A method for cultivating strontium-enriched cordyceps militaris
By leveraging the synergistic effects of a compound strontium source and various nutrients, and designing differentiated culture media and process parameters, the problems of low strontium enrichment efficiency and insufficient content of active ingredients were solved, thus achieving the cultivation of highly efficient strontium-enriched Cordyceps militaris.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- LIAONING YUANSHAN GREEN VALLEY ECOLOGICAL AGRI CO LTD
- Filing Date
- 2025-11-27
- Publication Date
- 2026-06-26
AI Technical Summary
Existing technologies make it difficult to achieve efficient enrichment of strontium, resulting in low biomass and core active ingredient content in Cordyceps militaris, which cannot meet specific nutritional supplementation needs. At the same time, excessive addition of strontium can damage the mycelial structure.
Using a strontium nitrate + strontium citrate composite strontium source, combined with silkworm pupa polypeptide powder, L-proline and fructooligosaccharides, liquid and solid culture media for differentiated cultivation stages were designed. Rice flour, barley seedling powder and plant polysaccharides were added, and a composite synergist of magnesium sulfate + zinc sulfate + selenomethionine = 5:3:1 was used to optimize the cultivation process parameters.
It achieves efficient enrichment of strontium, increases the biomass and core active ingredient content of Cordyceps militaris, avoids the toxic effects of excessive strontium on mycelium, and ensures stable product quality.
Abstract
Description
Technical Field
[0001] This invention relates to the field of microbial cultivation technology, and in particular to a method for cultivating strontium-enriched Cordyceps militaris. Background Technology
[0002] Cordyceps militaris, also known as North Cordyceps sinensis, is a precious fungus with both medicinal and edible value. Its active ingredients, such as cordycepin, adenosine, and polysaccharides, possess various physiological functions including immune regulation, anti-oxidation, and anti-fatigue effects, making it widely used in health foods and pharmaceuticals. However, natural Cordyceps militaris has a limited capacity to accumulate trace elements, making it difficult to meet specific nutritional supplementation needs.
[0003] With increasing consumer demand for health products, Cordyceps militaris products rich in beneficial minerals have gradually become a market hotspot. Among them, strontium, as one of the essential trace elements for the human body, has attracted much attention. Strontium participates in bone formation, regulates neuromuscular excitability, and improves cardiovascular function in the human body. It can also work synergistically with calcium to reduce the risk of osteoporosis, hypertension, and other diseases. However, because strontium is an exogenous ion, excessive addition can damage the cell membrane structure of Cordyceps militaris mycelium, inhibit metabolic enzyme activity, and lead to slow mycelial growth and decreased biomass. Traditional culture medium formulations (such as single carbon source or simple nitrogen source combinations) lack the synergistic effect of strontium ion absorption and transport, resulting in low strontium enrichment efficiency and a reduction in the content of core active ingredients such as cordycepin and adenosine. As a result, the current production of strontium-enriched Cordyceps militaris is limited, and its nutritional content is low and its quality is inconsistent, failing to meet people's needs.
[0004] Therefore, it is particularly important to develop a method for cultivating strontium-enriched Cordyceps militaris that can achieve efficient enrichment of strontium while ensuring the biomass and content of core active ingredients. Summary of the Invention
[0005] The purpose of this invention is to overcome the problems of existing technology and provide a method for cultivating strontium-enriched Cordyceps militaris that can achieve efficient enrichment of strontium while ensuring the biomass and content of core active ingredients of Cordyceps militaris.
[0006] To achieve the above objectives, the technical solution adopted by this invention is: a method for cultivating strontium-rich Cordyceps militaris, comprising the following steps:
[0007] Step S1: Preparation of culture medium: Dissolve each component in pure water according to the liquid seed culture medium formula, mix evenly, pour into culture flasks, seal, sterilize, and cool to obtain liquid seed culture medium; prepare solid culture medium according to the solid culture medium formula.
[0008] Step S2, strain activation: Take Cordyceps militaris strain and inoculate it on PDA slant medium. Incubate at 20-22℃ for 7-10 days. After the mycelium has covered the slant, wash it with sterile physiological saline to obtain a bacterial suspension.
[0009] Step S3, Liquid seed culture: Inoculate the bacterial suspension into the liquid seed culture medium, place it in a shaker, and culture at 20-22℃ and 150-180 r / min for 3-5 days to obtain the liquid seed culture;
[0010] Step S4, Solid Culture: Spray the liquid seed solution evenly onto the surface of the solid culture medium and place it in an incubator for solid culture;
[0011] Step S5, Harvesting and Drying: After the fruiting bodies of Cordyceps militaris mature, harvest the fruiting bodies and mycelium, rinse with clean water to remove surface impurities, vacuum dry at 55-65℃ to constant weight, and pulverize through an 80-100 mesh sieve to obtain strontium-rich Cordyceps militaris product.
[0012] Preferably, the liquid seed culture medium in step S1 is composed of the following components in the following amounts: glucose 20-25 g / L, peptone 10-12 g / L, yeast extract 3-5 g / L, strontium nitrate 0.5-0.8 g / L, strontium citrate 0.3-0.5 g / L, compound nutrients 0.5-0.8 g / L, vitamin B1 0.05-0.1 g / L, vitamin B6 0.03-0.05 g / L, calcium carbonate 0.6-1.2 g / L, ferrous sulfate 0.07-0.12 g / L, silkworm pupa polypeptide powder 6-8 g / L, L-proline 0.1-0.2 g / L, fructooligosaccharides 5-8 g / L, and the pH is adjusted to 5.5-6.5.
[0013] Preferably, the compound nutrient elements are composed of magnesium sulfate, zinc sulfate, and selenomethionine in a mass ratio of 5:2:1.
[0014] Preferably, the solid culture medium in step S1 is composed of the following components in the following proportions: 60-70 parts wheat grains, 15-20 parts silkworm pupa powder, 5-8 parts corn flour, 3-5 parts glucose, 0.5-0.8 parts strontium chloride, 0.3-0.5 parts strontium citrate, 0.3-0.5 parts compound synergist, 40-50 parts rice flour, 10-20 parts barley grass powder, 5-8 parts plant polysaccharides, and 120-150 parts water, with the pH adjusted to 5.8-6.2.
[0015] Preferably, the composite synergist is composed of magnesium sulfate, zinc sulfate, and selenomethionine in a mass ratio of 5:3:1.
[0016] Preferably, the plant polysaccharide is at least one of tea polysaccharide, wolfberry polysaccharide, and shiitake mushroom polysaccharide.
[0017] Preferably, the sterilization temperature in step S1 is 121°C and the time is 30 min.
[0018] Preferably, the Cordyceps militaris strain mentioned in step S2 is ACCC50632.
[0019] Preferably, the bacterial concentration in the bacterial suspension in step S2 is 1×10⁻⁶. 6 -5×10 6 cfu / mL.
[0020] Preferably, the inoculation amount of the bacterial suspension in step S3 is 5-8 vol.%.
[0021] Preferably, the inoculation amount of the liquid seed solution in step S4 is 10-15 vol.%.
[0022] Preferably, the solid-state culture conditions in step S4 are: temperature 18-22℃, relative humidity 60-70%, light intensity 1500-2000 lux, light cycle 12h light / 12h dark, 2 hours of blue light irradiation per day, and culture for 55-65 days.
[0023] Preferably, the maturation of the Cordyceps militaris fruiting body in step S5 is when its stroma length is 8 cm or more.
[0024] Due to the application of the above technical solution, the present invention has the following beneficial effects:
[0025] (1) Using a composite strontium source of “strontium nitrate + strontium citrate”, strontium citrate can reduce the toxicity of free strontium ions through complexation and at the same time form an absorption complement with strontium nitrate; simultaneously introducing bioactive components such as silkworm pupa polypeptide powder, L-proline and oligofructose, silkworm pupa polypeptide powder participates in cell membrane phospholipid synthesis to enhance structural stability, L-proline regulates cell osmotic pressure to enhance strontium tolerance, and oligofructose activates hexokinase activity to enhance carbon source utilization efficiency. The three work together to significantly improve mycelial dry weight and initial strontium absorption efficiency.
[0026] (2) Rice flour, barley grass powder and plant polysaccharides (tea polysaccharide, wolfberry polysaccharide, etc.) are added to the solid culture medium. Rice flour provides a slow-release carbon source to prolong the nutrient supply cycle. The natural vitamins and minerals in barley grass powder activate the activity of strontium transport-related enzymes. Plant polysaccharides remove strontium-induced reactive oxygen species through antioxidant effects. Combined with the compound synergist of "magnesium sulfate + zinc sulfate + selenomethionine = 5:3:1", zinc ions promote fruiting body differentiation and selenium ions protect the cordycepin synthesis pathway, resulting in high cordycepin and adenosine content in the product, and at the same time, a large final enrichment of strontium.
[0027] (3) Based on the physiological characteristics of different culture stages of Cordyceps militaris, a differentiated system was designed: during the liquid seed stage, a low concentration of compound strontium source was used in combination with compound trace elements to focus on mycelial proliferation and strontium tolerance acclimatization; during the solid culture stage, the concentration of strontium source was increased and compound synergists were introduced to focus on strontium accumulation in fruiting bodies and synthesis of active ingredients. The concentration of strontium source was controlled within the safe threshold throughout the process to avoid the safety risks caused by blindly increasing the concentration in the existing technology.
[0028] (4) By rationally selecting the liquid seed culture medium and solid culture medium formula, the components can work together to achieve the same effect. At the same time, by optimizing the specific process parameters in the cultivation method, the product can achieve both efficient enrichment of strontium and ensure the biomass and content of core active ingredients of Cordyceps militaris. Detailed Implementation
[0029] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.
[0030] Example 1
[0031] A method for cultivating strontium-enriched Cordyceps militaris includes the following steps:
[0032] Step S1: Preparation of culture medium: Dissolve each component in pure water according to the liquid seed culture medium formula, mix evenly, pour into culture flasks, seal, sterilize, and cool to obtain liquid seed culture medium; prepare solid culture medium according to the solid culture medium formula.
[0033] Step S2, strain activation: Take Cordyceps militaris strain and inoculate it into PDA slant medium. Incubate at 20℃ for 7 days. After the mycelium has covered the slant, wash with sterile physiological saline to obtain a bacterial suspension.
[0034] Step S3, Liquid seed culture: Inoculate the bacterial suspension into liquid seed culture medium, place it in a shaker, and culture at 20℃ and 150r / min for 3 days to obtain liquid seed culture;
[0035] Step S4, Solid Culture: Spray the liquid seed solution evenly onto the surface of the solid culture medium and place it in an incubator for solid culture;
[0036] Step S5, Harvesting and Drying: After the fruiting bodies of Cordyceps militaris mature, harvest the fruiting bodies and mycelium, rinse with clean water to remove surface impurities, vacuum dry at 65℃ to constant weight, pulverize and pass through an 80-mesh sieve to obtain strontium-rich Cordyceps militaris product.
[0037] The liquid seed culture medium described in step S1 consists of the following components in the following proportions: glucose 20 g / L, peptone 10 g / L, yeast extract 3 g / L, strontium nitrate 0.5 g / L, strontium citrate 0.3 g / L, compound nutrients 0.5 g / L, vitamin B1 0.05 g / L, vitamin B6 0.03 g / L, calcium carbonate 0.6 g / L, ferrous sulfate 0.07 g / L, silkworm pupa polypeptide powder 6 g / L, L-proline 0.1 g / L, and fructooligosaccharides 5 g / L, with the pH adjusted to 5.5; the compound nutrients consist of magnesium sulfate, zinc sulfate, and selenomethionine in a mass ratio of 5:2:1.
[0038] The solid culture medium in step S1 is composed of the following components in the following proportions: 60 parts wheat grains, 15 parts silkworm pupa powder, 5 parts corn flour, 3 parts glucose, 0.5 parts strontium chloride, 0.3 parts strontium citrate, 0.3 parts compound synergist, 40 parts rice flour, 10 parts barley seedling powder, 5 parts plant polysaccharide, and 120 parts water, with the pH adjusted to 5.8; the compound synergist is composed of magnesium sulfate, zinc sulfate, and selenomethionine in a mass ratio of 5:3:1; the plant polysaccharide is tea polysaccharide.
[0039] The sterilization temperature in step S1 is 121℃, and the time is 30 min; the Cordyceps militaris strain in step S2 is ACCC50632; the bacterial concentration in the bacterial suspension in step S2 is 1×10⁻⁶. 6 cfu / mL; the inoculation volume of the bacterial suspension in step S3 is 5 vol.%; the inoculation volume of the liquid seed solution in step S4 is 10 vol.%; the culture conditions for solid culture in step S4 are: temperature 18℃, relative humidity 60%, light intensity 1500 lux, photoperiod 12h light / 12h dark, 2 hours of blue light irradiation per day, culture for 55 days; the maturity of the Cordyceps militaris fruiting body in step S5 is when its stroma length is more than 8 cm.
[0040] Example 2
[0041] A method for cultivating strontium-enriched Cordyceps militaris includes the following steps:
[0042] Step S1: Preparation of culture medium: Dissolve each component in pure water according to the liquid seed culture medium formula, mix evenly, pour into culture flasks, seal, sterilize, and cool to obtain liquid seed culture medium; prepare solid culture medium according to the solid culture medium formula.
[0043] Step S2, strain activation: Take Cordyceps militaris strain and inoculate it into PDA slant medium. Incubate at 20.5℃ for 8 days. After the mycelium has covered the slant, wash it with sterile physiological saline to obtain a bacterial suspension.
[0044] Step S3, Liquid seed culture: Inoculate the bacterial suspension into the liquid seed culture medium, place it in a shaker, and culture at 20.5℃ and 160r / min for 3.5 days to obtain the liquid seed culture;
[0045] Step S4, Solid Culture: Spray the liquid seed solution evenly onto the surface of the solid culture medium and place it in an incubator for solid culture;
[0046] Step S5, Harvesting and Drying: After the fruiting bodies of Cordyceps militaris mature, harvest the fruiting bodies and mycelium, rinse with clean water to remove surface impurities, vacuum dry at 65℃ to constant weight, pulverize and pass through an 85-mesh sieve to obtain strontium-rich Cordyceps militaris product.
[0047] The liquid seed culture medium described in step S1 consists of the following components in the following proportions: glucose 22 g / L, peptone 10.5 g / L, yeast extract 3.5 g / L, strontium nitrate 0.6 g / L, strontium citrate 0.35 g / L, compound nutrients 0.6 g / L, vitamin B1 0.06 g / L, vitamin B6 0.035 g / L, calcium carbonate 0.7 g / L, ferrous sulfate 0.08 g / L, silkworm pupa polypeptide powder 6.5 g / L, L-proline 0.13 g / L, and fructooligosaccharides 6 g / L, with the pH adjusted to 5.8; the compound nutrients consist of magnesium sulfate, zinc sulfate, and selenomethionine in a mass ratio of 5:2:1.
[0048] The solid culture medium in step S1 is composed of the following components in the following proportions: 63 parts wheat grains, 17 parts silkworm pupa powder, 6 parts corn flour, 3.5 parts glucose, 0.6 parts strontium chloride, 0.35 parts strontium citrate, 0.35 parts compound synergist, 43 parts rice flour, 13 parts barley grass powder, 6 parts plant polysaccharide, and 130 parts water, with the pH adjusted to 5.9; the compound synergist is composed of magnesium sulfate, zinc sulfate, and selenomethionine in a mass ratio of 5:3:1; the plant polysaccharide is wolfberry polysaccharide.
[0049] The sterilization temperature in step S1 is 121℃, and the time is 30 min; the Cordyceps militaris strain in step S2 is ACCC50632; the bacterial concentration in the bacterial suspension in step S2 is 2×10⁻⁶. 6 cfu / mL; the inoculation volume of the bacterial suspension in step S3 is 6 vol.%; the inoculation volume of the liquid seed solution in step S4 is 12 vol.%; the culture conditions for solid culture in step S4 are: temperature 19℃, relative humidity 63%, light intensity 1600 lux, photoperiod 12h light / 12h dark, 2 hours of blue light irradiation per day, culture for 57 days; the maturity of the Cordyceps militaris fruiting body in step S5 is when its stroma length is more than 8 cm.
[0050] Example 3
[0051] A method for cultivating strontium-enriched Cordyceps militaris includes the following steps:
[0052] Step S1: Preparation of culture medium: Dissolve each component in pure water according to the liquid seed culture medium formula, mix evenly, pour into culture flasks, seal, sterilize, and cool to obtain liquid seed culture medium; prepare solid culture medium according to the solid culture medium formula.
[0053] Step S2, strain activation: Inoculate the Cordyceps militaris strain onto PDA slant medium and incubate at 21℃ for 8.5 days. After the mycelium has covered the slant, rinse with sterile physiological saline to obtain a bacterial suspension.
[0054] Step S3, Liquid seed culture: Inoculate the bacterial suspension into the liquid seed culture medium, place it in a shaker, and culture at 21℃ and 165r / min for 4 days to obtain the liquid seed culture;
[0055] Step S4, Solid Culture: Spray the liquid seed solution evenly onto the surface of the solid culture medium and place it in an incubator for solid culture;
[0056] Step S5, Harvesting and Drying: After the fruiting bodies of Cordyceps militaris mature, harvest the fruiting bodies and mycelium, rinse with clean water to remove surface impurities, vacuum dry at 65℃ to constant weight, pulverize and pass through a 90-mesh sieve to obtain strontium-rich Cordyceps militaris product.
[0057] The liquid seed culture medium in step S1 consists of the following components in the following proportions: glucose 23 g / L, peptone 11 g / L, yeast extract 4 g / L, strontium nitrate 0.65 g / L, strontium citrate 0.4 g / L, compound nutrients 0.65 g / L, vitamin B1 0.08 g / L, vitamin B6 0.04 g / L, calcium carbonate 0.9 g / L, ferrous sulfate 0.09 g / L, silkworm pupa polypeptide powder 7 g / L, L-proline 0.15 g / L, and fructooligosaccharides 6.5 g / L, with the pH adjusted to 6; the compound nutrients consist of magnesium sulfate, zinc sulfate, and selenomethionine in a mass ratio of 5:2:1.
[0058] The solid culture medium in step S1 consists of the following components in the following proportions: 65 parts wheat grains, 18 parts silkworm pupa powder, 6.5 parts corn flour, 4 parts glucose, 0.65 parts strontium chloride, 0.4 parts strontium citrate, 0.4 parts compound synergist, 45 parts rice flour, 15 parts barley sprout powder, 6.5 parts plant polysaccharide, and 135 parts water, adjusted to pH 6; the compound synergist is composed of magnesium sulfate, zinc sulfate, and selenomethionine in a mass ratio of 5:3:1; the plant polysaccharide is lentinan; the sterilization temperature in step S1 is 121℃, and the time is 30 min; the Cordyceps militaris strain in step S2 is ACCC50632; the bacterial concentration in the bacterial suspension in step S2 is 3×10⁻⁶. 6 cfu / mL; the inoculation volume of the bacterial suspension in step S3 is 6.5 vol.%; the inoculation volume of the liquid seed solution in step S4 is 13 vol.%; the culture conditions for solid culture in step S4 are: temperature 20℃, relative humidity 65%, light intensity 1800 lux, photoperiod 12h light / 12h dark, 2 hours of blue light irradiation per day, culture for 60 days; the maturity of the Cordyceps militaris fruiting body in step S5 is when its stroma length is more than 8 cm.
[0059] Example 4
[0060] A method for cultivating strontium-enriched Cordyceps militaris includes the following steps:
[0061] Step S1: Preparation of culture medium: Dissolve each component in pure water according to the liquid seed culture medium formula, mix evenly, pour into culture flasks, seal, sterilize, and cool to obtain liquid seed culture medium; prepare solid culture medium according to the solid culture medium formula.
[0062] Step S2, strain activation: Inoculate the Cordyceps militaris strain onto PDA slant medium and incubate at 21.5℃ for 9.5 days. After the mycelium has covered the slant, rinse with sterile physiological saline to obtain a bacterial suspension.
[0063] Step S3, Liquid seed culture: Inoculate the bacterial suspension into the liquid seed culture medium, place it in a shaker, and culture at 21.5℃ and 175r / min for 4.5 days to obtain the liquid seed culture;
[0064] Step S4, Solid Culture: Spray the liquid seed solution evenly onto the surface of the solid culture medium and place it in an incubator for solid culture;
[0065] Step S5, Harvesting and Drying: After the fruiting bodies of Cordyceps militaris mature, harvest the fruiting bodies and mycelium, rinse with clean water to remove surface impurities, vacuum dry at 65℃ to constant weight, pulverize and pass through a 95-mesh sieve to obtain strontium-rich Cordyceps militaris product.
[0066] The liquid seed culture medium in step S1 consists of the following components in the following proportions: glucose 24 g / L, peptone 11.5 g / L, yeast extract 4.5 g / L, strontium nitrate 0.75 g / L, strontium citrate 0.45 g / L, compound nutrients 0.75 g / L, vitamin B1 0.09 g / L, vitamin B6 0.045 g / L, calcium carbonate 1 g / L, ferrous sulfate 0.11 g / L, silkworm pupa polypeptide powder 7.5 g / L, L-proline 0.18 g / L, and fructooligosaccharides 7.5 g / L, with the pH adjusted to 6.3; the compound nutrients consist of magnesium sulfate, zinc sulfate, and selenomethionine in a mass ratio of 5:2:1.
[0067] The solid culture medium in step S1 consists of the following components in the following proportions: 68 parts wheat grains, 19 parts silkworm pupa powder, 7.5 parts corn flour, 4.5 parts glucose, 0.75 parts strontium chloride, 0.45 parts strontium citrate, 0.45 parts compound synergist, 48 parts rice flour, 18 parts barley sprout powder, 7.5 parts plant polysaccharides, and 145 parts water, adjusted to pH 6.1; the compound synergist is composed of magnesium sulfate, zinc sulfate, and selenomethionine in a mass ratio of 5:3:1; the plant polysaccharides are a mixture of tea polysaccharides, wolfberry polysaccharides, and shiitake mushroom polysaccharides in a mass ratio of 1:2:1; the sterilization temperature in step S1 is 121℃, and the time is 30 min; the Cordyceps militaris strain in step S2 is ACCC50632; the bacterial concentration in the bacterial suspension in step S2 is 4.5 × 10⁻⁶. 6cfu / mL; the inoculation amount of the bacterial suspension in step S3 is 7.5 vol.%; the inoculation amount of the liquid seed solution in step S4 is 14 vol.%; the culture conditions for solid culture in step S4 are: temperature 21℃, relative humidity 68%, light intensity 1900 lux, photoperiod 12h light / 12h dark, 2 hours of blue light irradiation per day, culture for 63 days; the maturity of the Cordyceps militaris fruiting body in step S5 is when its stroma length is more than 8 cm.
[0068] Example 5
[0069] A method for cultivating strontium-enriched Cordyceps militaris includes the following steps:
[0070] Step S1: Preparation of culture medium: Dissolve each component in pure water according to the liquid seed culture medium formula, mix evenly, pour into culture flasks, seal, sterilize, and cool to obtain liquid seed culture medium; prepare solid culture medium according to the solid culture medium formula.
[0071] Step S2, strain activation: Take Cordyceps militaris strain and inoculate it into PDA slant medium. Incubate at 22℃ for 10 days. After the mycelium has covered the slant, wash with sterile physiological saline to obtain a bacterial suspension.
[0072] Step S3, Liquid seed culture: Inoculate the bacterial suspension into liquid seed culture medium, place it in a shaker, and culture at 22℃ and 180r / min for 5 days to obtain liquid seed culture;
[0073] Step S4, Solid Culture: Spray the liquid seed solution evenly onto the surface of the solid culture medium and place it in an incubator for solid culture;
[0074] Step S5, Harvesting and Drying: After the fruiting bodies of Cordyceps militaris mature, harvest the fruiting bodies and mycelium, rinse with clean water to remove surface impurities, vacuum dry at 65℃ to constant weight, pulverize and pass through a 100-mesh sieve to obtain strontium-rich Cordyceps militaris product.
[0075] The liquid seed culture medium described in step S1 consists of the following components in the following proportions: glucose 25 g / L, peptone 12 g / L, yeast extract 5 g / L, strontium nitrate 0.8 g / L, strontium citrate 0.5 g / L, compound nutrients 0.8 g / L, vitamin B1 0.1 g / L, vitamin B6 0.05 g / L, calcium carbonate 1.2 g / L, ferrous sulfate 0.12 g / L, silkworm pupa polypeptide powder 8 g / L, L-proline 0.2 g / L, and fructooligosaccharides 8 g / L, with the pH adjusted to 6.5; the compound nutrients consist of magnesium sulfate, zinc sulfate, and selenomethionine in a mass ratio of 5:2:1.
[0076] The solid culture medium in step S1 consists of the following components in the following proportions: 70 parts wheat grains, 20 parts silkworm pupa powder, 8 parts corn flour, 5 parts glucose, 0.8 parts strontium chloride, 0.5 parts strontium citrate, 0.5 parts compound synergist, 50 parts rice flour, 20 parts barley sprout powder, 8 parts plant polysaccharide, and 150 parts water, adjusted to pH 6.2; the compound synergist is composed of magnesium sulfate, zinc sulfate, and selenomethionine in a mass ratio of 5:3:1; the plant polysaccharide is tea polysaccharide; the sterilization temperature in step S1 is 121℃, and the time is 30 min; the Cordyceps militaris strain in step S2 is ACCC50632; the bacterial concentration in the bacterial suspension in step S2 is 5 × 10⁻⁶. 6 cfu / mL; the inoculation volume of the bacterial suspension in step S3 is 8 vol.%; the inoculation volume of the liquid seed solution in step S4 is 15 vol.%; the culture conditions for solid culture in step S4 are: temperature 22℃, relative humidity 70%, light intensity 2000 lux, photoperiod 12h light / 12h dark, 2 hours of blue light irradiation per day, culture for 65 days; the maturity of the Cordyceps militaris fruiting body in step S5 is when its stroma length is more than 8 cm.
[0077] Comparative Example 1
[0078] A method for cultivating strontium-rich Cordyceps militaris is basically the same as in Example 1, except that strontium nitrate is used instead of strontium citrate in the liquid seed culture medium.
[0079] Comparative Example 2
[0080] A method for cultivating strontium-rich Cordyceps militaris is basically the same as in Example 1, except that barley grass powder and plant polysaccharides are not added.
[0081] To further illustrate the beneficial technical effects of the strontium-rich Cordyceps militaris cultivation methods involved in the various embodiments of the present invention, relevant performance tests were conducted on the products of Example 1 and Comparative Examples 1-2. The test results are shown in Table 1, and the test methods are as follows:
[0082] (1) Strontium content detection: Strontium content was detected according to the first method of GB 5009.268-2016;
[0083] (2) Cordycepin and adenosine detection: The material was detected by HPLC. The detection conditions were: ZORBAX SB-C18 column (4.6 mm × 250 mm, 5 μm), mobile phase methanol-water (22:78, v / v), flow rate 1.0 mL / min, detection wavelength 260 nm, column temperature 35 ℃, injection volume 20 μL, and external standard method for quantification.
[0084] (3) Biomass detection: After harvesting, vacuum dry (65℃, -0.09MPa) to constant weight, and weigh the dry weight using an electronic balance (accuracy 0.001g).
[0085] As shown in Table 1, the strontium-enriched Cordyceps militaris cultivated in the embodiments of the present invention has higher strontium content, cordycepin content, adenosine content and biomass than the comparative product; the combined use of strontium citrate, barley grass powder and plant polysaccharides has a synergistic effect that is more conducive to the enrichment of strontium, synthesis of active ingredients and biomass accumulation of strontium-enriched Cordyceps militaris.
[0086] Table 1. Performance test results of strontium-enriched Cordyceps militaris
[0087] project Example 1 Comparative Example 1 Comparative Example 2 Strontium content (mg / kg) 14.9 10.4 9.8 Cordycepin (g / 100g) 0.27 0.20 0.14 Adenosine (mg / 100g) 27.3 21.8 15.6 Biomass (g / plant) 1.23 1.06 0.81
[0088] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.
Claims
1. A method for cultivating strontium-enriched Cordyceps militaris, characterized in that, Includes the following steps: Step S1: Preparation of culture medium: Dissolve each component in pure water according to the liquid seed culture medium formula, mix evenly, pour into culture flasks, seal, sterilize, and cool to obtain liquid seed culture medium; prepare solid culture medium according to the solid culture medium formula. The liquid seed culture medium consists of the following components in the following proportions: glucose 20-25 g / L, peptone 10-12 g / L, yeast extract 3-5 g / L, strontium nitrate 0.5-0.8 g / L, strontium citrate 0.3-0.5 g / L, compound nutrients 0.5-0.8 g / L, vitamin B1 0.05-0.1 g / L, vitamin B6 0.03-0.05 g / L, calcium carbonate 0.6-1.2 g / L, ferrous sulfate 0.07-0.12 g / L, silkworm pupa polypeptide powder 6-8 g / L, L-proline 0.1-0.2 g / L, and fructooligosaccharides 5-8 g / L, with the pH adjusted to 5.5-6.5; the compound nutrients are composed of magnesium sulfate, zinc sulfate, and selenomethionine in a mass ratio of 5:2:1; the solid culture medium consists of the following components in the following proportions: wheat grains 60- The mixture contains 70 parts silkworm pupa powder, 15-20 parts corn flour, 5-8 parts glucose, 3-5 parts strontium chloride, 0.5-0.8 parts strontium citrate, 0.3-0.5 parts compound synergist, 40-50 parts rice flour, 10-20 parts barley grass powder, 5-8 parts plant polysaccharides, and 120-150 parts water, adjusted to pH 5.8-6.
2. The compound synergist is composed of magnesium sulfate, zinc sulfate, and selenomethionine in a mass ratio of 5:3:
1. Step S2, strain activation: Take Cordyceps militaris strain and inoculate it on PDA slant medium. Incubate at 20-22℃ for 7-10 days. After the mycelium has covered the slant, wash it with sterile physiological saline to obtain a bacterial suspension. Step S3, Liquid seed culture: Inoculate the bacterial suspension into the liquid seed culture medium, place it in a shaker, and culture at 20-22℃ and 150-180 r / min for 3-5 days to obtain the liquid seed culture; Step S4, Solid Culture: Spray the liquid seed solution evenly onto the surface of the solid culture medium and place it in an incubator for solid culture; Step S5, Harvesting and Drying: After the fruiting bodies of Cordyceps militaris mature, harvest the fruiting bodies and mycelium, rinse with clean water to remove surface impurities, vacuum dry at 55-65℃ to constant weight, and pulverize through an 80-100 mesh sieve to obtain strontium-rich Cordyceps militaris product.
2. The method for cultivating strontium-enriched Cordyceps militaris according to claim 1, characterized in that, The plant polysaccharide is at least one of tea polysaccharide, wolfberry polysaccharide, and shiitake mushroom polysaccharide.
3. The method for cultivating strontium-enriched Cordyceps militaris according to claim 1, characterized in that, The sterilization temperature in step S1 is 121℃, and the time is 30 min; the Cordyceps militaris strain in step S2 is ACCC50632; the bacterial concentration in the bacterial suspension in step S2 is 1×10⁻⁶. 6 -5×10 6 cfu / mL.
4. The method for cultivating strontium-enriched Cordyceps militaris according to claim 1, characterized in that, The inoculation volume of the bacterial suspension in step S3 is 5-8 vol.%; the inoculation volume of the liquid seed solution in step S4 is 10-15 vol.%.
5. The method for cultivating strontium-enriched Cordyceps militaris according to claim 1, characterized in that, The solid-state culture conditions described in step S4 are: temperature 18-22℃, relative humidity 60-70%, light intensity 1500-2000 lux, light cycle 12h light / 12h dark, 2 hours of blue light irradiation per day, and culture for 55-65 days.
6. The method for cultivating strontium-enriched Cordyceps militaris according to claim 1, characterized in that, The maturation of the Cordyceps militaris fruiting body in step S5 is defined as a stroma length of 8 cm or more.