Freeze-drying protective agent for preservation of campylobacter strain and preparation method thereof

Abstract

The invention relates to the technical field of freeze-drying protective agents, and provides a freeze-drying protective agent for campylobacter strain preservation and a preparation method thereof.The freeze-drying protective agent for campylobacter strain preservation is prepared from milk powder, bovine serum albumin, gelatin, trehalose and L-cysteine hydrochloride. According to the technical scheme, the problem that in the prior art, after campylobacter is freeze-dried, the preservation time of the strain is short is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of freeze-drying protectant, in particular, it relates to a freeze-drying protectant for preserving Campylobacter strains and a preparation method thereof. BACKGROUND

[0002] Campylobacter is an important pathogenic bacterium in food microbiological testing. With the rapid development of China's economy, the health status of residents and food consumption patterns have changed significantly, and Campylobacter has become an important pathogenic bacterium causing human diarrhea.

[0003] Campylobacter is a microaerophilic bacterium, which generally grows well in a gas environment containing 10% CO2 and 5% O2. Most Campylobacter can grow at 36℃, while Campylobacter jejuni, Campylobacter coli and Campylobacter gellidus can also grow well at 42℃, which are heat-resistant Campylobacter.

[0004] During the storage of bacterial strains, Campylobacter is more fragile and difficult to store and survive compared to other bacterial strains. The commonly used preservation method is glycerol ultra-low temperature refrigerator freezing method, which has a short preservation time of generally 1-2 years, and is also easily affected by the environment, such as the number of freeze-thaw cycles of the bacterial strain and the temperature change of the ultra-low temperature refrigerator.

[0005] There are three commonly used preservation methods at present. The first method is to cover the liquid medium or slant medium after culturing Campylobacter with glycerol or liquid paraffin, and store it at 4℃ for about one year. The second method is to mix the culture of Campylobacter in broth medium and add 50% glycerol ultra-low temperature (–70℃ or lower) to store it for more than one year or even several years. The disadvantage is that the bacterial strain needs to be kept in an ultra-low temperature environment all the time, and once the refrigerator fails, the bacterial strain may die. The storage period is generally 3-5 years, and the disadvantage is that it cannot be stored for a long time. The third method is freeze-drying technology, which can theoretically ensure a longer preservation time of Campylobacter, up to ten years or even longer.

[0006] Freeze-drying technology is a good preservation method for Campylobacter, but there are few studies on the freeze-drying method of Campylobacter at present. The research mainly focuses on Campylobacter jejuni and Campylobacter fetus, and there are few studies on the freeze-drying technology of Campylobacter coli, Campylobacter gellidus and Campylobacter upsaliensis. In the freeze-drying technology, the composition of the protectant is the key, which determines the preservation time of the bacterial strain after freeze-drying of Campylobacter. In the traditional bacterial strain preservation freeze-drying process, 10g / 100mL milk powder is commonly used as a freeze-drying protectant for direct freeze-drying, but the preservation period is short, and the bacterial strain will be inactivated after a few months. Therefore, a new freeze-drying protectant needs to be developed for the freeze-drying of Campylobacter to obtain a longer preservation time.

[0007] Patent application CN112899379A discloses a preservative that can be used for freeze-drying Campylobacter jejuni, the components of which include: fetal bovine serum, milk powder, lactate, inositol, L-cysteine ​​hydrochloride, etc.; however, there is no experimental data to prove its preservation effect on other Campylobacter species.

[0008] The national food safety standard GB 4789.9-2014, "National Food Safety Standard - Microbiological Examination of Food - Campylobacter jejuni Examination," covers Campylobacter species including Campylobacter jejuni, Campylobacter coli, Campylobacter guillier, and Campylobacter uppsala. In food microbiological testing, quality control for these Campylobacter species relies on reliable and stable Campylobacter strains. However, no freeze-drying process has yet been reported that is applicable to common strains such as Campylobacter jejuni, Campylobacter coli, Campylobacter guillier, and Campylobacter uppsala.

[0009] Therefore, it is necessary to develop a freeze-drying protectant for the preservation of common Campylobacter species, which can achieve a longer preservation time. Summary of the Invention

[0010] This invention proposes a freeze-drying protectant for the preservation of Campylobacter strains and its preparation method, which solves the problem of short preservation time of Campylobacter strains after freeze-drying in related technologies.

[0011] The technical solution of the present invention is as follows: This invention proposes a freeze-drying protectant for the preservation of Campylobacter strains, comprising the following components: milk powder, bovine serum albumin, gelatin, trehalose, and L-cysteine ​​hydrochloride.

[0012] As a further technical solution, the following components are included in mass concentration: milk powder 0.63~10g / 100mL, bovine serum albumin 0.31~20g / 100mL, gelatin 0.018~1g / 100mL, trehalose 5~20g / 100mL, and L-cysteine ​​hydrochloride 0.05~1.5g / 100mL.

[0013] As a further technical solution, the following components are included in mass concentration: milk powder 1.63g / 100mL, bovine serum albumin 0.45g / 100mL, gelatin 0.48g / 100mL, trehalose 12.3g / 100mL, and L-cysteine ​​hydrochloride 0.1g / 100mL.

[0014] This invention also proposes a method for preparing a freeze-drying protectant for the preservation of Campylobacter strains, comprising the following steps: The components of the lyophilization protectant for the preservation of Campylobacter strains were sterilized and then mixed to obtain the lyophilization protectant for the preservation of Campylobacter strains.

[0015] As a further technical solution, the sterilization method includes autoclaving and / or filtration sterilization.

[0016] As a further technical solution, the preparation method of the freeze-drying protectant for preserving Campylobacter strains includes the following steps: Milk powder and gelatin are autoclaved to obtain component A. Bovine serum albumin, trehalose, and L-cysteine ​​hydrochloride are filtered and sterilized to obtain component B. Component A and component B are mixed to obtain a freeze-drying protectant for the preservation of Campylobacter strains.

[0017] As a further technical solution, the high-pressure sterilization temperature is 115℃, the time is 15min, and the pressure is 0.067MPa.

[0018] As a further technical solution, the filtration and sterilization uses a 0.22μm sterile filter membrane.

[0019] The present invention also proposes the application of the freeze-drying protectant for the preservation of Campylobacter strains or the freeze-drying protectant for the preservation of Campylobacter strains prepared by the above preparation method in the preservation of Campylobacter strains.

[0020] As a further technical solution, the Campylobacter strains include one or more of Campylobacter jejuni, Campylobacter coli, Campylobacter guillier, and Campylobacter uppsala.

[0021] The working principle and beneficial effects of this invention are as follows: In this invention, a cryoprotectant suitable for freeze-drying Campylobacter was developed. The cryoprotectant comprises milk powder, bovine serum albumin, gelatin, trehalose, and L-cysteine ​​hydrochloride, which improves the stability of Campylobacter preservation. Stability testing showed that after 6 months of storage at -20°C, the bacterial count of four Campylobacter strains remained essentially unchanged. Accelerated stability storage at 37°C for 20 days resulted in a decrease of approximately two orders of magnitude in the bacterial count of all four strains, while maintaining a count of 10. 2 A level of CFU / sample or higher can meet the requirements for qualitative preservation of microbial strains. Attached Figure Description

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0023] Figure 1 This is a graph showing the stability results of the standard strains of Campylobacter jejuni, Campylobacter coli, Campylobacter guillier, and Campylobacter uppsala of Example 2 of the present invention at -20°C for 6 months. Figure 2 The graph shows the accelerated stability results at 37°C for the standard strains of Campylobacter jejuni, Campylobacter coli, Campylobacter guillier, and Campylobacter uppsala of Example 2 of the present invention. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] The following will describe in detail the freeze-drying protectant for preserving Campylobacter strains according to embodiments of the present invention and its preparation method.

[0026] According to one aspect of the present invention, a freeze-drying protectant for the preservation of Campylobacter strains is provided, comprising the following components: milk powder, bovine serum albumin, gelatin, trehalose, and L-cysteine ​​hydrochloride.

[0027] In this invention, milk powder, bovine serum albumin, gelatin, trehalose, and L-cysteine ​​hydrochloride are used as components of the freeze-drying protectant for the preservation of Campylobacter strains. The milk powder is rich in nutrients such as protein and lactose. The protein can form a protective film on the surface of Campylobacter, reducing the damage to the bacteria caused by ice crystals during freeze-drying. Lactose can form a glassy matrix in the dry state, encapsulating the Campylobacter and maintaining the stability of its structure and function. Bovine serum albumin can form a hydration layer around the Campylobacter, reducing cell dehydration and minimizing cell damage caused by water loss. Similarly, bovine serum albumin can bind to the macromolecules in the bacteria, stabilizing the structure of the bacterial proteins and improving the bacteria's resistance to environmental changes such as temperature and dryness, thereby maintaining the activity of the Campylobacter. Gelatin, as a macromolecule colloid, can form a protective film on the surface of the Campylobacter, isolating the bacteria from adverse external factors. Trehalose can bind to macromolecules in the freeze-drying process, replacing water molecules, inhibiting the formation of ice crystals, and maintaining the integrity of the cell membrane. The sulfhydryl groups in L-cysteine ​​hydrochloride have antioxidant effects, neutralizing free radicals and delaying oxidative damage to the Campylobacter during freeze-drying.

[0028] In this invention, the stability of Campylobacter preservation was improved by optimizing the mass concentrations of milk powder, bovine serum albumin, gelatin, trehalose, and L-cysteine ​​hydrochloride. When the mass concentrations of milk powder, bovine serum albumin, gelatin, trehalose, and L-cysteine ​​hydrochloride were 1.63 g / 100 mL, 0.45 g / 100 mL, 0.48 g / 100 mL, 12.30 g / 100 mL, and 0.10 g / 100 mL, better protection of Campylobacter was achieved during freeze-drying. In one embodiment of this invention, after using a freeze-drying protectant for Campylobacter strain preservation and stabilizing the cells at 37°C for 20 days, the four Campylobacter strains showed a decrease of approximately two orders of magnitude, all maintaining a stability of 10%. 2 CFU / sample level or above.

[0029] This invention also proposes a method for preparing a freeze-drying protectant for the preservation of Campylobacter strains, comprising the following steps: Milk powder and gelatin were autoclaved to obtain component A. Trehalose and L-cysteine ​​hydrochloride were filtered and sterilized to obtain component B. Component A, component B and bovine serum albumin were mixed to obtain a freeze-drying protectant for the preservation of Campylobacter strains.

[0030] The preparation process provided by this method can ensure the quality and performance of the freeze-drying protectant for the preservation of Campylobacter strains, thereby improving the preservation stability of Campylobacter.

[0031] In one embodiment of the present invention, the sterilization temperature is 115°C, the time is 15 min, and the pressure is 0.067 MPa.

[0032] In the preparation method of the freeze-drying protectant for the preservation of Campylobacter strains of the present invention, sterilization is used to eliminate potential microbial contamination and avoid the impact on the survival environment of Campylobacter due to the consumption of nutrients and the generation of metabolic waste by microorganisms during subsequent preservation. This ensures the purity and stability of the protectant itself, thereby providing a reliable protective basis for Campylobacter.

[0033] In one embodiment of the invention, a 0.22 μm sterile filter membrane is used for filtration sterilization.

[0034] In the preparation method of the freeze-drying protectant for the preservation of Campylobacter strains of the present invention, a high concentration solution of trehalose and L-cysteine ​​hydrochloride is filtered and sterilized using a 0.22 μm sterile filter membrane. This method can avoid the destruction of chemical components by high temperature during autoclaving.

[0035] Example 1 1.1 Culture conditions for screening strains: ATCC33291 Campylobacter jejuni was used as the validation strain; Campylobacter jejuni was cultured on Columbia agar, TSA agar, and Bolton broth. Bacterial cells were collected and mixed with 10 g / 100 mL milk powder and 10 g / 100 mL trehalose as freeze-drying protectants. The mixture was dispensed in 300 μL vials and pre-frozen at -70°C for 2 hours. The samples were then freeze-dried until completely dry. The freeze-dried samples were subjected to accelerated stability testing at 37°C to compare the stability differences under different culture conditions, as shown in Table 1.

[0036] Table 1. Comparison of freeze-drying effects of Campylobacter jejuni culture ATCC33291 on Columbia agar, TSA agar, and Bolton broth.

[0037] As shown in Table 1, the culture medium of TSA agar has the best stability. Therefore, TSA agar medium was selected as the culture condition for Campylobacter before freeze-drying.

[0038] 1.2 Screening for the optimal mass concentration of different protective agents 1.2.1 Screening for the optimal mass concentration of milk powder Based on a trehalose concentration of 10 g / 100 mL, the concentration of milk powder was varied from 0.63 to 10 g / 100 mL. Campylobacter jejuni ATCC33291 was freeze-dried, and its stability was evaluated by accelerating the destruction temperature to 37 °C. The figures in the table are the logarithmic values ​​of the Campylobacter content in the samples.

[0039] Table 2. Accelerated stability changes of ATCC33291 Campylobacter jejuni lyophilized samples of milk powder at different mass concentrations.

[0040] As can be seen from Table 2, the rate of decrease is slowest when the mass concentration of milk powder is 1.25 g / 100 mL, thus determining 1.25 g / 100 mL as its optimal mass concentration.

[0041] 1.2.2 Screening for the optimal mass concentration of bovine serum albumin Based on a trehalose concentration of 10 g / 100 mL, the concentration of bovine serum albumin was varied from 0.31 to 20.0 g / 100 mL to freeze-dry Campylobacter jejuni (ATCC33291). The stability of the samples was then evaluated by accelerating the degradation temperature to 37 °C, as shown in Table 3. The numbers in the table are the logarithmic values ​​of the Campylobacter content in the samples.

[0042] Table 3. Accelerated stability changes of ATCC33291 Campylobacter jejuni lyophilized samples under different concentrations of bovine serum albumin.

[0043] As shown in Table 3, the rate of decrease in bovine serum albumin was slowest when the concentration was 0.63 g / 100 mL, thus determining 0.63 g / 100 mL as its optimal concentration.

[0044] 1.2.3 Screening for the optimal mass concentration of gelatin Based on trehalose at a mass concentration of 10 g / 100 mL, gelatin was used with a mass concentration ranging from 0.018 to 1 g / 100 mL to freeze-dry Campylobacter jejuni. Its stability was then evaluated by accelerating the destruction temperature to 37 °C, as shown in Table 4. The numbers in the table are the logarithmic values ​​of the Campylobacter content in the samples.

[0045] Table 4. Accelerated stability changes of ATCC33291 Campylobacter jejuni lyophilized samples with different mass concentrations of gelatin

[0046] As can be seen from Table 4, the rate of decrease is slowest when the mass concentration of gelatin is 0.63 g / 100 mL, and 0.63 g / 100 mL is determined to be its optimal mass concentration.

[0047] 1.2.4 Screening for the optimal mass concentration of trehalose Based on lactose with a mass concentration of 10 g / 100 mL, trehalose with a mass concentration ranging from 5 to 20 g / 100 mL was used to freeze-dry Campylobacter jejuni. Then, its stability was evaluated by accelerating the destruction temperature to 37 °C, as shown in Table 5. The numbers in the table are the logarithmic values ​​of the Campylobacter content in the samples.

[0048] Table 5. Accelerated stability changes of lyophilized Campylobacter jejuni samples with different mass concentrations of trehalose (ATCC33291).

[0049] As can be seen from Table 5, the rate of decrease is slowest when the trehalose concentration is 15 g / 100 mL, thus determining 15 g / 100 mL as its optimal concentration.

[0050] 1.2.5 Screening for the optimal mass concentration of L-cysteine ​​hydrochloride Based on milk powder and trehalose with a mass concentration of 10 g / 100 mL and L-cysteine ​​hydrochloride with a mass concentration ranging from 0.05 to 1.50 g / 100 mL, Campylobacter jejuni was freeze-dried, and its stability was evaluated by accelerating the destruction temperature to 37 °C, as shown in Table 6. The numbers in the table are the logarithmic values ​​of the Campylobacter content in the samples.

[0051] Table 6. Accelerated stability changes of L-cysteine ​​hydrochloride-containing lyophilized Campylobacter jejuni samples at different mass concentrations.

[0052] As can be seen from the table, the rate of decrease is slowest when the mass concentration of L-cysteine ​​hydrochloride is 0.10 g / 100 mL, thus determining 0.10 g / 100 mL as its optimal mass concentration. 1.3 Based on the functions of the protective agents, the optimal combination of four factors—milk powder, gelatin, bovine serum albumin, and trehalose—was screened using Design-Expert 13 software based on response surface methodology. Since the primary function of L-cysteine ​​hydrochloride is anti-oxidation, the optimal concentration was determined to be 0.10 g / 100 mL. 1.3.1 Based on the above optimal response value range, the optimal addition amount and step size of the above factors are determined, as shown in Table 7.

[0055] Table 7. Levels of various factors in the protective agent

[0056] Based on the levels of the main factors mentioned above, response surface methodology was designed using Box-Behnken in Design-Expert 13 software, resulting in 29 combinations for experiments, as shown in Table 8.

[0057] Table 8 Recommended combinations for Box-Behnken response surface design in Design-Expert 13 software

[0058] Combinations 25, 26, 27, and 29 in Table 8 are repetitions of the central point, resulting in 26 different formulation combinations. Freeze-drying experiments were conducted on ATCC33291 Campylobacter jejuni using these 26 different formulation combinations. Accelerated experiments were performed on the freeze-dried samples of the 26 combinations at 36℃. Stability tests were conducted at 0, 1, 3, 5, 7, and 14 days. The bacterial count (CFU / sample) was converted to the logarithm of log10, and the decreasing trend was analyzed using Excel. The decreasing coefficient in the decreasing trend line formula was used as the response value for analysis in Design-Expert 13 software. The stability results and the decreasing trend line formula are shown in Table 9.

[0059] Table 9. Stability results and decreasing trend of 26 combinations of ATCC33291 Campylobacter jejuni samples after freeze-drying at 36℃ in accelerated stability test.

[0060] The coefficients of the downward trend lines of the above 26 combinations accelerated destruction at 36℃ were used as response values ​​and analyzed using Design-Expert13 software. The software recommended the following combination formulations: milk powder 1.63g / 100mL, gelatin 0.48g / 100mL, trehalose 12.30g / 100mL, bovine serum albumin 0.45g / 100mL, and L-cysteine ​​hydrochloride 0.10g / 100mL.

[0061] Example 2 The stability of standard strains of Campylobacter jejuni, Campylobacter coli, Campylobacter larifolium, and Campylobacter uppsaliensis was confirmed by freeze-drying using an optimal combination of 1.63 g / 100 mL milk powder, 0.48 g / 100 mL gelatin, 12.30 g / 100 mL trehalose, 0.45 g / 100 mL bovine serum albumin, and 0.10 g / 100 mL L-cysteine ​​hydrochloride. 2.1 In vivo culture: Campylobacter strains were inoculated onto TSA agar and cultured at 36°C under microaerophilic conditions (10% carbon dioxide, 5% oxygen) for 48 hours to obtain first-generation culture; then the first-generation strains were inoculated onto TSA agar again and cultured at 36°C under microaerophilic conditions for 48 hours to obtain fresh second-generation culture. Collect bacterial cells: scrape bacterial growth from the surface of TSA agar, mix it with lyophilization protectant, and obtain concentrated bacterial suspension; Preparation of the preservative: Milk powder and gelatin were sterilized at 115℃ and 0.067MPa for 15min to obtain component A. Trehalose and L-cysteine ​​hydrochloride were sterilized by filtration through a 0.22μm sterile filter membrane to obtain component B. Component A, component B and bovine serum albumin were mixed and water was added to bring the volume to 100mL to obtain the freeze-drying preservative for Campylobacter strains. Freeze-drying process: The bacterial suspension was dispensed into 300 μL / vial, pre-frozen at -70°C for 2 hours, and then freeze-dried in a freeze dryer until it was completely freeze-dried to obtain the freeze-dried sample.

[0063] 2.2 Stability Test 2.2.1 Stability test at –20℃ Freeze-dried Campylobacter samples were placed in a -20°C freezer. Two samples were taken out at 1 month, 2 months, 3 months, 4 months, 5 months, and 6 months to test the Campylobacter content. The test results are shown in Table 10. Figure 1 As shown in the figure; Figure 1 The X-axis represents the storage time at -20℃ (in months), and the Y-axis represents the logarithmic value of the bacterial content conversion in the sample. Table 10. Stability results of four standard strains of Campylobacter (Campylobacter jejuni, Campylobacter coli, Campylobacter guillier, and Campylobacter uppsala) after 6 months at –20℃.

[0064] As shown in Table 10, the number of Campylobacter remained essentially unchanged after being stored at -20°C for 6 months.

[0065] 2.2.2 Accelerated stability test at 37℃ The samples were placed at 37℃ and removed at 1, 3, 5, 7, and 14 days to test the Campylobacter content. The test results are shown in Table 11. Figure 2 As shown in the figure; Figure 2 The X-axis represents the storage time (in days) at 37℃ for accelerated stability, and the Y-axis represents the logarithmic value of bacterial content conversion in the sample. Add 1 mL of physiological saline to a lyophilized vial, shake to mix, and then perform a 1:10 serial dilution to prepare 1:10, 1:100, and 1:1000 dilutions. Select an appropriate dilution based on the bacterial content in the sample, take 100 μL and add it to a TSA agar plate, spread it, dry it, and then incubate it at 37°C for microaerophilic culture to count the bacteria, so that the bacterial count on the plate is between 30 and 300. Table 11. Accelerated stability results at 37℃ for standard strains of Campylobacter jejuni, Campylobacter coli, Campylobacter guillier, and Campylobacter uppsala.

[0066] As shown in Table 11, the Campylobacter content remained at 10 after 14 days of accelerated stability testing at 37℃. 3 CFU or above.

[0067] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A lyophilization protectant for the preservation of a Campylobacter strain, characterized in that, The freeze-drying protective agent for Campylobacter strain preservation comprises the following components: milk powder, bovine serum albumin, gelatin, trehalose, L-cysteine hydrochloride.

2. The freeze-drying protectant for Campylobacter strain preservation according to claim 1, characterized by The freeze-drying protective agent for Campylobacter strain preservation comprises the following components in the following mass concentrations: milk powder 0.63-10 g / 100 mL, bovine serum albumin 0.31-20 g / 100 mL, gelatin 0.018-1 g / 100 mL, trehalose 5-20 g / 100 mL, L-cysteine hydrochloride 0.05-1.5 g / 100 mL.

3. The freeze-drying protectant for Campylobacter strain preservation according to claim 2, characterized in that, The freeze-drying protective agent for Campylobacter strain preservation comprises the following components in the following mass concentrations: milk powder 1.63 g / 100 mL, bovine serum albumin 0.45 g / 100 mL, gelatin 0.48 g / 100 mL, trehalose 12.3 g / 100 mL, L-cysteine hydrochloride 0.1 g / 100 mL.

4. A method for the preparation of a freeze-drying protectant for the preservation of Campylobacter strains, characterized in that, The method for preparing the freeze-drying protective agent for Campylobacter strain preservation according to any one of claims 1-3 comprises the following steps: The components of the freeze-drying protective agent for Campylobacter strain preservation are sterilized and then mixed to obtain the freeze-drying protective agent for Campylobacter strain preservation.

5. The method for preparing a freeze-drying protective agent for a Campylobacter strain according to claim 4, characterized by, The sterilization method comprises autoclaving and / or filter sterilization.

6. The method for preparing a freeze-drying protective agent for a Campylobacter strain according to claim 4, characterized by, The method comprises the following steps: The milk powder and the gelatin are autoclaved to obtain component A, the trehalose and the L-cysteine hydrochloride are filter sterilized to obtain component B, and the component A, the component B and the bovine serum albumin are mixed to obtain the freeze-drying protective agent for Campylobacter strain preservation.

7. The method for preparing a freeze-drying protective agent for a Campylobacter strain according to claim 6, characterized by, The autoclaving is performed at a temperature of 115°C for 15 min under a pressure of 0.067 MPa.

8. The method for preparing a freeze-drying protective agent for a Campylobacter strain according to claim 6, characterized by, The filter sterilization uses a 0.22 μm sterile filter membrane.

9. The freeze-drying protective agent for Campylobacter strain preservation according to any one of claims 1-3 or prepared by the method according to any one of claims 4-8 is used in the preservation of a Campylobacter strain.

10. Use according to claim 9, characterized in that, The Campylobacter strain comprises one or more of Campylobacter jejuni, Campylobacter coli, Campylobacter gellidus and Campylobacter upsaliensis.

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