Gluconobacter oxydans and application thereof

Abstract

The present application relates to the field of microbial technology, and particularly to a strain of Gluconobacter oxydans and its application. Gluconobacter oxydans The present application provides a strain of Gluconobacter oxydans (Gluconobacter oxydans) named KUST4611, which has been preserved in the Guangdong Microbial Culture Collection Center on October 22, 2025, with a preservation number of GDMCC NO: 67143. The volatile substances produced by the strain provided by the present application during growth have a bacteriostatic effect. When the strain is applied to prepare a fresh-keeping gel, the volatile substances produced by the gel placed in a closed space can achieve good fresh-keeping effect, effectively reduce the occurrence of diseases, maintain the freshness of the peppers, and effectively prolong the fresh-keeping period of the peppers. Meanwhile, the preparation method of the fresh-keeping gel is simple, and the fresh-keeping effect can be easily and conveniently achieved, the cumbersome steps of postharvest preservation are reduced, and the postharvest preservation efficiency is further improved.

Description

Technical Field

[0001] This invention relates to the field of microbial technology, specifically to a strain of Staphylococcus oxidans and its applications. Background Technology

[0002] Chili peppers, as an important vegetable and condiment, are widely cultivated and consumed globally. However, chili peppers are extremely prone to dehydration, wilting, and rotting after harvest, leading to a significant decline in their commercial value and edible quality, resulting in substantial economic losses. With increasing demands for food safety and quality, the development of safe, efficient, and convenient chili pepper preservatives has become a research hotspot.

[0003] Currently, chili pepper preservation methods are divided into traditional methods and preservative methods. Traditional methods, such as low-temperature storage and controlled atmosphere storage, while extending the shelf life of chili peppers to some extent, still suffer from high costs, complex operations, and limited preservation effects. Preservative methods primarily utilize two categories of chili pepper preservatives: chemical preservatives and natural preservatives. While chemical preservatives offer significant preservation effects, they pose potential risks such as residual toxicity and environmental pollution. Natural preservatives, on the other hand, with their advantages of safety, non-toxicity, and biodegradability, are gradually becoming a research focus in the field of chili pepper preservation.

[0004] In recent years, volatile preservatives, as an emerging preservation technology, have shown great application potential in the field of fruit and vegetable preservation due to their advantages such as ease of use, high efficiency, and high safety. However, the application of existing volatile preservatives in chili pepper preservation still faces some problems, such as weak specificity and limited preservation effect. Therefore, developing a new type of volatile preservative for post-harvest chili peppers is of great significance for reducing post-harvest losses. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defects of existing chili preservatives, such as weak targeting, limited preservation effect, and the need to contact the surface of chili peppers to exert the preservation effect, thereby providing a strain of Staphylococcus oxidans and its application.

[0006] In a first aspect, the present invention provides a strain of Staphylococcus oxidans (Synthobacterium oxysporum) Gluconobacter oxydans ), which can be any one of the following (1) to (3):

[0007] (1) Strains whose 16S rDNA sequence is at least 85%, 90%, 95%, 98%, 99%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9%, 99.99% or 100% identical to the sequence shown in SEQ ID NO.1; (2) Staphylococcus oxidans ( Gluconobacter oxydansKUST4611 was deposited at the Guangdong Provincial Center for Microbial Culture Collection on October 22, 2025, with accession number GDMCC NO: 67143; (3) A strain whose 16S rRNA has at least 85%, 90%, 95%, 98%, 99%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9%, 99.99% or 100% identity with the strain described in (2).

[0008] Secondly, the present invention provides a microbial agent comprising the above-mentioned *Glucosium oxygenase*, or its bacterial suspension, or its culture medium, or its fermentation broth, or its fermentation broth supernatant, or its inactivated bacteria, or its metabolites; wherein the metabolites include volatile substances produced by *Glucosium oxygenase*.

[0009] Thirdly, the present invention provides a method for preparing a microbial agent, comprising activating and culturing the aforementioned *Glucosium oxygenase*.

[0010] Furthermore, the culture medium is selected from YPD culture medium.

[0011] In some alternative embodiments, the YPD culture medium comprises peptone, glucose, yeast extract, and water.

[0012] In some alternative embodiments, the YPD culture medium may also include agar.

[0013] Fourthly, the present invention provides the application of the above-mentioned *Glucosium oxysporum*, microbial inoculants, or microbial inoculants prepared by the above-mentioned method in any of the following: A1) Application in inhibiting pathogens; A2) Application in the preparation of pathogen inhibitors; A3) Application in fruit and vegetable preservation; A4) Application in the preparation of preservation products.

[0014] Fifthly, the present invention provides a preservation gel comprising an active ingredient, wherein the active ingredient is the aforementioned *Glucosium oxygenase* or the aforementioned microbial agent or a microbial agent prepared by the aforementioned method for preparing the microbial agent.

[0015] Furthermore, the preservation gel also includes one or more of the following components: sodium alginate, chitosan, gelatin, glycerin, and YPD liquid culture medium.

[0016] Furthermore, the active ingredient is added in the form of a bacterial suspension, wherein the concentration of *Gastrobacterium oxyphylla* in the bacterial suspension is 10. 6 -10 8 CFU / mL.

[0017] Furthermore, the mass-to-volume ratio of sodium alginate, chitosan, gelatin, glycerol, YPD liquid culture medium, and bacterial suspension is 1-4:0.5-3:0.5-3:1-3:80-120:80-120, in g:g:g:mL:mL:mL.

[0018] Sixthly, the present invention provides a method for preparing the above-mentioned preservation gel, comprising the following steps: Step S1: Mix sodium alginate and gelatin with YPD liquid culture medium, sterilize, and obtain solution A; Step S2: Mix chitosan with acetic acid, sterilize, and obtain solution B; Step S3: Mix the above solutions A and B with glycerol to obtain solution C; Step S4: After adding the active ingredient to solution C, mix it with the cross-linking agent solution, let it stand, and then rinse to obtain the preservation gel.

[0019] Furthermore, the volume ratio of the crosslinking agent solution to acetic acid is 5-15:80-120; Furthermore, the crosslinking agent solution is selected from a calcium chloride solution with a mass fraction of 1-5% and / or a calcium citrate solution with a mass fraction of 1-5%. Furthermore, the settling time is 15-20 minutes; Furthermore, the rinsing solution is selected from water or YPD medium; Furthermore, the preservation method of the preservation gel includes immersion in YPD liquid culture medium for preservation; Furthermore, in step S2, the mass fraction of the acetic acid is 0.5-1.5%.

[0020] In a seventh aspect, the present invention provides a preservation device, characterized in that it includes a container, the container having holes, and the container body containing the above-mentioned *Glucosium oxysporum* or the above-mentioned microbial agent or a microbial agent prepared by the preparation method of the above-mentioned microbial agent or the above-mentioned preservation gel or a preservation gel prepared by the above-mentioned preparation method.

[0021] When in use, the preservation device is placed in a sealed space containing the item to be preserved (such as vegetables that need to be preserved). The device is in addition to the item itself. The device releases volatile substances into the sealed space through Staphylococcus aureus, microbial agents, or preservation gels to inhibit the growth of microorganisms, thereby extending the shelf life and quality of the item.

[0022] Eighthly, the present invention provides a preservation method, wherein the above-mentioned *Glucosium oxysporum* or microbial agent or microbial agent prepared by the above-mentioned microbial agent preparation method or the above-mentioned preservation gel or preservation gel prepared by the above-mentioned preparation method is used as a preservative to preserve food.

[0023] Furthermore, the preservation gel can be used for preservation treatment with or without contact with food.

[0024] Furthermore, the non-contact preservation treatment refers to placing *Glucosobacterium oxysporum*, microbial agents, or preservation gels in a breathable container. By releasing volatile substances (antibacterial components) into the preserved item, microbial growth is inhibited without direct contact, thereby extending the shelf life and quality of the preserved item. The food mentioned includes one or more fruits and vegetables.

[0025] The technical solution of this invention has the following advantages: The present invention provides a strain of Staphylococcus oxidans ( Gluconobacter oxydans The strain, named KUST4611, was deposited at the Guangdong Provincial Microbial Culture Collection Center on October 22, 2025, with accession number GDMCC NO: 67143. The volatile substances produced by the strain during its growth have antibacterial effects. When applied to the preparation of a preservation gel, the gel, placed in a sealed space, produces volatile substances that achieve excellent preservation results, effectively reducing disease occurrence, maintaining the freshness of chili peppers, and extending their shelf life. Furthermore, the preparation method of this preservation gel is simple, easily and conveniently achieving preservation effects, reducing cumbersome post-harvest preservation steps, and further improving post-harvest preservation efficiency.

[0026] Biological Preservation Information: Gluconobacter oxydans KUST4611 was deposited at the Guangdong Provincial Center for Microbial Culture Collection on October 22, 2025, with accession number GDMCC NO: 67143. The address of the depository is 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou. Attached Figure Description

[0027] Figure 1 This is a morphological diagram of *Glucosobacterium oxysporum* KUST4611 on a plate in Example 2 of this invention; Figure 2 This is a microscopic image of Staphylococcus aureus KUST4611 in Example 2 of the present invention; Figure 3 This is a diagram showing the antibacterial experiment results of the Staphylococcus aureus KUST4611 strain in Example 3 of the present invention; Figure 4This is a graph showing the antibacterial test results of the five groups of liquid components in Example 4 of the present invention; Figure 5 This is a statistical chart of the diameter of bacterial growth in the five groups of antibacterial experiments of liquid components in Example 4 of the present invention. In the figure, a and b are the difference markers between groups. The same letter indicates that the difference is not significant (P>0.05), and different letters indicate that the difference is significant (P<0.05). Figure 6 This is a diagram showing the results of the antibacterial experiment on volatile substances in Example 4 of the present invention; Figure 7 This is a statistical chart of the diameter of bacterial growth in the volatile substance antibacterial experiment in Example 4 of the present invention. In the figure, a and b are the difference markers between groups. The same letter indicates that the difference is not significant (P>0.05), and different letters indicate that the difference is significant (P<0.05). Figure 8 This is a comparison diagram of the preservation effect of the preservation gel on a flat plate in Embodiment 6 of the present invention; Figure 9 This is a diagram of the container for placing the preservative gel in Embodiment 6 of the present invention; Figure 10 This is a comparison diagram of the preservation effect of the preservation gel on chili peppers in Embodiment 6 of the present invention.

[0028] Figure label: 1. Hole; 2. Container; 3. Preservative gel. Detailed Implementation

[0029] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0030] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0031] The culture medium used in the embodiments of the present invention is prepared according to the following method: YPD medium: Weigh 10g yeast extract, 20g peptone, 20g glucose, 20g agar (not added to liquid medium), and 1000mL distilled water. Sterilize at 115℃ for 20min and allow to cool naturally before use.

[0032] PDA medium: Peel and cut 200g of potatoes into chunks, add an appropriate amount of water and boil, filter through four layers of gauze, and bring the volume to 1L with distilled water. Add 2% glucose and 1.5-2% agar to the potato water and sterilize at 121℃ for 15min.

[0033] PDB medium: PDA medium without agar, all other conditions are the same.

[0034] Example 1 Isolation of strains 1. Sample collection: After the bayberries were left for several days, disease appeared. The diseased parts were picked off and collected for bacterial isolation.

[0035] 2. Strain strain isolation: includes the following steps: 1) Place the pulp from the diseased part of the bayberry in sterile water, mix thoroughly, and then take 50 μL and spread it on a PDA plate and incubate at 25°C. 2) Pick a single colony from the plate and place it in PDA medium, then incubate at 25°C.

[0036] Example 2 Identification and Preservation of Strains 1. Morphological identification According to the *Handbook of Bacterial Identification*, YPD medium was used for culture, and the plates were incubated upside down at 30°C for 2 days. The growth of colonies on the plates was observed and recorded visually. Figure 1 and 2 As shown, the colonies of strain Gastrospermia oxyphylla KUST4611 on YPD solid medium are round, smooth, moist, and initially cheese-colored, later turning brownish-red. In liquid culture, the colonies are uniformly turbid with slight precipitation. Under a microscope, the cells are oval or egg-shaped and Gram-negative. Based on the methods in the Handbook of Bacterial Identification, the strain was preliminarily identified as Gastrospermia oxyphylla.

[0037] 2. Molecular biological identification gDNA was extracted from the strain *Gastrospermum oxysporum* and sequence alignment was performed for identification. The specific procedures are as follows: 1) Select a small amount of bacterial cells and incubate them overnight in YPD liquid medium; 2) Centrifuge at 3000×g for 2 min to enrich bacterial cells; 3) Remove the supernatant and add 400 μL of lysis buffer and an equal volume of glass beads to the precipitate; 4) Oscillate for 90 seconds on a vortex oscillator; 5) After adding 400 μL PCI (phenol: chloroform: isoamyl alcohol = 25:24:1, V / V / V), vortex for 90 s; 6) Centrifuge at 13400×g for 5 minutes at 4℃, and transfer the supernatant to a new centrifuge tube; 7) Add 400 μL of isopropanol to the supernatant and incubate on ice for 15 min; 8) Centrifuge at 13400×g for 3 minutes, and you will see a white DNA precipitate at the bottom of the centrifuge tube; 9) Discard the supernatant, being careful not to discard the white DNA precipitate. Add 700 μL of 70% ethanol to wash the precipitate, repeating 3 times. 10) After the last wash, centrifuge at 10,000 rpm for 1 min, remove the ethanol, and let the centrifuge tube stand to allow the precipitate to air dry naturally; 11) Add 30 μL of ddH2O to dissolve the DNA.

[0038] Using the extracted gDNA as a template, PCR amplification was performed using universal 16S rDNA primers. The upstream primer sequence was 5'-AGAGTTTGATCCTGGCTCAG-3' (as shown in SEQ ID NO. 2); the downstream primer sequence was 5'-TACGGCTACCTTGTTACGACTT-3' (as shown in SEQ ID NO. 3). The PCR amplification products were sent to Sangon Biotech for sequencing, and the resulting sequence is shown in SEQ ID NO. 1.

[0039] The obtained DNA sequence was input into NCBI and compared with sequences in standard databases using the BLAST program. Sequence analysis showed that the strain isolated in this invention belongs to *Glucosobacterium oxysporum* (Glucosobacterium). Gluconobacter oxydans ).

[0040] 3. Biological preservation strain Staphylococcus oxidans ( Gluconobacter oxydans It was deposited on October 22, 2025 at the Guangdong Provincial Center for Microbial Culture Collection, named KUST4611, with accession number GDMCC NO: 67143, and the deposit address is 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou.

[0041] Example 3: Antibacterial effect of the strain 1. Preparation of bacterial suspension of *Gastroobacterium oxysporum*: 1) Add 1 mL of Glucosamine oxidase preserved in a glycerol tube to 200 mL of YPD liquid medium and incubate at 30 °C and 200 rpm / min for 48 h; 2) Centrifuge the cultured bacterial solution at 8000 rpm for 10 min to obtain bacterial cells, then wash the bacterial cells with 200 mL phosphate buffer (PBS) and repeat 3 times to remove residual culture medium. Finally, resuspend the bacterial cells in fresh 200 mL PBS to obtain a bacterial suspension. 3) The obtained bacterial suspension was serially diluted four times with sterile deionized water, i.e., diluted 10,000 times. Then it was spread on YPD solid medium and incubated in a constant temperature incubator at 30℃ for 48 hours. After that, the colony count was performed and the bacterial concentration in the bacterial suspension was calculated. 4) The bacterial concentration in the prepared bacterial suspension was determined to be 10⁻⁶ using the plate coating and counting method. 6 CFU / mL, for later use.

[0042] 2. Preparation of Alternaria capsici mycelial moss: 1) Add 1 mL of Alternaria solani stored in a glycerol tube to 200 mL of PDB liquid medium and incubate at 30 °C and 200 rpm / min for 48 h; 2) Take 50 μL of culture medium and spread it evenly in PDA medium, and incubate at 30℃ for 24 h; 3) Pick a single colony from the plate, place it in the center of PDA medium, and incubate at 30°C for 5 days; 4) Use a 5mm diameter punch to make holes at the edge of the colony, pick out the mycelium, and set aside.

[0043] 3. Antibacterial test: 100 μL of the above-mentioned *Glucosidobacterium oxysporum* suspension was taken as the experimental group and evenly spread on the surface of YPD solid medium. The control group was a blank YPD solid medium plate without yeast solution. A *Alternaria capsici* mycelium of the same size (5 mm in diameter) was placed in the middle of each medium. After sealing, the petri dishes were placed at 28°C for incubation. Each group had three replicates.

[0044] 4. Experimental results: such as Figure 3 As shown, a suspension of *Glucosamine oxidans* can inhibit the growth of *Alternaria capsici*.

[0045] Example 4: Source of antibacterial components in the strain To verify the source of the antibacterial components of *Gastroenterobacter oxidans*, the bacterial suspension was divided into 5 groups: A: Sterile distilled water; B: Cell-free culture medium (i.e., the liquid obtained after filtering the *Glucosobacterium oxygenase* suspension provided in Example 3 through a 0.22 μm organic filter membrane). C: The bacterial suspension of *Glucosium oxygenase* that has not been washed with PBS (i.e., the liquid obtained after step 1 of the preparation of the bacterial suspension of *Glucosium oxygenase* in Example 3). D: PBS-washed suspension of *Glucosium oxygenase* (i.e., the liquid obtained after step 2 of the preparation of the *Glucosium oxygenase* suspension in Example 3). E: Sterile YPD liquid culture medium.

[0046] Take 100 μL of the liquid components from the above 5 groups and spread them onto PDA solid culture medium. Place a 5 mm diameter Alternaria capsici mycelium in the center of the culture medium and incubate at 28°C for 5 days. Observe the antibacterial effect and record the growth diameter of the mycelium daily.

[0047] like Figure 4 and 5 As shown, during the entire culture process, groups A, B, and E could not effectively inhibit the growth of Alternaria capsici, while only groups C and D could significantly inhibit the growth of Alternaria capsici mycelia, and they had a good inhibitory effect throughout the entire culture process.

[0048] In addition, to verify whether *Glucosobacterium oxygenase* is a volatile substance with antibacterial effect, the above-mentioned Group C liquid (bacterial suspension of *Glucosobacterium oxygenase*) was spread on YPD medium as the experimental group (VOCs), and the unspread bacterial suspension (i.e., blank YPD solid medium plate) was used as the control group (CK). *Alternaria alternata* bacterial motifs with the same diameter of 5 mm were placed in the center of PDA medium. Then, the plates of the experimental group and the control group were respectively placed on top of the PDA plate of *Alternaria alternata* bacterial motifs. When placing them on top, the plates of the experimental group and the control group were used as the bottom, and the PDA plate of *Alternaria alternata* bacterial motifs was used as the top cover, ensuring that the two plates and the bacterial suspension and bacterial motifs on them did not come into contact. After being fixed with sealing film, they were incubated at 28°C for 5 days.

[0049] like Figure 6 and 7 As shown, the experimental group results indicated that the growth of *Alternaria alternata* was inhibited, while the control group showed no antibacterial effect. Furthermore, with increasing culture time, by days 4 and 5, the diameter of the bacterial colony in the experimental group remained almost unchanged, while the diameter of the bacterial colony in the control group continued to increase. This suggests that the volatile substances produced by *Glucosamine oxysporum* during its growth have an antibacterial effect, exerting this inhibitory effect even without direct contact with *Alternaria alternata*.

[0050] Example 5 Preparation of Preservative Gel 1. Weigh 1.5g sodium alginate and 1.0g gelatin and dissolve them in 100mL YPD medium. Heat to 50℃ and stir until completely dissolved. Sterilize at 121℃ for 15 min to obtain solution A. 2. Weigh 0.5g of chitosan and dissolve it in 100mL of dilute acetic acid (1% acetic acid). Stir until completely dissolved, filter through a 0.22μm filter membrane to remove bacteria, and obtain solution B. 3. Mix the above solutions A and B, add 1.0 mL of glycerol, and stir well to obtain solution C; 4. Take 100 mL of the bacterial suspension prepared in Example 3, centrifuge at 4000 rpm / min for 5 min, and resuspend it in the above solution C to ensure uniform dispersion.

[0051] 5. Pour the above solution into 500 mL of 2% calcium chloride solution and let it stand for 15 minutes to allow it to fully crosslink. 6. Rinse with 1000mL of deionized water to remove excess calcium ions and acetic acid, and obtain the preservation gel; 7. Transfer the above-mentioned preservation gel to fresh YPD medium and store at 4°C for later use.

[0052] Example 6: Preservation effect of preservative gel 1. The preservation effect of food preservation gel on a flat plate Take the preservation gel from Example 5 (total amount 50g) and prepare several spherical gels. Place them around a PDA medium plate inoculated with Alternaria alternatae fungal motifs of the same size (5mm in diameter). A control group without the preservation gel was used. Figure 8 It can be seen that, compared with the control group, the preservation gel can significantly inhibit the growth of Alternaria alternata and has a good antibacterial effect.

[0053] 2. The preservation effect of preservative gel on chili peppers Six post-harvest pepper fruits were taken, pricked, and *Alternaria alternata* fungal growth was inoculated onto the wounds. The fruits were then placed in a breathable food storage container lined with damp paper towels. The infected peppers were divided into two groups of three. The experimental group was placed in a container with 100g of the preservative gel 3 from Example 5. Figure 9 The bottom of container 2, as shown, has a circular hole 1 at the top for ventilation. This container was placed in a food storage box without contacting the chili peppers. The control group contained only the contaminated chili peppers and nothing else. Both groups were stored for 7 days. The experimental results are as follows: Figure 10 As shown, it is clear that the control group has developed diseases due to bacterial contamination, while the growth of Alternaria in the experimental group is significantly inhibited, the preservation effect is good, and no diseases occur. This indicates that the preservation gel provided by the present invention can have good antibacterial effect and safety without direct contact with peppers, thereby improving the post-harvest preservation effect of peppers.

[0054] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A strain of Staphylococcus oxidans ( Gluconobacter oxydans ), characterized in that, It can be any one of the following (1) to (3): (1) Strains whose 16S rDNA sequence is at least 85%, 90%, 95%, 98%, 99%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9%, 99.99% or 100% identical to the sequence shown in SEQ ID NO.1; (2) Staphylococcus oxidans ( Gluconobacter oxydans KUST4611 was deposited at the Guangdong Provincial Center for Microbial Culture Collection on October 22, 2025, with accession number GDMCC NO: 67143; (3) A strain whose 16S rRNA has at least 85%, 90%, 95%, 98%, 99%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9%, 99.99% or 100% identity with the strain described in (2).

2. A microbial inoculant, characterized in that, Includes the *Glucosobacterium oxidans* as described in claim 1, or its bacterial suspension, or its culture medium, or its fermentation broth, or its fermentation broth supernatant, or its inactivated bacteria, or its metabolites; Optionally, the metabolites include volatile substances produced by Staphylococcus aureus.

3. A method for preparing a microbial inoculant, characterized in that, This includes activating and culturing the *Glucosobacterium oxygenase* as described in claim 1.

4. The method for preparing the microbial inoculant according to claim 3, characterized in that, The culture medium is selected from YPD culture medium; Optionally, the YPD culture medium comprises peptone, glucose, yeast extract, and water; Alternatively, the YPD culture medium may also include agar.

5. The application of the microbial agent prepared by the method of preparing the *Glucosium oxysporum* according to claim 1, the microbial agent according to claim 2, or the microbial agent according to claim 3 or 4, in any of the following: A1) Application in inhibiting pathogens; A2) Application in the preparation of pathogen inhibitors; A3) Application in fruit and vegetable preservation; A4) Application in the preparation of preservation products.

6. A food preservation gel, characterized in that, It includes an active ingredient, which is the *Glucosobacterium oxygenase* as described in claim 1, or the microbial agent as described in claim 2, or the microbial agent prepared by the preparation method of the microbial agent as described in claim 3 or 4.

7. The preservative gel according to claim 6, characterized in that, The preservation gel also includes one or more of the following components: sodium alginate, chitosan, gelatin, glycerin, and YPD liquid culture medium; And / or, the active ingredient is added in the form of a bacterial suspension, wherein the concentration of *Staphylococcus oxidans* in the bacterial suspension is 10. 6 -10 8 CFU / mL; Optionally, the mass-to-volume ratio of sodium alginate, chitosan, gelatin, glycerol, YPD liquid culture medium, and bacterial suspension is 1-4:0.5-3:0.5-3:1-3:80-120:80-120, in g:g:g:mL:mL:mL.

8. The method for preparing the preservation gel according to claim 7, characterized in that, Includes the following steps: Step S1: Mix sodium alginate and gelatin with YPD liquid culture medium, sterilize, and obtain solution A; Step S2: Mix chitosan with acetic acid, sterilize, and obtain solution B; Step S3: Mix the above solutions A and B with glycerol to obtain solution C; Step S4: After adding the bacterial suspension to solution C, mix it with the cross-linking agent solution, let it stand, and then rinse to obtain the preservation gel. Optionally, the volume ratio of the crosslinking agent solution to acetic acid is 5-15:80-120; Optionally, the crosslinking agent solution is selected from a calcium chloride solution with a mass fraction of 1-5% and / or a calcium citrate solution with a mass fraction of 1-5%. Optionally, the settling time is 15-20 minutes; Optionally, the rinsing solution is selected from water or YPD medium; Optionally, the preservation method of the preservative gel includes preservation by immersion in YPD liquid culture medium; Optionally, in step S2, the mass fraction of the acetic acid is 0.5-1.5%.

9. A food preservation device, characterized in that, The invention includes a container with holes, and the container body contains the *Glucosobacterium oxysporum* of claim 1, or the microbial agent of claim 2, or the microbial agent prepared by the preparation method of the microbial agent of claim 3 or 4, or the preservation gel of claim 6 or 7, or the preservation gel prepared by the preparation method of claim 8.

10. A method for preserving food, characterized in that, The microbial agent prepared by the preparation method of the *Glucosobacterium oxysporum* according to claim 1, or the microbial agent according to claim 2, or the microbial agent according to claim 3 or 4, or the preservative gel according to claim 6 or 7, or the preservative gel prepared by the preparation method according to claim 8, can be used as a preservative to preserve food. Optionally, the preservation gel can be used for preservation treatment with or without contact with food.

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