An antibacterial peptide, its uses, and antibacterial drugs and preservatives prepared therefrom

Abstract

The present invention provides an antibacterial peptide, its uses, and antibacterial drugs and preservatives prepared therefrom, belonging to the field of biotechnology. The antibacterial peptide of the present invention is the amino acid sequence shown in SEQ ID NO:1, SEQ ID NO:2 or SEQ ID NO:3, or an amino acid sequence having more than 95% homology with the amino acid sequence shown in SEQ ID NO:1, SEQ ID NO:2 or SEQ ID NO:3. All three antibacterial peptides of the present invention have a broad-spectrum antibacterial effect, and have a significant inhibitory effect on Gram-positive bacteria, Gram-negative bacteria and fungi, and can be prepared into antibacterial drugs for use. At the same time, the antibacterial film agent prepared from the antibacterial peptide of the present invention can be used as an antibacterial preservative, which can delay the proliferation of spoilage bacteria in food or drugs, thereby extending the shelf life of food or drugs. For example, it can be used to prevent and control the soft rot of kiwifruit. The antibacterial peptide of the present invention has good application prospects in the fields of food, medicine, etc.

Description

Technical Field

[0001] The present invention belongs to the field of biotechnology, and particularly relates to an antibacterial peptide, its uses, and antibacterial drugs and preservatives prepared therefrom. Background Art

[0002] Foodborne pathogens can be transmitted through media such as air, water, soil, and the surface of utensils, and are the primary factor causing foodborne diseases (FBD), seriously affecting environmental safety and public health. According to reports from the World Health Organization (WHO), approximately 10% of the world's population suffers from various diseases each year due to the ingestion of contaminated food. Currently, using antibiotics to treat foodborne diseases caused by pathogenic bacteria in food is the most direct and effective prevention and control strategy. However, the long-term use and abuse of antibiotics may accelerate bacterial drug resistance, making it increasingly difficult to control pathogens. In addition, although chemical preservatives (such as thymol, sodium benzoate, and propyl gallate) can inhibit microbial growth, at high concentrations, their toxic side effects may have a negative impact on human health. Therefore, the control of foodborne pathogens remains a major challenge in fields such as the food industry, water and soil monitoring, and the ecological environment, and there is an urgent need to develop new, green, and highly efficient antibacterial agents.

[0003] Antibacterial peptides (AMPs) are usually composed of 10 to 50 amino acids and are a class of small peptides widely present in organisms. They act on microorganisms through various mechanisms, such as cell membrane damage, interference with cell wall synthesis, inhibition of nucleic acid or protein synthesis, etc., and can effectively resist the invasion of pathogens, and are important components for exerting immune functions. However, existing antibacterial peptides have problems such as limited sources, limited antibacterial spectra, and insufficient antibacterial activities. In addition, although antibacterial peptides are not easily induced to develop drug resistance, in long-term applications, some pathogenic bacteria may gradually adapt, reducing the antibacterial effect of antibacterial peptides. Therefore, developing new antibacterial peptides for controlling the contamination of pathogenic bacteria in food is of great significance for human health and the living environment. Summary of the Invention

[0004] The purpose of the present invention is to provide an antibacterial peptide, its uses, and antibacterial drugs and preservatives prepared therefrom.

[0005] First, the present invention provides an antibacterial peptide, which is the amino acid sequence shown in SEQ ID NO:1, SEQ ID NO:2, or SEQ ID NO:3, or an amino acid sequence having more than 95% homology with the amino acid sequence shown in SEQ ID NO:1, SEQ ID NO:2, or SEQ ID NO:3.

[0006] The amino acid sequence shown in SEQ ID NO:1 is LLLKKPLLLLL;

[0007] The amino acid sequence shown in SEQ ID NO:2 is LLLLPKK;

[0008] The amino acid sequence shown in SEQ ID NO:3 is LLLLLSKKLL.

[0009] Furthermore, the antimicrobial peptide is the amino acid sequence shown in SEQ ID NO:1, SEQ ID NO:2 or SEQ ID NO:3, or an amino acid sequence having more than 99% homology with the amino acid sequence shown in SEQ ID NO:1, SEQ ID NO:2 or SEQ ID NO:3.

[0010] Furthermore, the antimicrobial peptide is the amino acid sequence shown in SEQ ID NO:1, SEQ ID NO:2 or SEQ ID NO:3.

[0011] The present invention also provides the use of the aforementioned antimicrobial peptide in the preparation of antibacterial drugs or preservatives against Gram-positive bacteria, Gram-negative bacteria and / or fungi.

[0012] Furthermore, the Gram-positive bacteria are Staphylococcus aureus and Listeria monocytogenes; the Gram-negative bacteria are Cronobacter and Escherichia coli; the fungi are Botryosphaeria dothidea and Diaporthe ulmi.

[0013] Furthermore, the antibacterial drug or preservative is a film agent.

[0014] Furthermore, the film agent is a film agent for preventing and treating kiwifruit soft rot.

[0015] The present invention also provides an antibacterial drug preparation or preservative, which is a drug preparation or preservative prepared from the aforementioned antimicrobial peptide as an active ingredient and pharmaceutically or food-acceptable excipients.

[0016] Furthermore, the antibacterial drug preparation or preservative is a film agent.

[0017] Furthermore, the film agent is prepared by mixing raw materials with the following mass-volume percentages:

[0018] The mass percentage of the aforementioned antimicrobial peptide is 4-10%, the mass percentage of chitosan is 1-5%, the volume percentage of acetic acid is 1-5%, the mass percentage of glycerol is 0.1-1%, the mass percentage of gelatin is 1-5%, and the balance is water.

[0019] The present invention has achieved the following beneficial effects:

[0020] (1) The present invention uses a three-step method of "organic solvent extraction - gel chromatography - reverse-phase high-performance liquid chromatography" to obtain three novel antibacterial peptides hz-01, hz-02, and hz-03 from the fermentation supernatant of Bacillus amyloliquefaciens, solving the current narrow source of antibacterial peptides and pioneering the application of Bacillus amyloliquefaciens antibacterial peptides in the preparation method of bacteriostatic agents.

[0021] (2) The three novel antibacterial peptides obtained by the present invention have broad-spectrum antibacterial activity and have significant inhibitory effects on a variety of Gram-positive bacteria, Gram-negative bacteria, and fungi, and can be used as antibacterial drugs.

[0022] (3) The antibacterial peptide bacteriostatic film agent prepared with the antibacterial peptide of the present invention can be used as an antibacterial drug or as a preservative used in fields such as medicine and food, and can inhibit the proliferation of a variety of spoilage bacteria and extend the shelf life of foods, drugs, etc.

[0023] In summary, the present invention provides three novel antibacterial peptides. These three antibacterial peptides all have broad-spectrum antibacterial effects, have significant inhibitory effects on Gram-positive bacteria, Gram-negative bacteria, and fungi, and can be prepared into antibacterial drugs for use. At the same time, the antibacterial film agent prepared with the antibacterial peptide of the present invention can be used as an antibacterial preservative, can delay the proliferation of spoilage bacteria in food or drugs, thereby extending the shelf life of food or drugs. For example, it can be used to prevent and control the soft rot of kiwifruit. The antibacterial peptides of the present invention have good application prospects in fields such as food and medicine.

[0024] Obviously, based on the above content of the present invention, according to the common general knowledge and conventional means in the art, without departing from the above basic technical idea of the present invention, other various forms of modifications, substitutions, or changes can be made.

[0025] The following is a further detailed description of the above content of the present invention through specific embodiments in the form of examples. However, this should not be construed as limiting the scope of the above subject matter of the present invention to the following examples. All technologies implemented based on the above content of the present invention belong to the scope of the present invention. Brief Description of the Drawings

[0026] Figure 1 It is a comparison chart of the antibacterial activities of the crude extracts of antibacterial peptides obtained by different extraction methods.

[0027] Figure 2 It is a detection spectrum diagram of the purification process of antibacterial peptides by gel column chromatography.

[0028] Figure 3 It is a detection spectrum diagram of the purification process of antibacterial peptides by RP-HPLC.

[0029] Figure 4 It is the first-level mass spectrum diagram of the antibacterial peptide hz-01 of the present invention.

[0030] Figure 5 This is the first-order mass spectrum of the antimicrobial peptide hz-02 of the present invention.

[0031] Figure 6 This is the first-order mass spectrum of the antimicrobial peptide hz-03 of the present invention.

[0032] Figure 7 This is the second-order mass spectrum of the antimicrobial peptide hz-01 of the present invention.

[0033] Figure 8 This is the second-order mass spectrum of the antimicrobial peptide hz-02 of the present invention.

[0034] Figure 9 This is the second-order mass spectrum of the antimicrobial peptide hz-03 of the present invention.

[0035] Figure 10 This is the bacteriostatic effect diagram of the synthetic antimicrobial peptides hz-01, hz-02, and hz-03 of the present invention against Escherichia coli, Cronobacter, Staphylococcus aureus, Listeria monocytogenes, Botryosphaeria dothidea, and Diaporthe ulmi.

[0036] Figure 11 This is the result diagram of the inhibitory effect of the antimicrobial peptide bacteriostatic film solution on the inoculation of Botryosphaeria dothidea in kiwifruit fruits: A is the result diagram of the fruit lesion diameter of different treatment groups; B is the result diagram of the disease incidence of different treatment groups after inoculation in the fruit; in the figure, a is the sterile water control group (negative control group), b is the pathogenic bacteria control group (positive control group), c is the antimicrobial peptide composite film solution treatment group, d is the prochloraz treatment group, and each row in Figure B has 5 parallel samples.

[0037] Figure 12 This is the result diagram of the inhibitory effect of the antimicrobial peptide bacteriostatic film solution on the inoculation of Diaporthe ulmi in kiwifruit fruits: A is the result diagram of the fruit lesion diameter of different treatment groups; B is the result diagram of the disease incidence of different treatment groups after inoculation in the fruit; in the figure, a is the sterile water control group (negative control group), b is the pathogenic bacteria control group (positive control group), c is the antimicrobial peptide composite film solution treatment group, d is the prochloraz treatment group, and each row in Figure B has 5 parallel samples. Detailed implementation methods

[0038] Unless otherwise specified, the chemical reagents used in the detailed implementation methods are all conventional commercially available reagents, and the technical means used are all conventional means well-known to those skilled in the art.

[0039] The antibacterial peptide extracted in the present invention is derived from Bacillus amyloliquefaciens strain 906 in our laboratory. This strain was deposited at the China Center for Type Culture Collection (abbreviated as CCTCC) located in Wuhan University, Wuhan, Hubei on March 31, 2012, and the deposit number is CCTCC NO: M2012095. At the same time, this strain is recorded in a Chinese patent with an application date of April 27, 2012 and an application number of 201210128153.5.

[0040] Example 1. Isolation, purification and identification of the antibacterial peptide of the present invention

[0041] (1) Preparation of cell-free fermentation supernatant

[0042] Streak the Bacillus amyloliquefaciens strain 906 stored at -80°C on an LB solid medium and culture it at a temperature of 37°C. Pick a single colony into 15 mL of LB liquid medium and culture it until the logarithmic growth phase to obtain a seed solution. Transfer it to an LB liquid medium containing 1% NaCl at an inoculation amount of 1% and culture it at 37°C and 180 r / min for 24 h. The obtained fermentation broth is centrifuged at 4°C and 12,000 r / min for 30 min to obtain a cell-free fermentation supernatant.

[0043] (2) Determination of the method for crude extraction of antibacterial peptide

[0044] Ammonium sulfate precipitation method: Take 30 mL of cell-free fermentation supernatant, slowly add ammonium sulfate under ice bath and stirring conditions, and add it to a final ammonium sulfate concentration of 30%, 40%, 50%, and 60% respectively. Then place it in a 4°C refrigerator and let it stand for 12 h, and centrifuge it at 12,000 r / min at low temperature (4°C) for 20 min to obtain a precipitate and a centrifugate. The precipitate is dissolved in phosphate buffer solution to obtain a crude extract of antibacterial peptide.

[0045] Organic solvent extraction method: Mix the pre-cooled (4°C) cell-free fermentation supernatant (30 mL) with different organic solvents (n-butanol, ethyl acetate or chloroform) at a volume ratio of 1:1, and then incubate it in a 37°C shaking incubator at 120 r / min for 2 h. Place the mixture on a separatory funnel, and collect the organic phase after obvious stratification. Remove the organic solvent with a rotary evaporator to obtain a crude extract of antibacterial peptide.

[0046] Acid precipitation method: Take 30 mL of cell-free fermentation supernatant, adjust the pH of the solution to 2.0 with 6 mol / L hydrochloric acid aqueous solution, stir gently, place it at 4°C and let it stand for 12 h, and then centrifuge it at 4°C and 12,000 r / min for 20 min. Collect the supernatant and the precipitate respectively. After drying the precipitate, extract it fully with methanol to obtain a crude extract of antibacterial peptide.

[0047] Using *Listeria monocytogenes* as an indicator bacterium, antibacterial experiments were conducted on the above-mentioned crude extracts of antibacterial peptides. The agar-diffusion method was used for the determination (according to the method described in Test Example 1, 1 mL of the crude extract of antibacterial peptide was dissolved in 0.01 mol / L phosphate buffer (pH 6.8) before use, and the inhibition zones of the crude extracts of antibacterial peptides were observed. The inhibition zones of some extraction methods are as Figure 1 shown. Through comparison, it was found that the crude extract of antibacterial peptide obtained by ethyl acetate extraction method had the best antibacterial effect. Therefore, the crude extraction method of antibacterial peptide was determined to be ethyl acetate extraction method, and the crude extract of antibacterial peptide obtained by ethyl acetate extraction method was used for subsequent purification.

[0048] (3)Gel column chromatography

[0049] The crude extract of antibacterial peptide was subjected to preliminary purification by Sephadex LH-20 gel column chromatography. The mobile phase was 80% methanol aqueous solution, the flow rate was 2 mL / min, the automatic collector collected 5 mL each time, and the detection wavelength was 280 nm. The detection chromatogram of the gel column chromatography purification process of antibacterial peptide is as Figure 2 shown. Subsequently, the antibacterial activity was determined according to the method described in “(2) Determination of the crude extraction method of antibacterial peptide”, and the eluate components with antibacterial properties were selected as samples for further purification. The antibacterial test showed that the 37th tube separation components with stronger antibacterial activity were selected, combined and collected, and then stored at -80 °C for standby.

[0050] (4)Purification by reversed-phase high performance liquid chromatography

[0051] The antibacterial fraction obtained in step (3) was filtered through a 0.22 μm filter membrane and then subjected to fine purification by preparative C18 reversed-phase high performance liquid chromatography. The chromatographic column was Agilent ZORBAX 300SB-C18 (5 µm, 9.4 × 250 mm); the injection volume was 0.6 mL, the mobile phase A was an aqueous solution containing 0.1% trifluoroacetic acid, the mobile phase B was an acetonitrile solution containing 0.1% trifluoroacetic acid, the flow rate was 3 mL / min, and the detection wavelength was 220 nm; binary high-pressure gradient method and ultraviolet detector were used for analysis, and the elution program was: 0-20 min, 10-40%B; 20-60 min, 40-80%B; 60-70 min, 80-93%B; 70-80 min, 93-10%B; 80-85 min, 10%B. The purification results are as Figure 3 shown. After purification by RP-HPLC, the absorption peak intensity was the highest at 41.73 min in the chromatogram. This component was collected for lyophilization and stored at -80 °C for use in the structural identification of antibacterial peptide.

[0052] (5)Structural identification of antibacterial peptide

[0053] The molecular weights of the antibacterial peptides after purification by RP-HPLC were determined using liquid chromatography tandem mass spectrometry (LC-MS / MS). Liquid chromatography conditions: mobile phase A was 0.1% formic acid aqueous solution, and mobile phase B was 80% acetonitrile aqueous solution (containing 0.1% formic acid); the mobile phase gradient elution program was as follows: 0 - 2 min, mobile phase B: 4 - 8%; 2 - 35 min, mobile phase B: 8 - 28%; 35 - 55 min, mobile phase B: 28 - 40%; 55 - 56 min, mobile phase B: 40 - 95%; 56 - 66 min, mobile phase B: 95%. The antibacterial peptides were analyzed by a liquid chromatography tandem mass spectrometer. The primary mass spectrum was obtained in the range of 350 to 1800 m / z, and the secondary mass spectrometry data were obtained by stepwise normalized collision energy. The mass spectrometry output data were searched against a database using PEAKS software to obtain the structural sequences of three antibacterial peptides, namely hz-01, hz-02, and hz-03. The primary mass spectra of antibacterial peptides hz-01, hz-02, and hz-03 are shown in turn as Figures 4 - 6 shown. The secondary mass spectra of antibacterial peptides hz-01, hz-02, and hz-03 are shown in turn as Figures 7 - 9 shown. The molecular weights of the purified antibacterial peptides were determined by LC-MS / MS mass spectrometry, and the results showed that the molecular weights were 1276.74 Da (hz-01), 824.08 Da (hz-02), and 1153.48 Da (hz-03), respectively. The amino acid sequence of antibacterial peptide hz-01 was LLLKKPLLLLL (SEQ ID NO:1); the amino acid sequence of antibacterial peptide hz-02 was LLLLPKK (SEQ ID NO:2); the amino acid sequence of antibacterial peptide hz-03 was LLLLLSKKLL (SEQ ID NO:3). Through online BlastP alignment analysis (ProteinBLAST: search protein databases using a protein query (nih.gov)), the amino acid sequences of these three antibacterial peptides had no homology with the identified and reported antibacterial peptides, indicating that they were novel antibacterial peptides and were studied, identified, and reported by the inventors for the first time.

[0054] Example 2. Preparation of the antibacterial film agent of the present invention

[0055] The antibacterial film agent of the present invention is prepared by dissolving 1.25% by mass of chitosan and 4 - 10% of antibacterial peptides (hz - 01, hz - 02 or hz - 03) in an aqueous acetic acid solution with a volume fraction of 1% (v / v), adding 0.3% by mass of glycerol and 1% of gelatin as plasticizers, stirring with a magnetic stirrer at 40°C for 4 h until the chitosan and gelatin are completely dissolved, standing for 30 min, and then degassing by ultrasonic treatment for 2 h to obtain an antibacterial composite film solution. A protective film will be formed after the composite film solution is dried.

[0056] The beneficial effects of the present invention are demonstrated by the following specific test examples.

[0057] Test Example 1: Determination of the antibacterial spectrum of the antibacterial peptides of the present invention

[0058] 1. Experimental method

[0059] According to the amino acid sequence obtained in Example 1, the corresponding antibacterial peptides were synthesized by Jie Peptide Biotechnology (Nanjing) Co., Ltd., with a purity > 95%. The antibacterial effects of the antibacterial peptides were verified by the inhibition zone experiment.

[0060] Six kinds of bacteria were selected, including Gram - positive bacteria (Staphylococcus aureus, Listeria monocytogenes), Gram - negative bacteria (Cronobacter spp., Escherichia coli), and fungi (Botryosphaeria dothidea, Diaporthe ulmi). The antibacterial spectrum was determined by the agar - diffusion method. A total of 15 mL of liquid medium containing indicator bacteria (10 6 CFU / mL) was poured into a sterile petri dish containing Oxford cups. 150 μl of the antibacterial peptide solution (the solvent was an aqueous acetonitrile solution, and the antibacterial peptide concentration was 25 mg / ml) was transferred into the Oxford cups and cultured overnight at 37°C, and the diameter of the inhibition zone was measured.

[0061] 2. Experimental results

[0062] The experimental results are as Figure 10 shown in Table 1.

[0063] Table 1. Comparison of the antibacterial effects of antibacterial peptides hz - 01, hz - 02, and hz - 03 against Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Cronobacter spp., Botryosphaeria dothidea, and Diaporthe ulmi

[0064]

[0065] Note: "-" in the table indicates no antibacterial activity.

[0066] As can be seen from Figure 10 and Table 1: The antibacterial peptides prepared by the present invention all have broad - spectrum antibacterial properties and good antibacterial activities against most pathogenic bacteria. Among them, the antibacterial peptide hz - 01 has the best broad - spectrum property.

[0067] It is reported that the antimicrobial peptides produced by most Bacillus mainly inhibit the growth of Gram-positive bacteria, while the antimicrobial peptides of the present invention also have an inhibitory effect on Gram-negative bacteria (such as Cronobacter and Escherichia coli). At the same time, studies have shown that the antimicrobial peptides of the present invention have no inhibitory effect on beneficial bacteria such as Lactobacillus. Therefore, the antimicrobial peptides of the present invention make up for the defects of most existing Bacillus antimicrobial peptides in antibacterial aspects, and thus have potential application value in the fields of food safety and the like.

[0068] Test Example 2. Protective effect of the antimicrobial peptide of the present invention against soft rot pathogens

[0069] 1. Experimental method

[0070] Select healthy kiwifruits with uniform fruits and no injuries or diseases. Soak them in 0.5% sodium hypochlorite for 2 minutes for disinfection, rinse them 3 times with clear water, and then dry them in a clean bench. Pierce the epidermis at the equator of the fruit with a sterile 1.8 mm blunt needle, create a wound 5 mm deep with a 6 mm sterile puncher, and accurately fill and inoculate with a 6 mm activated Botryosphaeria dothidea and Diaporthe ulmi mycelial disc to ensure consistent wound contact. Only place sterile distilled water and a 6 mm pathogen mycelial disc on the fruit as negative control and positive control. Add 50 μL of the composite film solution prepared in Example 2 and 50 μL of 100 mg / L prochloraz disinfectant to the two treatment groups, and place them at room temperature for 7 days to observe the fresh-keeping effect of the antimicrobial film solution on kiwifruits.

[0071] The sterile water control group (negative control) is treated with sterile distilled water according to the above method; the pathogenic bacteria control group (positive control) is treated with Botryosphaeria dothidea or Diaporthe ulmi according to the above method; the antimicrobial peptide composite film solution treatment group is treated with the composite film solution of Example 2 according to the above method; the prochloraz treatment group is treated with prochloraz according to the above method.

[0072] 2. Experimental results

[0073] The fresh-keeping effect of the antimicrobial film solution prepared in the present invention on kiwifruits is as Figure 11 and Figure 12 shown: The antimicrobial peptide composite film solution of the present invention has a significant control effect on kiwifruit soft rot caused by Botryosphaeria dothidea and Diaporthe ulmi, can effectively reduce the decay rate of kiwifruits under normal temperature storage conditions, and improve the fresh-keeping effect on kiwifruits.

[0074] In summary, the present invention provides three novel antibacterial peptides. All of these three antibacterial peptides have broad-spectrum antibacterial effects, and have significant inhibitory effects on Gram-positive bacteria, Gram-negative bacteria, and fungi, and can be prepared into antibacterial drugs for use. At the same time, the antibacterial film agent prepared by using the antibacterial peptide of the present invention can be used as an antibacterial preservative, which can delay the proliferation of spoilage bacteria in food or drugs, thereby extending the shelf life of food or drugs. For example, it can be used to prevent and control the soft rot of kiwifruit. The antibacterial peptide of the present invention has good application prospects in the fields of food, medicine, etc.

Claims

1. An antibacterial peptide, characterized in that: The antimicrobial peptide is the amino acid sequence shown in SEQ ID NO:1, SEQ ID NO:2 or SEQ ID NO:

3.

2. Use of the antimicrobial peptide according to claim 1 in the preparation of an antimicrobial drug or a preservative; Among them, Use of the antimicrobial peptide with the amino acid sequence shown in SEQ ID NO:1 in the preparation of an antimicrobial drug or a preservative against Staphylococcus aureus, Listeria monocytogenes, Cronobacter spp., Escherichia coli and / or Diaporthe ulmi; Use of the antimicrobial peptide with the amino acid sequence shown in SEQ ID NO:2 in the preparation of an antimicrobial drug or a preservative against Staphylococcus aureus and / or Listeria monocytogenes; Use of the antimicrobial peptide with the amino acid sequence shown in SEQ ID NO:3 in the preparation of an antimicrobial drug or a preservative against Staphylococcus aureus, Botryosphaeria dothidea and / or Diaporthe ulmi; 3. The use according to claim 2, wherein: The antimicrobial drug or preservative is a film agent.

4. The use according to claim 3, wherein: The film agent is a film agent for preventing and controlling kiwifruit soft rot.

5. An antibacterial drug preparation or preservative, characterized in that: It is a pharmaceutical preparation or preservative prepared from the antimicrobial peptide according to claim 1 as an active ingredient plus pharmaceutically or food-acceptable excipients.

6. The antimicrobial agent preparation or preservative according to claim 5, characterized in that: The antimicrobial pharmaceutical preparation or preservative is a film agent.

7. The antibacterial pharmaceutical preparation or preservative according to claim 6, characterized in that: The film agent is prepared by mixing raw materials in the following mass-volume percentages: The mass percentage of the antimicrobial peptide according to claim 1 is 4-10%, the mass percentage of chitosan is 1-5%, the volume percentage of acetic acid is 1-5%, the mass percentage of glycerol is 0.1-1%, the mass percentage of gelatin is 1-5%, and the balance is water.

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