Application of tea polyphenol in improving yield of cordycepin in cordyceps militaris fermentation

Abstract

The invention discloses application of tea polyphenol and a composition thereof in improving the yield of cordycepin in cordyceps militaris fermentation, the yield of cordycepin can be effectively improved after the tea polyphenol is added into a cordyceps militaris fermentation culture medium, and meanwhile, the yield of cordycepin can be effectively improved by further adding Fe < 2 + > and glycine into the fermentation culture medium. Under the fermentation conditions, the cordycepin yield can be effectively increased by about 56.71%, and the method has the advantages of being easy to operate, low in cost and the like. The invention further provides a fermentation culture medium and a fermentation culture method for improving the cordycepin yield of cordyceps militaris fermentation, the cordycepin yield can be improved only by adjusting the fermentation culture medium without gene modification, and the process is simple, convenient and efficient.

Description

Technical Field

[0001] The invention belongs to the technical field of biological fermentation, and in particular relates to a Cordyceps militaris fermentation culture medium and a method for improving the yield of cordycepin in Cordyceps militaris fermentation. Background Art

[0002] Cordyceps militaris, also known as northern cordyceps, is a well-known edible medicinal filamentous fungus, widely praised by Southeast Asian countries. Cordyceps militaris belongs to the Ascomycetes, Ergotaceae, and is a combination of the fruiting body and the pupa formed by the Cordyceps militaris fungus parasitizing on the pupa of the Lepidoptera Noctuids insect. It was published at the 1727 Paris Academy of Sciences under the genus and species name Cordyceps militarys. It was first discovered in Jilin Province, my country in 1958. It is also distributed in Yunnan, Sichuan, Guangxi, Anhui, Shaanxi, Hebei, etc. It is one of the most studied and developed Cordyceps fungi at present, and is also a model fungus in Cordyceps. Cordyceps sinensis and Cordyceps militaris are the most studied and widely used Cordyceps fungi. Because the medicinal and nutritional value of Cordyceps militaris is very similar to that of Cordyceps sinensis, it is usually considered to be the best substitute for Cordyceps sinensis. Many biologically active ingredients have been found in Cordyceps militaris, including cordycepin, pentostatin, cordycepic acid, cordyceps polysaccharides, ergosterol, etc., among which cordycepin is one of the main active ingredients.

[0003] Cordycepin (COR), also known as 3′-deoxyadenosine, is a natural nucleoside antibiotic composed of adenosine and deoxypentose with carbon branches. It was first isolated by Cunningham's team in Cordyceps militaris culture medium in 1950. Cordycepin has high medicinal and nutritional value. Its main pharmacological effects include: immunomodulatory, anti-inflammatory, antibacterial, antiviral, anti-tumor, neuroprotective, sexual function protection, and anti-radiation. Because it is very beneficial to human health, it is currently being widely studied.

[0004] Studies have shown that the production of beneficial secondary metabolites in Cordyceps militaris can be increased by changing the culture medium components, temperature, adjusting the pH and other fermentation conditions, mutation breeding, genetic engineering and other methods. Among them, the method of increasing the yield of cordycepin by changing the fermentation conditions is difficult to obtain significant results, and the process is cumbersome; mutation breeding requires a lot of screening, the workload is large and time-consuming, the randomness is too high, and it is difficult to obtain the target strain; genetic engineering is complex at the molecular level, and it is difficult to screen positive transformants. Therefore, it is necessary to regulate the metabolism of Cordyceps militaris in a more efficient way to increase the production of COR.

[0005] CN115044636A discloses a Cordyceps militaris liquid fermentation method for increasing the yield of cordycepin, and by adding an appropriate amount of rotenone after the Cordyceps militaris fermentation for a period of time, the yield of cordycepin in the Cordyceps militaris fermentation liquid can be significantly increased. Compared with the yield of 189.66mg / L of traditional fermentation without adding rotenone, the yield after adding rotenone is as high as 804.69mg / L, that is, the total yield of cordycepin is increased by 324.28%. The method is simple in process, and there is no need to improve enzyme activity by means such as genetic modification; the production cost is low, and there is no need to continuously feed adenine and other substrates required for cordycepin synthesis, and the total fermentation time of cordycepin is short, and the production efficiency is significantly improved, which is suitable for industrial production.

[0006] CN107604026A discloses a method for improving the yield of cordycepin in Cordyceps militaris fermentation liquid, the steps are: the strain is transferred to sterile PDA slant medium for cultivation and activation, and the slant mother species is obtained; the slant mother species is transferred to the plate medium for cultivation, and the plate mother species is obtained; the plate mother species is inoculated into the seed medium, and the shaking table is cultivated to obtain the seed liquid; the seed liquid is inoculated into the optimized medium and the triangular bottle mouth is sealed with a sterile polypropylene bag, and the shaking table is cultivated to obtain the fermentation liquid to be supplemented; according to the adenine supplement formula, the adenine supplement solution is prepared, and 100mL of adenine supplement solution is added to the fermentation liquid to be supplemented, so that the fermentation liquid adenine reaches its optimized mass concentration, and the supplemented fermentation liquid is obtained; after the supplemented fermentation liquid is cultured on the shaking table, it is continued to be statically cultivated to obtain the fermentation liquid containing mycelium; the mycelium in the fermentation liquid containing mycelium is filtered out to obtain the cordycepin fermentation filtrate. Its process is simple, pollution-free, and the cordycepin yield of Cordyceps militaris fermentation liquid is as high as 956.02μg / mL.

[0007] Therefore, increasing the yield of cordycepin by adjusting the fermentation medium is a convenient, effective and easy-to-operate method. Summary of the invention

[0008] Purpose of the invention: The technical problem to be solved by the present invention is to provide a method for regulating the metabolism of Cordyceps militaris without genetic modification, with a simple process and high efficiency, and to increase the yield of cordycepin in the fermentation of Cordyceps militaris in view of the deficiencies of the prior art.

[0009] Specifically, the present application discloses the application of tea polyphenols (TP) and a composition thereof in increasing the yield of cordycepin in Cordyceps militaris fermentation.

[0010] Specifically, when used, tea polyphenols are added to the Cordyceps militaris fermentation medium at a concentration of 0.5 to 9 g / L. Preferably, tea polyphenols are added to the Cordyceps militaris fermentation medium at a concentration of 4 to 6 g / L. More preferably, tea polyphenols are added at a concentration of 5 g / L.

[0011] Wherein, the composition further comprises Fe 2+, or both of glycine.

[0012] Preferably, Fe in the Cordyceps militaris fermentation medium 2+ The concentration of Fe is 0.2-2 g / L, and the concentration of glycine is 10-30 g / L. 2+ The concentration of Fe is 0.5-0.8 g / L, and the concentration of glycine is 15-25 g / L. More preferably, Fe 2+ The concentration of is 0.6g / L, and the concentration of glycine is 20g / L.

[0013] In one embodiment, the Cordyceps militaris fermentation medium comprises the following components: 10-50 g / L glucose, 10-25 g / L peptone, 2-14 g / L yeast powder, 0.1-1 g / L KH2PO4, 0.1-1 g / L K2HPO4, 0.1-1 g / L anhydrous magnesium sulfate, and the solvent is purified water.

[0014] Preferably, the Cordyceps militaris fermentation medium comprises the following components: 40 g / L glucose, 17 g / L peptone, 9 g / L yeast powder, 0.5 g / L KH2PO4, 0.5 g / L K2HPO4, 0.5 g / L anhydrous magnesium sulfate, and the solvent is purified water.

[0015] Preferably, the Cordyceps militaris fermentation medium further comprises adenine, wherein the concentration of adenine is 1 to 8 g / L.

[0016] The present application also provides a fermentation medium for improving the yield of cordycepin in Cordyceps militaris fermentation, which comprises the following components in concentrations: 10-50 g / L glucose, 10-25 g / L peptone, 2-14 g / L yeast powder, 0.1-1 g / L KH2PO4, 0.1-1 g / L K2HPO4, 0.1-1 g / L anhydrous magnesium sulfate and 0.5-9 g / L tea polyphenols.

[0017] Preferably, the fermentation medium further comprises adenine, Fe 2+ , glycine, wherein the amount of adenine added is 1 to 8 g / L, Fe 2+ The addition amount of is 0.2~2g / L, and the addition amount of glycine is 10~30g / L.

[0018] The present invention also provides a fermentation method for improving the yield of cordycepin in Cordyceps militaris fermentation. Cordyceps militaris mycelium is transferred to a seed culture medium for dark culture for 3 to 7 days to obtain Cordyceps militaris seed liquid, which is transferred to the fermentation culture medium at an inoculation rate of 5% to 20% (V / V) for culture.

[0019] Preferably, the culture conditions in the fermentation medium are: temperature 22-30° C., rotation speed 120-180 rpm, pH 5-6.5, and dark culture for 18-26 days.

[0020] Beneficial effect: The present invention can effectively increase the yield of cordycepin by adding tea polyphenols to the fermentation medium of Cordyceps militaris. 2+ , glycine, under the above fermentation conditions, the COR yield can be effectively increased by about 56.71%, and it has the advantages of simple operation and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Effects of different concentrations of TP on the COR production of Cordyceps militaris strains in fermentation medium, where the horizontal axis is different concentrations of TP, and the vertical axis is the cordycepin production in the fermentation broth measured after the shake flask culture of Cordyceps militaris;

[0022] Figure 2 When the optimal TP concentration was added, Fe 2+ , the effect of glycine on the COR production of Cordyceps militaris strains in the fermentation medium, wherein the horizontal axis 1 is comparative example 1, the horizontal axis 2 is example 6, the horizontal axis 3 is example 7, the horizontal axis 4 is example 8, and the vertical axis is the cordycepin production in the fermentation broth measured after the shake flask culture of Cordyceps militaris is completed. DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more clear.

[0024] The experimental methods in the following examples are conventional methods unless otherwise specified. The experimental materials used in the following examples are from conventional biochemical reagent suppliers unless otherwise specified. The present invention is further described in detail below in conjunction with the accompanying drawings.

[0025] Example 1: Preparation of TP Cordyceps militaris fermentation medium with different concentrations.

[0026] 1) Preparation of fermentation medium: Accurately weigh 40 g glucose, 17 g peptone, 9 g yeast powder, 0.5 g KH2PO4, 0.5 g K2HPO4, 0.5 g anhydrous magnesium sulfate, and 4 g adenine, add to pure water, fully dissolve and mix, dilute to 1 L, and adjust the pH to 5.8.

[0027] 2) Accurately weigh 0.5 g of TP and add it to the fermentation medium that has not been fixed to volume in step 1) above, mix well, and fix the volume to 1 L. This medium is numbered as 0.5 g / L TP fermentation medium.

[0028] 3) Accurately weigh 1 g of TP and add it to the fermentation medium that has not been fixed to volume in step 1) above, mix well, and fix the volume to 1 L. This medium is numbered as 1 g / L TP fermentation medium.

[0029] 4) Accurately weigh 2 g of TP and add it to the fermentation medium that has not been fixed to volume in step 1) above, mix well, and fix the volume to 1 L. This medium is numbered as 2 g / L TP fermentation medium.

[0030] 5) Accurately weigh 3 g of TP and add it to the fermentation medium that has not been fixed to volume in step 1) above, mix well, and fix the volume to 1 L. This medium is numbered as 3 g / L TP fermentation medium.

[0031] 6) Accurately weigh 4 g of TP and add it to the fermentation medium that has not been fixed to volume in step 1) above, mix well, and fix the volume to 1 L. This medium is numbered as 4 g / L TP fermentation medium.

[0032] 7) Accurately weigh 5 g of TP and add it to the fermentation medium that has not been fixed to volume in step 1) above, mix well, and fix the volume to 1 L. This medium is numbered as 5 g / L TP fermentation medium.

[0033] 8) Accurately weigh 6 g of TP and add it to the fermentation medium that has not been fixed to volume in step 1) above, mix well, and fix the volume to 1 L. This medium is numbered as 6 g / L TP fermentation medium.

[0034] 9) Accurately weigh 7 g of TP and add it to the fermentation medium that has not been fixed to volume in step 1) above, mix well, and fix the volume to 1 L. This medium is numbered as 7 g / L TP fermentation medium.

[0035] 10) Accurately weigh 8 g of TP and add it to the fermentation medium that has not been fixed to volume in step 1) above, mix well, and fix the volume to 1 L. This medium is numbered as 8 g / L TP fermentation medium.

[0036] 11) Accurately weigh 9 g of TP and add it to the fermentation medium that has not been fixed to volume in step 1) above, mix well, and fix the volume to 1 L. This medium is numbered as 9 g / L TP fermentation medium.

[0037] 12) The culture medium prepared in the above steps was dispensed into 500 ml Erlenmeyer flasks with a working volume of 100 ml. After complete dispensing, the flasks were sealed, sterilized at 115° C. for 20 min, and cooled to obtain the culture medium.

[0038] Example 2: Adding Fe at the optimal TP concentration 2+ Culture medium preparation.

[0039] 1) Preparation of 5g / L TP fermentation medium: accurately weigh 5g TP, 40g glucose, 17g peptone, 9g yeast powder, 0.5g KH2PO4, 0.5g K2HPO4, 0.5g anhydrous magnesium sulfate, and 4g adenine, add to pure water, fully dissolve and mix, dilute to 1L, and adjust the pH to 5.8.

[0040] 2) Accurately weigh 0.6g of ferrous sulfate and add it to the 5g / L TP fermentation medium that has not been fixed to volume in step 1) above, mix well, and fix the volume to 1L. This medium is numbered TP+Fe 2+ Fermentation medium.

[0041] 3) The culture medium prepared in step 2) was dispensed into 500 ml Erlenmeyer flasks with a working volume of 100 ml. After complete dispensing, the flasks were sealed, sterilized at 115° C. for 20 min, and cooled to obtain the culture medium.

[0042] Example 3: Preparation of culture medium with addition of glycine at optimal TP concentration.

[0043] 1) Preparation of 5g / L TP fermentation medium: accurately weigh 5g TP, 40g glucose, 17g peptone, 9g yeast powder, 0.5g KH2PO4, 0.5g K2HPO4, 0.5g anhydrous magnesium sulfate, and 4g adenine, add to pure water, fully dissolve and mix, dilute to 1L, and adjust the pH to 5.8.

[0044] 2) Accurately weigh 20 g of glycine and add it to the 5 g / L TP fermentation medium that has not been fixed to volume in step 1) above, mix well, and fix the volume to 1 L. This medium is numbered as TP+glycine fermentation medium.

[0045] 3) The culture medium prepared in step 2) was dispensed into 500 ml Erlenmeyer flasks with a working volume of 100 ml. After complete dispensing, the flasks were sealed, sterilized at 115° C. for 20 min, and cooled to obtain the culture medium.

[0046] Example 4: Adding Fe at the optimal TP concentration 2+ , preparation of glycine medium.

[0047] 1) Preparation of 5g / L TP fermentation medium: accurately weigh 5g TP, 40g glucose, 17g peptone, 9g yeast powder, 0.5g KH2PO4, 0.5g K2HPO4, 0.5g anhydrous magnesium sulfate, and 4g adenine, add to pure water, fully dissolve and mix, dilute to 1L, and adjust the pH to 5.8.

[0048] 2) Accurately weigh 0.6g of ferrous sulfate and add it to the 5g / L TP fermentation medium that has not been fixed to volume in step 1) above, mix well, and fix the volume to 1L. This medium is numbered TP+Fe2+ Fermentation medium.

[0049] 3) Accurately weigh 20g of glycine and add it to the 5g / L TP fermentation medium that has not been fixed to volume in step 2) above, mix well, and fix the volume to 1L. This medium is numbered TP+Fe 2+ +Glycine fermentation medium.

[0050] 4) The culture medium prepared in step 3) is dispensed into 500 ml Erlenmeyer flasks with a working volume of 100 ml. After complete dispensing, the flasks are sealed, sterilized at 115° C. for 20 min, and cooled to obtain the culture medium.

[0051] Example 5: Application of additives in the fermentation process of Cordyceps militaris.

[0052] 1) Cordyceps militaris seed culture: Cordyceps militaris strain (the Cordyceps militaris strain used in this embodiment is called CY1909, which has been deposited in the General Microbiological Center of the China Microbiological Culture Collection Administration Committee, and the deposit number is CGMCCNo.18581, and its detailed information is disclosed in CN111117896A) is provided by Nanjing High-tech University of Technology Biotechnology Research Institute, and Cordyceps militaris hyphae are in solid culture medium. In a clean bench, after all the Cordyceps militaris hyphae in the solid culture medium are scraped off using an alcohol lamp to burn the sterilized and cooled inoculation loop, the hyphae are transferred to a seed culture medium (glucose 40g / L, peptone 17g / L, yeast powder 9g / L, KH2PO4 0.5g / L, K2HPO4 0.5g / L, anhydrous magnesium sulfate 0.5g / L, pH5.8), 26°C, 150rpm, dark culture for 5 days.

[0053] 2) The Cordyceps militaris seed solution cultured for 5 days was transferred to the fermentation medium with different TP concentrations of Example 1 at a transfer rate of 10% (V / V), and cultured in the dark at 26° C. for 22 days.

[0054] Example 6: Application of additives in the fermentation process of Cordyceps militaris.

[0055] 1) Cordyceps militaris seed culture: Cordyceps militaris strain (strain name CY1909, deposited in the General Microbiological Center of China Microbiological Culture Collection Administration Committee, deposit number CGMCC No.18581) was provided by the Institute of Biotechnology of Nanjing High-tech University of Technology, and the Cordyceps militaris mycelium was in a solid culture medium. In an ultra-clean workbench, an alcohol lamp was used to burn and sterilize the cooled inoculation loop to scrape off all the Cordyceps militaris mycelium in the solid culture medium, and then the mycelium was transferred to a seed culture medium (glucose 40g / L, peptone 17g / L, yeast powder 9g / L, KH2PO4 0.5g / L, K2HPO4 0.5g / L, anhydrous magnesium sulfate 0.5g / L, pH5.8), 26°C, 150rpm, dark culture for 5 days.

[0056] 2) The above-mentioned Cordyceps militaris seed solution cultured for 5 days was transferred to the TP+Fe 2+ The culture medium was placed in a dark chamber at 26°C for 22 days.

[0057] Example 7: Application of additives in the fermentation process of Cordyceps militaris.

[0058] 1) Cordyceps militaris seed culture: Cordyceps militaris strain (strain name CY1909, deposited in the General Microbiological Center of China Microbiological Culture Collection Administration Committee, deposit number CGMCC No.18581) was provided by the Institute of Biotechnology of Nanjing High-tech University of Technology, and the Cordyceps militaris mycelium was in a solid culture medium. In an ultra-clean workbench, an alcohol lamp was used to burn and sterilize the cooled inoculation loop to scrape off all the Cordyceps militaris mycelium in the solid culture medium, and then the mycelium was transferred to a seed culture medium (glucose 40g / L, peptone 17g / L, yeast powder 9g / L, KH2PO4 0.5g / L, K2HPO4 0.5g / L, anhydrous magnesium sulfate 0.5g / L, pH5.8), 26°C, 150rpm, dark culture for 5 days.

[0059] 2) The Cordyceps militaris seed solution cultured for 5 days was transferred to the fermentation medium of TP+glycine in Example 3 at a transfer rate of 10% (V / V), and cultured in the dark at 26° C. for 22 days.

[0060] Example 8: Application of additives in the fermentation process of Cordyceps militaris.

[0061] 1) Cordyceps militaris seed culture: Cordyceps militaris strain (strain name CY1909, deposited in the General Microbiological Center of China Microbiological Culture Collection Administration Committee, deposit number CGMCC No.18581) was provided by the Institute of Biotechnology of Nanjing High-tech University of Technology, and the Cordyceps militaris mycelium was in a solid culture medium. In an ultra-clean workbench, an alcohol lamp was used to burn and sterilize the cooled inoculation loop to scrape off all the Cordyceps militaris mycelium in the solid culture medium, and then the mycelium was transferred to a seed culture medium (glucose 40g / L, peptone 17g / L, yeast powder 9g / L, KH2PO4 0.5g / L, K2HPO4 0.5g / L, anhydrous magnesium sulfate 0.5g / L, pH5.8), 26°C, 150rpm, dark culture for 5 days.

[0062] 2) The above-mentioned Cordyceps militaris seed solution cultured for 5 days was transferred to the TP+Fe 2+ + glycine fermentation medium at 26°C in a dark incubation chamber for 22 days.

[0063] Comparative Example 1:

[0064] 1) Preparation of Cordyceps militaris fermentation medium: Accurately weigh 40 g of glucose, 17 g of peptone, 9 g of yeast powder, 0.5 g of KH2PO4, 0.5 g of K2HPO4, 0.5 g of anhydrous magnesium sulfate, and 4 g of adenine, add them into pure water, fully dissolve and mix, make up to 1 L, and adjust the pH to 5.8.

[0065] 2) The culture medium prepared in step 1) is dispensed into 500 ml Erlenmeyer flasks with a working volume of 100 ml. After complete dispensing, the flasks are sealed, sterilized at 115° C. for 20 min, and cooled to obtain the culture medium.

[0066] 3) Cordyceps militaris seed culture: Cordyceps militaris strain (strain name CY1909, deposited in the General Microbiological Center of China Microbiological Culture Collection Administration Committee, deposit number CGMCC No.18581) was provided by the Institute of Biotechnology of Nanjing High-tech University of Technology, and the Cordyceps militaris mycelium was in a solid culture medium. In the clean bench, the Cordyceps militaris mycelium in the solid culture medium was scraped off with an alcohol lamp after sterilization and cooling by inoculation loop, and then the mycelium was transferred to the seed culture medium (glucose 40g / L, peptone 17g / L, yeast powder 9g / L, KH2PO4 0.5g / L, K2HPO4 0.5g / L, anhydrous magnesium sulfate 0.5g / L, pH5.8), 26°C, 150rpm, dark culture for 5 days.

[0067] 4) The Cordyceps militaris seed solution cultured for 5 days was transferred to the fermentation medium of step 2) at a transfer rate of 10% (V / V), and cultured in the dark at 26° C. for 22 days.

[0068] Detection of cordycepin content in fermentation broth

[0069] After 22 days of fermentation, 1 ml of the Cordyceps militaris fermentation liquid of Examples 5-8 and Comparative Example 1 was taken into a 1.5 ml centrifuge tube, centrifuged at 10000 rpm for 10 min, and the supernatant was diluted 20 times with purified water and used for high performance liquid chromatography to detect the cordycepin content. Each of the above fermentation mediums was repeated three times.

[0070] The detection conditions of the HPLC method are as follows: ZORBAX 300SB~C18 column (250mm×4.6mm, 5μm), column temperature 30°C, detection wavelength 254nm, mobile phase methanol (chromatographic grade)-10mmol / L potassium dihydrogen phosphate buffer 25:75, flow rate 0.600ml / min, injection volume 20μL.

[0071] Analysis of test results

[0072] After the test results are processed, Figure 1It can be seen that when the TP concentration is within the range of 0.5-5g / L, as the TP concentration increases, the COR production increases first and then decreases. When the TP concentration is 5g / L, the COR production reaches the highest level, which can reach 6.75g / L. Figure 1 It can be seen that after adding the optimal concentration of TP to the Cordyceps militaris fermentation medium, it also contains Fe 2+ , glycine, COR yield reached the highest, 8.40g / L, which was higher than that without adding TP, Fe 2+ , glycine was about 56.71% higher.

[0073] The present invention provides a fermentation medium and method for improving the yield of cordycepin in Cordyceps militaris fermentation. There are many methods and approaches to specifically implement the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can also be made, and these improvements and modifications should also be regarded as the scope of protection of the present invention. Each component not clearly defined in this embodiment can be implemented with existing technology.

Claims

1. Application of tea polyphenols and their compositions in increasing the yield of cordycepin in Cordyceps militaris fermentation.

2. The use according to claim 1, It is characterized in that When used, tea polyphenols are added to the Cordyceps militaris fermentation medium at a concentration of 0.5~9 g / L.

3. The use according to claim 1, It is characterized in that The composition also comprises Fe 2+ , or both of glycine.

4. The use according to claim 3, It is characterized in that Fe in Cordyceps militaris fermentation medium 2+ The concentration of isocyanate is 0.2~2g / L, and the concentration of glycine is 10~30 g / L.

5. The use according to claim 2, It is characterized in that The Cordyceps militaris fermentation medium comprises the following components: 10-50 g / L glucose, 10-25 g / L peptone, 2-14 g / L yeast powder, KH 2 PO 4 0.1~1 g / L, K 2 HPO 4 0.1~1 g / L, anhydrous magnesium sulfate 0.1~1 g / L, the solvent is pure water.

6. The use according to claim 5, It is characterized in that The Cordyceps militaris fermentation medium further comprises adenine, wherein the concentration of adenine is 1-8 g / L.

7. A fermentation medium for increasing the yield of cordycepin in Cordyceps militaris fermentation, It is characterized in that It contains the following components: glucose 10~50 g / L, peptone 10~25 g / L, yeast powder 2~14 g / L, KH 2 PO 4 0.1~1 g / L, K 2 HPO 4 0.1~1 g / L, anhydrous magnesium sulfate 0.1~1 g / L and tea polyphenols 0.5~9 g / L.

8. The fermentation medium according to claim 7, It is characterized in that It also includes adenine, Fe 2+ , glycine, wherein the amount of adenine added is 1-8 g / L, Fe 2+ The addition amount of is 0.2~2 g / L, and the addition amount of glycine is 10~30 g / L.

9. A fermentation method for increasing the yield of cordycepin in Cordyceps militaris fermentation, It is characterized in that The mycelium of Cordyceps militaris is transferred to a seed culture medium and cultured in the dark for 3 to 7 days to obtain a Cordyceps militaris seed solution, which is then transferred to the fermentation medium of claim 7 or 8 at an inoculation rate of 5% to 20% (V / V) for culture.

10. The fermentation method according to claim 9, It is characterized in that The culture conditions in the fermentation medium are: temperature 22~30°C, rotation speed 120~180 rpm, pH 5~6.5, and dark culture for 18~26 days.

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