A kind of glutamine aminotransferase culture medium and its preparation method and fermentation process

Abstract

The present application discloses a transglutaminase culture medium and a preparation method and fermentation process thereof, belonging to the field of microbial fermentation. A transglutaminase culture medium comprises the following raw materials: sucrose 25-35 g / L, sodium nitrate 1-3 g / L, dipotassium hydrogen phosphate 0.5-1.5 g / L, magnesium sulfate 0.3-0.6 g / L, potassium chloride 0.3-0.6 g / L, ferrous sulfate 0.01-0.02 g / L, agar 15-25 g / L, malt juice 40-60 mL / L, Jerusalem artichoke juice 20-40 mL / L, and the rest is water. The present application has the effect of improving the enzyme activity level of the strain culture fermentation for producing transglutaminase.

Description

Technical Field

[0001] The present application relates to the field of microbial fermentation, and in particular to a glutamine transaminase culture medium and a preparation method and fermentation process thereof. Background Art

[0002] Glutamine transaminase, or TG enzyme, has the function of catalyzing the acyl transfer reaction between proteins and causing covalent cross-linking between proteins. Therefore, it can be used in meat products, dairy products and pasta products to improve the nutritional value and texture of protein.

[0003] The existing production of glutamine transaminase usually relies on a specific microbial fermentation system, the most common of which is to promote the production of glutamine transaminase by screening suitable strains and using suitable culture conditions. During the fermentation process, the level of microbial strains directly reflects the fermentation level, and the culture medium as the basis of microorganisms also affects the effect of microbial fermentation. For example, the composition of the culture medium has an important influence on the concentration of fermentation products and bacterial growth.

[0004] At present, the method for producing glutamine transaminase mainly involves inoculating actinomycetes into a culture medium for activation and then fermentation. However, the problem with this method is that the enzyme activity level detected after fermentation is low, resulting in a low final yield of glutamine transaminase. Summary of the invention

[0005] In order to improve the enzyme activity level of the strain culture and fermentation for producing glutamine transaminase, the present application provides a glutamine transaminase culture medium and a preparation method and fermentation process thereof.

[0006] In the first aspect, the glutamine transaminase culture medium provided in the present application adopts the following technical scheme:

[0007] A glutamine transaminase culture medium comprising the following raw materials:

[0008] Sucrose 25~35g / L, sodium nitrate 1~3g / L, dipotassium hydrogen phosphate 0.5~1.5g / L, magnesium sulfate 0.3~0.6g / L, potassium chloride 0.3~0.6g / L, ferrous sulfate 0.01~0.02g / L, agar 15~25g / L, malt extract 40~60mL / L, Jerusalem artichoke juice 20~40mL / L, and the rest is water.

[0009] By adopting the above technical scheme, the above culture medium is added with malt extract and Jerusalem artichoke juice on the basis of the composition of Czapek medium, and the rich nutrients and growth-promoting factors in malt extract and Jerusalem artichoke juice are utilized to promote the balance of carbon-nitrogen ratio and the growth of the starting strain. It is particularly suitable for Streptomyces that produces glutamine transaminase, and the enzyme activity level is improved, thereby ultimately increasing the production of glutamine transaminase.

[0010] Optionally, the culture medium includes the following raw materials: 30 g / L sucrose, 2 g / L sodium nitrate, 1 g / L potassium dihydrogen phosphate, 0.5 g / L magnesium sulfate, 0.5 g / L potassium chloride, 0.01 g / L ferrous sulfate, 20 g / L agar, 50 mL / L malt extract, 30 mL / L Jerusalem artichoke juice, and the rest is water.

[0011] By adopting the above technical solution, since the reproductive ability of Streptomyces is not absolutely proportional to the ability to produce glutamine transaminase, the specific combined concentration of malt extract and Jerusalem artichoke juice in the culture medium can improve the reproductive ability of Streptomyces while maintaining the enzyme production at a higher level, thereby improving the enzyme activity level.

[0012] Optionally, the culture medium is a slant culture medium.

[0013] By adopting the above technical solution, the slant culture medium has the advantages of large thickness and rich nutrition, and is easy to inoculate, suitable for subsequent expansion and transfer of strains, and is therefore suitable for use as a glutamine transaminase culture medium.

[0014] In a second aspect, the present application provides a method for preparing a glutamine transaminase culture medium using the following technical scheme:

[0015] A method for preparing a glutamine transaminase culture medium comprises the following steps:

[0016] Mix sucrose, sodium nitrate, dipotassium hydrogen phosphate, magnesium sulfate, potassium chloride, ferrous sulfate and water together, add agar, heat to dissolve the agar, stop heating after the agar is completely dissolved, add malt juice and Jerusalem artichoke juice while hot, mix evenly, make up to volume, package while hot, sterilize, and obtain glutamine aminotransferase culture medium.

[0017] By adopting the above technical solution, agar needs to be heated to dissolve, and malt juice and Jerusalem artichoke juice are added after the heating is stopped, thereby reducing the influence of continuous heating on the effects of malt juice and Jerusalem artichoke juice, and then the wort and Jerusalem artichoke juice are packaged while hot.

[0018] Optionally, the method for preparing the wort comprises the following steps:

[0019] Add malt powder into water and mix, the weight ratio of malt powder to water is 1: (3.5~4.5), heat at 60~70℃ until saccharification is complete, filter and obtain malt juice.

[0020] Optionally, the method for preparing the malt powder comprises the following steps:

[0021] Soak the barley in water for 6-12 hours, germinate the soaked barley in a cool place, cover the barley with gauze, and dry it at 60-70℃ after the malt has grown to more than twice the size of the grain. Grind it into malt powder and pass it through a 100-mesh sieve to control the moisture content to ≤10% to obtain malt powder.

[0022] Optionally, the method for preparing Jerusalem artichoke juice comprises the following steps:

[0023] The Jerusalem artichokes are heated in water to inactivate enzymes, and then the Jerusalem artichokes are crushed to obtain Jerusalem artichoke powder, and the Jerusalem artichoke powder is added into water and mixed, the weight ratio of the Jerusalem artichoke powder to water being 1:(5-6), and heated at 75-85° C. until saccharification is complete, and filtered to obtain Jerusalem artichoke juice.

[0024] By adopting the above technical solution, the starch in malt and Jerusalem artichoke is decomposed into small molecule sugars through saccharification, providing the energy and nutrients required for the growth of the strain.

[0025] In a third aspect, the present application provides a fermentation process for glutamine transaminase using the following technical solution:

[0026] Select an appropriate amount of the starting strain and spread it on the surface of the glutamine aminotransferase culture medium, and culture it at a constant temperature of 28-32°C for 6-8 days;

[0027] Pick up an appropriate amount of bacterial moss on the surface of the glutamine transaminase culture medium and inoculate it into the seed liquid culture medium, and culture it in a constant temperature shaker at 26~29℃ and a rotation speed of 250~350rpm. Then inoculate the seed liquid into the fermentation liquid culture medium at an inoculation rate of 7~12% (v / v), and culture it in a constant temperature shaker at 26~29℃ and a rotation speed of 250~350rpm to complete the fermentation.

[0028] By adopting the above technical scheme, after the strain is fully cultured in the glutamine transaminase culture medium, the growth activity is enhanced, and then shake flask fermentation is carried out to expand the number of strains and obtain a good enzyme activity level.

[0029] Optionally, the starting strain is Streptomyces.

[0030] Optionally, the starting strain is Streptomyces sp. KL-Q1, with the accession number being GDMCC No: 60371.

[0031] By adopting the above technical solution, the above Streptomyces has the characteristics of high enzyme production activity and is suitable as a starting strain.

[0032] In summary, this application has the following beneficial effects:

[0033] 1. Glutamine transaminase culture medium is based on the composition of Czapek medium, and malt extract and Jerusalem artichoke juice are added. The rich nutrients and growth-promoting factors in malt extract and Jerusalem artichoke juice are used to promote the balance of carbon-nitrogen ratio and the growth of the starting strain. It is particularly suitable for Streptomyces that produce glutamine transaminase, and improves the enzyme activity level, ultimately increasing the yield of glutamine transaminase.

[0034] 2. Since the reproductive capacity of Streptomyces is not in absolute direct proportion to its ability to produce glutamine transaminase, the specific combined concentration of malt extract and Jerusalem artichoke juice in the culture medium can improve the reproductive capacity of Streptomyces while maintaining a high level of enzyme production, thereby improving the enzyme activity level. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is the enzyme activity level of the fermentation broth of Example 3 and Comparative Example 1 of the present application. DETAILED DESCRIPTION

[0036] The following is combined with Figure 1 This application is described in further detail.

[0037] The present application adopts Streptomyces to produce glutamine transaminase. Streptomyces belongs to a family of the order Actinomycetes. Currently, Czapek medium is commonly used to culture actinomycetes. However, it is actually found that for the culture method of using Streptomyces to produce glutamine transaminase, the obtained strain concentration and enzyme activity level are both low and cannot meet the production requirements.

[0038] Therefore, the present application adds malt extract and Jerusalem artichoke juice to the composition of Czapek medium to synergistically promote the energy supply and nutrient supply of the strain, so as to increase the strain concentration and enzyme activity level.

[0039] Preparation Example 1

[0040] The method for preparing wort comprises the following steps:

[0041] Soak the barley in water for 6 hours, germinate the soaked barley in a cool place, cover the barley with gauze, and dry it at 60°C after the malt extends to more than twice the size of the grain. Grind the grain with the malt into malt powder and pass it through a 100-mesh sieve, control the moisture to 10wt%, and obtain malt powder.

[0042] Add malt powder into water and mix, the weight ratio of malt powder to water is 1:3.5, heat at 60°C until saccharification is complete, filter with gauze to obtain malt juice.

[0043] The method to check whether the saccharification is complete is to take 0.5 ml of saccharification solution and add 2 drops of iodine solution. If no blue color appears, it means that the saccharification is complete.

[0044] Preparation Example 2

[0045] The method for preparing wort comprises the following steps:

[0046] Soak the barley in water for 12 hours, germinate the soaked barley in a cool place, cover the barley with gauze, and dry it at 70°C after the malt extends to more than twice the size of the grain. Grind the grain with the malt into malt powder and pass it through a 100-mesh sieve, control the moisture to 10wt%, and obtain malt powder.

[0047] Add malt powder into water and mix, the weight ratio of malt powder to water is 1:4.5, heat at 70°C until saccharification is complete, filter with gauze to obtain malt juice.

[0048] Preparation Example 3

[0049] The preparation method of Jerusalem artichoke juice comprises the following steps:

[0050] The Jerusalem artichoke tuber part is taken, and the Jerusalem artichoke is heated in water to inactivate enzymes. Specifically, a water-proof rack is placed on boiling water, and the Jerusalem artichoke is placed 5 cm above the boiling water surface and heated and cooked for 20 minutes. After the cooking, the Jerusalem artichoke is naturally dried, and then the Jerusalem artichoke is crushed to obtain Jerusalem artichoke powder. The Jerusalem artichoke powder is added into water and mixed, and the weight ratio of the Jerusalem artichoke powder to water is 1:5. The mixture is heated at 75° C. until saccharification is complete, and filtered with gauze to obtain Jerusalem artichoke juice.

[0051] Preparation Example 4

[0052] The preparation method of Jerusalem artichoke juice comprises the following steps:

[0053] The Jerusalem artichoke tuber part is taken, and the Jerusalem artichoke is heated in water to inactivate enzymes. Specifically, a water-proof rack is placed on boiling water, and the Jerusalem artichoke is placed 5 cm above the boiling water surface and heated and cooked for 20 minutes. After the cooking, the Jerusalem artichoke is naturally dried, and then the Jerusalem artichoke is crushed to obtain Jerusalem artichoke powder. The Jerusalem artichoke powder is added into water and mixed, and the weight ratio of the Jerusalem artichoke powder to water is 1:6. The mixture is heated at 85° C. until saccharification is complete, and filtered with gauze to obtain Jerusalem artichoke juice.

[0054] Example 1

[0055] The method for preparing a glutamine transaminase culture medium comprises the following steps:

[0056] Weigh 25 g of sucrose, 1 g of sodium nitrate, 0.5 g of dipotassium hydrogen phosphate, 0.3 g of magnesium sulfate, 0.3 g of potassium chloride, 0.01 g of ferrous sulfate, 40 mL of malt juice, 20 mL of Jerusalem artichoke juice, and 15 g of agar. The malt juice is prepared by Preparation Example 1, and the Jerusalem artichoke juice is prepared by Preparation Example 3.

[0057] Mix sucrose, sodium nitrate, dipotassium hydrogen phosphate, magnesium sulfate, potassium chloride, ferrous sulfate and water together, add agar, heat and boil to dissolve the agar, stop heating after the agar is completely dissolved, add malt juice and Jerusalem artichoke juice while hot, continue to add water to make the solution volume to 1000 mL, package while hot, solidify into a slant, sterilize, and obtain glutamine aminotransferase culture medium.

[0058] Example 2

[0059] The method for preparing a glutamine transaminase culture medium comprises the following steps:

[0060] Weigh 35 g of sucrose, 3 g of sodium nitrate, 1.5 g of dipotassium hydrogen phosphate, 0.6 g of magnesium sulfate, 0.6 g of potassium chloride, 0.02 g of ferrous sulfate, 60 mL of malt juice, 40 mL of Jerusalem artichoke juice, and 25 g of agar. The malt juice is prepared by Preparation Example 2, and the Jerusalem artichoke juice is prepared by Preparation Example 4.

[0061] Mix sucrose, sodium nitrate, dipotassium hydrogen phosphate, magnesium sulfate, potassium chloride, ferrous sulfate and water together, add agar, heat and boil to dissolve the agar, stop heating after the agar is completely dissolved, add malt juice and Jerusalem artichoke juice while hot, continue to add water to make the solution volume to 1000 mL, package while hot, solidify into a slant, sterilize, and obtain glutamine aminotransferase culture medium.

[0062] Example 3

[0063] The method for preparing a glutamine transaminase culture medium comprises the following steps:

[0064] Weigh 30 g of sucrose, 2 g of sodium nitrate, 1 g of dipotassium hydrogen phosphate, 0.5 g of magnesium sulfate, 0.5 g of potassium chloride, 0.01 g of ferrous sulfate, 50 mL of malt juice, 30 mL of Jerusalem artichoke juice, and 20 g of agar. The malt juice is prepared by Preparation Example 1, and the Jerusalem artichoke juice is prepared by Preparation Example 3.

[0065] Mix sucrose, sodium nitrate, dipotassium hydrogen phosphate, magnesium sulfate, potassium chloride, ferrous sulfate and water together, add agar, heat and boil to dissolve the agar, stop heating after the agar is completely dissolved, add malt juice and Jerusalem artichoke juice while hot, continue to add water to make the solution volume to 1000 mL, package while hot, solidify into a slant, sterilize, and obtain glutamine aminotransferase culture medium.

[0066] Comparative Example 1

[0067] The method for preparing a glutamine transaminase culture medium comprises the following steps:

[0068] Weigh 30 g of sucrose, 2 g of sodium nitrate, 1 g of dipotassium hydrogen phosphate, 0.5 g of magnesium sulfate, 0.5 g of potassium chloride, 0.01 g of ferrous sulfate, and 20 g of agar.

[0069] Mix sucrose, sodium nitrate, dipotassium hydrogen phosphate, magnesium sulfate, potassium chloride, ferrous sulfate and water together, add agar, heat and boil to dissolve the agar, stop heating after the agar is completely dissolved, continue to add water to make the solution volume up to 1000 mL, package it while hot, solidify it into a slant, sterilize it, and obtain glutamine aminotransferase culture medium.

[0070] Comparative Example 2

[0071] The method for preparing a glutamine transaminase culture medium comprises the following steps:

[0072] Weigh 150 mL of malt juice, 90 mL of Jerusalem artichoke juice, and 5 g of agar, wherein the malt juice is prepared by Preparation Example 1, and the Jerusalem artichoke juice is prepared by Preparation Example 3.

[0073] Mix agar and 50 mL of water, heat to dissolve the agar, stop heating after the agar is completely dissolved, add malt juice and Jerusalem artichoke juice while hot, mix well and package while hot, solidify into a slant, sterilize, and obtain glutamine aminotransferase culture medium.

[0074] Comparative Example 3

[0075] The method for preparing a glutamine transaminase culture medium comprises the following steps:

[0076] Weigh 30 g of sucrose, 2 g of sodium nitrate, 1 g of dipotassium hydrogen phosphate, 0.5 g of magnesium sulfate, 0.5 g of potassium chloride, 0.01 g of ferrous sulfate, 80 mL of malt juice, and 20 g of agar, wherein the malt juice is prepared in Preparation Example 1.

[0077] Mix sucrose, sodium nitrate, dipotassium hydrogen phosphate, magnesium sulfate, potassium chloride, ferrous sulfate and water together, add agar, heat and boil to dissolve the agar, stop heating after the agar is completely dissolved, add malt juice while hot, continue to add water to make the solution volume to 1000 mL, package while hot, solidify into a slant, sterilize, and obtain glutamine aminotransferase culture medium.

[0078] Comparative Example 4

[0079] The method for preparing a glutamine transaminase culture medium comprises the following steps:

[0080] Weigh 30 g of sucrose, 2 g of sodium nitrate, 1 g of dipotassium hydrogen phosphate, 0.5 g of magnesium sulfate, 0.5 g of potassium chloride, 0.01 g of ferrous sulfate, 80 mL of Jerusalem artichoke juice, and 20 g of agar. The Jerusalem artichoke juice is prepared in Preparation Example 3.

[0081] Mix sucrose, sodium nitrate, dipotassium hydrogen phosphate, magnesium sulfate, potassium chloride, ferrous sulfate and water together, add agar, heat and boil to dissolve the agar, stop heating after the agar is completely dissolved, add Jerusalem artichoke juice while hot, continue to add water to make the solution volume to 1000 mL, package while hot, solidify into a slant, sterilize, and obtain glutamine aminotransferase culture medium.

[0082] Application Example 1

[0083] A fermentation process for transglutaminase comprises the following steps:

[0084] Slant culture: Use an inoculation loop to pick up a 0.5 cm 2 The starting strain was coated on the surface of the glutamine transaminase medium and cultured at a constant temperature of 28°C for 8 days. The glutamine transaminase medium was prepared by Example 1, and the starting strain was Streptomyces sp. KL-Q1, with a preservation number of GDMCC No: 60371, which was deposited in the Guangdong Provincial Microbiological Culture Collection Center on May 18, 2018, and the preservation address was: 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou, Guangdong Institute of Microbiology.

[0085] The biomaterial sample has been disclosed in CN108893428A.

[0086] Shake flask fermentation: Use an inoculation loop to pick a 0.5 cm 2 The bacterial moss was inoculated into the seed liquid culture medium, 50 ml of the liquid was filled into a 250 ml Erlenmeyer flask, and the culture was incubated at 26°C constant temperature shaker with a rotation speed of 250 rpm for 22 h. Then the seed liquid was inoculated into the fermentation liquid culture medium at an inoculation rate of 12% (v / v), 50 ml of the liquid was filled into a 250 ml Erlenmeyer flask, and the culture was incubated at 26°C constant temperature shaker with a rotation speed of 250 rpm for 44 h to complete the fermentation.

[0087] The composition of the seed liquid culture medium is: 20g / L glycerol, 10g / L yeast extract, 10g / L soybean protein powder, 14g / L fish peptone, 2g / L potassium dihydrogen phosphate, 2g / L magnesium sulfate, and the rest is water.

[0088] The composition of the fermentation medium: glycerol 20g / L, yeast extract 15g / L, soy protein powder 5g / L, fish peptone 20g / L, potassium dihydrogen phosphate 2g / L, magnesium sulfate 2g / L, calcium caseinate 3g / L, sodium lipoate 1g / L, light calcium carbonate 5g / L, and the rest is water.

[0089] Application Example 2

[0090] A fermentation process for transglutaminase comprises the following steps:

[0091] Slant culture: Use an inoculation loop to pick up a 0.5 cm 2 The starting strain was coated on the surface of the glutamine transaminase medium and cultured at a constant temperature of 32°C for 6 days. The glutamine transaminase medium was prepared by Example 2, and the starting strain was Streptomyces sp. KL-Q1, with a preservation number of GDMCC No: 60371, which was deposited in the Guangdong Provincial Microbiological Culture Collection Center on May 18, 2018, and the preservation address was: 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou, Guangdong Institute of Microbiology.

[0092] The biomaterial sample has been disclosed in CN108893428A.

[0093] Shake flask fermentation: Pick a 0.5 cm 2 The bacterial moss was inoculated into the seed liquid culture medium, 50 ml of the liquid was filled into a 250 ml Erlenmeyer flask, and the culture was incubated at 29°C constant temperature shaker with a rotation speed of 350 rpm for 22 h. Then the seed liquid was inoculated into the fermentation liquid culture medium at an inoculation rate of 7% (v / v), 50 ml of the liquid was filled into a 250 ml Erlenmeyer flask, and the culture was incubated at 29°C constant temperature shaker with a rotation speed of 350 rpm for 44 h to complete the fermentation.

[0094] The composition of the seed liquid culture medium is: 20g / L glycerol, 10g / L yeast extract, 10g / L soybean protein powder, 14g / L fish peptone, 2g / L potassium dihydrogen phosphate, 2g / L magnesium sulfate, and the rest is water.

[0095] The composition of the fermentation medium: glycerol 20g / L, yeast extract 15g / L, soy protein powder 5g / L, fish peptone 20g / L, potassium dihydrogen phosphate 2g / L, magnesium sulfate 2g / L, calcium caseinate 3g / L, sodium lipoate 1g / L, light calcium carbonate 5g / L, and the rest is water.

[0096] Application Example 3

[0097] A fermentation process for glutamine transaminase. The difference between this application example and application example 1 is that the glutamine transaminase culture medium is prepared by Example 3.

[0098] Comparative application example 1

[0099] A fermentation process for glutamine transaminase. The difference between this application example and application example 3 is that the glutamine transaminase culture medium is prepared by comparative example 1.

[0100] Comparative Application Example 2

[0101] A fermentation process for glutamine transaminase. The difference between this application example and application example 3 is that the glutamine transaminase culture medium is prepared by comparative example 2.

[0102] Comparative Application Example 3

[0103] A fermentation process for glutamine transaminase. The difference between this application example and application example 3 is that the glutamine transaminase culture medium is prepared by comparative example 3.

[0104] Comparative Application Example 4

[0105] A fermentation process for glutamine transaminase. The difference between this application example and application example 3 is that the glutamine transaminase culture medium is prepared by comparative example 4.

[0106] Performance data

[0107] Seed liquid strain concentration detection: After the strain is shaken in the seed liquid culture medium, 2 ml of seed liquid is pipetted into a centrifuge tube, centrifuged at 7000 r / min for 10 min, the supernatant is removed, and the weight percentage of the precipitate is calculated as the bacterial concentration. The results are shown in Table 1.

[0108] Enzyme activity detection: The substrate reagent contains 0.1 mol / L hydroxylamine hydrochloride, 30 mol / L CBZ-GIN-GLY, 0.2 mol / L Tris-Hcl buffer (pH 6.0), and 10 mol / L reduced glutathione. Take 2 ml of substrate reagent and 0.2 ml of fermentation filtrate, preheat at 37 ° C for 10 min, mix, react for 10 min, quickly add 2 ml of ferric chloride-trichloroacetic acid reagent (5% FeCl3: 12% CCl3COOH: 3 mol / L HCl = 1:1:1) to terminate the reaction, centrifuge at 3000 r / min, and measure the absorbance of the supernatant at 525 nm. The amount of enzyme (u / ml) required to catalyze the formation of 1 Lmol hydroxamic acid per minute at 37 ° C is defined as 1 enzyme activity unit, and the results are shown in Table 2.

[0109] Table 1

[0110]

[0111] Table 2

[0112]

[0113] Combined with the data analysis in Table 1, the strain concentration after slant culture in the glutamine aminotransferase medium of Application Examples 1-3 was significantly higher than that of the strain cultured in the ordinary Czapek medium, which proved that the glutamine aminotransferase medium of Application Examples 1-3 can cultivate bacteria with strong growth activity and increase the growth rate of the strain during fermentation expansion to produce a higher enzyme activity level.

[0114] Combination Figure 1Compared with the data analysis in Table 2, the enzyme activity level of the strain cultured on the slant of the glutamine aminotransferase medium of Application Examples 1-3 is significantly higher than that of the strain cultured on the ordinary Czapek medium, which proves that the glutamine aminotransferase medium of Application Examples 1-3 can promote the enzyme production of Streptomyces and ultimately increase the production of glutamine aminotransferase.

[0115] In summary, combined with the data analysis of comparative application examples 2-4, it can be seen that the addition of malt extract and Jerusalem artichoke juice to the composition of Czapek medium can provide nutrients and a culture environment that can effectively promote the growth of Streptomyces and the production of transglutaminase, thereby increasing the production of transglutaminase. In addition, the transglutaminase culture medium is used for Streptomyces, and has a weaker promoting effect on other strains that can produce transglutaminase, such as Bacillus.

[0116] This specific implementation manner is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the specific implementation manner as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A glutamine transaminase culture medium, characterized in that: Including the following ingredients: Sucrose 25~35g / L, sodium nitrate 1~3g / L, dipotassium hydrogen phosphate 0.5~1.5g / L, magnesium sulfate 0.3~0.6g / L, potassium chloride 0.3~0.6g / L, ferrous sulfate 0.01~0.02g / L, agar 15~25g / L, malt extract 40~60mL / L, Jerusalem artichoke juice 20~40mL / L, and the rest is water; The method for preparing the wort comprises the following steps: Add malt powder to water and mix, the weight ratio of malt powder to water is 1: (3.5-4.5), heat at 60-70°C until saccharification is complete, filter, and obtain malt juice; The preparation method of Jerusalem artichoke juice comprises the following steps: The Jerusalem artichokes are heated in water to inactivate enzymes, and then the Jerusalem artichokes are crushed to obtain Jerusalem artichoke powder, and the Jerusalem artichoke powder is added into water and mixed, the weight ratio of the Jerusalem artichoke powder to water being 1:(5-6), and heated at 75-85° C. until saccharification is complete, and filtered to obtain Jerusalem artichoke juice.

2. A glutamine aminotransferase culture medium according to claim 1, characterized in that: The invention comprises the following raw materials: 30 g / L sucrose, 2 g / L sodium nitrate, 1 g / L potassium dihydrogen phosphate, 0.5 g / L magnesium sulfate, 0.5 g / L potassium chloride, 0.01 g / L ferrous sulfate, 20 g / L agar, 50 mL / L malt extract, 30 mL / L Jerusalem artichoke juice, and the rest is water.

3. A glutamine aminotransferase culture medium according to claim 1, characterized in that: The culture medium is a slant culture medium.

4. A method for preparing a glutamine aminotransferase culture medium according to any one of claims 1 to 3, characterized in that: The following steps are involved: Mix sucrose, sodium nitrate, dipotassium hydrogen phosphate, magnesium sulfate, potassium chloride, ferrous sulfate and water together, add agar, heat to dissolve the agar, stop heating after the agar is completely dissolved, add malt juice and Jerusalem artichoke juice while hot, mix evenly, make up to volume, package while hot, and sterilize to obtain a glutamine transaminase culture medium; The method for preparing the wort comprises the following steps: Add malt powder to water and mix, the weight ratio of malt powder to water is 1: (3.5-4.5), heat at 60-70°C until saccharification is complete, filter, and obtain malt juice; The preparation method of Jerusalem artichoke juice comprises the following steps: The Jerusalem artichokes are heated in water to inactivate enzymes, and then the Jerusalem artichokes are crushed to obtain Jerusalem artichoke powder, and the Jerusalem artichoke powder is added into water and mixed, the weight ratio of the Jerusalem artichoke powder to water being 1:(5-6), and heated at 75-85° C. until saccharification is complete, and filtered to obtain Jerusalem artichoke juice.

5. The method for preparing a glutamine transaminase culture medium according to claim 4, characterized in that: The preparation method of the malt powder comprises the following steps: Soak the barley in water for 6-12 hours, germinate the soaked barley in a cool place, cover the barley with gauze, and dry it at 60-70℃ after the malt has grown to more than twice the size of the grain. Grind it into malt powder and pass it through a 100-mesh sieve to control the moisture content to ≤10% to obtain malt powder.

6. A fermentation process for transglutaminase, characterized in that: The following steps are involved: The starting strain is selected and coated on the surface of the glutamine aminotransferase culture medium according to any one of claims 1 to 3, and cultured at a constant temperature of 28-32° C. for 6-8 days; the starting strain is Streptomyces sp. KL-Q1, with a preservation number of GDMCC No: 60371; Pick up bacterial moss on the surface of glutamine transaminase culture medium and inoculate it into seed liquid culture medium, culture it in a constant temperature shaker at 26~29℃ and a rotation speed of 250~350rpm, then inoculate the seed liquid into the fermentation liquid culture medium at an inoculation rate of 7~12% (v / v), culture it in a constant temperature shaker at 26~29℃ and a rotation speed of 250~350rpm to complete the fermentation.

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