A strong lysis and hyperosmotic-resistant Shewanella algae phage and its application

Abstract

The present invention provides a Shewanella algae bacteriophage PKP-SH23103 and its application. The Shewanella algae bacteriophage was deposited in the China General Microbiological Culture Collection Center on November 29, 2023, with a deposit number of CGMCC NO.45783. The present invention also provides a phage composition comprising the Shewanella algae bacteriophage PKP-SH23103. The phage described in the present invention is isolated from a natural water environment and maintains a high level of titer (10 10 PFU / mL), has strong genetic stability and thermal stability, and is resistant to hyperosmosis, and can effectively respond to disease outbreaks caused by the massive reproduction of pathogens when water environmental conditions change. The bacteriophage obtained by the present invention can be used for the prevention and treatment of diseases caused by Shewanella algae, is safe and environmentally friendly, and effectively replaces the use of antibiotics in aquaculture, reducing water pollution caused by the abuse of antibiotics, enhanced bacterial resistance, and drug residues, and has good practical application value.

Description

Technical Field

[0001] The present invention relates to the field of biotechnology, in particular to a highly lytic and hyperosmotic resistant algae Shewanella phage and application thereof. Background Art

[0002] Shewanella algae, belonging to the genus Shewanella, is a Gram-negative facultative anaerobic bacillus. The bacteria are straight or curved rods, and colonies on blood agar plates are round, white, smooth, and moist, with neat edges and convex surfaces. Shewanella algae is commonly found in aquatic products and aquatic environments. It is pathogenic to sea cucumbers, turbot, sea urchins, corvina, and bream, causing a staged loss of movement and feeding behavior in aquatic animals, possibly accompanied by swelling of the snout. It is a new pathogen of aquatic animals and is invasive to both aquatic animals and humans.

[0003] Shewanella algae is a major pathogenic bacteria that causes zoonotic diseases. It is widely distributed in nature, especially in marine environments, and poses a significant threat to human health. Shewanella algae can cause sepsis, skin and soft tissue infections, abdominal and hepatobiliary infections, respiratory infections, ear and eye infections, bone infections, and meningitis. Tetrodotoxin (TTX) is a highly toxic alkaloid. Some of the most common Vibrio and Shewanella species in seawater can produce TTX. Although the production is low, TTX can be adsorbed on marine organisms such as algae and conchs, where it accumulates and accumulates. Therefore, when disease occurs or immunity is weakened, these TTX-producing bacteria may become dominant, further increasing TTX production and causing TTX poisoning in humans and terrestrial animals that consume seafood. Therefore, aquatic products contaminated by Shewanella algae are likely to become another significant risk factor for foodborne infections in coastal areas. Currently, antibiotics are commonly used to prevent and control this bacterium. Therefore, the widespread use of antibiotics has led to the increase in bacterial resistance, and opportunistic infections caused by these opportunistic pathogens are also increasing.

[0004] Currently, the primary means of combating bacterial diseases is antibiotics, but this has led to problems such as antibiotic resistance and environmental pollution. Therefore, the development of antibiotic alternatives suitable for aquatic animals is crucial. Bacteriophages are naturally occurring organisms with simple structures, are non-toxic and chemically free, possess high host specificity, and are less susceptible to developing drug resistance. They hold great potential for preventing and treating bacterial diseases and have been used to treat a variety of bacterial diseases. In aquaculture, the hyperosmotic tolerance of phages is also of great value. Seawater itself is a hyperosmotic environment, and the ability of phages of Shewanella salina to survive in these conditions offers a new avenue for disease prevention and control in aquaculture. If phages of Shewanella salina can function stably in hyperosmotic seawater, they could effectively control the growth of Shewanella salina, reduce disease incidence, and improve aquaculture yield and quality. However, the development and application of phages specifically targeting Shewanella salina are limited, and this area of ​​research warrants further research and exploration.

[0005] Therefore, the existing technology needs to be further improved. Summary of the Invention

[0006] The present invention aims to solve the above problems and provides a strong lysis and hyperosmotic resistant algae Shewanella phage and its application.

[0007] The specific technical solutions are as follows:

[0008] In the first aspect, the present invention provides a Shewanella algae bacteriophage PKP-SH23103, which was deposited in the China General Microbiological Culture Collection Center on November 29, 2023, with a deposit number of CGMCC NO.45783.

[0009] Electron microscopy revealed that phage RKP-SH23103 has a polyhedral, three-dimensionally symmetrical head encapsulating nucleic acid, with a diameter of 43 nm, a tail approximately 28 nm long, and a neck connecting the head and tail. According to the Ninth Report on the Taxonomy of Viruses of the International Organization for Taxonomy of Viruses, this phage is classified in the family Myoviridae of the order Caudata.

[0010] In a second aspect, the present invention provides a phage composition, comprising the Shewanella algae phage PKP-SH23103 as described in the first aspect.

[0011] In a third aspect, the present invention provides use of the Shewanella algae phage PKP-SH23103 as described in the first aspect or the phage composition as described in the second aspect in preventing and treating diseases of aquatic animals infected with Shewanella algae.

[0012] In a fourth aspect, the present invention provides the use of the Shewanella algae phage PKP-SH23103 as described in the first aspect or the phage composition as described in the second aspect in the preparation of a drug for preventing and treating diseases caused by Shewanella algae infection, an aquatic feed additive, a water environment disinfectant, or a biostatic agent for treating fresh or frozen aquatic products.

[0013] As used herein, the term "prevention" refers to both prevention and treatment. "Prevention" refers to all actions that inhibit or delay the disease by administering the bacteriophage. The term "treatment" refers to all actions that ameliorate or improve the disease by administering the bacteriophage. Diseases described herein include aquatic animal diseases caused by infection with Shewanella algae. For example, when aquatic animals such as fish, shrimp, and shellfish become infected with Shewanella algae and develop a disease, the Shewanella algae phage PKP-SH23103 specifically infects Shewanella algae, reduces its number by lysing host cells, thereby preventing or treating the disease caused by the bacteria and improving the survival rate and growth performance of the aquatic animals.

[0014] In a fifth aspect, the present invention further provides a phage pharmaceutical preparation, wherein the active ingredient of the phage pharmaceutical preparation includes the Shewanella algae phage PKP-SH23103 as described in the first aspect or the phage composition as described in the second aspect.

[0015] Furthermore, the phage pharmaceutical preparation further comprises a pharmaceutically acceptable carrier, and its dosage form is a solution, powder, emulsion, gel, granule or lyophilized agent.

[0016] Further preferably, the titer of the phage in the phage pharmaceutical preparation is 1×10 9 PFU / g or above.

[0017] In a sixth aspect, the present invention further provides an aquatic feed additive, wherein the active ingredient of the aquatic feed additive includes the Shewanella algae bacteriophage PKP-SH23103 as described in the first aspect or the bacteriophage composition as described in the second aspect.

[0018] In a seventh aspect, the present invention further provides a water environment disinfectant, wherein the active ingredient of the water environment disinfectant includes the algae Shewanella phage PKP-SH23103 as described in the first aspect or the phage composition as described in the second aspect.

[0019] In an eighth aspect, a biological antibacterial agent for treating fresh or frozen aquatic products, the active ingredient of the antibacterial agent includes the Shewanella algae phage PKP-SH23103 as described in the first aspect or the phage composition as described in the second aspect.

[0020] The present invention has the following advantages / benefits:

[0021] (1) The present invention discovered and isolated a strain of Shewanella salina SH23103, and used the Shewanella salina as a host to obtain a bacteriophage RKP-SH23103. The bacteriophage has strong lytic activity against Shewanella salina, with a lysis rate of up to 88.04%. It can effectively prevent and treat sepsis, ulcer disease, bacterial enteritis, and ulcer disease caused by Shewanella salina.

[0022] (2) The bacteriophages of the present invention are isolated from natural water environment and maintain high titer (10 10 PFU / mL), has strong genetic stability and thermal stability, and is resistant to hyperosmosis, which can effectively respond to disease outbreaks caused by the massive reproduction of pathogens when water environmental conditions change;

[0023] (3) The bacteriophage obtained by the present invention can be used for the prevention and treatment of diseases caused by Shewanella algae. It is safe and environmentally friendly, and can effectively replace the use of antibiotics in the aquaculture process, reduce water pollution caused by the abuse of antibiotics, increase in bacterial resistance, and drug residues, and has good practical application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only one embodiment of the present invention. Those skilled in the art can also derive other implementation drawings based on the provided drawings without inventive effort.

[0025] Figure 1 : Colony morphology of Shewanella algae of the present invention on TCBS plate (A) and LB solid medium plate (B);

[0026] Figure 2 : Phage plaques of the present invention against host bacteria;

[0027] Figure 3 : Electron microscope observation photo of the Shewanella algae phage (RKP-SH23103) of the present invention;

[0028] Figure 4 : The optimal multiplicity of infection of the Shewanella algae phage (RKP-SH23103) of the present invention;

[0029] Figure 5 : One-step growth curve of the Shewanella algae phage (RKP-SH23103) of the present invention;

[0030] Figure 6 : The optimal growth temperature of the Shewanella algae phage (RKP-SH23103) of the present invention;

[0031] Figure 7 : pH stability of the Shewanella algae phage (RKP-SH23103) of the present invention;

[0032] Figure 8 : Genetic experiment on the stability of Shewanella algae phage (RKP-SH23103) of the present invention;

[0033] Figure 9 : The death number curve of Semilaevis semilaevis of the present invention. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. The following embodiments are only for illustrating the present invention, and are not intended to limit the scope of the present invention in any way. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention. The experimental methods used in the present invention are conventional methods unless otherwise specified. The materials, reagents, etc. used in the present invention, unless otherwise specified, can be obtained from commercial channels. In addition, other terms used in the present invention, unless otherwise specified, generally have the meanings commonly understood by those of ordinary skill in the art.

[0035] In the present invention, Shewanella algae SH23103 may be referred to as "SH23103" for short, and Shewanella algae bacteriophage PKP-SH23103 may be referred to as "bacteriophage PKP-SH23103" or "PKP-SH23103" for short.

[0036] Example 1: Phage screening and identification

[0037] 1.1 Isolation and identification of Shewanella algae SH23103:

[0038] (1) Samples were collected from the farm and inoculated into LB liquid culture medium, which was then cultured at a constant temperature of 28°C for 12 h. The samples were then streaked onto TCBS plates, cultured at a constant temperature of 28°C, and the colony morphology was observed. A single colony with a transparent appearance was selected and streaked onto an LB solid culture medium plate. The colony was observed to be opaque, round, and smooth. The samples were further transferred and purified 2-3 times to obtain colonies with uniform morphology. A single colony was then picked and inoculated into 3 mL of LB liquid culture medium, and cultured at 160 rpm and 28°C for 12 h.

[0039] (2) The prepared bacterial suspension was identified by 16S rRNA gene sequencing technology. After identification, the bacterial suspension was inoculated densely on the LB solid culture medium plate and cultured at 28°C for 12 hours. The bacterial moss was then scraped and placed in 2216E liquid culture medium. After mixing, it was mixed with 60% glycerol broth in a 1:1 ratio and stored at -80°C.

[0040] 1.2 Isolation and purification of hyperosmotic-resistant algae Shewanella phage:

[0041] (1) Wastewater treatment: Mix and filter the nearshore water sample, centrifuge at 12,000 rpm for 5 min, take the supernatant and filter it through a membrane (0.22 μmol), mix the filtrate with the host bacterial solution in the logarithmic growth phase at a ratio of 1:1, culture it on a shaker at 28°C for 3 days, and regularly detect OD600. When the value drops significantly, take out the sample and centrifuge it (10,000 rpm, centrifuge for 5 min), then collect the supernatant and filter it through a membrane (0.22 μmol), and store the filtrate at 4°C for later use;

[0042] (2) Phage enrichment: 0.1 mL of Shewanella algae suspension and 1 mL of filtrate ① were added to 5 mL of LB liquid medium containing 3% NaCl and 5% NaCl, respectively. The mixture was shaken at 160 rpm and 28°C for 12 h, and then centrifuged at 12,000 rpm for 10 min. The supernatant was filtered through a 0.22 μm filter, and the filtrate ② was stored at 4°C for later use.

[0043] (3) Phage isolation: The double plate method was used to isolate phages. 0.1 mL of the host algae Shewanella suspension was mixed with 0.6% LB soft agar of two salt concentrations (3% NaCl and 5% NaCl) and spread on an LB solid plate. After the soft agar solidified, 0.1 mL of the filtrate ② was spotted on the plate and allowed to stand until the mixture was absorbed. After culturing in a 28°C incubator for 6-8 h, plaques were observed in both the culture medium containing 3% and 5% NaCl. Subsequently, the transparent plaques appearing in the high-salt concentration culture medium (5% NaCl) were picked up with an inoculation loop and placed in 2 mL of SM buffer. The plaques were stored at 4°C overnight to allow the phages to be completely released. Thus, the hyperosmotic-resistant algae Shewanella phages were initially obtained.

[0044] (4) Phage purification: Phages were isolated using the double plate method. 0.1 mL of phage extract stored overnight at 4°C was mixed with 0.1 mL of the host algae Shewanella suspension, and then soft agar cooled to about 50°C was added and mixed evenly. The mixture was then spread on two plates and placed in a 28°C incubator for 6-8 hours. A single transparent spot with smooth edges was picked and placed in 1 mL of SM buffer and stored at 4°C overnight. Then, 0.1 mL of the extract stored overnight was mixed with 0.1 mL of the bacterial suspension, and soft agar cooled to about 50°C was added and mixed evenly. The mixture was then spread on two plates and placed in a 28°C incubator for 4-6 hours. This step was repeated 3-5 times until plaques of uniform size and smooth edges were purified, thus completing the phage purification.

[0045] (5) Preparation of phage: 0.2 mL of Shewanella algae suspension and 1 mL of phage solution were added to 50 mL of LB broth, cultured overnight at 160 rpm and 28°C in a shaker, and then centrifuged at 10,000 rpm for 10 min. The supernatant was filtered through a membrane (0.22 μmol), and the phage filtrate was used for later use;

[0046] (6) Phage preservation: A strain of Shewanella algae phage RKP-SH23103 was isolated and the phage suspension was added to 60% glycerol in a 1:1 ratio and stored at -80°C.

[0047] 1.3 Electron microscopic observation of bacteriophages

[0048] Take 20 μL of liquid containing crude phage particles and drop it on a copper mesh. Let it settle naturally for 15 minutes, and use filter paper to absorb excess liquid from the side. Add a drop of 2% phosphotungstic acid (PTA) on the copper mesh to stain the phage for 10 minutes, then use filter paper to absorb the staining liquid from the side. After the sample is dry, use an electron microscope to observe the phage morphology, such as Figure 3 shown.

[0049] Bacteriophage RKP-SH23103 has a polyhedral, three-dimensionally symmetrical head encapsulating nucleic acid, with a diameter of 43 nm. It also has a tail approximately 28 nm long, connected by a neck. According to the Ninth Report on the Taxonomy of Viruses of the International Organization for Taxonomy of Viruses, this phage is classified in the family Myoviridae of the order Caudata.

[0050] Example 2: Fermentation performance analysis

[0051] 2.1 Determination of phage titer

[0052] 100 μL of host bacterial culture at the exponential phase was added to a 5 mL centrifuge tube. LB semi-solid medium was added and mixed thoroughly. The mixture was then poured onto LB semi-solid agar, completely covering a 20 mL LB solid agar plate (9 cm diameter). After drying and solidification, 100 μL of the purified phage RKP-SH23103 concentrate was pipetted onto the plate and incubated overnight at 28°C. Plaques were then removed and placed in 20 mL of SM buffer and stored at 4°C overnight. The next day, the supernatant was collected and filtered through a 0.22 μm filter. 100 μL of the filtrate was serially diluted 10-fold with sterile water. 100 μL of each bacterial and phage solution was then mixed onto two plates and incubated overnight at 28°C in an incubator. Countable plates were selected for phage plaque count. The phage titer (PFU / mL) was calculated as the number of plaques multiplied by the dilution factor / sample volume (mL).

[0053] The titer of bacteriophage RKP-SH23103 was determined to be 10 10 PFU / mL.

[0054] 2.2 Determination of optimal phage infection multiplicity (MOI)

[0055] The concentration of the host bacterial solution cultured to the exponential phase was adjusted to 10 8 CFU / mL. Set the MOI at 0.001, 0.01, 0.1, 1, and 10. Add 100 μL of the titered phage solution to the host bacterial solution in the appropriate proportions. Mix thoroughly and incubate at 200 rpm and 28°C with shaking for 5 hours. Centrifuge at 12,000 rpm for 5 minutes and measure the phage titer. The optimal MOI is the one with the highest titer.

[0056] The results are as follows Figure 4 As shown, when the multiplicity of infection was 0.01, the titer of phage RKP-SH23103 was the highest, which also indicated that this phage strain was suitable for large-scale production.

[0057] 2.3 One-step growth curve of phage

[0058] Take 500 μL of phage liquid and host bacterial liquid respectively and mix them in the ratio required for the optimal multiplicity of infection (MOI = 0.01), incubate at room temperature for 10 minutes, and then centrifuge at 12,000 rpm for 10 minutes, discard the supernatant, wash with LB liquid culture medium, and centrifuge again (12,000 rpm, 1 minute). Repeat the above operation, wash the precipitate 3 times, and then add 10 mL of LB liquid culture medium preheated at 37°C, mix thoroughly and quickly place it in a 28°C shaker for shaking culture. Take a sample once every 10 minutes at the beginning and thereafter, draw 200 μL, then centrifuge at 12,000 rpm for 2 minutes, and draw 100 μL of supernatant for determining the phage titer. Finally, draw a one-step growth curve with the infection time as the horizontal axis and the logarithm of the phage titer in the infection system as the vertical axis.

[0059] The one-step growth curve of bacteriophage RKP-SH23103 is as follows Figure 5 As shown in the figure, the number of phages did not increase significantly within 50 minutes after the phages infected the host bacteria, indicating that the phage incubation period was 50 minutes. From 50 to 90 minutes after the infection of the host bacteria, the number of phages increased rapidly, and this period was the phage outbreak period, that is, the phage outbreak period was about 40 minutes, and the phage outbreak amount was about 10 4 PFU / mL; the number of phages remained unchanged in the subsequent 60 minutes, that is, the phage reached a stable growth period.

[0060] 2.4 Determination of the optimal growth temperature of phage

[0061] Take a sterile 2mL centrifuge tube and add 1mL of phage stock solution (initial titer 1.37×10 10 ) and incubated at 20°C, 30°C, 40°C, 50°C, 60°C, and 70°C for 30, 60, 90, 120, and 150 minutes, respectively. After the incubation period, the sample tubes were removed and diluted to the appropriate concentration. 100 μL of each of the treated phage solution and host bacterial solution was taken for phage titer determination using the double-plate assay.

[0062] The results are as follows Figure 6 As shown, phage RKP-SH23103 survives readily at 40°C. At 20°C and 60°C, the phage titer decreases to varying degrees after a period of exposure. When the temperature rises to 70°C, the phage is essentially inactivated. This phage strain exhibits excellent stability at 30-50°C and can be stored for long periods.

[0063] 2.5 Determination of pH stability of bacteriophage

[0064] Take 5 mL sterile test tubes and add 3 mL LB liquid culture medium respectively, and adjust the pH value to 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12, and then place them in a 37°C constant temperature water bath. After the temperature is balanced, add 100 μL of phage stock solution and host bacterial solution respectively, and place them at 37°C for action. The phage titer is determined by the double-layer plate method after the action time is 1 h, 2 h, and 3 h, respectively.

[0065] like Figure 7 As shown in the figure, the phage RKP-SH23103 was treated in the pH range of 6 to 10 for 3 h, and the phage titer did not change significantly and remained at 10 9 ~10 10 High level titer of PFU / mL.

[0066] 2.6 Phage Stability Genetic Experiment

[0067] The phage was serially passaged by adding equal amounts of phage and host bacteria to the culture medium and culturing for 6 h. After 29 consecutive passages of phage, the phage titer was determined by the double plate method.

[0068] Depend on Figure 8 It can be seen that the overall titer of the phage remains stable during the passage process, indicating that the phage has good biological genetic stability and is an excellent choice for the production process.

[0069] Example 3: Lysis rate experiment

[0070] The double-layer plate method was used to determine the lysis efficacy of Shewanella spp. phage RKP-SH23103 against 92 Shewanella spp. strains stored in a strain library. A culture of the Shewanella spp. strain library was revived. 100 μL of each of the test culture and the Shewanella spp. phage were then added to LB semi-solid medium, mixed again, and quickly poured onto LB solid medium plates. After cooling and solidification, the plates were incubated at 28°C for 12 hours. The successful lysis was determined by observing for the appearance of plaques.

[0071] The 92 strains of Shewanella algae in the strain library were isolated from shrimp and fish samples collected in Wenchang, Hainan; Qingdao, Shandong; Zhangzhou, Fujian; and Lianyungang, Jiangsu. As shown in Table 1, the Shewanella algae phage RKP-SH23103 was able to lyse 81 of these 92 strains, achieving a lysis rate of 88.04%. Specifically, the lysis rates for strains isolated from shrimp feces were 78.57%, for strains isolated from shrimp samples were 88.46%, for strains isolated from a small number of sea cucumber samples were 66.67%, and for strains isolated from fish samples reached 93.48%.

[0072] Table 1 Lysis effect of Shewanella algae phage RKP-SH23 1 03

[0073]

[0074]

[0075] Note: “+” indicates cleavage, “-” indicates no cleavage.

[0076] Example 4: Phage treatment experiment on Cynoglossus semilaevis

[0077] 120 healthy semi-smooth tongue soles of similar weight were selected and randomly divided into 4 groups, with 30 fish in each group. The negative control group received no treatment; the positive control group received intraperitoneal injection of 200 μL / fish with sterile saline; the infection group received intraperitoneal injection of 200 μL / fish with bacterial suspension; the treatment group received intraperitoneal injection of 200 μL / fish with bacterial suspension. 2 hours after infection, 200 μL / fish with RKP-SH23103 phage solution (titer: 10 9 PFU / mL). The animals were observed for 3 consecutive days after infection. The number of deaths and mortality of semilaevis semilaevis in each group were counted at 0 h before infection and 12 h, 24 h, 36 h, 48 h, 60 h, and 72 h after infection.

[0078] The bacterial suspension was prepared as follows: SH23103 strain was inoculated into sterile 2216E liquid culture medium, cultured at 28°C for 12 h, and then centrifuged at 10,000 rpm for 1 min. The bacterial cells were collected and suspended in sterile physiological saline (0.9%) to obtain 1.0 × 10 8 CFU / mL of bacterial suspension.

[0079] Table 2 Phage treatment experiments on Cynoglossus semilaevis

[0080]

[0081] As shown in the experimental results in Table 2, no semilaevis deaths occurred in the negative control group, while a small number of deaths occurred in the positive control group, indicating that the semilaevis were in good health. In the infected group, the onset of disease was rapid and the disease deteriorated severely within 12 to 24 hours of infection, leading to a sharp increase in the number of deaths in the semilaevis, with a mortality rate as high as 86%. Injection of the phage solution in the treatment group, 2 hours after infection, significantly alleviated the onset of disease in the semilaevis and significantly reduced mortality, with a post-treatment survival rate of 77%. This demonstrates that the Shewanella marinum phage RKP-SH23103 can be used to treat aquatic diseases caused by Shewanella marinum.

[0082] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solutions and concepts of the present invention, and all these changes or substitutions should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A Shewanella algae bacteriophage PKP-SH23103, characterized in that: The deposit number of the Shewanella algae phage PKP-SH23103 is: CGMCC No.45783.

2. A phage composition, characterized in that: The phage composition comprises the Shewanella algae phage PKP-SH23103 according to claim 1.

3. A bacteriophage pharmaceutical preparation, characterized in that: The active ingredient of the phage pharmaceutical preparation includes the Shewanella algae phage PKP-SH23103 according to claim 1 or the phage composition according to claim 2; the titer of the phage in the phage pharmaceutical preparation is 1×10 9 PFU / g or above.

4. A bacteriophage pharmaceutical preparation according to claim 3, characterized in that: The bacteriophage pharmaceutical preparation further comprises a pharmaceutically acceptable carrier, and the bacteriophage pharmaceutical preparation is a solution, a powder, an emulsion, a gel, a granule or a lyophilized agent.

5. A water environment disinfectant, characterized in that: The active ingredient of the water environment disinfectant includes the algae Shewanella phage PKP-SH23103 according to claim 1 or the phage composition according to claim 2, and the titer of the phage in the water environment disinfectant is 1×10 9 PFU / g or above.

6. A bio-antibacterial agent for treating fresh or frozen aquatic products, characterized in that: The active ingredient of the biological antibacterial agent includes the algae Shewanella phage PKP-SH23103 according to claim 1 or the phage composition according to claim 2, and the titer of the phage in the biological antibacterial agent is 1×10 9 PFU / g or above.

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