Amino acid-containing culture medium and method for delaying degeneration of pleurotus geesteranus strain

Abstract

The invention belongs to the technical field of agricultural microorganisms, and particularly relates to an amino acid-containing culture medium and method for delaying degradation of a pleurotus geesteranus strain. The amino acid-containing culture medium is prepared by adding amino acid with the final concentration of 0.15-0.25 wt% into a PDA culture medium, and the amino acid is one or more of serine and alanine. The amino acid-containing culture medium can effectively delay the degeneration phenomenon of a pleurotus geesteranus strain in subculture, effectively improves the stability of the pleurotus geesteranus strain in subculture, and is simple in operation method and low in cost.

Description

Technical Field

[0001] The invention belongs to the technical field of agricultural microorganisms, and in particular relates to an amino acid-containing culture medium and a method for delaying the degradation of Pleurotus geesteranus strains. Background Art

[0002] Pleurotus geesteranus PleurotuspulmonariusSinger .) is the trade name of Pleurotus ostreatus, also known as small oyster mushroom, pocket mushroom, oyster mushroom, coral mushroom, pearl mushroom, mini oyster mushroom, etc. It belongs to the genus Pleurotus ostreatus (Eumycota), class Basidiomycetes, order Agaricales, family Pleurotus ostreatus (Pleurotaceae) ( Pleurotus ). The mushrooms of Pleurotus geesteranus are small and beautiful, with a stalk length of about 6cm and a cap diameter of about 4cm. When flattened, they are flat and semicircular. The mushroom body is crisp and tender, sweet and refreshing, and has a strong umami flavor. It is known as the "MSG mushroom" for its unique flavor. According to research, Pleurotus geesteranus contains 3.34%~3.41% protein, 0.17%~0.20% crude fat, 0.46%~3.34% total sugar, 1.16%~1.21% vitamins, and various active polysaccharides, such as β-(1,3)-glucan, 3-o-methyl galactomannan, PFP-1 polysaccharide, etc., as well as a variety of minerals, amino acids and trace elements. It has certain antioxidant and anti-tumor effects and is a rare edible fungus that is deeply loved by consumers.

[0003] Strain degeneration refers to the phenomenon that some excellent traits of the strain deteriorate due to various factors during the cultivation or preservation process. It is mainly due to the existence of spontaneous mutations, which changes the genetic material and causes negative mutations of related genes, thus leading to the loss of some excellent traits of the strain. In the cultivation of Pleurotus geesteranus, strain degeneration occurs from time to time, and once it occurs, it will cause irreparable losses, such as reduced mycelial vitality, reduced fruiting body quality and yield, etc. Therefore, exploring how to effectively delay the degeneration of Pleurotus geesteranus strains has broad application prospects. Summary of the invention

[0004] The object of the present invention is to provide an amino acid-containing culture medium and method for delaying the degeneration of Pleurotus geesteranus strains.

[0005] To achieve the above object, the present invention adopts the following technical solution: An amino acid-containing medium for delaying the degeneration of Pleurotus geesteranus strains, the amino acid-containing medium being prepared by adding amino acids with a final concentration of 0.15wt% to 0.25wt% to a PDA medium, wherein the amino acids are one or more of serine and alanine; Further, the amino acid-containing medium is prepared by adding an amino acid with a final concentration of 0.15 wt % to the PDA medium, and the amino acid is serine; Further, the amino acid-containing medium is prepared by adding an amino acid with a final concentration of 0.25 wt % to the PDA medium, and the amino acid is alanine; Furthermore, the bacterial strain degradation is manifested as any one or more of the following: 1) The average daily growth rate of mycelium decreased; 2) Decrease in mycelial biomass; 3) The mycelial polysaccharide content decreased.

[0006] Application of the above-mentioned amino acid-containing culture medium in delaying the degradation of Pleurotus geesteranus strains; Furthermore, the bacterial strain degradation is manifested as any one or more of the following: 1) The average daily growth rate of mycelium decreased; 2) Decrease in mycelial biomass; 3) The mycelial polysaccharide content decreased.

[0007] A method for delaying the degeneration of Pleurotus geesteranus strains comprises the following steps: S1: Take out the Pleurotus geesteranus strains from the 4°C storage box, pick out the bacterial blocks and inoculate them into PDA culture medium, place them at 25°C in the dark for activation culture, and obtain activated culture strain colonies; S2: using a puncher to punch out a bacterial cake at the edge of the activated culture bacterial colony, and then transferring the bacterial cake to the amino acid-containing culture medium according to any one of claims 1 to 4, and placing it at 25° C. in the dark for subculture; Furthermore, the bacterial strain degradation is manifested as any one or more of the following: 1) The average daily growth rate of mycelium decreased; 2) Decrease in mycelial biomass; 3) The mycelial polysaccharide content decreased.

[0008] The significant advantages of the present invention are: The invention adds serine and alanine to the PDA medium for subculture of Pleurotus geesteranus. The results show that the addition of serine and alanine to the PDA medium can effectively delay the degeneration of Pleurotus geesteranus strains during subculture, effectively improve the stability of Pleurotus geesteranus strains during subculture, and the operation method is simple and low in cost. DETAILED DESCRIPTION

[0009] In order to make the contents of the present invention easier to understand, the technical solution of the present invention is further described below in conjunction with specific implementation methods, but the present invention is not limited thereto.

[0010] Embodiment 1: In this embodiment, the PDA medium formula: 200g potato (boiled extract), 20g glucose, 20g agar, 1000ml purified water, natural pH; amino acid medium formula: L-serine was added to the PDA medium at a final concentration of 0.15wt%; the medium sterilization conditions were: high pressure sterilization pot at 121°C, sterilization time 20min.

[0011] Take out the Pleurotus geesteranus strains from the 4℃ storage box, pick up the strain blocks with an inoculation shovel and inoculate them in the center of a 9cm diameter PDA culture medium plate, place it in a 25℃ constant temperature and humidity incubator and culture it in the dark until the mycelium covers the entire culture medium, and obtain the activated culture strain colony; use a hole puncher to punch out a 9mm diameter cake at the edge of the activated culture strain colony, and then transfer the cake to the center of a 9cm diameter amino acid culture medium plate, place it in a 25℃ constant temperature and humidity incubator and culture it in the dark until the mycelium covers the entire culture medium, and obtain the first generation strain colony; use a hole puncher to punch out a 9mm diameter cake at the edge of the first generation strain colony, and then transfer the cake to the center of a 9cm diameter amino acid culture medium plate, place it in a 25℃ constant temperature and humidity incubator and culture it in the dark until the mycelium covers the entire culture medium, and obtain the first generation strain colony. The mycelia covered the entire culture medium, and the second-generation bacterial colony was obtained; a 9mm diameter bacterial cake was punched out at the edge of the second-generation bacterial colony with a cork hole, and then the bacterial cake was transferred to the center of a 9cm diameter amino acid culture medium plate, and placed in a 25℃ constant temperature and humidity incubator for dark culture until the mycelia covered the entire culture medium, and the third-generation bacterial colony was obtained; a 9mm diameter bacterial cake was punched out at the edge of the third-generation bacterial colony with a cork hole, and then the bacterial cake was transferred to the center of a 9cm diameter amino acid culture medium plate, and placed in a 25℃ constant temperature and humidity incubator for dark culture until the mycelia covered the entire culture medium, and the fourth-generation bacterial colony was obtained; a 9mm diameter bacterial cake was punched out at the edge of the fourth-generation bacterial colony with a cork hole, and then the bacterial cake was transferred to a 9cm diameter amino acid culture medium plate The plate was placed in a constant temperature and humidity incubator at 25°C and cultured in the dark until the mycelium covered the entire culture medium, thereby obtaining the fifth-generation bacterial colony; a 9mm diameter bacterial cake was punched out at the edge of the fifth-generation bacterial colony with a cork hole puncher, and then the bacterial cake was transferred to the center of a 9cm diameter amino acid culture medium plate, and placed in a constant temperature and humidity incubator at 25°C and cultured in the dark until the mycelium covered the entire culture medium, thereby obtaining the sixth-generation bacterial colony; a 9mm diameter bacterial cake was punched out at the edge of the sixth-generation bacterial colony with a cork hole puncher, and then the bacterial cake was transferred to the center of a 9cm diameter amino acid culture medium plate, and placed in a constant temperature and humidity incubator at 25°C and cultured in the dark until the mycelium covered the entire culture medium, thereby obtaining the seventh-generation bacterial colony; a 9mm diameter bacterial cake was punched out at the edge of the seventh-generation bacterial colony with a cork hole puncher , and then the bacterial cake was transferred to the center of a 9-cm diameter amino acid culture medium plate, placed in a constant temperature and humidity incubator at 25°C for dark culture until the mycelium covered the entire culture medium, and the 8th generation bacterial colony was obtained; a 9-mm diameter bacterial cake was punched out with a hole puncher at the edge of the 8th generation bacterial colony, and then the bacterial cake was transferred to the center of a 9-cm diameter amino acid culture medium plate, placed in a constant temperature and humidity incubator at 25°C for dark culture until the mycelium covered the entire culture medium, and the 9th generation bacterial colony was obtained; a 9-mm diameter bacterial cake was punched out with a hole puncher at the edge of the 9th generation bacterial colony, and then the bacterial cake was transferred to the center of a 9-cm diameter amino acid culture medium plate, placed in a constant temperature and humidity incubator at 25°C for dark culture until the mycelium covered the entire culture medium, and the 10th generation bacterial colony was obtained.

[0012] Determination of mycelium growth rate: Use a hole puncher to take 9 mm diameter cakes from the edge of the 1st and 10th generation colonies, respectively. Then transfer the cakes to the center of a 9 cm diameter PDA culture medium plate, place it in a constant temperature and humidity incubator at 25°C for dark culture, and measure the diameter (mm) of the colony with a ruler with the inoculated cake as the center. Use the cross method to measure, and use the mycelium growing all over the culture dish as the measurement end point. Record the number of growth days, and calculate the average daily growth rate of mycelium. The average daily growth rate of mycelium (mm / d) = colony diameter (mm) / number of mycelium growth days (d).

[0013] Determination of mycelial biomass: Mycelium was separated by filtration from the 1st and 10th generation bacterial colonies, dried at 60°C to constant weight, and the mycelial biomass was calculated.

[0014] Determination of mycelial polysaccharide content: The mycelia separated by filtration from the 1st and 10th generation bacterial colonies were dried at 60°C to constant weight, 0.1 g was accurately taken into a centrifuge tube, 5 mL of distilled water was added, and the mixture was extracted in a water bath at 90°C for 4 h, and centrifuged at 5000 rpm for 10 min to obtain the first supernatant and the first precipitate; 2 mL of distilled water was added to the first precipitate, and the mixture was extracted in a water bath at 90°C for 4 h, and centrifuged at 5000 rpm for 10 min to obtain the second supernatant and the second precipitate; the first supernatant and the second precipitate were combined, 3 times the volume of anhydrous ethanol was added, the mixture was stored at 4°C overnight, and centrifuged at 5000 rpm for 10 min, the supernatant was discarded, and the precipitate was dissolved with 25 mL of distilled water to obtain a mycelial polysaccharide extract; 1 mL of mycelial polysaccharide extract was accurately taken, and 0.5 mL of 50 g / L phenol solution and 5 mL of concentrated sulfuric acid were added in sequence, mixed, placed in a water bath at 30°C for 20 min, and the absorbance was measured at a wavelength of 490 nm.

[0015] Embodiment 2: In this embodiment, the PDA medium formula is: 200g potato (boiled extract), 20g glucose, 20g agar, 1000ml purified water, and natural pH; the amino acid medium formula is: L-alanine is added to the PDA medium at a final concentration of 0.25wt%; the medium sterilization conditions are: high pressure sterilization pot at 121°C and sterilization time for 20min.

[0016] Take out the Pleurotus geesteranus strains from the 4℃ storage box, pick up the strain blocks with an inoculation shovel and inoculate them in the center of a 9cm diameter PDA culture medium plate, place it in a 25℃ constant temperature and humidity incubator and culture it in the dark until the mycelium covers the entire culture medium, and obtain the activated culture strain colony; use a hole puncher to punch out a 9mm diameter cake at the edge of the activated culture strain colony, and then transfer the cake to the center of a 9cm diameter amino acid culture medium plate, place it in a 25℃ constant temperature and humidity incubator and culture it in the dark until the mycelium covers the entire culture medium, and obtain the first generation strain colony; use a hole puncher to punch out a 9mm diameter cake at the edge of the first generation strain colony, and then transfer the cake to the center of a 9cm diameter amino acid culture medium plate, place it in a 25℃ constant temperature and humidity incubator and culture it in the dark until the mycelium covers the entire culture medium, and obtain the first generation strain colony. The mycelia covered the entire culture medium, and the second-generation bacterial colony was obtained; a 9mm diameter bacterial cake was punched out at the edge of the second-generation bacterial colony with a cork hole, and then the bacterial cake was transferred to the center of a 9cm diameter amino acid culture medium plate, and placed in a 25℃ constant temperature and humidity incubator for dark culture until the mycelia covered the entire culture medium, and the third-generation bacterial colony was obtained; a 9mm diameter bacterial cake was punched out at the edge of the third-generation bacterial colony with a cork hole, and then the bacterial cake was transferred to the center of a 9cm diameter amino acid culture medium plate, and placed in a 25℃ constant temperature and humidity incubator for dark culture until the mycelia covered the entire culture medium, and the fourth-generation bacterial colony was obtained; a 9mm diameter bacterial cake was punched out at the edge of the fourth-generation bacterial colony with a cork hole, and then the bacterial cake was transferred to a 9cm diameter amino acid culture medium plate The plate was placed in a constant temperature and humidity incubator at 25°C and cultured in the dark until the mycelium covered the entire culture medium, thereby obtaining the fifth-generation bacterial colony; a 9mm diameter bacterial cake was punched out at the edge of the fifth-generation bacterial colony with a cork hole puncher, and then the bacterial cake was transferred to the center of a 9cm diameter amino acid culture medium plate, and placed in a constant temperature and humidity incubator at 25°C and cultured in the dark until the mycelium covered the entire culture medium, thereby obtaining the sixth-generation bacterial colony; a 9mm diameter bacterial cake was punched out at the edge of the sixth-generation bacterial colony with a cork hole puncher, and then the bacterial cake was transferred to the center of a 9cm diameter amino acid culture medium plate, and placed in a constant temperature and humidity incubator at 25°C and cultured in the dark until the mycelium covered the entire culture medium, thereby obtaining the seventh-generation bacterial colony; a 9mm diameter bacterial cake was punched out at the edge of the seventh-generation bacterial colony with a cork hole puncher , and then the bacterial cake was transferred to the center of a 9-cm diameter amino acid culture medium plate, placed in a constant temperature and humidity incubator at 25°C for dark culture until the mycelium covered the entire culture medium, and the 8th generation bacterial colony was obtained; a 9-mm diameter bacterial cake was punched out with a hole puncher at the edge of the 8th generation bacterial colony, and then the bacterial cake was transferred to the center of a 9-cm diameter amino acid culture medium plate, placed in a constant temperature and humidity incubator at 25°C for dark culture until the mycelium covered the entire culture medium, and the 9th generation bacterial colony was obtained; a 9-mm diameter bacterial cake was punched out with a hole puncher at the edge of the 9th generation bacterial colony, and then the bacterial cake was transferred to the center of a 9-cm diameter amino acid culture medium plate, placed in a constant temperature and humidity incubator at 25°C for dark culture until the mycelium covered the entire culture medium, and the 10th generation bacterial colony was obtained.

[0017] Determination of mycelium growth rate: Use a hole puncher to take 9 mm diameter cakes from the edge of the 1st and 10th generation colonies, respectively. Then transfer the cakes to the center of a 9 cm diameter PDA culture medium plate, place it in a constant temperature and humidity incubator at 25°C for dark culture, and measure the diameter (mm) of the colony with a ruler with the inoculated cake as the center. Use the cross method to measure, and use the mycelium growing all over the culture dish as the measurement end point. Record the number of growth days, and calculate the average daily growth rate of mycelium. The average daily growth rate of mycelium (mm / d) = colony diameter (mm) / number of mycelium growth days (d).

[0018] Determination of mycelial biomass: Mycelium was separated by filtration from the 1st and 10th generation bacterial colonies, dried at 60°C to constant weight, and the mycelial biomass was calculated.

[0019] Determination of mycelial polysaccharide content: The mycelia separated by filtration from the 1st and 10th generation bacterial colonies were dried at 60°C to constant weight, 0.1 g was accurately taken into a centrifuge tube, 5 mL of distilled water was added, and the mixture was extracted in a water bath at 90°C for 4 h, and centrifuged at 5000 rpm for 10 min to obtain the first supernatant and the first precipitate; 2 mL of distilled water was added to the first precipitate, and the mixture was extracted in a water bath at 90°C for 4 h, and centrifuged at 5000 rpm for 10 min to obtain the second supernatant and the second precipitate; the first supernatant and the second precipitate were combined, 3 times the volume of anhydrous ethanol was added, the mixture was stored at 4°C overnight, and centrifuged at 5000 rpm for 10 min, the supernatant was discarded, and the precipitate was dissolved with 25 mL of distilled water to obtain a mycelial polysaccharide extract; 1 mL of mycelial polysaccharide extract was accurately taken, and 0.5 mL of 50 g / L phenol solution and 5 mL of concentrated sulfuric acid were added in sequence, mixed, placed in a water bath at 30°C for 20 min, and the absorbance was measured at a wavelength of 490 nm.

[0020] Comparative Example: In this embodiment, the PDA medium formula is: 200g potato (boiling extract), 20g glucose, 20g agar, 1000ml purified water, pH natural; the medium sterilization conditions are: high pressure sterilization pot 121°C, sterilization time 20min.

[0021] Take out the Pleurotus geesteranus strain from the 4℃ storage box, pick up the strain block with an inoculation shovel and inoculate it in the center of a 9cm diameter PDA culture medium plate, place it in a 25℃ constant temperature and humidity incubator and culture it in the dark until the mycelium covers the entire culture medium, and obtain the activated culture strain colony; use a hole puncher to punch out a 9mm diameter cake at the edge of the activated culture strain colony, and then transfer the cake to the center of a 9cm diameter PDA culture medium plate, place it in a 25℃ constant temperature and humidity incubator and culture it in the dark until the mycelium covers the entire culture medium, and obtain the first generation strain colony; use a hole puncher to punch out a 9mm diameter cake at the edge of the first generation strain colony, and then transfer the cake to the center of a 9cm diameter PDA culture medium plate, place it in a 25℃ constant temperature and humidity incubator and culture it in the dark until the mycelium covers the entire culture medium, and obtain the first generation strain colony. The mycelia covered the entire culture medium, and the second-generation bacterial colony was obtained; a 9mm diameter bacterial cake was punched out at the edge of the second-generation bacterial colony with a cork hole, and then the bacterial cake was transferred to the center of a 9cm diameter PDA culture medium plate, and placed in a 25℃ constant temperature and humidity incubator for dark culture until the mycelia covered the entire culture medium, and the third-generation bacterial colony was obtained; a 9mm diameter bacterial cake was punched out at the edge of the third-generation bacterial colony with a cork hole, and then the bacterial cake was transferred to the center of a 9cm diameter PDA culture medium plate, and placed in a 25℃ constant temperature and humidity incubator for dark culture until the mycelia covered the entire culture medium, and the fourth-generation bacterial colony was obtained; a 9mm diameter bacterial cake was punched out at the edge of the fourth-generation bacterial colony with a cork hole, and then the bacterial cake was transferred to a 9cm diameter PDA culture medium plate The plate was placed in a 25°C constant temperature and humidity incubator and cultured in the dark until the mycelium covered the entire culture medium, thereby obtaining the 5th generation bacterial colony; a 9mm diameter bacterial cake was punched out at the edge of the 5th generation bacterial colony with a cork hole, and then the bacterial cake was transferred to the center of a 9cm diameter PDA culture medium plate, and placed in a 25°C constant temperature and humidity incubator and cultured in the dark until the mycelium covered the entire culture medium, thereby obtaining the 6th generation bacterial colony; a 9mm diameter bacterial cake was punched out at the edge of the 6th generation bacterial colony with a cork hole, and then the bacterial cake was transferred to the center of a 9cm diameter PDA culture medium plate, and placed in a 25°C constant temperature and humidity incubator and cultured in the dark until the mycelium covered the entire culture medium, thereby obtaining the 7th generation bacterial colony; a 9mm diameter bacterial cake was punched out at the edge of the 7th generation bacterial colony with a cork hole , and then the bacterial cake was transferred to the center of a 9-cm diameter PDA culture medium plate, placed in a constant temperature and humidity incubator at 25°C for dark culture until the mycelium covered the entire culture medium, and the 8th generation bacterial colony was obtained; a 9-mm diameter bacterial cake was punched out with a hole puncher at the edge of the 8th generation bacterial colony, and then the bacterial cake was transferred to the center of a 9-cm diameter PDA culture medium plate, placed in a constant temperature and humidity incubator at 25°C for dark culture until the mycelium covered the entire culture medium, and the 9th generation bacterial colony was obtained; a 9-mm diameter bacterial cake was punched out with a hole puncher at the edge of the 9th generation bacterial colony, and then the bacterial cake was transferred to the center of a 9-cm diameter PDA culture medium plate, placed in a constant temperature and humidity incubator at 25°C for dark culture until the mycelium covered the entire culture medium, and the 10th generation bacterial colony was obtained.

[0022] Determination of mycelium growth rate: Use a hole puncher to take 9 mm diameter cakes from the edge of the 1st and 10th generation colonies, respectively. Then transfer the cakes to the center of a 9 cm diameter PDA culture medium plate, place it in a constant temperature and humidity incubator at 25°C for dark culture, and measure the diameter (mm) of the colony with a ruler with the inoculated cake as the center. Use the cross method to measure, and use the mycelium growing all over the culture dish as the measurement end point. Record the number of growth days, and calculate the average daily growth rate of mycelium. The average daily growth rate of mycelium (mm / d) = colony diameter (mm) / number of mycelium growth days (d).

[0023] Determination of mycelial biomass: Mycelium was separated by filtration from the 1st and 10th generation bacterial colonies, dried at 60°C to constant weight, and the mycelial biomass was calculated.

[0024] Determination of mycelial polysaccharide content: The mycelia separated by filtration from the 1st and 10th generation bacterial colonies were dried at 60°C to constant weight, 0.1 g was accurately taken into a centrifuge tube, 5 mL of distilled water was added, and the mixture was extracted in a water bath at 90°C for 4 h, and centrifuged at 5000 rpm for 10 min to obtain the first supernatant and the first precipitate; 2 mL of distilled water was added to the first precipitate, and the mixture was extracted in a water bath at 90°C for 4 h, and centrifuged at 5000 rpm for 10 min to obtain the second supernatant and the second precipitate; the first supernatant and the second precipitate were combined, 3 times the volume of anhydrous ethanol was added, the mixture was stored at 4°C overnight, and centrifuged at 5000 rpm for 10 min, the supernatant was discarded, and the precipitate was dissolved with 25 mL of distilled water to obtain a mycelial polysaccharide extract; 1 mL of mycelial polysaccharide extract was accurately taken, and 0.5 mL of 50 g / L phenol solution and 5 mL of concentrated sulfuric acid were added in sequence, mixed, placed in a water bath at 30°C for 20 min, and the absorbance was measured at a wavelength of 490 nm.

[0025] The results of the daily average growth rate, biomass and polysaccharide content of mycelium are shown in Table 1. In Example 1, the daily average growth rate, biomass and polysaccharide content of the 10th generation mycelium decreased by 11.02%, 11.32% and 24.26% respectively compared with the 1st generation mycelium, in Example 2, the daily average growth rate, biomass and polysaccharide content of the 10th generation mycelium decreased by 9.47%, 20% and 6.62% respectively compared with the 1st generation mycelium, and in the comparative example, the daily average growth rate, biomass and polysaccharide content of the 10th generation mycelium decreased by 15.33%, 26.58% and 23.89% respectively compared with the 1st generation mycelium. It shows that by adding serine and alanine to the culture medium, the degradation of Pleurotus geesteranus strains can be effectively delayed.

[0026] Table 1 Average daily growth rate, biomass and polysaccharide content of the 1st and 10th generation mycelium

[0027] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. An amino acid-containing culture medium for delaying the degradation of Pleurotus geesteranus strains, characterized in that: The amino acid-containing culture medium is prepared by adding amino acids with a final concentration of 0.15wt% to 0.25wt% to the PDA culture medium, and the amino acids are one or more of serine and alanine.

2. The amino acid-containing medium according to claim 1, characterized in that: The amino acid-containing culture medium is prepared by adding amino acids with a final concentration of 0.15 wt % to the PDA culture medium, and the amino acid is serine.

3. The amino acid-containing medium according to claim 1, characterized in that: The amino acid-containing culture medium is prepared by adding amino acids with a final concentration of 0.25 wt % to the PDA culture medium, and the amino acid is alanine.

4. The amino acid-containing medium according to claim 1, characterized in that: The bacterial degradation is manifested as any one or more of the following: 1) The average daily growth rate of mycelium decreased; 2) Decrease in mycelial biomass; 3) The mycelial polysaccharide content decreased.

5. Use of the amino acid-containing culture medium according to any one of claims 1 to 4 in delaying the degeneration of Pleurotus geesteranus strains.

6. The use according to claim 5, characterized in that: the degradation of the strain is manifested by any one or more of the following: 1) The average daily growth rate of mycelium decreased; 2) Decrease in mycelial biomass; 3) The mycelial polysaccharide content decreased.

7. A method for delaying the degeneration of Pleurotus geesteranus strains, characterized in that: The following steps are involved: S1: Take out the Pleurotus geesteranus strains from the 4°C storage box, pick out the bacterial blocks and inoculate them into the PDA medium, place them at 25°C in the dark for activation culture, and obtain activated culture strain colonies; S2: Punch a bacterial cake at the edge of the activated culture bacterial colony with a hole puncher, then transfer the bacterial cake to the amino acid-containing culture medium according to any one of claims 1 to 4, and place it at 25° C. in the dark for subculture.

8. The method according to claim 7, characterized in that: the degradation of the strain is manifested by any one or more of the following: 1) The average daily growth rate of mycelium decreased; 2) Decrease in mycelial biomass; 3) The mycelial polysaccharide content decreased.

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