Method suitable for manufacturing microbial specimen by UV (ultraviolet) adhesive sealing

Abstract

The invention discloses a method suitable for manufacturing a microbial specimen by sealing UV glue, and belongs to the technical field of microbial specimen manufacturing, microorganisms are inoculated to a plate culture medium for culture, then a cultured microbial plate is sterilized and dried, the preheated UV glue is poured into the dried microbial plate, and the microbial specimen is obtained. And carrying out auxiliary defoaming by using a hot air gun or a syringe needle or a vacuum pump, and finally, irradiating for 5 minutes or 8 minutes by using a 36W ultraviolet lamp, so as to obtain the microbial specimen. The method is mainly used for keeping morphological characteristics such as bacterial colony shape and color of microorganisms to the greatest extent after a series of specimen manufacturing process steps are carried out on a cultured microorganism plate with relatively obvious bacterial colony morphological characteristics, the processing steps are simple, convenient and safe, the prepared specimen is stable, and the method is suitable for large-scale popularization and application. The exhibition period is longer, and the exhibition effect is better.

Description

Technical Field

[0001] This invention relates to a method for preparing microbial specimens using UV adhesive sealing, specifically involving a process for safely sealing microbial colony morphology based on UV adhesive photocuring reaction, and belonging to the field of microbial specimen preparation technology. Background Technology

[0002] Microorganisms are widely distributed throughout the world and are a prerequisite factor related to human health and food security. Popularizing science and establishing a public knowledge system about microorganisms is very important. Microbial colony plate specimens can not only be widely used as a tool for promoting microbiology in public places, such as museum exhibitions, to quickly help the public establish an understanding of the basic morphology of microorganisms, but also be widely used as a new and portable teaching tool to enhance the scientific literacy and interest of young people.

[0003] The main methods for preparing microbial colony plate specimens include: (1) The formaldehyde fumigation method used by Mai Zhuoxiong et al. in “Study on Long-term Preservation of Microbiology Teaching Specimens” (Journal of Sun Yat-sen University of Medical Sciences, 1989, No. 3) to preserve microbial specimens. It was found that the best microbial killing effect was achieved when the amount of formaldehyde solution (formaldehyde content of 36%) in a sealed glass jar was 1 / 10 of the jar volume. This method is inexpensive, but it requires continuous observation of the killing effect and cannot determine the complete killing time of different microorganisms, that is, it is impossible to formulate a uniform treatment time for different bacteria and fungi with formaldehyde solution. (2) A method for preparing dried specimens of filamentous fungal cultures disclosed in Chinese Patent CN201510214489.7. This patent uses wet filter paper with multiple holes to obtain filamentous fungal cultures, and obtains dried specimens of filamentous fungal cultures after formaldehyde fumigation and natural drying. This method makes the conidia evenly distributed on the filter paper, which is convenient for observing the sporulation phenotype. However, the operation of this method is complicated and it is mainly for conidial fungi, and cannot be applied to the preparation of bacterial specimens. (3) Chinese patent CN202111273803.0 discloses a method for preparing a large fungal original state dripping specimen. This patent freezes the sample and then uses epoxy resin to fill and embed it, which can maintain the color and shape of the sample for several months. However, the epoxy resin used needs to be cured by a curing agent to initiate the curing reaction, and this process usually takes several hours or even several days to complete, which consumes a lot of time and costs. In addition, due to its low transparency, it will cause a corresponding decrease in ornamental value. (4) Chinese Patent CN2015103880332.2 discloses a method for plasticizing fungal specimens that have been soaked in a treatment solution (mainly formaldehyde) with polyethylene glycol. The biological specimens prepared by this method have a dense structure and are not easily deformed. However, the plasticizing process and pretreatment method used are relatively complicated. In addition, polyethylene glycol, as the main plasticizer, has the characteristic of being difficult to decompose, which may cause certain pollution to water quality and soil, and seriously harm the surrounding ecological environment.

[0004] Although the aforementioned methods have been practically applied to the preparation and preservation of microbial specimens, they still have some shortcomings. In particular, the formaldehyde solution used in specimen preparation can cause serious toxicity to humans, posing a safety hazard and hindering large-scale commercial application. Other drawbacks include long preparation times, narrow applicability, and high operational difficulty. Furthermore, polyethylene glycol's hygroscopic nature may cause surface bubbling in specimens during preservation, resulting in short preservation times or poor preservation effects. To enable wider and more portable use of microbial colony specimens and achieve optimal display results, we urgently need to establish a colony plate specimen preparation method applicable to a variety of microorganisms.

[0005] UV adhesive, also known as UV light-curing adhesive, is composed mainly of base resin, active monomers, and photoinitiators, along with stabilizers, crosslinking agents, and coupling agents. When exposed to ultraviolet light, the photoinitiator rapidly generates free radicals or ions, which in turn initiate the polymerization and crosslinking of the base resin and active monomers into a network structure, thereby achieving the purpose of bonding materials. Besides stable chemical properties, UV adhesive also features fast curing speed, energy saving, and environmental friendliness. More importantly, UV adhesive is a transparent polymer with higher transparency than materials such as epoxy resin, allowing it to preserve the most authentic state of the sample. Specimens prepared using UV adhesive have excellent visual appeal. Therefore, this invention will use UV dispensing to prepare microbial plate specimens. The entire preparation process is simple, does not involve toxic reagents, is harmless to the human body, and features long-term storage at room temperature and excellent visual appeal. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing microbial specimens using UV adhesive sealing. This method is mainly used to preserve the morphological characteristics of microbial colonies, such as shape and color, to the greatest extent possible after a series of specimen preparation steps on microbial plates with obvious colony morphological characteristics after culture. The processing steps are simple, convenient, and safe, and the resulting specimens are stable, have a long exhibition period, and have good display effects.

[0007] This invention is achieved through the following technical solution: a method for preparing microbial specimens using UV glue sealing, wherein microorganisms are inoculated onto a plate culture medium for cultivation, the cultured microbial plates are then sterilized and dried, preheated UV glue is poured into the dried microbial plates, defoaming is assisted by using a hot air gun, syringe needle, or vacuum pump, and finally, the microbial specimens are obtained by irradiation with a 36 W UV lamp for 5 or 8 minutes.

[0008] The plate culture media include LB agar medium, potato dextrose agar medium, and MRS agar medium.

[0009] During inoculation, the thickness of the culture medium on the plate is kept consistent.

[0010] During inoculation, the central single-point inoculation method, three-point inoculation method, streak plate method, or creative pattern drawing method are used; during cultivation, the size of the colonies is ensured to facilitate observation of colony morphology.

[0011] The creative pattern drawing method includes the following two approaches: Ⅰ. Cut out the desired pattern using kraft paper, cover it on the surface of a culture medium evenly coated with bacterial solution, then expose the surface of the culture medium to a UV lamp until all bacteria outside the desired pattern are killed, and then incubate at 37°C until the colonies form a clear pattern. II. Print the creative design on a round piece of white paper, then attach the paper to the back of the culture medium, and use a sterile inoculation needle to draw lines by dipping it in bacterial solution or picking up bacteria.

[0012] The sterilization process involves irradiating the cultured microbial plates with ultraviolet light for 3–5 hours.

[0013] The drying process involves placing the sterilized microbial plates in an oven at 40–50°C and baking them for 30 minutes.

[0014] The preheating process involves placing the UV adhesive in a 65°C oven.

[0015] Compared with the prior art, the present invention has the following advantages and beneficial effects: This invention fills the gap in current museum exhibitions of physical microbial specimens, solves the problems of safety and intuitiveness in microbial exhibitions, and develops a method for preparing microbial plate specimens based on UV epoxy resin. It has the characteristics of simple operation, high safety, good exhibition and viewing effect, and long preservation period. Compared with the display of microorganisms by pictures, it has a better popular science effect and intuitive experience for the public.

[0016] Based on the excellent chemical stability of UV-coated resin, this invention provides the following advantages for microbial plate specimens prepared through processes such as inoculation, UV sterilization, drying, UV coating, degassing, and UV curing: A. Covering the colony surface with cured UV adhesive can effectively slow down moisture evaporation and isolate it from the air, thereby effectively preventing the culture medium from deteriorating due to oxidation or moisture loss, and maintaining the colony morphology and culture medium state to a large extent.

[0017] B. After solidification, microbial plate specimens have a light transmittance of over 90%, allowing for clear observation of the fine morphology of colonies. This facilitates the display of colonies with various shapes and forms, thus maintaining good aesthetic appeal.

[0018] C. After the specimen is cured, the surface hardness increases, which makes it easier to preserve and transport, and can effectively avoid deformation caused by external force and other factors.

[0019] D. Due to the chemical stability of UV adhesive, specimens can be stored for a relatively long period without yellowing, fogging, or other oxidation.

[0020] E. The equipment involved is energy-saving and environmentally friendly, the materials and reagents are harmless to the human body, the manufacturing process is simple, and it is expected to achieve industrialized assembly line production. Attached Figure Description

[0021] Figure 1 The flowchart of the method for preparing microbial colony specimens based on UV adhesive technology provided by the present invention is shown.

[0022] Figure 2 This is a schematic diagram of a self-made ultraviolet lamp chamber.

[0023] Figure 3 Example diagram of preparing Escherichia coli colony specimens.

[0024] Figure 4 Example diagram of Staphylococcus aureus colony specimen preparation.

[0025] Figure 5 Example diagram of Bacillus colony preparation in Haikou.

[0026] Figure 6 Example image of preparing a specimen of *Morchella* colony.

[0027] Figure 7 Example image of preparing a Penicillium colony specimen.

[0028] Figure 8 Example image of preparing a Botrytis cinerea colony specimen.

[0029] Figure 9 The curves show the correlation between time and color difference for some example strains.

[0030] Figure 10 To monitor changes in color difference values ​​of some sample strains over several months. Detailed Implementation

[0031] The invention's objective, technical solution, and beneficial effects will be further explained in detail below.

[0032] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the claimed invention. Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0033] This invention aims to provide a method for preparing microbial plate biological specimens that is simple to operate, does not use toxic reagents, and can preserve the morphology of microbial colonies to the greatest extent. The method employs UV dispensing technology to prepare the microbial specimens. After UV sterilization and oven drying of the cultured microbial plates, they are then sealed with UV dispensing. This method can preserve the morphological characteristics of the colonies on the cultured microbial plates to the greatest extent, and has a longer exhibition period and better display effect. The resulting microbial plate biological specimens can also be used for museum exhibitions and microbial observation, and further, the color changes of the microbial plate specimens during storage can be tracked to preliminarily explore the optimal storage conditions.

[0034] Combination Figure 1 The specific steps of the manufacturing method described in this invention are as follows: Step 1, Preparation of plate culture medium: Use disposable 90mm×90mm agar plates. Different culture media (approximately 15mL) are used for different microorganisms. Bacteria are generally cultured on LB agar, fungi on potato dextrose agar (PDA), and lactic acid bacteria on MRS agar, etc. When pouring the plates, the thickness of the culture medium should be kept relatively uniform. It should not be too thin to avoid curling at the edges during subsequent drying, nor too thick to avoid affecting the visual appearance.

[0035] Step 2, Inoculation and Culture: Activate the corresponding bacterial strains before inoculation. For fungi, use either a central single-point inoculation or a three-point inoculation method, and culture at 28°C until colonies reach the size of a coin. For bacteria such as Bacillus, use streak plating or creative pattern drawing methods, and culture at 37°C until well-grown colonies are formed. It is important to strictly control the culture time to ensure colony size is suitable for observation of colony morphology. Simultaneously, monitor the spore production of fungi and Bacillus to avoid affecting the overall visual appeal.

[0036] There are two methods for drawing the above-mentioned creative patterns: one is to cut out the desired pattern from kraft paper, cover it on the surface of a culture medium that has been evenly coated with a certain amount of bacterial solution (it is recommended to use bacteria that do not produce or produce less spores, such as Escherichia coli), and then expose the surface of the culture medium to a UV lamp for about 30 minutes to completely kill bacteria other than the desired pattern, and then incubate at 37°C until the colonies form a clear pattern; the other is to print the creative pattern on a 90mm diameter circular white paper, then stick the white paper to the back of the culture medium, and use a sterile inoculation needle to dip into the bacterial solution or pick up bacteria to draw the lines.

[0037] Step 3, sterilization treatment: The cultured microbial plates were sterilized by irradiating them with ultraviolet light for 3-5 hours.

[0038] Step 4, Drying treatment: The moisture content of the culture medium will affect the subsequent sealing effect, so the drying process before sealing is particularly important. However, the drying temperature should not be too high and the treatment time should not be too long, otherwise the culture medium may curl up or even crack. Use an oven (40-50℃) to bake for about 30 minutes and observe it at any time.

[0039] Step 5, UV epoxy resin sealing: First, preheat the UV adhesive in a 65°C oven to eliminate most of the air bubbles. Then, slowly pour the preheated UV adhesive into a dried microbial plate. Use a heat gun or syringe needle to further defoam. If air bubbles remain at the bottom due to fungal hyphae growth, a vacuum pump can be used to remove them. Finally, place the plate in a 36W homemade UV lamp chamber (see [link to product]). Figure 2Irradiate for 5 min (bacteria) or 8 min (fungi) as shown.

[0040] The present invention will be further described in detail below with reference to embodiments, but the embodiments of the present invention are not limited thereto. The strains used in the following embodiments are all strains isolated and preserved by the Sichuan Provincial Key Laboratory of Resource Microbiology and Microbial Technology.

[0041] Example 1: Remove the *E. coli* strain to be revived from the -80°C ultra-low temperature freezer and quickly place it in a pre-cooled ice box. After the bacterial suspension has completely thawed naturally, add 100 μL of the bacterial suspension to 10 mL of sterile LB nutrient broth, label it, and incubate overnight in a shaker at 37°C. If the strain has been frozen for a long time, repeat the above steps three times to obtain a bacterial suspension with better activity. Spread the diluted bacterial suspension onto LB agar plates. Place a 90 mm diameter circular paper disc with a creative pattern on the bottom of the petri dish, then use a sterile inoculation needle to pick up a single colony and inoculate it, outlining the colony onto a uniformly thick LB nutrient agar plate. Incubate at 37°C for 16–18 h, sterilize with UV irradiation for 3 h, and then dry in an oven at 40–50°C for 30 min. Finally, a thin, preheated (65°C) layer of UV adhesive was slowly and evenly poured onto the surface of the culture medium. The surface was then defoamed using a hot air blower or syringe needle. Finally, the mixture was placed in a 36W self-made UV lamp chamber for 5 minutes for sealing and curing. The results are shown below. Figure 3 As shown.

[0042] Example 2: Remove the Staphylococcus aureus strain to be revived from the -80℃ ultra-low temperature freezer and quickly place it in a pre-cooled ice box. After the bacterial suspension has thawed completely, add 100 μL of the bacterial suspension to 10 mL of sterile LB nutrient broth, label it, and incubate overnight in a 37℃ constant temperature shaker. If the strain has been frozen for a long time, repeat the above steps three times to obtain a bacterial suspension with better activity. Spread the diluted bacterial suspension onto LB agar plates. Place a 90 mm diameter circular paper piece with a creative pattern on the bottom of the petri dish, then use a sterile inoculation needle to pick up a single colony and inoculate it, outlining the colony onto a uniformly thick LB nutrient agar plate. Incubate at 37℃ for 16–18 h, sterilize with UV irradiation for 3 h, and then dry in an oven at 40–50℃ for 30 min. Finally, a thin, preheated (65℃) layer of UV adhesive was slowly and evenly poured onto the surface of the culture medium. Surface defoaming was performed using a hot air blower or syringe needle. The medium was then placed in a 36W self-made UV lamp chamber for 5 minutes for sealing and curing. The results are shown below. Figure 4 As shown.

[0043] Example 3: Remove the *Bacillus haikouensis* strain to be revived from the -80℃ ultra-low temperature freezer and quickly place it in a pre-cooled ice box. After the bacterial suspension has completely thawed naturally, add 100 μL of the bacterial suspension to 10 mL of sterile 2216E liquid medium, label it, and incubate overnight in a 37℃ constant temperature shaker. If the strain has been frozen for a long time, repeat the above steps three times to obtain a bacterial suspension with better activity. Spread the diluted bacterial suspension onto 2216E agar plates. Place a 90 mm diameter circular paper piece with a creative pattern on the bottom of the petri dish, then use a sterile inoculation needle to pick up a single colony and inoculate it, outlining the colony onto a uniformly thick 2216E agar plate. Incubate at 37℃ for 16 h, sterilize with ultraviolet light for 4 h, and then dry in an oven at 40–50℃ for 30 min. Finally, a thin, preheated (65℃) layer of UV adhesive was slowly and evenly poured onto the surface of the culture medium. Surface defoaming was performed using a hot air blower or syringe needle. The medium was then placed in a 36W self-made UV lamp chamber for 5 minutes for sealing and curing. The results are shown below. Figure 5 As shown.

[0044] Example 4: The *Morchella* strain to be revived was removed from the -80℃ ultra-low temperature freezer and quickly placed in a pre-cooled ice box. After the bacterial culture was completely thawed naturally, it was inoculated into PDA agar medium using a sterile inoculation needle. After three generations of rejuvenation, a viable *Morchella* strain was obtained. This strain was then inoculated at three points into a uniformly thick PDA agar medium, labeled, and incubated in a 28℃ incubator for 2–3 days. When the *Morchella* colonies reached the size of a coin, they were sterilized by continuous UV irradiation for 5 hours, followed by drying in a 70℃ oven for 5 minutes. Then, a slightly thick layer of UV adhesive preheated to 65℃ was slowly and evenly poured onto the surface of the medium (the fungus produces hyphae, forming protrusions on the surface of its colonies; if the hyphae are to be completely covered, the UV adhesive needs to be poured thicker, but not too thick, otherwise it will affect the sealing and viewing effect). The air between the hyphae was first removed using a vacuum pump, and then the surface was defoamed using a hot air blower or syringe needle. Finally, it was placed in a 36W self-made UV lamp chamber for 8 minutes for sealing and curing (see results). Figure 6 ).

[0045] Example 5: The Penicillium strain to be revived was taken out of the -80℃ ultra-low temperature freezer and quickly placed in a pre-cooled ice box. After the bacterial culture was completely thawed naturally, it was inoculated into PDA agar medium using a sterile inoculation needle. After three generations of rejuvenation, a viable Penicillium strain was obtained. This strain was then inoculated at three points into a PDA agar medium of uniform thickness, labeled, and incubated in a 28℃ constant temperature incubator for 3-4 days. When the Penicillium colonies reached the size of lentils, they were sterilized by continuous UV irradiation for 5 hours, followed by drying in an oven at 70℃ for 5 minutes. Then, a slightly thick layer of UV adhesive preheated to 65℃ was slowly and evenly poured onto the surface of the medium (the fungus produces hyphae, forming protrusions on the surface of its colonies; if the UV adhesive is to completely cover the hyphae, it needs to be poured thicker, but not too thick, otherwise it will affect the sealing and viewing effect). The air between the hyphae was first removed using a vacuum pump, and then the surface was defoamed using a hot air blower or syringe needle. Finally, it was placed in a 36W self-made UV lamp chamber for 8 minutes for sealing and curing. The results are shown in the figure. Figure 7 As shown.

[0046] Example 6: The *Gyroderma* strain to be revived was removed from the -80℃ ultra-low temperature freezer and quickly placed in a pre-cooled ice box. After the bacterial culture was completely thawed naturally, it was inoculated into PDA agar medium using a sterile inoculation needle. After three generations of rejuvenation, a viable *Gyroderma* strain was obtained. This strain was then inoculated at three points on a PDA agar medium of uniform thickness, labeled, and incubated in a 28℃ incubator for 3–4 days. Once the *Gyroderma* colonies reached the size of lentils, they were sterilized by continuous UV irradiation for 5 hours, followed by drying in a 70℃ oven for 5 minutes. Then, a slightly thick layer of preheated UV adhesive (at 65℃) was slowly and evenly poured onto the surface of the medium (the fungus produces hyphae, forming protrusions on the surface of its colonies; to completely cover the hyphae, the UV adhesive needs to be poured thicker, but not too thick, otherwise it will affect the sealing and viewing effect). Air was first removed from between the hyphae using a vacuum pump, followed by surface defoaming using a hot air blower or syringe needle. Finally, the medium was irradiated in a 36W self-made UV lamp chamber for 8 minutes for sealing and curing. The results are shown in [Figure 1]. Figure 8 As shown.

[0047] Given that a major challenge in preparing microbial plate specimens is that the color and transparency of the solidified culture medium change due to oxidation, resulting in yellowing, curling edges, and other phenomena, thus reducing the visual appeal, this invention also monitors the color difference value of the solidified specimens in real time over several months after preparation. The colorimeter used utilizes a photoelectric integrating element with specific spectral sensitivity, which can directly measure the colorimetric changes of the object surface based on the CIE Lab color space.

[0048] This invention uses 18 specimens of *Penicillium*, *Botrytis*, *Morchella*, *Bacillus haikouensis*, *Escherichia coli*, and *Staphylococcus aureus*, stored at room temperature and protected from light for one month as examples (the specimen preparation process is described in Examples 1 to 6). Color difference changes were observed over a 20-day period. Three points were evenly selected from each specimen and the average was calculated. L*, a*, and b* were measured at fixed points every 4 days, and the results were calculated using the formula: Calculate ΔE*ab for each specimen to represent the specific situation of a particular specimen.

[0049] Taking *Penicillium*, *Botrytis*, *Morchella*, and *Bacillus haikouensis* as examples, correlation curves between time and color difference were fitted and plotted. The results are shown in […]. Figure 9 As shown, within a certain time range, the color difference values ​​of Penicillium, Botrytis, and Moraxella fluctuated little, and ΔE*ab remained basically unchanged. However, the ΔE*ab of Bacillus haikouensis showed a more obvious increasing trend within the 20-day observation period.

[0050] Taking *Penicillium*, *Botrytis*, *Morchella*, *Escherichia coli*, *Staphylococcus aureus*, and *Bacillus haikouensis* as examples, the distribution of color difference values ​​after several months of storage (approximately 50–60 days) was plotted. The results are shown in […]. Figure 10 As shown, the results indicate that, except for Bacillus haikouensis, whose final ΔE*ab average value slightly exceeded 2 NBS, the ΔE*ab values ​​of the other five strains were all below 2 NBS. This suggests that after most strains were cured by UV dispensing and stored at room temperature (25℃) in the dark for several months, the surface color of the culture medium did not show significant differences, meaning that the morphology and color of the bacteria could be maintained. The specimens could still maintain their excellent ornamental value within a time range of 50 to 60 days, indicating that they can be well preserved under the conditions of room temperature (25℃) in the dark.

[0051] Based on the above, it can be demonstrated that the method of the present invention can be successfully applied to the preparation of various microbial colony specimens with different properties, and has high stability during subsequent preservation at room temperature and in the dark. It can maintain the clear morphology and color of the colonies, keep the color of the culture medium basically unchanged, and maintain the aesthetics of the microbial plate specimens for a long period of time.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for making a microbial specimen using UV glue encapsulation, the method comprising: The microorganism is inoculated into a flat plate culture medium for culture, then the cultured microorganism flat plate is sterilized and dried, the preheated UV glue is poured into the dried microorganism flat plate, a hot air gun or a syringe needle or a vacuum pump is used for auxiliary defoaming, finally a 36 W ultraviolet lamp is used for irradiation for 5 min or 8 min, and the microorganism specimen is prepared. ​ 2. The method of claim 1, wherein: The flat plate culture medium comprises LB agar medium, potato glucose agar medium and MRS agar medium.

3. The method of claim 1, wherein: During the inoculation, the thickness of the culture medium on the flat plate is controlled to be uniform.

4. The method of claim 1, wherein: During the inoculation, the central single-point inoculation method, the three-point inoculation method, the flat plate streaking method or the creative pattern drawing method is used; during the culture, the colony size is ensured to be convenient for observation of the colony morphology.

5. The method of claim 1, wherein: The creative pattern drawing method comprises the following two modes: I. a cowhide paper is cut into a required pattern, is covered on the culture medium surface uniformly coated with a bacterial liquid, then the culture medium surface is exposed to an ultraviolet lamp, is irradiated until the bacteria outside the required pattern are completely killed, and is cultured at 37 DEG C until the colony forms a clear pattern; II. a creative pattern is printed on a circular white paper, the white paper is pasted on the back of the culture medium, and a sterile inoculation needle is used to draw lines by dipping the bacterial liquid or picking the bacterial body.

6. The method of claim 1, wherein: The sterilization is that the cultured microorganism flat plate is irradiated by ultraviolet light for 3-5 h.

7. The method of claim 1, wherein: The drying is that the microorganism flat plate after sterilization is placed in an oven at 40-50 DEG C for baking for 30 min.

8. The method of claim 1, wherein: The preheating is that the UV glue is placed in a 65 DEG C oven for treatment.

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