A tilapia npe antibacterial peptide, its coding sequence and use and preparation method

Abstract

The application discloses a tilapia Npy antibacterial peptide, a coding sequence, and a use and a preparation method thereof, and relates to the following technical scheme: based on a multi-omics method, an antibacterial peptide precursor gene sequence is screened and recognized from a tilapia multi-omics data set based on biological big data, and then the tilapia Npy antibacterial peptide amino acid sequence is obtained through translation design, as shown in SEQ ID NO: 3; through activity simulation prediction and in-vitro experiment verification, the tilapia Npy antibacterial peptide shows inhibitory activity to gram-positive streptococcus agalactiae, staphylococcus aureus and gram-negative escherichia coli, especially to streptococcus agalactiae and staphylococcus aureus, and shows good antibacterial effect at a low concentration (2.5 μmol / L), and can be used for preparing antibacterial products, including preparation of an antibacterial agent, preparation of a medicine or preparation of an additive, and has good practical value and social ecological benefits.

Description

Technical Field

[0001] This invention relates to the field of biomedical technology, specifically to a basa fish Npy antimicrobial peptide, its coding sequence, uses, and preparation method. Background Technology

[0002] Basa fish (scientific name: *Pangasius bocourti*), also known as Mekong catfish or Vietnamese catfish, is a tropical freshwater fish belonging to the order Siluriformes, family Siluridae, and genus *Pangasius*. It is mainly distributed in the Mekong River basin of Southeast Asia. Basa fish is an important freshwater aquaculture species in Southeast Asian countries, possessing advantages such as good meat quality, rapid growth, large size, omnivorous diet, tolerance to low oxygen levels, and ease of harvesting. It has also been introduced to my country as an aquaculture species. Because of its tender, white flesh with few intramuscular bones, making it easy to process, basa fish is often sold as sole, sea bream, or cod. Currently, basa fish is mainly exported from Vietnam, with Europe, America, the Middle East, and my country being its main consumer markets.

[0003] In 2021, BGI Genomics published the world's first chromosome-level genome of a basa fish in the international journal *Genomics*. The research team obtained a 731.7 Mb chromosome-level reference genome by sequencing and assembling the entire genome of the basa fish (Pangasianodon hypophthalmus), with contigs and scaffold N50 of 3.5 Mb and 29.5 Mb, respectively. This achievement lays the foundation for genomic research on basa fish, not only elucidating its genetic basis but also providing rich data resources and broad prospects for molecular biology research and applications in basa fish.

[0004] Antimicrobial peptides (AMPs) are an important component of an organism's innate immune defense system. They are a class of naturally occurring, disease-fighting active polypeptide factors formed during long-term evolution. The mechanism of action of antimicrobial peptides mainly involves adsorption onto the bacterial cell membrane surface, forming pores or altering the membrane structure, leading to leakage of cell contents or cell membrane disintegration, thereby killing the bacteria. Because bacteria do not have time to undergo genetic mutations to compensate for this damage, they are less likely to develop into superbugs and are considered a promising green biological resource to replace antibiotics.

[0005] Neuropeptide Y (Npy) is a 36-amino acid polypeptide widely distributed in the central and peripheral nervous systems of animals. It participates in various physiological and pathological processes and is an important neurotransmitter and hormone, belonging to the insulin-releasing peptide (PP) family, possessing a highly conserved structure. Npy exerts its effects by binding to G protein-coupled receptors (GPCRs), primarily Y1, Y2, Y4, and Y5 receptors. Currently, Npy's functions include regulating appetite, stress response, mood regulation, cardiovascular function, immunity, cell proliferation, and energy metabolism. Additionally, some studies have reported insecticidal activity in neuropeptides identified from certain insects (AU2022402535(A1)).

[0006] Research on neuropeptide Y in fish is limited. Chinese patent application CN101824435A discloses an expression system for recombinant neuropeptide Y protein in tilapia, revealing that Npy can act on tilapia growth and development. Another Chinese patent application CN116173183B discloses the application of neuropeptide Y in the preparation of formulations for treating Streptococcus agalactiae infection and related diseases in tilapia. This reveals that Npy increases the expression of anti-inflammatory factors and reduces the expression of pro-inflammatory factors in the telencephalon, hypothalamus, head kidney, and spleen of tilapia, enhancing the immune function and improving the innate immune level and antioxidant defense capacity of tilapia, thereby achieving the effect of preventing bacterial diseases and resisting damage caused by pathogens. However, the antibacterial function of Npy has not been reported, especially regarding antimicrobial peptides in basa fish; currently, no relevant antimicrobial peptide sequences have been reported.

[0007] To date, only slightly over 3,000 antimicrobial peptides have been identified from animals, fungi, plants, and bacteria. Most of these peptides suffer from limited antimicrobial function, narrow antimicrobial spectrum, and insignificant antibacterial effects. Furthermore, the naturally occurring antimicrobial peptides identified as having antimicrobial activity are extremely rare in organisms, making isolation and purification very difficult. In addition, some antimicrobial peptides still possess certain toxicity, posing safety risks when used in the preparation of pharmaceuticals or additives for in vivo disinfection. For example, some antimicrobial peptides have high hemolytic activity, causing red blood cell rupture and harm to living organisms during in vivo disinfection. Given the current situation where antibiotic overuse has led to bacterial resistance and excessive residues of conventional drugs, posing a serious threat to aquaculture, finding more biologically derived antibiotics to replace traditional antibiotics is of great significance for the green development and healthy aquaculture practices. Summary of the Invention

[0008] To address the aforementioned issues of insufficient existing bio-derived antimicrobial peptide resources, particularly the scarcity of research on antimicrobial peptides from basa fish, the lack of reported antimicrobial peptide sequences, and the absence of studies on the antibacterial function of Npy (basa fish nystatin) peptides, this invention provides a basa fish Npy antimicrobial peptide, its encoding sequence, uses, and preparation method. Based on a multi-omics approach, antimicrobial peptide precursor gene sequences are identified from basa fish multi-omics datasets through biological big data screening. Then, through translational design, an antimicrobial basa fish Npy antimicrobial peptide with antimicrobial activity is artificially synthesized. Activity simulation prediction and in vitro experimental verification show that this basa fish Npy antimicrobial peptide exhibits inhibitory activity against Gram-positive Streptococcus agalactiae, Staphylococcus aureus, and Gram-negative Escherichia coli. The specific technical solution is as follows: One objective of this invention is to provide a basa fish Npy antimicrobial peptide, the amino acid sequence of which is shown in SEQ ID NO:3.

[0009] The aforementioned basa fish Npy antimicrobial peptide contains an α-double helix structure.

[0010] The second objective of this invention is to provide a precursor of the aforementioned basa fish Npy antimicrobial peptide, the amino acid sequence of which is shown in SEQ ID NO:2.

[0011] The third objective of this invention is to provide a precursor gene for the aforementioned basa Npy antimicrobial peptide, the nucleotide sequence of which is shown in SEQ ID NO:1.

[0012] The fourth objective of this invention is to provide an application of the aforementioned basa fish Npy antimicrobial peptide in the preparation of antibacterial products, wherein the bacteria include Gram-positive Streptococcus agalactiae, Staphylococcus aureus, and Gram-negative Escherichia coli.

[0013] As a preferred technical solution, the aforementioned application of basa fish Npy antimicrobial peptide in the preparation of antibacterial products includes at least one of the following: preparation of antibacterial agents, preparation of drugs, or preparation of additives.

[0014] As a preferred technical solution, the aforementioned application of basa fish Npy antimicrobial peptide in the preparation of antibacterial products, in products against Gram-positive Streptococcus agalactiae and Staphylococcus aureus, the concentration of basa fish Npy antimicrobial peptide is not less than 2.5 μmol / L; in products against Gram-negative Escherichia coli, the concentration of basa fish Npy antimicrobial peptide is not less than 20 μmol / L.

[0015] As a further preferred technical solution, the aforementioned application of basa fish Npy antimicrobial peptide in the preparation of antibacterial products, wherein when the antibacterial agent, drug and additive product is used for live disinfection, the concentration of basa fish Npy antimicrobial peptide is 2.5 μmol / L to 20 μmol / L.

[0016] As a further preferred technical solution, the aforementioned application of basa fish Npy antimicrobial peptide in the preparation of antibacterial products, wherein when the antibacterial agent, drug and additive product is used for live disinfection, the concentration of basa fish Npy antimicrobial peptide is 2.5 μmol / L, 5 μmol / L, 10 μmol / L or 20 μmol / L.

[0017] The fifth objective of this invention is to provide a method for preparing the aforementioned basa fish Npy antimicrobial peptide. This method involves identifying antimicrobial peptide precursor gene sequences from a basa fish multi-omics dataset using homology alignment, translating the identified precursor genes into antimicrobial peptide precursor proteins, and then designing the potential mature active peptide regions of the translated precursor proteins using known antimicrobial peptides as reference sequences to obtain the amino acid sequence of the basa fish Npy antimicrobial peptide. The basa fish multi-omics dataset includes the basa fish genome, transcriptome dataset, and protein dataset. The basa fish genome is an assembled basa fish T2T genome. The transcriptome and protein datasets are derived from eight tissues of the basa fish: eyes, gills, gonads, kidneys, liver, muscle, skin, and spleen.

[0018] The beneficial effects of this invention are: 1) This invention is based on a multi-omics approach, which screens and identifies the precursor gene sequence of antimicrobial peptide from a multi-omics dataset of basa fish at the level of biological big data, and then obtains the amino acid sequence of the basa fish Npy antimicrobial peptide through translation design. Through activity simulation prediction and in vitro experimental verification, the basa fish Npy antimicrobial peptide shows inhibitory activity against Gram-positive Streptococcus agalactiae, Staphylococcus aureus and Gram-negative Escherichia coli. In particular, it shows good antibacterial effect against Streptococcus agalactiae and Staphylococcus aureus at a low concentration (2.5 μmol / L), and can be used to prepare antibacterial products, including the preparation of antibacterial agents, drugs or additives.

[0019] 2) This invention presents a novel antimicrobial peptide from basa fish (Npy), representing the first time that neuropeptide Y has been revealed to possess antimicrobial activity. Furthermore, it is the first in-depth exploration of the basa fish genome, providing a new source for antimicrobial peptides. This valuable biological genetic resource provides a solid theoretical foundation for the in-depth development of novel marine antimicrobial drugs and the research on the clinical therapeutic applications of antimicrobial peptides. It also further enriches the existing antimicrobial peptide database, offering more options for biologically derived antibiotics to replace traditional antibiotics.

[0020] 3) The basa fish Npy antimicrobial peptide of this invention has a low hemolysis rate. No hemolysis was caused at concentrations of 2.5 μmol / L, 5 μmol / L and 10 μmol / L. Even at a concentration of 20 μmol / L, the hemolytic activity was only 8.19%. When the concentration is controlled at 20 μmol / L and below, it can be used to disinfect live bacteria, providing a better guarantee for green and healthy aquaculture and other aquaculture industries. It has good practical value and social and environmental benefits. Attached image description: Figure 1 The three-dimensional structure diagram of the basa fish Npy antimicrobial peptide was constructed; Figure 2 The results of liquid chromatography analysis of synthesized basa fish Npy antimicrobial peptides; Figure 3 Mass spectrometry results of synthesized basa fish Npy antimicrobial peptides; Figure 4 The inhibitory effects of 2.5μM, 5μM, 10μM, 20μM, and 40μM basa fish Npy antimicrobial peptides on Streptococcus agalactiae were evaluated. Figure 5 The inhibitory effects of 2.5μM, 5μM, 10μM, 20μM, and 40μM basa fish Npy antimicrobial peptides on Escherichia coli were evaluated. Figure 6 The inhibitory effects of 2.5μM, 5μM, 10μM, 20μM, and 40μM basa fish Npy antimicrobial peptides on Staphylococcus aureus were evaluated. Figure 7 The graph shows the hemolysis rate test results of 2.5μM, 5μM, 10μM, 20μM, and 40μM basa fish Npy antimicrobial peptides. Detailed Implementation

[0021] The specific embodiments of the present invention will be further described in detail below with reference to examples. Reagents not provided in the following experiments are all commercially available reagents, and methods not described in detail are all conventional and well-known experimental methods. The abbreviations used in the full-length amino acid sequences are abbreviations commonly used by those skilled in the art. Specifically, R represents arginine (Arg), L represents leucine (Leu), G represents glycine (Gly), N represents asparagine (Asn), C represents cysteine ​​(Cys), T represents threonine (Thr), V represents valine (Val), M represents methionine (Met), A represents alanine (Ala), K represents lysine (Lys), F represents phenylalanine (Phe), S represents serine (Ser), P represents proline (Pro), E represents glutamic acid (Glu), I represents isoleucine (Ile), Q represents glutamine (Gln), and W represents tryptophan (Trp).

[0022] The specific implementation method is as follows: Example 1: Obtaining the precursor gene DNA and encoding precursor protein sequence of basa Npy antimicrobial peptide. 1) Preparation of multi-omics datasets The multi-omics dataset includes a basa fish genome, transcriptome dataset, and protein dataset. The basa fish genome is an assembled T2T genome, a complete genome without any missing parts, exhibiting higher integrity compared to previously published genomes. Since genes in different organs are specifically expressed, the transcriptome and protein datasets in this embodiment were obtained from samples of eight basa fish tissues: eyes, gills, gonads, kidneys, liver, muscle, skin, and spleen, to obtain as many expressed gene sequences as possible for analysis and comparison.

[0023] The protein-coding regions of each transcript were predicted using TransDecoder software, and the transcriptional level of genes was calculated using FPKM values. All protein-coding sequences from the genome and transcriptome were translated into amino acids to construct a comprehensive protein set for basa fish.

[0024] 2) Screening antimicrobial peptide precursor gene DNA sequences from multi-omics datasets First, an index library for sequence alignment was established using the gene set annotated from the basa fish genome. Potential AMP precursor genes were predicted from the genome using the TBLASTN algorithm in the Blast software (e-value less than 1e-5), retaining sequences with an alignment rate greater than 60%. The AMPml software (2021, China, 2021SR0424886) was used to predict the activity of segments containing potential antimicrobial peptide protein sequences, retaining alignment sequences with a value greater than 0.5 in both the CTDD and PAAC models.

[0025] Then, using the same alignment method, antimicrobial peptide precursor genes were predicted from transcriptome datasets of eight transcriptomes. Subsequently, the common antimicrobial peptide precursor gene sequences in the genomic and transcriptome datasets were aligned with the proteome data to build an index library. Blastp software was used for sequence similarity alignment to obtain the final common antimicrobial peptide sequence set of the three omics datasets, where sequences with an alignment length greater than 60% and an alignment rate greater than 80% were considered reliable sequences.

[0026] Finally, we obtained the DNA sequence of a potential antimicrobial peptide precursor gene from the genomic, transcriptomic, and proteomic datasets, as shown in SEQ ID NO:1. Homology sequence alignment identified it as the Neuropeptide Y gene (Npy gene), which we named the basa Npy antimicrobial peptide precursor gene. Using transcription rules, the basa Npy antimicrobial peptide precursor gene was translated into the corresponding precursor protein sequence, namely the basa Npy antimicrobial peptide precursor protein, whose amino acid sequence is shown in SEQ ID NO:2.

[0027] SEQ ID NO:1: Nucleic acid coding sequence of basa fish Npy antimicrobial peptide precursor gene ATGCAGGGGACAGTGAACCAGGTCCTGCCAAGGCAGAACCTGAAGGAGAAGATGCGTCCTCGTGCAAACGTGTGTGTCGGCTGGGCCGCGTGCATCCTGCTTGTTGTGTGTTTGAGCGCGATGGCGGAAGGATATCCAACAAAGCCGCAGAACCCAGGAGAGGACGCAC CTGTGGAGGAACTAGCCAAGTATTACTCCGCGTTGAGACACTACATCAACCTCATCACAAGGCAGAGGTATGGGAAAAGGTCAAACTCTGACGCATTAACCCCAGACCTGCTGTTTGGAGAGGCAGAGATGCGACTGCAGTCCAGATATGGTGACCCTTTGATGTGGTGA SEQ ID NO:2: Amino acid sequence of basa fish Npy antimicrobial peptide precursor gene MQGTVNQVLPRQNLKEKMRPRANVCVGWAACILLVVCLSAMAEGYPTKPQNPGEDAPVEELAKYYSALRHYINLITRQRYGKRSNSDALTPDLLFGEAEMRLQSRYGDPLMW Example 2: Prediction and Synthesis of Active Structure of Basa Fish Npy Antimicrobial Peptide The 2927 validated antimicrobial peptides in the public antimicrobial peptide database APD3 were used as reference sequences.

[0028] Based on the basa Npy antimicrobial peptide precursor protein (sequence SEQ ID NO:2) identified from the multi-omics dataset in Example 1, the potential mature active peptide region was designed with reference to the known antimicrobial peptide sequences in the public antimicrobial peptide database APD3, and the amino acid sequence of the basa Npy antimicrobial peptide was obtained as shown in SEQ ID NO:3.

[0029] SEQ ID NO:3: Polypeptide amino acid sequence of basa fish Npy antimicrobial peptide LAKYYSALRHYINLITRQRY The physicochemical properties of basa fish antimicrobial peptides were predicted using the ProtParam tool on the Expasy website (https: / / web.expasy.org / protparam / ), including molecular weight, isoelectric point, net charge value, and average hydrophilicity, as shown in Table 1.

[0030] Table 1. Prediction of physicochemical properties of Npy antimicrobial peptides from basa fish

[0031] The three-dimensional structure of the antimicrobial peptide was constructed using PEP-FOLD3 software, which is suitable for short peptides. Figure 1 As shown.

[0032] To ensure a high probability of the peptides possessing antibacterial activity, the obtained peptides all meet the following conditions: (1) Polypeptides are positively charged cations; (2) Isoelectric point is greater than 8.0; (3) CTDD and PAAC values ​​are greater than 0.5; (4) It has an α-helix, β-fold, ring, or extended structure; (5) The sequence contains fewer than 5 cysteine ​​residues; (6) The sequence length does not exceed 30 amino acids.

[0033] Based on the designed amino acid sequence and constructed three-dimensional model of the basa fish Npy antimicrobial peptide, a basa fish Npy antimicrobial peptide containing an α-helix structure was synthesized using a chemical method. In this embodiment, the full sequence of the basa fish Npy antimicrobial peptide was synthesized using a standard amino acid resin chemical synthesis method, which was customized by Sangon Biotech (Shanghai) Co., Ltd. The synthesized peptide product was purified using a high-performance liquid chromatography (HPLC) system, followed by elution with an acetonitrile gradient of 1 mL / min. The parameters were as follows: column type: SHIMADZU shim-pack GIST C18 (4.6*250MM*5UM), phase A: 0.1% trifluoroacetic acid acetic acid solution, phase B: 0.1% trifluoroacetic acid aqueous solution; detection method: 0.5 mg of sample was dissolved in 0.5 mL of 30% acetic acid aqueous solution (v / v) for elution; volume: 30 μL, detection wavelength: 214 nm, flow rate: 1.0 mL / min. The detection results are as follows. Figure 2As shown, the purity of the Npy peptide powder determined by HPLC-MS / MS is above 85%. The synthesized peptide product was analyzed by mass spectrometry with the following parameters: 0.1 mg sample dissolved in 0.5 mL of 50% ACN aqueous solution; injection volume: 1 μL; interface: ESI; bias voltage: +4.5 kV; pointer: -0.2 kV; nebulizer gas flow rate: 1.50 L / min; CDL temperature: 250℃; CDL volume: 0 v; block temperature: 200℃; T.Flow: 0.2 mL / min; B.conc: 50% methanol aqueous solution (v / v). The detection results are as follows. Figure 3 As shown in the figure, the molecular weight of the synthesized linear peptide is 2457.02 Daltons (Da), which is the basa fish Npy antimicrobial peptide. Finally, it was freeze-dried into powder and packaged (1 mg each) and stored at -80℃.

[0034] Example 3: Activity test of NpY antimicrobial peptides in basa fish fry The polypeptide synthesized in Example 2 (1 mg / tube) was dissolved in phosphate buffer (PBS, NaCl 136.89 mM; KCl 2.67 mM; Na2HPO4 8.1 mM; KH2PO4 1.76 mM) for dilution and set aside for later use.

[0035] In this embodiment, the inhibitory effects of basa fish fry NpY antimicrobial peptide on *Streptococcus agalactiae*, *Salmonella enterica*, *Staphylococcus aureus*, *Vibrio anguillarum*, *Escherichia coli*, and *Aeromonas hydrophila* are verified in detail. This does not imply that basa fish fry NpY antimicrobial peptide has an inhibitory effect only on these specific bacteria. The purpose of this embodiment is to demonstrate that basa fish fry NpY antimicrobial peptide has an inhibitory effect on bacteria including those mentioned above, and that it can be used in the preparation of antibacterial products, including the preparation of antibacterial agents, drugs, or additives. Specific verification is as follows: Streptococcus agalactiae, Salmonella enteritidis, Staphylococcus aureus, Vibrio anguillarum, Escherichia coli, and Aeromonas hydrophila were cultured separately. Each strain was cultured to the logarithmic growth phase and then diluted with medium (10⁻⁶). 4CFU / mL). 100 μL of the diluted bacterial culture was added to each well of a 96-well plate containing 100 μL of the antimicrobial peptide, resulting in antimicrobial peptide concentrations of 2.5 μM (μmol / L), 5 μM, 10 μM, 20 μM, and 40 μM, respectively. An equal volume of PBS (previously prepared) was added for negative control. All 96-well plates were incubated at 37°C in a microbial incubator. OD600 values ​​were measured at 0 h, 2 h, 4 h, 8 h, and 20 h, for a total of 20 hours, to plot the growth curve of the detected microorganisms. Each peptide was used in triplicate, and all experiments were repeated twice to obtain reliable results. All data were analyzed using the Social Science Statistical Package and GraphPadPrism software, and are expressed as mean ± standard deviation (n = 3). Paired-samples t-tests and multiple comparisons were used to test the significance of differences between groups. Results are shown in Table 2. Figures 4 to 6 As shown.

[0036] Table 2: Antimicrobial activity of Npy antimicrobial peptides from basa fish

[0037] From Table 2 and Figures 4 to 6 The results showed that the Npy antimicrobial peptide from basa fish exhibited inhibitory effects against three different microorganisms: Gram-positive Streptococcus agalactiae, Staphylococcus aureus, and Gram-negative Escherichia coli. Specifically, the minimum inhibitory concentration (MIC) of the Npy antimicrobial peptide against Streptococcus agalactiae and Staphylococcus aureus was 2.5 μM, and the MIC against Escherichia coli was 20 μM. Therefore, this verifies that the Npy antimicrobial peptide identified in basa fish possesses different antibacterial abilities, particularly showing significant efficacy against Streptococcus agalactiae and Staphylococcus aureus at low effective inhibitory concentrations.

[0038] Example 4: Detection of hemolytic activity of Npy antimicrobial peptides To further verify the cytotoxicity of the Npy antimicrobial peptide, its hemolytic activity was tested in this embodiment. The procedure is as follows: (1) Dissolve and dilute the Npy antimicrobial peptides with PBS (NaCl 136.89 mM; KCl 2.67 mM; Na2HPO4 8.1 mM; KH2PO4 1.76 mM) to 80 μM, 40 μM, 20 μM, 10 μM and 5 μM for later use; (2) Take 100 μL of diluted antimicrobial peptide + 100 μL of 4% red blood cell suspension; Negative: 100μL PBS + 100μL 4% red blood cell suspension; Positive result: 100 μL 0.2% Tritonx-100 + 100 μL red blood cells; (3) As for 37℃ for 1 hour; (4) Centrifuge at 2500 rpm for 5 min, transfer the supernatant to a new 96-well plate and measure the OD value at λ=576 nm; (5) Calculation: Hemolysis rate (%) = [(sample - negative) / (positive - negative)] * 100%; The test results are shown in Table 3 and Figure 7 As shown.

[0039] Table 3. Hemolytic activity of basa fish Npy antimicrobial peptides

[0040] From Table 3 and Figure 7 The identification results showed that the hemolytic activity of the basa fish Nyp antimicrobial peptide was 32.39% at 40 μM and only 8.19% at 20 μM. No hemolysis was induced at 5 μM and 10 μM, indicating that it has very low hemolytic activity. When applying it, the concentration should be controlled below 20 μM. It can be used for sterilization of live organisms, which can provide better guarantee for green and healthy aquaculture and other aquaculture industries. It has good practical value and social and environmental benefits.

[0041] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered exemplary and not restrictive in all respects. Furthermore, it should be understood that although this specification describes embodiments, it does not encompass only one technical solution. This descriptive method is merely for clarity, and those skilled in the art should consider the specification as a whole. The technical solutions in the embodiments can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. The application of a basa fish Npy antimicrobial peptide in the preparation of antibacterial products, characterized in that: The amino acid sequence of the basa Npy antimicrobial peptide is shown in SEQ ID NO:3; The bacteria it combats are Gram-positive agalactolytic streptococci and Gram-negative Escherichia coli; among them, the concentration of basa fish Npy antimicrobial peptide in the product used to combat Gram-positive agalactolytic streptococci is 2.5-20 μmol / L; and the concentration of basa fish Npy antimicrobial peptide in the product used to combat Gram-negative Escherichia coli is 20 μmol / L.

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