Antibacterial peptide, application thereof and antibacterial medicine and preservative prepared from antibacterial peptide

Abstract

The invention provides an antibacterial peptide, application of the antibacterial peptide and an antibacterial drug and a preservative prepared from the antibacterial peptide, and belongs to the technical field of biology. The antibacterial peptide is an amino acid sequence as shown in SEQ ID NO: 1, SEQ ID NO: 2 or SEQ ID NO: 3 or an amino acid sequence which has more than 95% of homology with the amino acid sequence as shown in SEQ ID NO: 1, SEQ ID NO: 2 or SEQ ID NO: 3. The three antibacterial peptides have broad-spectrum antibacterial effects, have obvious inhibition effects on gram-positive bacteria, gram-negative bacteria and fungi, and can be prepared into antibacterial drugs for use. And simultaneously. The antibacterial film agent prepared from the antibacterial peptide can be used as an antibacterial preservative, and can delay proliferation of putrefying bacteria in food or medicines, so that the shelf life of the food or medicines is prolonged, for example, the antibacterial peptide can be used for preventing and treating soft rot of kiwi fruits. The antibacterial peptide has a good application prospect in the fields of food, medicine and the like.

Description

Technical Field

[0001] The present invention belongs to the field of biotechnology, and particularly relates to an antimicrobial peptide, its uses, and an antimicrobial drug and a preservative prepared therefrom. Background Art

[0002] Foodborne pathogenic bacteria can be transmitted through media such as air, water, soil, and the surface of utensils, and are the primary factor causing foodborne diseases (FBDs), seriously affecting environmental safety and public health. According to the World Health Organization (WHO) report, 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, leading to an increasing difficulty in controlling pathogens. In addition, although chemical preservatives (such as thymol, sodium benzoate, propyl gallate) can inhibit microbial growth, when reaching high concentrations, their toxic side effects may have a negative impact on human health. Therefore, the control of foodborne pathogenic bacteria 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] Antimicrobial 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 antimicrobial peptides have problems such as limited sources, limited antibacterial spectra, and insufficient antibacterial activities. In addition, although antimicrobial peptides are not easily induced to develop drug resistance, in the long-term application, some pathogenic bacteria may gradually adapt, reducing the antibacterial effect of antimicrobial peptides. Therefore, developing new antimicrobial peptides for controlling the contamination of pathogenic bacteria in food is of great significance to human health and the living environment. Summary of the Invention

[0004] The purpose of the present invention is to provide an antimicrobial peptide, its uses, and an antimicrobial drug and a preservative prepared therefrom.

[0005] First, the present invention provides an antimicrobial 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; The amino acid sequence shown in SEQ ID NO:2 is LLLLPKK; The amino acid sequence shown in SEQ ID NO:3 is LLLLLSKKLL.

[0007] 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 a homology of more than 99% with the amino acid sequence shown in SEQ ID NO:1, SEQ ID NO:2 or SEQ ID NO:3.

[0008] Furthermore, the antimicrobial peptide is the amino acid sequence shown in SEQ ID NO:1, SEQ ID NO:2 or SEQ ID NO:3.

[0009] The present invention also provides the use of the aforementioned antimicrobial peptide in the preparation of an antimicrobial drug or preservative against Gram-positive bacteria, Gram-negative bacteria and / or fungi.

[0010] 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.

[0011] Furthermore, the antimicrobial drug or preservative is a film agent.

[0012] Furthermore, the film agent is a film agent for preventing and treating kiwifruit soft rot.

[0013] The present invention also provides an antimicrobial 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.

[0014] Furthermore, the antimicrobial drug preparation or preservative is a film agent.

[0015] Furthermore, the film agent is prepared by mixing raw materials in the following mass-volume percentages: 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.

[0016] The present invention has achieved the following beneficial effects: (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 antibacterial peptides from Bacillus amyloliquefaciens in the preparation method of bacteriostatic agents.

[0017] (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.

[0018] (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 or food, and can inhibit the proliferation of a variety of spoilage bacteria, extending the shelf life of foods, drugs, etc.

[0019] 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, which can delay the proliferation of spoilage bacteria in foods or drugs, thereby extending the shelf life of foods 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.

[0020] 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, various other forms of modifications, substitutions, or changes can be made.

[0021] 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 fall within the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a comparison chart of the antibacterial activities of the crude extracts of antibacterial peptides obtained by different extraction methods.

[0023] Figure 2 It is a detection spectrum diagram of the gel column chromatography purification process of antibacterial peptides.

[0024] Figure 3 It is a detection spectrum diagram of the RP-HPLC purification process of antibacterial peptides.

[0025] Figure 4 It is the first-level mass spectrum diagram of the antibacterial peptide hz-01 of the present invention.

[0026] Figure 5 This is the first - level mass spectrum of the antimicrobial peptide hz - 02 of the present invention.

[0027] Figure 6 This is the first - level mass spectrum of the antimicrobial peptide hz - 03 of the present invention.

[0028] Figure 7 This is the second - level mass spectrum of the antimicrobial peptide hz - 01 of the present invention.

[0029] Figure 8 This is the second - level mass spectrum of the antimicrobial peptide hz - 02 of the present invention.

[0030] Figure 9 This is the second - level mass spectrum of the antimicrobial peptide hz - 03 of the present invention.

[0031] 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.

[0032] 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 lesion diameter of fruit bodies in different treatment groups; B is the result diagram of the disease incidence of fruit bodies inoculated with bacteria in different treatment groups; 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.

[0033] 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 lesion diameter of fruit bodies in different treatment groups; B is the result diagram of the disease incidence of fruit bodies inoculated with bacteria in different treatment groups; 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 manners

[0034] Unless otherwise specified, the chemical reagents used in the detailed implementation manners are all conventional commercially available reagents, and the technical means used are all conventional means well - known to those skilled in the art.

[0035] 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 Province 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.

[0036] Example 1: Isolation, purification and identification of the antibacterial peptide of the present invention (1) Preparation of cell-free fermentation supernatant Streak the Bacillus amyloliquefaciens strain 906 stored at -80°C on an LB solid medium and culture it at 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. Centrifuge the obtained fermentation broth at 4°C and 12000 r / min for 30 min to obtain a cell-free fermentation supernatant.

[0037] (2) Determination of the method for crude extraction of antibacterial peptide 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 concentration of ammonium sulfate of 30%, 40%, 50%, and 60% respectively. Then place it in a refrigerator at 4°C and let it stand for 12 h. Centrifuge it at 12000 r / min at low temperature (4°C) for 20 min to obtain a precipitate and a centrifugate. Dissolve the precipitate in phosphate buffer to obtain a crude extract of antibacterial peptide.

[0038] 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 shaker incubator at 37°C at 120 r / min for 2 h. Place the mixture on a separating funnel, and after obvious stratification, collect the organic phase and remove the organic solvent with a rotary evaporator to obtain a crude extract of antibacterial peptide.

[0039] 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, then centrifuge it at 4°C and 12000 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.

[0040] Using Listeria monocytogenes as an indicator bacterium, antibacterial experiments were carried out on the above-mentioned crude extracts of antibacterial peptides. The agar-diffusion method was used for the experiment (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) and then used to observe the inhibition zones of the crude extracts of antibacterial peptides. 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.

[0041] (3)Gel column chromatography 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 component with stronger antibacterial activity was selected and collected, and then stored at -80 °C for standby.

[0042] (4)Purification by reverse-phase high performance liquid chromatography After passing the antibacterial component obtained in step (3) through a 0.22 μm filter membrane, preparative C18 reverse-phase high performance liquid chromatography was used for fine purification. 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 freeze-drying and stored at -80 °C for use in the structural identification of antibacterial peptides.

[0043] (5)Structural identification of antibacterial peptide 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 liquid chromatography tandem mass spectrometer. The primary mass spectrum was obtained in the range of 350 to 1800 m / z. The secondary mass spectrometry data were obtained by stepwise normalized collision energy. The mass spectrometry output data were retrieved from the database using PEAKS software, and the structural sequences of three antibacterial peptides were obtained. The three antibacterial peptides were hz-01, hz-02, and hz-03. The primary mass spectra of antibacterial peptides hz-01, hz-02, and hz-03 were successively Figures 4 - 6 as shown. The secondary mass spectra of antibacterial peptides hz-01, hz-02, and hz-03 were successively Figures 7 - 9 as shown. The molecular weights of the purified antibacterial peptides were determined by LC-MS / MS mass spectrometry. 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 first studied, identified, and reported by the inventors.

[0044] Example 2. Preparation of the antibacterial film agent of the present invention The antibacterial film agent of the present invention is prepared by dissolving chitosan with a mass percentage of 1.25% and antibacterial peptides (hz-01, hz-02 or hz-03) with a mass percentage of 4-10% in an aqueous acetic acid solution with a volume fraction of 1% (v / v), adding glycerol with a mass percentage of 0.3% and gelatin with a mass percentage of 1% as plasticizers, stirring with a magnetic stirrer at 40 °C for 4 h until all the chitosan and gelatin are dissolved, standing for 30 min, and then degassing by ultrasound for 2 h to obtain an antibacterial composite film solution. A protective film will be formed after the composite film solution is dried.

[0045] The beneficial effects of the present invention are demonstrated by the following specific test examples.

[0046] Test Example 1: Determination of the antibacterial spectrum of the antibacterial peptides of the present invention 1. Experimental method According to the amino acid sequence obtained in Example 1, the corresponding antibacterial peptides were synthesized by Jiepeptide Biotechnology (Nanjing) Co., Ltd., with a purity > 95%. The antibacterial effects of the antibacterial peptides were verified by the inhibition zone experiment.

[0047] Six types of bacteria were selected, including Gram-positive bacteria (Staphylococcus aureus, Listeria monocytogenes), Gram-negative bacteria (Cronobacter spp., Escherichia coli), and fungi (Botryosphaeria spp., 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 antibacterial peptide solution (the solvent was an aqueous acetonitrile solution, and the antibacterial peptide concentration was 25 mg / ml) was transferred to the Oxford cups and cultured overnight at 37 °C. The diameter of the inhibition zone was measured.

[0048] 2. Experimental results The experimental results are as Figure 10 shown in Table 1.

[0049] 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 spp., and Diaporthe ulmi Note: "-" in the table indicates no antibacterial property.

[0050] 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.

[0051] 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 lactic acid bacteria. Therefore, the antimicrobial peptides of the present invention make up for the defects of most existing Bacillus antimicrobial peptides in terms of antibacterial activity, and thus have potential application value in the fields of food safety and the like.

[0052] Test Example 2: Protective effect of the antimicrobial peptide of the present invention against soft rot pathogens 1. Experimental method Healthy kiwifruits with uniform fruits and no injuries or diseases were selected, soaked and disinfected in 0.5% sodium hypochlorite for 2 minutes, rinsed 3 times with clean water, and then dried in a laminar flow cabinet. The epidermis of the equator of the fruit was punctured with a sterile 1.8 mm blunt needle, and a wound with a depth of 5 mm was made with a 6 mm sterile puncher. The activated mycelia of Botryosphaeria dothidea and Diaporthe ulmi with a diameter of 6 mm were accurately filled and inoculated to ensure consistent wound contact. Only sterile distilled water and a 6 mm pathogen cake were placed on the fruit as negative control and positive control. 50 μL of the composite film solution prepared in Example 2 and 50 μL of 100 mg / L prochloraz disinfectant were added to the two treatment groups, and the fruit was placed at room temperature for 7 days to observe the fresh-keeping effect of the antimicrobial film solution on kiwifruit.

[0053] The sterile water control group (negative control) was treated with sterile distilled water according to the above method; the pathogenic bacteria control group (positive control) was treated with Botryosphaeria dothidea or Diaporthe ulmi according to the above method; the antimicrobial peptide composite film solution treatment group was treated with the composite film solution of Example 2 according to the above method; the prochloraz treatment group was treated with prochloraz according to the above method.

[0054] 2. Experimental results The fresh-keeping effect of the antimicrobial film solution prepared in the present invention on kiwifruit 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 kiwifruit under normal temperature storage conditions, and improve the fresh-keeping effect on kiwifruit.

[0055] In summary, the present invention provides three novel antimicrobial peptides. These three antimicrobial peptides all have broad-spectrum antibacterial activity, 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 antimicrobial film agent prepared by using the antimicrobial peptides of the present invention can be used as an antibacterial fresh-keeping agent, 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 kiwifruit soft rot. The antimicrobial peptides of the present invention have good application prospects in the fields of food, medicine and the like.

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

7. The antimicrobial agent 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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