34 results about "Coliform bacilli" patented technology

The invention relates to the technical field of biology, in particular to a beta-1, 4-galactosyl transferase mutant and a method for biologically synthesizing lactose-N-neotetraose by using the beta-1, 4-galactosyl transferase mutant. The invention discloses a protein, which is a protein HpgalT-186 or a protein HpgalT-146-186, a protein HpgalT-146 and a protein HpgalT-146. The protein HpgalT-186 is a protein obtained by mutating an amino acid residue at the 186th site of a wild type HpgalT; the protein HpgalT-146-186 is a protein obtained by carrying out mutation on an amino acid residue at the 186 site and an amino acid residue at the 146 site of wild type HpgalT. On the basis, a series of escherichia coli is constructed and optimized, the yield of the LNnT synthesized through shake flask fermentation of the finally obtained strain reaches 1.73-4.1 g / L, the highest yield in a 5L fermentation tank reaches 20-45.2 g / L, and efficient synthesis of the LNnT is achieved.

The invention discloses a heme oxygenase mutant and application of the heme oxygenase mutant in preparation of bilirubin through multienzyme coupling, and belongs to the field of biological catalysis engineering. The forward mutant of the heme oxygenase is obtained through a directed evolution technology, and heme can be efficiently catalyzed to synthesize biliverdin; the bilirubin is synthesized by further introducing biliverdin reductase, coupling cytochrome P450 reductase and formate dehydrogenase, and coupling the two core enzymes with foreign assistant enzymes to construct recombinant escherichia coli to catalyze heme to synthesize bilirubin. In the system, NADPH does not need to be exogenously added, the reaction time is about 4 h, the yield of bilirubin reaches 2.10 g / L, accumulation of intermediate products is not observed in the catalysis process, and the highest yield and the shortest reaction time in bilirubin synthesis reported at home and abroad at present are achieved. Compared with the traditional pig bile extraction, the method disclosed by the invention breaks through the resource limitation, is simple to operate and high in yield, and realizes efficient and green synthesis of bilirubin.

The invention discloses a casein-sourced multifunctional peptide, and belongs to the field of food science and nutriology. The casein is subjected to enzymolysis through pepsin, a method combining activity verification and mass spectrum identification is adopted, the novel multifunctional peptide YPE with a clear sequence is screened and verified, the highest ABTS clearance rate of the casein peptide YPE can reach 77.76%, the highest hydroxyl radical clearance rate of the casein peptide YPE can reach 40.18%, and the casein peptide YPE can be used for preparing the novel multifunctional peptide YPE. The inhibition rate of alpha-glucosidase reaches 30.47%, the inhibition rate of escherichia coli is 10.18%, and the limitation of an existing single-function peptide in application is overcome.

The invention discloses a recombinant uricase mutant derived from arthrobacter globiforme as well as a purification method and application thereof, and belongs to the field of biological medicines. The mutant is mutated at 32-34 sites, 161 sites and 184 sites of an N end of recombinant uricase derived from arthrobacter globiforme, and the mutated amino acid sequence is as shown in SEQ ID NO: 1. On the basis of obtained uricase fermentation thalli, uricase is obtained through thalli splitting decomposition, centrifugation, nickel column affinity chromatography, liquid exchange, anion chromatography and liquid exchange, in the purification method, target protein uricase is enriched through nickel column affinity chromatography, then the purity of target protein can be increased to 95% or above through anion chromatography, and the purity of the target protein can be increased to 95% or above through anion chromatography. And finally, carrying out SUMO enzyme digestion to obtain the tag-free protein. The chromatography process is used for preparing uricase in an escherichia coli recombinant expression and purification mode, and the purity and yield of uricase are greatly improved.

The invention discloses a recombinant bacterium for producing mevalonic acid by taking glucose and acetone as co-substrates as well as a construction method and application of the recombinant bacterium, and belongs to the technical field of genetic engineering. The problems that an existing mevalonic acid biosynthesis mode is low in carbon atom economy, limited in theoretical yield and the like are solved. According to the invention, acetone carboxylase, acetoacetyl coenzyme A synthetase, 3-hydroxy-3-methylglutaryl coenzyme A reductase and hydroxymethyl glutaryl-CoA synthetase are subjected to heterologous expression in escherichia coli with an acetyl coenzyme A acetyltransferase gene atoB and a histidine protein kinase gene atoS knocked out, and self carbonic anhydrase is over-expressed; and a new way for synthesizing MVA by using glucose and acetone as a co-substrate is constructed. According to the method, one molecule of CO2 can be fixed in the biosynthesis of mevalonic acid, the yield of carbon atoms in the synthesis process of mevalonic acid is increased, the problem of low yield of carbon atoms in the synthesis process of mevalonic acid by taking glucose as a single substrate is solved, and a new thought is provided for constructing a carbon neutralization type biological manufacturing technology.

The invention relates to the technical field of modified calcium carbonate, in particular to modified calcium carbonate, which comprises the following structures: an inner core: lithium battery recycled calcium carbonate slag, which comprises 1.2-1.8 wt% of Li2CO3 and 0.5-1.2 wt% of MgCO3; the middle layer is a polydopamine (PDA) coating film, the thickness of the polydopamine (PDA) coating film is 50-80 nm, and the polydopamine (PDA) coating film is used for providing active amino (-NH2); the shell is a fluorine-containing silane and polylactic acid-glycolic acid copolymer (PLGA) composite layer, the grafting rate is larger than or equal to 90%, and the molar ratio of lactic acid to glycolic acid of PLGA is 75: 25. Quantized data of performance improvement and dispersibility are as follows: the oil absorption value is 18 ml / 100 g (compared with 28-32 ml / 100 g in the prior art), and the bulk density is 0.25 g / cm < 3 > (loose agglomeration). Functions are as follows: flame retardance: the oxygen index (LOI) reaches 34.5% (no flame retardance exists in the prior art); the antibacterial property is that the Escherichia coli inhibition rate is 99.2% (ASTM E2149 standard), and the environmental protection property is that 2.8 tons of limestone can be reduced for each ton of products, and 1.2 tons of CO2 emission can be reduced.

The application discloses a metal-MOF nano-enzyme, a preparation method and application thereof, and aims to provide a metal-MOF nano-enzyme with hydrogen peroxide mimetic enzyme activity, which can significantly improve the antibacterial effect on E. coli and S. aureus and can be applied to E. coli and S. aureus bacteriostatic agents. The technical scheme is that metal salt solution is added into 2-methyl imidazole solution, and metal-MOF nano-enzyme is synthesized through ultrasonic water bath. The application belongs to the technical field of nano-mimetic enzymes and medical antibacterial technology.

The invention discloses an application of intestinal flora metabolite salicylic acid as a predictive marker of Escherichia coli calf diarrhea. The obviously up-regulated metabolite salicylic acid is screened out from the diarrhea calf feces through a non-targeted metabonomics technology, and in a group of new independent samples, it is verified through an ELISA test that the salicylic acid concentration of the diarrhea calf feces is obviously higher than that of a healthy group. ROC curve analysis shows that the area under curve (AUC) of SA for predicting escherichia coli calf diarrhea is 0.8148, and the method has good prediction capability. The invention provides a non-invasive, cheap, rapid and high-specificity prediction method, can be used for early warning and auxiliary diagnosis of Escherichia coli calf diarrhea, and has important significance for guiding clinical precise medication and reducing the death rate of calves.

The application discloses a novel group B meningococcal outer membrane protein bifunctional carrier, relates to the technical field of biopharmaceutical processes, and discloses a group B meningococcal outer membrane protein bifunctional carrier and application of the bifunctional carrier in a meningitis combined vaccine. The bifunctional carrier is human H factor binding protein fHbp, and comprises two kinds of recombinant proteins BA and BB, and the amino acid sequences of the two kinds of recombinin proteins are SEQ ID No. 62 and SEQ ID No. 63 respectively. The BA protein is coupled with group A capsule polysaccharide to form a group A combined vaccine, the BB protein is coupled with group C capsule polysaccharide to form a group C combined vaccine, and the two are mixed to form a group ABC triple vaccine. Each dose of the triple vaccine contains 40 μg of group A / C polysaccharide, 160 μg of BA / BB protein in total and 1.0 mg of aluminum adjuvant. The BA and BB proteins are expressed by E. coli, are broken by high-pressure homogenization, and are purified by anion exchange chromatography, and the purity is greater than or equal to 95%. The triple vaccine can simultaneously induce immune responses to groups A, B and C of meningitis, the serum bactericidal titer is greater than or equal to 1:32 after primary immunization, and the titer is maintained for more than 56 days after three immunizations.

This invention discloses a recombinant *E. coli* strain for producing phenyllactic acid, a lactate dehydrogenase mutant, a whole-cell catalytic method for preparing phenyllactic acid, and the application of the aforementioned recombinant *E. coli* strain or lactate dehydrogenase mutant in the catalytic preparation of phenylpyruvic acid from phenyllactic acid. This invention significantly improves catalytic efficiency by modifying the 52nd amino acid of lactate dehydrogenase through site-directed mutagenesis. After mutating glutamine (Q) to valine (V) at position 52 of the *Lactobacillus mucosa* lactate dehydrogenase, the catalytic efficiency is significantly improved even at low cell density (OD). 600 =15) and substrate 15 g / L conditions, almost complete conversion was achieved; and combined with high-density catalysis and surface display optimization, the yield of phenyl lactic acid was increased while the downstream separation and purification costs were significantly reduced, greatly enhancing the potential for industrial production.

The present invention relates to lactic acid bacterial strains capable of producing or inducing the production of melatonin, for use in the production of melatonin in a subject. Preferred strains for such uses are capable of producing or inducing the production of adenosine. Therapeutic uses of such strains include the treatment or prevention of diseases associated with melatonin deficiency, for example infantile colic. Novel strains are also provided.

The invention belongs to the field of bioengineering, and particularly relates to a method for efficiently synthesizing recombinant human lactoferrin. The invention provides a synthetic method of recombinant human lactoferrin, which comprises the following steps: constructing escherichia coli recombinant host cells, performing fermentation culture, and separating and purifying the recombinant human lactoferrin, optimizing fermentation culture conditions, so that the fermentation process is in an optimal state, the yield of the recombinant human lactoferrin can be obviously improved, and the yield of the recombinant human lactoferrin can be obviously increased. And the large-scale production requirement is met. The efficient purification process established under the synthetic method can gradually remove impurities, so that the product purity is improved, the endotoxin content is lower than 10EU / mg protein, the safety standard of infant food is met, and a guarantee is provided for producing high-quality infant milk powder.

The application discloses a semi-chemical synthesis method of an N-terminal domain of matrix metalloproteinase inhibitor-2 (N-TIMP2) and application thereof. The N-TIMP2 is divided into three fragments, wherein a key tyrosine post-translational modification site is located in the fragment 2; the polypeptide resins of the fragment 1 and the fragment 2 are synthesized by using a solid-phase polypeptide synthesis technology, and the fragment 1 and the fragment 2 with a C-terminal hydrazide are obtained after cleavage, deprotection, extraction and purification; the fragment 3 is obtained by combining an E. coli recombinant expression technology and a three-step one-pot selective protection reaction of side chains of mercapto; the fragment 1, 2 connecting product is obtained through a first-step natural chemical connecting reaction; the full-length linear protein is obtained through a second-step natural chemical connecting reaction, desulfurization and deprotection; and finally, the N-TIMP2 protein is obtained through a refolding reaction. The semi-chemically synthesized N-TIMP2 protein has a comparable MMP-14 inhibiting activity to the N-TIMP2 protein obtained by using the E. coli recombinant expression technology.

The application discloses a beta-lactoglobulin mutant, a preparation method and application, relates to the technical field of genetic engineering, and the amino acid sequence of the beta-lactoglobulin mutant is shown as SEQ ID NO. 1; the preparation method is as follows: designing a forward primer, a reverse primer, a forward mutant primer and a reverse mutant primer; using a wild-type beta-Lg plasmid as a template, a mutant DNA segment is obtained by using overlap extension PCR technology; after the mutant DNA segment is connected with an empty vector, the obtained recombinant plasmid is transformed into an E. coli competent cell, cultured and identified; the recombinant plasmid is transformed into the E. coli competent cell, cultured and lysed; the cell supernatant is collected, purified, and the beta-lactoglobulin mutant is obtained; the application improves the binding property of the beta-lactoglobulin with specific IgE antibodies, enhances the immunological activity of the beta-lactoglobulin allergen, and enhances the sensitivity and specificity of the allergen specific IgE antibody detection result.

The invention discloses a coding gene of cutinase CutBJB6 for synthesizing a plurality of fatty acid ethyl esters from a Lacnella arida source and an application of the coding gene of cutinase CutBJB6. The amino acid sequence of the cutinase CutBJB6 is as shown in SEQ ID NO. 1, and the nucleotide sequence of the coding gene of the cutinase CutBJB6 is as shown in SEQ ID NO. 2. The invention belongs to the technical field of biosynthesis, and particularly discloses a coding gene of the Lacnellada-derived cutinase CutBJB6 and construction of an escherichia coli expression vector carrying the gene, and also discloses application of the Lacnellada-derived cutinase CutBJB6 in catalytic synthesis of ethyl butyrate, ethyl valerate, ethyl hexanoate, ethyl caprylate and ethyl caprate in a water-phase system. The invention further discloses a preparation method of the Lacnellada-derived cutinase CutBJB6 and application of the Lacnellada-derived cutinase CutBJB6 in the field of biosynthesis of the Lacnellada-derived cutinase CutBJB6. The invention firstly provides the cutinase CutBJB6 which has the capability of synthesizing fatty acid ethyl ester in a water phase system and is derived from the Lacnella arida and the coding gene of the cutinase CutBJB6.

A pheromonicin against SARS-COV-2. Antibody mimetics, i.e., two 28-residues are designed for the first time by selecting the E protein and M protein of SARS-COV-2, which are relatively conserved and have low probability of mutation, as targets. Pharmacodynamic experiments performed using three SARS-COV-2 strains (the epidemic strain GD108, the South Africa strain SA and the India strain IND) respectively prove that fusion proteins obtained by linking the 28-residues to colicin can provide effective protective efficacy against pulmonary lesions induced by SARS-COV-2, and can be used as drugs for treating and preventing SARS-COV-2.

This invention discloses a β-lactoglobulin mutant, its preparation method, and its application, relating to the field of genetic engineering technology. The amino acid sequence of the β-lactoglobulin mutant is shown in SEQ ID NO.1. The preparation method is as follows: designing forward primers, reverse primers, forward mutation primers, and reverse mutation primers; using wild-type β-Lg plasmid as a template, obtaining a mutant DNA fragment using overlap extension PCR technology; ligating the mutant DNA fragment into an empty vector and transforming it into competent E. coli cells for culture and identification to obtain a recombinant plasmid; transforming the recombinant plasmid into competent E. coli cells, culturing, lysing, collecting the cell supernatant, purifying, and obtaining the β-lactoglobulin mutant. This invention, through structural modification of β-lactoglobulin, improves its binding to specific IgE antibodies, enhances the immunogenicity of β-lactoglobulin allergens, and improves the sensitivity and specificity of its allergen-specific IgE antibody detection results.

This invention discloses a strain that produces high levels of L-homoserine, its construction method, and its applications, belonging to the field of amino acid fermentation. This invention provides a strain for efficient fermentation production of L-homoserine, its construction method, and its applications. This strain utilizes a cofactor homogenization scheme to introduce a heterologous NADH-dependent dehydrogenase to replace the original NADPH-dependent dehydrogenase in *E. coli*, thereby removing cofactor limitations, knocking out the main byproduct pathway, enhancing precursor supply, and strengthening efflux protein expression. Fed-batch fermentation in a fermenter achieves a yield as high as 155 g / L.

The invention belongs to the technical field of nucleoside medicine preparation, and particularly discloses a method for efficiently preparing 2-deoxy-D-ribose. According to the method, reactants are added into Escherichia coli fermentation liquor for recombinant expression of thymidine phosphorylase, and acid hydrolysis treatment is carried out after one-step catalytic reaction to directly generate 2-deoxy-D-ribose. The method can be used for catalytically preparing the high-concentration 2-deoxy-D-ribose, so that the production of the 2-deoxy-D-ribose reaches a kilogram level, and large-scale industrialization is realized. The preparation process disclosed by the invention does not need to purify recombinase, is simple, saves cost, saves energy, reduces emission, reduces equipment investment, and further reduces production cost.

The invention relates to the technical field of high polymer materials, and particularly discloses a degradable antibacterial modified ABS material and a preparation method thereof.The degradable antibacterial modified ABS material is prepared from, by mass, ABS resin, auxiliaries, an initiator, a heat stabilizer, antioxidant particles, a dispersion compatilizer and a composite antibacterial agent; the composite antibacterial agent is mainly used for releasing zinc ions for bacteriostasis, added hemicellulose is treated to react with zinc phosphate and phosphite to form a stable zinc ion release channel while being used for bacteriostasis, and antistatic particles are treated and mixed with ferric oxyhydroxide to modify diatomite to adsorb and destroy a bacterial structure so as to play a role in bacteriostasis and antioxidation. The prepared modified ABS material is a green degradable material with effective antibacterial performance, the antibacterial rate of the modified ABS material on escherichia coli, staphylococcus aureus and other florae can reach 99% or above, and meanwhile the modified ABS material has good mechanical performance and flame retardant performance and is biodegradable.

This application relates to the technical field of *Fermentomonas motilityis*, specifically to engineered strains of *Fermentomonas motilityis*, complex proteins, and methods. The engineered strain is *Fermentomonas motilityis* containing genes encoding exoglucanase, endoglucanase, β-glucosidase, coliformin E protein, and a protein that interacts with the coliformin E protein. This engineered strain can efficiently express exoglucanase, endoglucanase, β-glucosidase, coliformin E protein, and the protein that interacts with the coliformin E protein, and facilitates the formation of complex enzyme assemblies, thereby increasing the enzyme activity and glucose yield in cellulose hydrolysis, and reducing the energy consumption of cellulose hydrolysis, thus possessing significant industrial application value.

The present application relates to a kind of preparation and application of recombinant protein for inflammatory bowel disease treatment, and the gene of the recombinant protein is derived from intestinal bacteria Akkermansia muciniphila, and the name is Amuc_1434.The present application research shows that the recombinant protein has good therapeutic effect on inflammatory bowel disease.We successfully cloned Amuc_1434 gene into e. coli expression vector, then after induction expression purification, the recombinant protein Amuc_1434 is obtained.Experiments show that the recombinant protein Amuc_1434 provided by the present application can significantly alleviate the symptoms of UC mice, slow down the shortening of colon, reduce the level of inflammatory cytokines, reduce the body oxidative stress, reduce the degree of intestinal tissue lesions.In addition, the recombinant protein Amuc_1434 also shows the protective effect on kidney, and the effect is better than the common colitis treatment drug mesalazine on the market.The present application provides scientific basis for the application of recombinant protein Amuc_1434 in inflammatory bowel disease treatment, and lays a foundation for further development of new recombinant protein drug for inflammatory bowel disease treatment.

Present invention relates to a method of making a recombinant p80 polypeptide using an E. coli culture comprising a plurality of E. coli host cells each transformed or transfected with an expression vector containing a DNA fragment encoding a recombinant p80 polypeptide; and inducing the E. coli culture by adding a 0.2% L-Arabinose. The isolated, recombinant p80 is added to a pharmaceutical composition, wherein it binds to a therapeutic agent comprising one or more of: drugs, dyes, small molecules, biomolecules, proteins or a combination thereof. The p80 polypeptide enhances the transportation of the therapeutic agent into the bloodstream by the p80 functioning as a tight junction modulator to enhance the permeability of the intestinal epithelium to the therapeutic agent.

This invention discloses a polypeptide derived from human lactoferrin and its applications. This invention relates to the field of biotechnology, providing the application of the polypeptide or related biomaterials in the preparation of products with anti-inflammatory and soothing functions; the amino acid sequence of the polypeptide is shown in SEQ ID NO:1. The lactoferrin peptide of this invention can reduce the expression of the inflammatory factor IL-6 in cells, exhibiting anti-inflammatory and soothing effects. Simultaneously, this lactoferrin peptide has an inhibitory effect on the growth of Gram-negative and Gram-positive bacteria, represented by *Escherichia coli* and *Staphylococcus aureus*. This lactoferrin peptide shows promising application prospects in the preparation of drugs and cosmetics for the prevention and / or treatment of bacterial infectious diseases.

The application provides a traditional Chinese medicine composition for treating avian colibacillosis and a preparation method thereof, and belongs to the technical field of traditional Chinese medicine preparations.The preparation method is as follows: 12-15 parts of Huangqin, 9-11 parts of Huanglian, 3.5-4.5 parts of Jinyinhua, 5-7 parts of Chuanxinlian and 5-7 parts of Pugongying are mixed, crushed, 8-10 times of the mass of an acidic ethanol solution is added, extracted, filtered, and a composite liquid one is obtained; 11-13 parts of Gegen, 10-12 parts of Baotouweng, 4-5 parts of Cebaiye, 6-7 parts of Wuhezi and 7-9 parts of Zixingujia are mixed, crushed, 8-10 times of the mass of an ethanol aqueous solution is added, extracted, filtered, and a composite liquid two is obtained; the composite liquid one and the composite liquid two are respectively vacuum rotary evaporated to a relative density of 1.09-1.13, mixed, and spray dried, and the traditional Chinese medicine composition is obtained.The traditional Chinese medicine composition prepared by the application has a fast effect speed and a remarkable curative effect for treating avian colibacillosis of chicks.

The invention discloses an antibacterial and deodorant polyester fiber and a preparation method thereof, and belongs to the technical field of functional polyester fiber preparation. The method comprises the following steps: preparing a mixed slurry containing triethanolamine, g-C3N4 / X (X is one or more of Ag < + > or Cu < 2 + > or Fe < 3 + >), terephthalic acid and ethylene glycol, sequentially carrying out esterification reaction, pre-polycondensation reaction and final polycondensation reaction to obtain modified polyester, and carrying out hollow special-shaped melt spinning and water treatment with a sodium hydroxide aqueous solution to obtain the hollow g-C3N4 / X / terephthalic acid modified polyester. The antibacterial and deodorant polyester fiber with the micro-porous penetrating structure is obtained. Through a'copolymerization + blending 'composite modification mode, the mechanical property and the antibacterial deodorization function of the fiber are synergistically improved, the mechanical strength of the fiber is larger than or equal to 3.0 cN / dtex, the antibacterial rate to candida albicans, escherichia coli and staphylococcus aureus is larger than or equal to 95%, the reduction rate of isovaleric acid is larger than or equal to 90%, the reduction rate of ammonia gas is larger than or equal to 85%, the function is long-acting and stable, and the fiber can be widely applied to the fields of clothes, home textiles and the like.

The invention relates to the technical field of garment fabric processing, and discloses an antibacterial garment fabric and a processing technology thereof.The processing technology comprises the following steps that firstly, pretreatment is conducted, cotton base cloth is soaked in a solution containing 0.5-3 wt% of sodium hydroxide, treatment is conducted for 30 min at the temperature of 60 DEG C, and washing is conducted till the cotton base cloth is neutral; the pretreated base cloth is soaked in a conditioning agent solution (the solid content is 10%-15%), two times of soaking and two times of rolling are carried out, the liquid carrying rate is 70%-80%, and a conditioning agent comprises, by weight, 40-60 parts of modified zeolite powder (the particle size is smaller than or equal to 100 nm); 20 to 30 parts of carboxymethyl chitosan quaternary ammonium salt; 5 to 10 parts of a silane coupling agent KH-560; 10 to 15 parts of polyethylene glycol diacrylate; 100 to 120 parts of deionized water; through the synergistic effect of the steps of pretreatment, modified zeolite powder application, stepped hot-pressing activation, shock cooling solidification, hot-pressing-shock cooling synergism, carboxymethyl chitosan quaternary ammonium salt addition and the like, the remarkable beneficial effect is brought that in the aspect of antibacterial performance, the antibacterial rate on staphylococcus aureus and escherichia coli is larger than or equal to 99%.

The invention belongs to the technical field of animal medicines, and provides veterinary apramycin sulfate soluble powder and a preparation method thereof, and the veterinary apramycin sulfate soluble powder comprises the following components in parts by weight: 25-35 parts of apramycin sulfate, 10-15 parts of baicalin, 8-12 parts of a suspending aid, 10-15 parts of a solubilizer and 4-6 parts of a stabilizer. According to the veterinary apramycin sulfate soluble powder, the treatment effect on piglet colibacillosis is remarkably better than that of apramycin sulfate and baicalin, and apramycin sulfate and baicalin play a remarkable synergistic effect in the aspect of treating the piglet colibacillosis. The veterinary apramycin sulfate soluble powder disclosed by the invention has a better treatment effect, and provides a better choice and a better treatment effect for livestock.

The application discloses a microfluidic chip and a method for detecting water quality by embedding coliform group in alginate hydrogel, and the microfluidic chip comprises a sample inlet, an oil phase inlet, an alginate aqueous solution inlet, a droplet mixing flow channel, an incubation chamber and an outlet; wherein the oil phase inlet is connected with the sample flow channel through two oil phase flow channels which are divided into two parts and meet at a cross-shaped port, the alginate aqueous solution inlet is connected with the flow channel from the cross-shaped port through a water phase flow channel and meets at a T-shaped port; a contraction section flow channel and a first serpentine flow channel are sequentially arranged between the T-shaped port and the droplet mixing flow channel, and are respectively used for extruding and fusing the bacterial liquid droplet and the alginate droplet. The application solves the problem that the detection effect is poor due to the spontaneous fusion of droplets caused by the increase of incubation temperature in the prior art by combining the alginate with the calcium salt solution to form the hydrogel through ion cross-linking, and has a good application prospect in the detection of coliform group in water samples.