Polypeptide and application thereof

Abstract

The invention discloses a polypeptide and application thereof, 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 vibrio parahaemolyticus at 128 [mu] M, inhibit the growth of vibrio harveyi, vibrio alginolyticus and vibrio anguillarum at 256 [mu] M and inhibit the growth of aeromonas hydrophila at 512 [mu] M, and can be used for preparing products with bacteriostatic and / or bactericidal performance, such as food or aquaculture products.

Description

Technical Field

[0001] The present application relates to the technical field of peptide inhibitors, specifically, to polypeptides and their applications. More specifically, the present application relates to polypeptides, methods for inhibiting and / or killing bacteria, uses of polypeptides in preparing products having antibacterial and / or antibacterial properties, polypeptide-containing food preservatives, fresh food preservatives, aquaculture feed additives, aquaculture facility treatment agents, disease control preparations, pharmaceutical compositions, and antibacterial additives. Background Art

[0002] Microbial infection is one of the serious problems in aquaculture. For a long time, antibiotics have been widely used in aquaculture to prevent and treat microbial infections, but this has led to an increase in bacterial resistance, seriously affecting the safety of aquatic products and the sustainable development of the aquaculture industry. 副溶血性弧菌 harveyi ( 弧菌属 哈维氏弧菌 )、Vibrio alginolyticus( 溶藻弧菌 )、Vibrio anguillarum( 鳗弧菌 ) and Aeromonas hydrophila ( 嗜水气单胞菌 ) are common pathogens in aquaculture. They manifest in aquatic animals such as fish and shellfish as enteritis, sepsis, skin ulcers, and liver lesions, and in severe cases can cause mass mortality. Furthermore, Vibrio parahaemolyticus and Aeromonas hydrophila can be transmitted to humans through aquatic products, causing foodborne illnesses and wound infections.

[0003] Antimicrobial peptides are a class of small peptides that can fight a wide range of microorganisms, including bacteria, fungi, viruses, and parasites. These peptides primarily bind to the cell membrane or cell wall of microorganisms, causing the leakage of intracellular substances and ultimately killing the microorganisms. Furthermore, antimicrobial peptides are not susceptible to developing drug resistance and are residue-free. After use, they do not contaminate water or aquatic products, thus ensuring the safety of these products.

[0004] However, the antimicrobial peptides currently applicable to aquatic products are still relatively limited, so there is a need to continuously explore new antimicrobial peptide resources. Summary of the Invention

[0005] The present application aims to address, at least to some extent, at least one of the technical problems existing in the prior art. To this end, one object of the present application is to provide a polypeptide and its application, which exhibits broad-spectrum antibacterial activity against Vibrio parahaemolyticus, Vibrio harveyi, Vibrio alginolyticus, Vibrio anguillarum, and Aeromonas hydrophila. The polypeptide is not susceptible to developing drug resistance, exhibits low mammalian cytotoxicity, low hemolytic toxicity, and high cell selectivity, and can be used to prepare antimicrobial compositions for treating Vibrio parahaemolyticus, Vibrio harveyi, Vibrio alginolyticus, Vibrio anguillarum, and Aeromonas hydrophila. It can also be used as a peptide inhibitor in aquaculture and food applications.

[0006] Specifically, the technical solution of this application is as follows: In a first aspect, the present application provides a polypeptide. According to an embodiment of the present application, the polypeptide has an amino acid sequence as shown in SEQ ID NO: 1; the polypeptide has antibacterial and / or bactericidal functions.

[0007] FPSGLDRVDRLVDLVHKLVRG (SEQ ID NO: 1).

[0008] In a second aspect, the present application provides a method for inhibiting and / or killing bacteria. According to an embodiment of the present application, the method comprises contacting the polypeptide described in the first aspect of the present application with a sample to be treated.

[0009] According to an embodiment of the present application, the bacteria include at least one of Vibrio parahaemolyticus, Vibrio harveyi, Vibrio alginolyticus, Vibrio anguillarum and Aeromonas hydrophila.

[0010] According to an embodiment of the present application, the bacteria include Vibrio parahaemolyticus, and the minimum concentration of the polypeptide in the contact system is 128 μM.

[0011] According to an embodiment of the present application, the bacteria include at least one of Vibrio harveyi, Vibrio alginolyticus and Vibrio anguillarum, and the minimum concentration of the polypeptide in the contact system is 256 μM.

[0012] According to an embodiment of the present application, the bacteria include Aeromonas hydrophila, and the minimum concentration of the polypeptide in the contact system is 512 μM.

[0013] In a third aspect, the present application proposes the use of the polypeptide described in the first aspect in the preparation of a product having antibacterial and / or bactericidal properties.

[0014] It is understandable that the aforementioned products include but are not limited to antibacterial agents, preservatives, feed, preservatives, etc.

[0015] According to an embodiment of the present application, the bacteria include at least one of Vibrio parahaemolyticus, Vibrio harveyi, Vibrio alginolyticus, Vibrio anguillarum and Aeromonas hydrophila.

[0016] According to an embodiment of the present application, the minimum inhibitory concentration of the polypeptide against Vibrio parahaemolyticus is 128 μM.

[0017] According to an embodiment of the present application, the minimum inhibitory concentration of the polypeptide against Vibrio harveyi, Vibrio alginolyticus or Vibrio anguillarum is 256 μM.

[0018] According to the examples of the present application, the minimum inhibitory concentration of the polypeptide against Aeromonas hydrophila is 512 μM.

[0019] In a fourth aspect, the present application provides a food preservative or fresh food preservative. According to an embodiment of the present application, the food preservative or fresh food preservative comprises the polypeptide described in the first aspect of the present application; the food preservative or fresh food preservative does not involve disease prevention or treatment functions. It is understood that the aforementioned polypeptide is the active ingredient of the food preservative or fresh food preservative.

[0020] According to an embodiment of the present application, the fresh food preservative is selected from at least one of a fruit preservative and a vegetable preservative.

[0021] In a fifth aspect, the present application provides an aquaculture feed additive, an aquaculture facility treatment agent, or a disease control agent. According to embodiments of the present application, the aquaculture feed additive, aquaculture facility treatment agent, or disease control agent comprises the polypeptide described in the first aspect of the present application. It is understood that the aforementioned polypeptide is the active ingredient of the aquaculture feed additive, aquaculture facility treatment agent, or disease control agent.

[0022] In a sixth aspect, the present application provides a pharmaceutical composition. According to an embodiment of the present application, the pharmaceutical composition comprises the polypeptide described in the first aspect of the present application. It is understood that the aforementioned polypeptide is the active ingredient of the pharmaceutical composition.

[0023] According to an embodiment of the present application, the pharmaceutical composition further includes pharmaceutically acceptable excipients, such as thickeners, dispersants, emulsifiers, preservatives, and the like.

[0024] In a seventh aspect, the present application provides an antibacterial additive, which includes the polypeptide described in the first aspect of the present application. It is understood that the aforementioned polypeptide is the active ingredient of the antibacterial additive.

[0025] The polypeptide described in this application has the following beneficial technical effects: 1) It has been verified that the polypeptide of the present application has broad-spectrum antibacterial activity against Vibrio parahaemolyticus, Vibrio harveyi, Vibrio alginolyticus, Vibrio anguillarum or Aeromonas hydrophila; 2) It has been verified that the polypeptide of the present application is not prone to drug resistance, has low mammalian cytotoxicity, low hemolytic toxicity and high cell selectivity, and can be used to prepare antibacterial compositions for infections caused by Vibrio parahaemolyticus, Vibrio harveyi, Vibrio alginolyticus, Vibrio anguillarum or Aeromonas hydrophila; in addition, the polypeptide can be used as a peptide inhibitor in food preservation, aquaculture and medicine.

[0026] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the HPLC detection results of the antimicrobial peptide cAMP093 provided in one embodiment of the present application; Figure 2 This is a schematic diagram of the LC-MS detection results of the antimicrobial peptide cAMP093 provided in one embodiment of the present application; Figure 3 The minimum inhibitory concentration of the antimicrobial peptide cAMP093 provided in one embodiment of the present application is determined; wherein (a) is Vibrio parahaemolyticus 副溶血性弧菌 ; (b) Vibrio harveyi 哈维氏弧菌 ; (c) Vibrio alginolyticus V. 溶藻弧菌 ; (d) Vibrio anguillarum 鳗弧菌 ; (e) Aeromonas hydrophila 嗜水气单胞菌 ; Figure 4 This is a schematic diagram of the mammalian cell toxicity assay results of the antimicrobial peptide cAMP093 provided in one embodiment of the present application; Figure 5 This is a schematic diagram of the hemolytic toxicity assay results of the antimicrobial peptide cAMP093 provided in one embodiment of the present application. DETAILED DESCRIPTION

[0028] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0029] It should be noted that the terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or server that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products, or devices.

[0030] As used herein, the term "pharmaceutical composition" generally refers to a unit dosage form and can be prepared by any of the methods well known in the pharmaceutical art. All methods include the step of bringing the active ingredient into association with a carrier which constitutes one or more accessory ingredients. Generally, the composition is prepared by uniformly and thoroughly combining the active antibody or antigen-binding fragment with a liquid carrier, a finely divided solid carrier, or both.

[0031] As used herein, the term "pharmaceutically acceptable excipient" may include any solvent, solid excipient, diluent, or other liquid excipient, etc., suitable for the specific target dosage form. Except to the extent that any conventional excipient is incompatible with the antibody or antigen-binding fragment of the present application, such as by producing any adverse biological effect or interacting in a deleterious manner with any other component of the pharmaceutically acceptable composition, their use is also contemplated by the present application.

[0032] This application is based on the global extreme environment microbiome database (The Extreme Environment Microbiome Catalogue, EEMC) constructed by Sanya BGI Life Sciences Institute to mine and screen new antimicrobial peptides. First, the antiSMASH (v7.0) tool (Kai Blin, Simon Shaw, Hannah E Augustijn, et al., antiSMASH 7.0: new and improved predictions for detection, regulation, chemical structures and visualization, Nucleic Acids Research, Volume 51, Issue W1, 5 July 2023, Pages W46–W50) was used with the parameter set to --minlength 5000 to identify biosynthesis gene clusters (BGCs) in the genomes of extreme environment microorganisms. Deep learning models (RNN, LSTM) were used to predict the core peptide sequences in BGCs of ribosomal postsynthetic modified polypeptides (RiPPs). Furthermore, the obtained core peptide sequences were used to predict low-toxicity antimicrobial peptides using three pre-trained protein language models (ESM2-3B, ESM3, and PTRANS). Peptide sequences ranked in the top 50% by each model's prediction score were selected as candidate low-toxicity antimicrobial peptides. The candidate antimicrobial peptides were then compared with peptides in a database of known antimicrobial peptides. Peptide sequences that matched those in the database were removed to identify novel candidate low-toxicity antimicrobial peptide sequences, which were then experimentally validated. Through these sequence mining and experimental validation steps, an antimicrobial peptide, named cAMP093, was ultimately identified, derived from the genome of a deep-sea microorganism. The following describes the antimicrobial function and toxicity verification of this antimicrobial peptide using wet experiments.

[0033] The technology of this application is described below through specific examples. If specific techniques or conditions are not specified in the examples, the techniques or conditions described in the literature in this field or the product instructions are used. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be obtained through commercial purchase.

[0034] In the following embodiments 副溶血性弧菌 Vibrio parahaemolyticus (Beinuo Biotechnology, ATCC 17802), V. 哈维氏弧菌 Vibrio harveyi (Beinuo Biotechnology, ATCC 14126), 溶藻弧菌 Vibrio alginolyticus (Beinuo Biotechnology, ATCC 17749),鳗弧菌 Vibrio anguillarum (Beinuo Biotechnology, ATCC 43307), 嗜水气单胞菌 The strain is Aeromonas hydrophila (Beinuo Biotechnology, ATCC 7966).

[0035] Example 1: Synthesis and purification of antimicrobial peptide cAMP093 Shanghai Sangon Biotechnology Co., Ltd. was commissioned to chemically synthesize the antimicrobial peptide cAMP093 through solid-phase peptide synthesis. The purity of the antimicrobial peptide was then determined using high-performance liquid chromatography (HPLC), and the exact molecular weight of the antimicrobial peptide was then detected using liquid chromatography-mass spectrometry (LC-MS).

[0036] HPLC determination: The HPLC analytical column model used was Shimadzu Shim-pack GIST C18 column (4.6mm×250 mm, 5μm), the mobile phase A was deionized water containing 0.1% trifluoroacetic acid, and the mobile phase B was acetonitrile containing 0.1% trifluoroacetic acid. Take 0.1mg of antimicrobial peptide and dissolve it in a mixture of formic acid: acetonitrile: water with a volume ratio of 10:30:60, with a final volume of 0.5mL. Inject 30 μL of the test sample, set the total flow rate of the mobile phase to 1 mL / min, the detection wavelength to 214 nm, and use a linear gradient elution program. From 0 to 20min, phase B increased from 20% to 80%, and phase A decreased from 80% to 20% accordingly. Record the chromatogram and analyze the retention time and peak shape characteristics. The results are as follows: Figure 1 shown.

[0037] LC-MS detection: The liquid chromatography-mass spectrometry instrument used is Shimadzu LCMS-2020. The mobile phase is a mixture of methanol and water in a ratio of 1:1 (v / v), with equal proportions and isocratic elution (isocratic mobile phase), and the flow rate is set to 0.2 mL / min. The sample preparation method is as follows: 0.1 mg of antimicrobial peptide is dissolved in a 50% acetonitrile-50% water mixture (v / v), and the final volume is 0.5 mL. The detection conditions are set as follows: the nebulizing gas flow rate is 1.50 L / min, the CDL temperature is 250°C, the CDL voltage is 0 v, the module temperature is 200°C, the rod front deviation is +4.5 kv, the detector is -0.2 kv, and T.Flow is 0.2 mL / min. After the sample is loaded and tested, the mass spectrometry signal, including the mass-to-charge ratio (m / z) and ion intensity, is recorded to confirm the molecular weight information of the antimicrobial peptide. The test results are as follows Figure 2 shown. Figure 1 The results show that the purity of the synthesized antimicrobial peptide cAMP093 is greater than 95%. The amino acid sequence is FPSGLDRVDRLVDLVHKLVRG (SEQ ID NO: 1).

[0038] According to the amino acid sequence, the theoretical molecular weight of the antimicrobial peptide cAMP093 is 2391.79. Figure 2 The results showed that the molecular weight of the synthesized antimicrobial peptide cAMP093 was consistent with the theoretical molecular weight.

[0039] Example 2: Activity analysis of antimicrobial peptides (1) Minimum inhibitory concentration (MIC) determination Five aquatic pathogenic bacteria strains, including Vibrio parahaemolyticus 副溶血性弧菌 , Vibrio harveyi V. 哈维氏弧菌 , Vibrio alginolyticus 溶藻弧菌 , Vibrio anguillarum 鳗弧菌 , and Aeromonas hydrophila A. 嗜水气单胞菌 Streak out on Columbia blood agar medium and incubate at 37 °C overnight.

[0040] Single colonies of the five aquatic pathogenic bacterial strains were picked into Mueller-Hinton Broth (MHB) liquid medium and shaken at 120 rpm at 37°C overnight. The culture was diluted 1:100 with fresh MHB and then cultured to the exponential phase (OD 600 The cell concentration was adjusted to 1 × 10 6 cfu / mL. The antimicrobial peptide cAMP093 was dissolved in MHB to prepare a stock solution with an initial concentration of 1024 μM. A two-fold serial dilution (1:1) was performed to obtain working solutions with concentrations ranging from 1024 μM, 512 μM, 256 μM, 128 μM, 64 μM, 32 μM, 16 μM, 8 μM, 4 μM, and 2 μM. Subsequently, 100 μL of the antimicrobial peptide solution at each concentration was added to a 96-well plate, followed by 100 μL of bacterial culture, resulting in a final antimicrobial peptide concentration in the well ranging from 512 μM to 1 μM. A negative control group consisted of 100 μL of bacterial culture added to 100 μL of MHB liquid medium, and a blank group consisted of 200 μL of MHB medium. The plates were incubated at 37°C for 16–18 hours. Considering that some antimicrobial peptides have poor solubility in culture medium, which may cause slight turbidity and interfere with naked eye judgment, this experiment used spectrophotometry to measure the absorbance of the liquid in each well at a wavelength of 600 nm (OD 600 ), as an indirect quantitative indicator of bacterial growth. 600 It is a parameter widely used in microbiology to reflect the cell density in bacterial suspensions and has a good linear correlation. 600 A value close to the negative control group usually reflects an increase in bacterial concentration, that is, good bacterial growth; a value significantly lower than the negative control group indicates that bacterial growth is inhibited or not growing. The blank group is used to correct the OD value of the negative control group and the peptide group.600 Value. 600 The concentration group where the value showed a significant decrease was defined as the MIC value of the antimicrobial peptide, and the lowest concentration of the antimicrobial peptide at which no bacterial growth was observed was used. All experiments were repeated 3 times, and the results are shown in Figure 2. Figure 3 shown.

[0041] like Figure 3 The experimental results shown in the figure show that the antimicrobial peptide cAMP093 has an 副溶血性弧菌 The MIC of 哈维氏弧菌 、 溶藻弧菌 or 鳗弧菌 The MIC of A. 嗜水气单胞菌 The MIC of this drug was 512 μM.

[0042] (2) Mammalian cell toxicity assay To evaluate the cytotoxicity of the antimicrobial peptide cAMP093 to mammalian cells, four experimental conditions were set up: a blank control group (Blank), a negative control group (Control), a positive control group (cisplatin-treated), and an antimicrobial peptide-treated group (cAMP093). The blank control group consisted of MHB culture medium supplemented with 10% fetal bovine serum (04-001-1acs, Biological Industries, Israel) per well on a 96-well plate. L-02 human hepatocytes (Beina Biotech) and 293T human embryonic kidney cells (Pneusai) were prepared into single cell suspensions using MHB culture medium supplemented with 10% fetal bovine serum. Except for the blank control group, 90 μL of 5×10 cells were seeded into each well of the 96-well plate. 4 Adherent cells were plated at a concentration of 1 μg / mL and incubated in a 5% CO₂, 37°C incubator for 24 hours. After 24 hours, 10 μL of the different treatment solutions were added to each group: the negative control group received PBS buffer; the positive control group received a 600 μM cisplatin solution in PBS (D8810, Solarbio) to a final cisplatin concentration of 60 μM; and the antimicrobial peptide group received a 600 μM cAMP093 solution in PBS to a final antimicrobial peptide concentration of 60 μM. Each group was incubated for a further 48 hours. After incubation, the culture medium and drug solution were discarded, and 100 μL of CCK-8 working solution (BS350A, White Shark Biotechnology), diluted tenfold in serum-free MHB medium to a final concentration of 10% (v / v), was added to each well of the 96-well plate. Incubation continued for 1 hour in the dark, 5% CO₂, and 37°C. Absorbance at 450 nm was measured using a microplate reader, and raw data were recorded. The formula for calculating the inhibition rate of mammalian cells is (OD Control -OD cAMP093 / 顺铂 ) / (OD Control -OD Blank) × 100%. All experiments were repeated 3 times, and the results are shown in Figure 4 shown.

[0043] Figure 4 The results showed that compared with the positive control group (cisplatin-treated group), the antimicrobial peptide cAMP093 group had a lower inhibition rate and significantly lower mammalian cell cytotoxicity. The inhibition rate of the antimicrobial peptide cAMP093 on L-02 human hepatocytes was 0.45%, and the inhibition rate on 293T human embryonic kidney cells was 5.90%.

[0044] (3) Hemolytic toxicity assay To evaluate the hemolytic toxicity of the antimicrobial peptide cAMP093, blank, positive control (Triton X-100), and antimicrobial peptide (cAMP093) groups were established. Fresh defibrinated sheep blood (Beekman Biotech, China) was centrifuged at 1500 rpm for 10 minutes to separate red blood cells (RBCs), and the plasma was discarded. The RBCs were then washed three to four times with PBS buffer until the supernatant was clear and colorless. The washed RBCs were resuspended in PBS to prepare a 4% (v / v) RBC suspension. 100 μL of this RBC suspension was dispensed into each well of a 96-well plate. In the positive control, Triton X-100 (final concentration of 1%) was added to each well to induce complete hemolysis. In the antimicrobial peptide group, a cAMP093 solution in PBS was added to each well to a final concentration of 60 μM. The blank group contained only the RBC suspension and PBS buffer, without any hemolytic agent or antimicrobial peptide. Place the 96-well plate in a 37°C incubator and incubate for 1 hour. After incubation, centrifuge at 4°C and 1500 rpm for 10 minutes. Collect the supernatant from each well onto a new 96-well plate and measure the absorbance at 570 nm using a microplate reader. Record the raw data. The hemolysis rate is calculated as (OD cAMP093 -OD Blank ) / (OD Control -OD Blank ) × 100%. All experiments were repeated 4 times, and the results are shown in Figure 5 shown.

[0045] Figure 5 The results showed that compared with the positive control group (Control group), the antimicrobial peptide cAMP093 group had a lower OD value and significantly lower hemolytic toxicity. The hemolytic rate of the antimicrobial peptide cAMP093 was calculated to be 2.40%.

[0046] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0047] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A polypeptide, characterized in that The polypeptide has an amino acid sequence as shown in SEQ ID NO: 1; The polypeptide has bacteriostatic and / or bactericidal functions.

2. A bacteriostatic and / or sterilizing method, characterized in that: The polypeptide according to claim 1 is contacted with a sample to be treated.

3. The method according to claim 2, characterized in that The bacteria include at least one of Vibrio parahaemolyticus, Vibrio harveyi, Vibrio alginolyticus, Vibrio anguillarum and Aeromonas hydrophila.

4. The method according to claim 2, characterized in that The bacteria include Vibrio parahaemolyticus, and the lowest concentration of the polypeptide in the contact system is 128 μM.

5. The method according to claim 2, characterized in that The bacteria include at least one of Vibrio harveyi, Vibrio alginolyticus and Vibrio anguillarum, and the minimum concentration of the polypeptide in the contact system is 256 μM.

6. The method according to claim 2, characterized in that The bacteria include Aeromonas hydrophila, and the lowest concentration of the polypeptide in the contact system is 512 μM.

7. Use of the polypeptide according to claim 1 in the preparation of a product having bacteriostatic and / or bactericidal properties.

8. The use according to claim 7, characterized in that The bacteria include at least one of Vibrio parahaemolyticus, Vibrio harveyi, Vibrio alginolyticus, Vibrio anguillarum and Aeromonas hydrophila.

9. A food preservative or fresh food preservative, characterized in that: comprising the polypeptide of claim 1; The food preservatives or fresh food preservatives do not involve disease prevention and treatment functions.

10. An aquaculture feed additive, aquaculture facility treatment agent or disease control preparation, characterized in that: Comprising the polypeptide of claim 1.

11. A pharmaceutical composition, characterized in that include: The polypeptide according to claim 1.

12. An antibacterial additive, characterized in that include: The polypeptide according to claim 1.

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