522 results about "Enterobacteriales" patented technology

The invention discloses a salt and alkali tolerant phosphate-solubilizing growth-promoting bacterium and application thereof, and belongs to the technical field of biology, the salt and alkali tolerant phosphate-solubilizing growth-promoting bacterium is named as Enterobacter hormaechei P03 and preserved in the China Center for Type Culture Collection (CCTCC), and the preservation number is CCTCC No: M 20242250. The enterobacter hormaechei P03 provided by the invention has good salt resistance, acid and alkali resistance, growth promotion and phosphate solubilizing effects, grows well under high salinity, acidic conditions and alkaline conditions, has better phosphate solubilizing capacity, and can generate indoleacetic acid in the growth process to promote plant growth.

The invention discloses an antibacterial peptide and application thereof, and belongs to the technical field of biology. The antibacterial peptide with an inhibition effect on various clinically common pathogenic microorganisms is obtained, and the antibacterial peptide comprises gram-negative bacteria such as escherichia coli, klebsiella pneumoniae, pseudomonas aeruginosa, acinetobacter baumannii, vibrio parahaemolyticus, salmonella gallinarum, salmonella typhimurium and enterobacter sakazakii, and gram-positive bacteria. The antibacterial peptide provided by the invention can be used as an antibacterial peptide, such as staphylococcus aureus, listeria monocytogenes and bacillus cereus, and the antibacterial peptide provided by the invention is novel in structure and easy to prepare.

The invention belongs to the technical field of antibacterial peptides, and particularly relates to an antibacterial peptide and application thereof. The amino acid sequence of the antibacterial peptide is shown as SEQ ID NO: 1, the number of amino acids is small, the synthesis cost is low, the antibacterial peptide has high antibacterial activity on gram-negative bacteria and gram-positive bacteria, the minimum inhibitory concentration of the antibacterial peptide on acinetobacter baumannii, escherichia coli, pseudomonas aeruginosa and staphylococcus aureus is 4.68-37.5 mu g / mL, and the antibacterial peptide has the advantages of broad-spectrum antibacterial property, good stability and good application prospect. No obvious cytotoxicity and hemolysis effect exist; moreover, end-to-end amido bond cyclization is carried out, so that the antibacterial activity is further enhanced, the antibacterial effect on acinetobacter baumannii, escherichia coli, pseudomonas aeruginosa and staphylococcus aureus is enhanced by 2-4 times, and the minimum inhibitory concentration is reduced to 2.34-9.38 mu g / mL; after the end-to-end amido bonds are cyclized, the plasma stability and safety of the antibacterial peptide are further improved, and the cytotoxicity and hemolysis are reduced.

The invention relates to the field of environment and agricultural biotechnology, in particular to an application of a composite phosphate-solubilizing bacterial agent in promoting wheat growth, which is characterized in that germinated wheat is cultivated firstly, then the germinated wheat is placed in soil mixed with the composite phosphate-solubilizing bacterial agent to be cultivated, and then the germinated wheat is cultivated in soil mixed with the composite phosphate-solubilizing bacterial agent. Furthermore, the growth of wheat is promoted by the cooperation of enterobacter hormaechei HS6, pantoea agglomerans CT3 and wheat bran in the compound phosphate-solubilizing bacterium agent. Wherein the enterobacter hormaechei HS6 and the pantoea agglomerans CT3 can efficiently convert insoluble phosphorus in the soil into soluble phosphorus, the utilization rate of phosphorus in the soil is effectively increased, the use amount of chemical phosphate fertilizer is reduced, nutritional ingredients are increased for the soil, the physical and chemical properties of the soil are improved, wheat growth can be well promoted, and the application prospect is good.

The invention belongs to the field of nano biosensors, and discloses an in-situ preparation method of a silicon-gold-aptamer nanowire array for escherichia coli detection, which comprises the following steps: preparing a nanowire array material on a silicon wafer by using an in-situ synthesis method, loading gold nanoparticles and escherichia coli aptamers on the nanowire array in situ by using a chemical reduction method, and preparing the silicon-gold-aptamer nanowire array. A metal film is plated on the back surface of the silicon wafer, and the surface is connected with a circuit when the silicon wafer is used, so that an electric signal generated by the silicon-gold-aptamer nanowire array in a test is input into the circuit through conduction of the silicon wafer. The escherichia coli aptamer can specifically adsorb escherichia coli in a test solution to the surface of a material and generate current response linearly related to the concentration of a bacterial solution, and the sensor has good sensitivity due to the huge surface area of the in-situ synthesized electrode with the nano array structure. The high-performance nano biosensor provides a novel practical method for on-site rapid detection of food-borne pathogenic bacteria.

The invention provides recombinant ensifer adhesion as well as a construction method and application thereof. The recombinant ensifer adhesion provided by the invention is applied to preparation of 1, 3-propylene glycol through mixed fermentation with recombinant escherichia coli, and glycerol can be converted into 1, 3-propylene glycol without adding expensive coenzyme vitamin B12 in the fermentation process. And the ensifer adhesion and recombinant escherichia coli mixed bacterium system has good synergy, the growth of the recombinant ensifer adhesion does not generate obvious interference on the escherichia coli in the mixed bacterium system, and the normal growth and metabolism state of the escherichia coli can be basically kept. Experiments prove that after the recombinant ensifer adhesion and the recombinant microorganism escherichia coli are subjected to mixed fermentation, the product yield can be higher than that of fermentation of single-strain recombinant escherichia coli.

The invention discloses a heavy metal pollution remediation material combining minerals and bacteria and a preparation and remediation method thereof. The heavy metal pollution remediation material comprises the following components in parts by mass: 50 parts of clay minerals, 30 parts of phosphate minerals, 10 parts of bacteria and the balance of organic fertilizer as a matrix, wherein the clay mineral is attapulgite, the phosphate mineral is apatite, and the bacteria are one of enterobacter. By combining the characteristics of minerals and bacteria, the remediation material has strong adsorption capacity and can effectively remove heavy metal ions in soil. Meanwhile, the enterobacter converts heavy metal ions into insoluble precipitates through a bioremediation mechanism of the enterobacter, such as adsorption, reduction, chelation and the like, so that subsequent treatment is facilitated. The metabolic activity of the enterobacter in the soil can promote the growth and activity of soil microorganisms, increase the content of beneficial elements in the soil, improve the soil structure and improve the soil quality.

The invention discloses enterobacter hormaechei XW-01 and a microbial preparation thereof, the strain (preservation number is CCTCC NO: M 20242595) can efficiently degrade protein, total sugar and nicotine in tobacco leaves, sensory indexes such as aroma and aroma quantity are remarkably improved, and protease activity is remarkably improved when the enterobacter hormaechei XW-01 and wheat bran act synergistically. The microbial preparation is obtained through the processes of strain activation, fermentation culture and microbial agent preparation, and when the microbial preparation is applied to tobacco leaf treatment, through the steps of water content adjustment, preparation spraying, sealed fermentation, low-temperature drying and the like, the technical breakthrough that the protein content is reduced, the tar release amount is reduced, and the comprehensive quality grade is improved is achieved. Compared with a traditional method, the technology has the advantages that the treatment period is shortened, the cost is greatly reduced, the COD value of wastewater is greatly reduced, the cigarette quality and the production environmental protection property are remarkably improved, and the method has a wide industrial application prospect.

The invention provides a method for detecting salmonella enteritidis, which comprises the following steps of: 1, expressing a nano antibody for resisting salmonella enteritidis FliC by using escherichia coli, and verifying the nano antibody; step 2, preparing immunomagnetic beads for resisting FliC protein, and verifying the immunomagnetic beads; step 3, carrying out specific enrichment on the target bacteria; 4, performing rapid splitting decomposition to release nucleic acid; step 5, carrying out isothermal amplification on the target DNA fragment; and step 6, CRISPR / Cas12a mediated signal amplification and detection are carried out. The kit has the effects of ultra-fast detection, high sensitivity, high specificity, portability, easiness in operation, no need of bacterial culture and the like.

The invention discloses an Escherichia coli mutant strain which is classified and named as Escherichia coli, the strain number is CR-TK01, and the preservation number is CGMCC (China General Microbiological Culture Collection Center) No.35554. The invention further discloses a preparation method of the Escherichia coli mutant strain. The Escherichia coli CR-TK01 with high yield of cytidine provided by the invention has the characteristics of high yield and stable high-yield character, glucose is used as a carbon source, the Escherichia coli CR-TK01 is used for fermentation production of cytidine under a certain fermentation condition, and the yield of cytidine is as high as 97.23 g / L; the strain is not degraded after passage for more than 20 generations, the performance of high-yield cytidine is maintained in the passage fermentation process, and the yield of cytidine in passage fermentation is improved. The method for producing cytidine through fermentation is simple in process, high in yield and suitable for industrialization.

The invention provides a plug-and-play Mi3 protein nanocage fusion protein with a VNP6 tag and a preparation method and application of the plug-and-play Mi3 protein nanocage fusion protein, the fusion protein comprises the VNP6 tag, a SpyCatch003 component, a Mi3 protein nanocage and a functional protein sequence, and the VNP6 tag is located at the N end of the fusion protein. The VNP6 peptide sequence or the variant thereof is utilized to induce a vesicle or vesicle-like structure beneficial to protein folding and stabilization in escherichia coli, so that the correct folding rate and activity of recombinant protein are improved while the overall intracellular molecular crowding effect is relieved. The core idea of the invention lies in that the internal structure of cells is regulated at low temperature, and the internal microenvironment of an escherichia coli expression system is optimized, so that protein molecules under high expression load can obtain more reasonable spatial distribution, and the problems of misfolding and aggregation caused by molecular crowding are reduced.

The invention relates to the technical field of biology, and particularly discloses a fusion protein containing an SUMO tag and a preparation method and application thereof. The fusion protein provided by the invention comprises an SUMO tag and an antibacterial peptide, the antibacterial peptide can inhibit escherichia coli and staphylococcus aureus, and the amino acid sequence of the antibacterial peptide is as shown in SEQ ID No. 10, SEQ ID No. 6, SEQ ID No. 8, SEQ ID No. 12, SEQ ID No. 15 or SEQ ID No. 17. The fusion protein can be efficiently expressed through a prokaryotic expression system, renaturation of the antibacterial peptide can be successfully achieved after enzyme digestion and purification, the antibacterial activity of the antibacterial peptide is recovered, and therefore efficient preparation of the antibacterial peptide is achieved.

The invention discloses a polypeptide derived from deep sea microorganisms, and belongs to the technical field of peptide inhibitors. The polypeptide has an amino acid sequence as shown in SEQ ID NO: 1; the polypeptide has a bacteriostatic and / or bactericidal function. The polypeptide can inhibit the growth of acinetobacter baumannii at 8 [mu] M and inhibit the growth of escherichia coli and multi-drug-resistant acinetobacter baumannii at 16 [mu] M, and can be used for preparing products with bacteriostatic and / or bactericidal performance, such as food, daily necessities or medical products.

The invention relates to the field of environment, resource utilization and agricultural biotechnology, in particular to application of a composite solid phosphate-solubilizing bacterial agent to remediation of cadmium-contaminated soil and improvement of soil quality, in the application, the composite solid phosphate-solubilizing bacterial agent comprises phosphate-solubilizing bacteria, bone black, a culture medium and an organic matrix; the phosphate solubilizing bacteria are pantoea agglomerans CT-3 and enterobacter hormaechei HS-6; the composite solid phosphate-solubilizing bacterial agent is applied to Cd-polluted soil, the bio-availability of Cd in the soil is reduced through synergy of pantoea agglomerans CT-3, enterobacter hormaechei HS-6 and micron-nano multi-stage bone black, and meanwhile, the soil quality is improved. On one hand, the application can effectively promote conversion of insoluble phosphate into soluble phosphate, so that the content of available phosphorus in soil is increased by 98.19%; on the other hand, soil heavy metal Cd can be fixed, so that the content of available Cd in the soil is reduced by about 52.50%, and the soil remediation agent has excellent Cd fixation capacity, can relieve Cd stress of crops, and has good application value in the aspects of farmland Cd pollution remediation, soil quality improvement and environmental protection.

The invention provides mulberry enterobacter, a microbial agent as well as a preparation method and application of the microbial agent. The bacterial strain XJ 10 is classified and named as Enterobacter mori, and is preserved in the Guangdong Microbial Culture Collection Center on February 20, 2025, the preservation number is GDMCC No.65928, and the preservation date is February 20, 2025. The strain XJ 10 can tolerate cadmium-lead combined pollution, has the capabilities of fixing nitrogen, dissolving phosphorus and dissolving potassium, can promote residual cadmium and lead in soil to be converted into effective cadmium and lead, can promote absorption of enrichment plants or hyperaccumulator to cadmium and lead, and can improve the physicochemical properties of the soil at the same time.

The invention belongs to the technical field of microbial fermentation, and particularly relates to a new enterobacter rorrhizae strain as well as a separation and screening method and application thereof. In order to enrich microbial resources for producing pyrazine substances through metabolism in the white spirit industry, an enterobacter rorrhizae strain is separated and screened from a mixture of yeast for making hard liquor and fermented grains, and the preservation number is CGMCC No.33262. The strain has good tolerance to pH, salt and alcohol, and can adapt to the growth environment in the white spirit production process; and various pyrazine substances represented by tetramethylpyrazine can be produced. Besides, the strain has strong adaptability to fermented grains, the yield of tetramethylpyrazine is high in a culture medium taking bran, wheat and five grains as the fermented grains, and meanwhile, various flavor substances such as ethyl acetate, ethyl hexanoate, ethyl caprylate, 2, 3-butanediol, guaiacol and 4-vinyl guaiacol can be produced. Therefore, the enterobacter rorrhizae disclosed by the invention can be widely used for brewing white spirit.

The invention discloses enterobacter mori capable of resisting fish aeromonas and application of the enterobacter mori, the bacterial strain is classified and named as enterobacter mori SCH0241, the enterobacter mori SCH0241 is preserved in the China Center for Type Culture Collection on October 17, 2024, and the preservation number is CCTCC NO: M 20242236. The enterobacter mori SCH0241 disclosed by the invention is derived from the intestinal tract of high-stress-resistance healthy hybrid crucian carassius auratus No. 2, has good contact dependence antibacterial activity on aeromonas veronii, and can improve the capability of resisting aeromonas veronii infection of zebra fish. Through construction of an insertion mutation library and phenotype screening, it is found that a gene cluster of SCH0241, which exerts contact inhibition toxicity, is T6SS-2. The enterobacter mori SCH0241 disclosed by the invention provides a new powerful tool for biological prevention and treatment of fish diseases caused by aeromonas veronii.

The invention discloses escherichia coli recombinant engineering bacteria for producing citicoline as well as a construction method and application of the escherichia coli recombinant engineering bacteria, and belongs to the technical field of biology. A genome cytidine deaminase coding gene cdd is knocked out on the basis of Escherichia coli K-12 MG1655, a temperature control expression vector PBV220 is used for expressing a SpnCCT-SpnCKI-pRpLpyrG mutant gene cluster, the expression of choline transporter protein BetT is enhanced, the gene locus of Escherichia coli ptsH-ptsI-crr is destroyed, meanwhile, a glucose permease gene glf and a glucokinase gene glk from Zymomonas mobilis are introduced, and the mutant gene cluster of the Escherichia coli K-12 MG1655 is obtained. The escherichia coli recombinant engineering bacterium ZMCB02NCL capable of efficiently biosynthesizing citicoline is obtained, and the preservation number of the escherichia coli recombinant engineering bacterium ZMCB02NCL is CCTCC NO: M 2025483.

A protein capable of inhibiting type I fimbriae of Escherichia coli (E. coli) is identified, where the protein is named as Type I fimbrial repressor (TIFR) protein, and is encoded by a TIfr gene with an ID of GW576_23830. A method is further provided for inhibiting the growth of type I fimbriae of an E. coli strain, in which the TIfr gene is transformed into the strain.

The invention discloses an anti-bacteriophage escherichia coli chassis cell based on combination of bacteriophage adaptive evolution and a bacterial anti-bacteriophage defense system. Receptor genes of bacteriophages are excavated through co-evolution of bacteriophages T1, T4, T7, vBEcoMP251 and vBEcoMP255 and escherichia coli strains, the resistance of escherichia coli to the bacteriophages is enhanced by knocking out screened bacteriophage receptors on the genome level, and meanwhile, defense systems shedu and septu with the ability to resist the bacteriophages are obtained through screening. The resistance of escherichia coli to the bacteriophage is further enhanced by integrating the gene to the ylbe and yeeP gene loci, construction of multi-resistant broad-spectrum chassis cells of the bacteriophage is completed, and certain application prospects are achieved.

The invention discloses a method for producing mRNA (messenger ribonucleic acid) template plasmids by fermenting escherichia coli. When the recombinant escherichia coli is fermented and cultured, a seed solution of the recombinant escherichia coli is inoculated into a basic culture medium to be fermented and cultured until the OD600 value of fermentation liquor is 18-22, then a fed-batch culture medium is continuously added at the feeding rate of 5-15 mL / L / h to be subjected to continuous fed-batch fermentation culture, the basic culture medium contains 0.05-0.2 mmoL / L of ferric salt compound and 0.05-0.2 mmoL / L of copper chloride dihydrate, and the basic culture medium contains 0.05-0.2 mmoL / L of ferric salt compound and 0.05-0.2 mmoL / L of copper chloride dihydrate. The basal culture medium contains 10-15 g / L of copper chloride dihydrate and 100-300 mg / L of p-hydroxybenzoic acid, the carbon source of the basal culture medium contains 0.1-0.3 mmoL / L of a ferric salt compound, 0.1-0.3 mmoL / L of copper chloride dihydrate and 100-300 mg / L of p-hydroxybenzoic acid, the carbon source of the fed-batch culture medium contains 360-480 g / L of glycerol, and the ferric salt compound is one or more of ferrous citrate, ferric ammonium citrate or ferrous sulfate heptahydrate. According to the method, the yield and superhelix content of the mRNA template plasmids are improved by optimizing the culture medium formula and culture conditions, and large-scale production of the high-quality target mRNA template plasmids is facilitated.

The present invention belongs to the field of cellulose synthesis, and specifically relates to a heterologous expression Escherichia coli biosynthesis system of cellulose synthase subunits PtCesA1 and PtCesA8 and its application, including a heterologous expression vector of cellulose synthase subunit PtCesA1 or a heterologous expression vector of cellulose synthase subunit PtCesA8; and a heterologous cell containing the above vector. PtCesA1 and PtCesA8 are expressed in heterologous cells respectively to form cellulose synthase, which is used to catalyze the synthesis of cellulose microfibrils. The present invention realizes the biosynthesis of cellulose in vivo, and directly synthesizes a cellulose product with high purity similar to plants and free of lignin and hemicellulose from the bacteria by heterologously expressing plant cellulose synthase subunits in Escherichia coli.

The invention discloses an enterobacter strain and application thereof in improving stress resistance of plants. The invention relates to the field of biological agriculture, and provides Enterobacter sphaeroides YJD-AD2-2, and the enrollment number of the Enterobacter sphaeroides YJD-AD2-2 in the General Microbiological Culture Collection Center of the China Committee for Culture Collection of Microorganisms is CGMCC No.29524. The Enterobacter sphaeroides YJD-AD2-2 can be used for preparing the enterobacter sphaeroides YJD-AD2-2. The enterobacter sphaeroides YJD-AD2-2 provided by the invention can improve the resistance of arabidopsis thaliana, alfalfa, corn and rice to salt and alkali stress, specifically, the dry weight, fresh weight, plant length, leaf area and chlorophyll content are increased, the oxidation resistance is improved, wilt is reduced, and physiological and biochemical indexes are improved. The YJD-AD2-2 microbial inoculum improves the property and activity of saline alkali soil and improves the abundance and composition of microbial communities. Detection shows that the YJD-AD2-2 strain has the capabilities of secreting IAA (Indoleacetic Acid), ACC (Acetyl Cellulose) deaminase and siderophore, dissolving phosphorus and fixing nitrogen. The indexes show that the YJD-AD2-2 microbial inoculum has the potential of growth-promoting bacteria and has important application value in the field of agriculture.

Provided are a tetrahedral framework nucleic acid and a preparation method therefor. Escherichia coli is used as a host to produce an M13 bacteriophage so as to obtain single-stranded DNA (ssDNA) in the M13 bacteriophage, ssDNA required for assembling the tetrahedral framework nucleic acid is obtained by cleavage with restriction endonuclease II, and then the tetrahedral framework nucleic acid is obtained by self-assembly of the ssDNA. The production costs of TDN are reduced while achieving large-scale industrial production of the TDN, and the present invention has good practicability.

The invention discloses an Escherichia coli endogenous alcohol dehydrogenase EcYjgB mutant and application thereof. The mutant is obtained by performing any one of the following mutations (a) to (c) on Escherichia coli endogenous alcohol dehydrogenase EcYjgB as shown in SEQ ID NO.1: (a) mutating serine at the 200th site into arginine; (b) the serine at the 199th site is mutated into aspartic acid, and the serine at the 200th site is mutated into arginine; and (c) the serine at the 199th site is mutated into aspartic acid, the serine at the 200th site is mutated into arginine, and the asparagine at the 240th site is mutated into tryptophan. The mutant is used for efficiently catalyzing reduction of HMF or furfural to respectively synthesize BHMF and furfuryl alcohol, so that the purposes of improving the production efficiency, reducing the production cost and improving the environmental effect are achieved.

The present invention belongs to the field of new microbial application technology, specifically a Ludwig's Enterobacter and its application in improving inflammatory bowel disease. The strain is named Ludwig's Enterobacter (Enterobacter ludwigii) LS-57, which is deposited in the China General Microbiological Culture Collection Management Center on July 22, 2024, and the deposit number is CGMCC NO. 31424. The strain has the ability of cluster movement, has a strong adaptability to the intestinal environment, tolerates the acidity of gastric juice well, is sensitive to a variety of commonly used antibiotics, and has a good improvement effect on colitis.

The invention relates to the field of environment, resource utilization and agricultural biotechnology, in particular to a method for converting insoluble phosphorus by using enterobacter hormaechei microorganisms, a high-efficiency phosphate-solubilizing bacterial agent and application, and the high-efficiency phosphate-solubilizing bacterial agent comprises phosphate-solubilizing bacteria, bone black and a culture medium; the phosphate solubilizing bacteria are enterobacter hormaechei HS-6. By combining the enterobacter hormaechei HS-6 with the bone black, the phosphorus dissolving capacity of the enterobacter hormaechei HS-6 can be utilized, the phosphorus resource of the bone black can be fully utilized, the surface of the bone black can provide a growth and reproduction carrier for strains, and insoluble phosphorus can be converted into soluble phosphorus. The phosphate-solubilizing bacterial agent has good prospects in the application of biological bacterial fertilizer preparation, agricultural soil improvement, bone charcoal phosphorus resource recovery and crop growth promotion. The method for converting the insoluble phosphorus by using the enterobacter hormaechei microorganisms not only can effectively improve the utilization efficiency of phosphorus resources and reduce the dependence on limited phosphorite resources, but also has important significance for promoting agricultural sustainable development.

According to the scheme, the invention provides the recombinant macrolide enzyme as well as the preparation method and the application thereof, the amino acid sequence of the recombinant macrolide enzyme is as shown in SEQ ID NO.1, and the recombinant macrolide enzyme is derived from an EreC esterase family of enterobacter hormaechei and is obtained through site-specific mutagenesis; the mutation sites are as follows: glutamic acid at the 44th site is mutated into asparagine, tyrosine at the 55th site is mutated into proline, proline at the 76th site is mutated into arginine, phenylalanine at the 153rd site is mutated into alanine, and serine at the 219th site is mutated into glutamic acid. The method is expected to remove macrolide antibiotic pollution, and has good economic benefits and practical values.

A method for producing L-arginine using a recombinant Escherichia coli, and a recombinant bacterium used therein. Specifically, the present invention relates to a method for producing L-arginine using a recombinant Escherichia coli, and a recombinant bacterium used therein. The recombinant Escherichia coli is a recombinant bacterium obtained by means of over-expressing a gene encoding a cyanate transporter in a receptor Escherichia coli, or a recombinant bacterium obtained by means of over-expressing a gene encoding a carbonic anhydrase in a receptor Escherichia coli. The cyanate transporter is a protein having an amino acid sequence of SEQ ID NO: 4, and the carbonic anhydrase is a protein having an amino acid sequence of SEQ ID NO: 5. By means of regulating the expression of the cyanate transporter or carbonic anhydrase, the yield of arginine is significantly improved. The method provides a new line of thought for the synthesis of bio-based L-arginine, and has wide application space and market prospects.

The invention belongs to the technical field of biological medicines, and particularly relates to a composition containing probiotics and application of the composition in regulating intestinal flora. The active polypeptide disclosed by the invention can be directly absorbed and utilized by small intestines without being digested by a human body, is high in absorption speed and high in bioavailability, and can effectively promote growth and reproduction of bifidobacterium and also promote generation of acetic acid. When the active polypeptide is independently used or combined with probiotics, the number recovery of bifidobacteria in intestinal tracts can be promoted, the growth and reproduction of enterobacter can be inhibited, and the flora balance of the intestinal tracts can be maintained.