacteria, and has a wide application prospect.

The invention discloses a pSY1A plasmid vector for a wheat germ cell-free expression system, which is characterized in that on the basis of partial sequence of escherichia coli plasmid pUC19, an ampicillin resistance gene, an Ori replicon, a T7 promoter, a translation enhancer, MCS multiple cloning sites, a 3 '-UTR sequence and a T7 terminator sequence are introduced to construct the plasmid vector pSY1A. According to the pSY1A plasmid vector provided by the invention, the vector has multiple cloning sites into which exogenous genes can be inserted, and the multiple cloning sites and a transcription component form a transcription module, so that the transcription module can be stored by storing plasmids, and the in-vitro transcription of a wheat germ cell-free expression system becomes more convenient and quicker.

The invention discloses a bacillus amyloliquefaciens genetically engineered bacterium with high antibiotic resistance as well as a construction method and application thereof, the construction of the engineered bacterium comprises the following steps: bacillus amyloliquefaciens is taken as a starting strain, an RNA (Ribonucleic Acid) molecular chaperonin hfq coding gene is knocked out, and the nucleotide sequence of the RNA molecular chaperonin hfq is shown as SEQ ID NO.1. The RNA molecular chaperonin hfq is obtained through cloning, the tolerance of engineering bacteria to erythromycin and ampicillin is increased by 2.44 times and 3.79 times by knocking out the gene or reducing the expression of the gene, and the enhancement of the antibiotic resistance of bacillus is crucial to the threat of drug-resistant bacteria, the improvement of environmental adaptability and the development of biotechnology application. By strengthening the resistance gene, drug-resistant pathogens can be efficiently inhibited, the antibacterial curative effect can be improved, the metabolic activity can be maintained in a complex antibiotic environment, and the pollution repair and industrial fermentation efficiency can be guaranteed.

The present invention discloses a method for large-scale extraction of extracellular membrane vesicles (OMV / FGF2) secreted by Escherichia coli that has ampicillin resistance and can secrete bFGF protein after gene editing. The method cultured Escherichia coli in LB liquid containing 100ug / mL ampicillin, and used ultrasonic separation and filtration technology to effectively separate the extracellular membrane vesicles loaded with bFGF protein from Escherichia coli without Escherichia coli cells. The extraction method is simple and easy to operate, and the yield of extracellular membrane vesicles is greatly improved under the premise of retaining most of the effective biological components of bacterial outer membrane vesicles. At the same time, the method effectively removes the live bacterial cells of Escherichia coli, ensures the safety of the body, and greatly reduces the risk of bacteremia or scurvy induced by microorganisms entering the blood. In addition, the OMV / FGF2 extracted by the method was applied to colitis wounds, and it was found that it could significantly promote the healing of colitis wounds.

The present invention provides a Bacillus subtilis strain selected from the group consisting of a) the strain deposited as DSM32324,b) the strain deposited as DSM32325, and c) a mutant strain of (a) or (b) which has sensitivity for ampicillin, vancomycin, gentamicin, kanamycin, streptomycin, erythromycin, clindamycin, tetracycline, and chloramphenicol; and has inhibitory activity against E. coli and Clostridium perfringens. The invention further relates to Bacillus compositions comprising at least one Bacillus subtilis strain of the invention, preferably the Bacillus subtilis strain DSM32324 and / or the Bacillus subtilis strain DSM32325, as Direct Fed Microbial (DFM), premix, animal feed additive or animal feed. The invention provides a method of improving one or more animal performance parameters selected from the group consisting of i) increased weight gain (WG), ii) lower feed conversion ratio (FCR), iii) lower necrotic enteritis lesion scoring, iv) lower necrotic enteritis frequency, v) lower necrotic enteritis mortality, vi) increased European Production Efficacy Factor (EPEF), and vii) lower mortality, by feeding a strain or a composition according to the invention to an animal.