A culture method of pleurotus ostreatus mycelium rich in essential amino acids and polysaccharides
By adding trace elements and applying a static magnetic field to the culture of oyster mushroom mycelium, the problem of insufficient nutrients in oyster mushroom mycelium was solved, the content of essential amino acids and polysaccharides was increased, and the biomass was increased, while reducing operating costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- JIANGNAN UNIV
- Filing Date
- 2023-12-26
- Publication Date
- 2026-06-23
Smart Images
Figure CN117730733B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for cultivating oyster mushroom mycelium rich in essential amino acids and polysaccharides, specifically belonging to the field of edible fungi technology. Background Technology
[0002] Oyster mushrooms (Pleurotus djamor) belong to the phylum Basidiomycota, order Agaricales, family Pleurotaceae. Also known as oyster mushrooms, rough-skinned oyster mushrooms, green mushrooms, and white shiitake mushrooms, they are highly resistant to adverse conditions and have high economic value. They are used for both food and medicinal purposes and are among the most common edible fungi on the market. Statistics show that in 2018, oyster mushroom production reached 6.4282 million tons, accounting for 16.73% of total edible fungi production, making it the highest-yielding fresh edible fungus.
[0003] In recent years, the development and utilization of edible fungi have attracted increasing attention. Oyster mushrooms are a healthy food high in protein and low in fat, containing various essential amino acids, vitamins, minerals, and active polysaccharides. However, the proportion of essential amino acids in oyster mushrooms is still relatively low compared to other amino acids. Furthermore, edible fungal polysaccharides, as a non-specific immune booster, possess various biological effects such as anti-tumor, antiviral, anti-aging, lipid-lowering, blood sugar-lowering, liver protection, and promotion of nucleic acid and protein biosynthesis, earning them the international reputation of "biological response modifiers (BRM)." Current research on oyster mushroom polysaccharides mainly focuses on their functional activity and extraction processes, while methods for enriching polysaccharides are still limited. Therefore, it is necessary to use technological means to increase the proportion of various essential amino acids in the total amino acid content and the polysaccharide content of oyster mushrooms, thereby increasing their commercial application value.
[0004] To achieve optimal growth and production capacity of edible fungi, many researchers have investigated alternative methods for regulating their growth and metabolic behavior, including optimizing culture conditions, innovating fermentation processes, and mutagenesis and hybridization breeding. However, these methods generally suffer from drawbacks such as high implementation costs and complex operations. Furthermore, there are currently no reports on increasing the nutritional content of oyster mushroom mycelium. If an oyster mushroom mycelium rich in essential amino acids and polysaccharides could be cultivated, it would not only increase the nutritional content and economic benefits of oyster mushrooms but also provide technical support for the extraction of active polysaccharides from edible fungi. Summary of the Invention
[0005] To address the shortcomings of the existing technologies, this invention provides a method for cultivating oyster mushroom mycelium. The aim is to solve the problem that there is currently no suitable method to increase the nutritional components of oyster mushroom mycelium, and that existing methods for improving the nutritional components of edible fungi generally have high implementation costs and complex operation. The goal is to cultivate oyster mushroom mycelium rich in essential amino acids and polysaccharides.
[0006] The first technical solution provided by the present invention is a method for cultivating oyster mushroom mycelium rich in essential amino acids and polysaccharides. The method involves adding 0.6 to 1.2 mmol / L of trace elements to the culture medium during the expansion culture of oyster mushroom mycelium, and applying a continuous static magnetic field to the mycelium.
[0007] In some embodiments, the trace element is Mg. 2+ Zn 2+ and Mn 2+ One or more trace elements in it.
[0008] Preferably, the trace element is Zn. 2+ and Mn 2+ The Zn 2+ and the Mn 2+ The concentration ratio is 1:1.
[0009] In some embodiments, the intensity of the static magnetic field treatment is 8 to 10 mT, preferably 10 mT.
[0010] In some embodiments, the frequency of the static magnetic field treatment is 50 Hz, and the duration of the magnetic field treatment is 24 to 180 hours.
[0011] The second technical solution provided by this invention is a method for cultivating oyster mushroom mycelium, comprising the following steps:
[0012] (1) Activation of microbial strains
[0013] Small pieces of the low-temperature preserved oyster mushroom slant culture were inoculated into an activation medium for 7-8 days of activating culture.
[0014] (2) Expand cultivation
[0015] Using a 0.5cm diameter punch, pick out pieces of the same size and thickness along the same circumference centered on the center of the oyster mushroom mycelium plate. Inoculate these pieces onto a culture medium plate containing 0.6–1.2 mmol / L of trace elements and apply a continuous static magnetic field.
[0016] In some embodiments, both the activation medium and the expansion medium are PDA agar medium.
[0017] In some embodiments, the culture temperature is 22–25°C, preferably 23°C.
[0018] In some embodiments, the trace element is Mg. 2+ Zn 2+ and Mn 2+ One or more trace elements in it.
[0019] In some embodiments, the intensity of the magnetic field treatment is 8 to 10 mT, preferably 10 mT.
[0020] In some embodiments, the frequency of the magnetic field treatment is 50 Hz, and the duration of the magnetic field treatment is 24 to 180 hours.
[0021] The third technical solution provided by the present invention is the application of the method described in the first technical solution or the method described in the second technical solution in the preparation of products containing oyster mushroom mycelium.
[0022] In some embodiments, the product is food, medicine, or health product.
[0023] Compared with the prior art, the present invention has the following beneficial effects:
[0024] (1) Existing research on the mycelial growth and metabolism of oyster mushrooms is relatively limited compared to other edible fungi. The oyster mushrooms selected in this invention are rich in nutrients, can be cultivated under extensive conditions, and have high economic benefits. Oyster mushrooms are rich in protein, dietary fiber, vitamins, and polysaccharides, and have excellent antioxidant, lipid-lowering, and immunity-enhancing effects. They can be used for food, medicine, and ornamental purposes. In this invention, after adding a certain concentration and combination of trace elements to the culture medium and treating it with a magnetic field, the content of essential amino acids in oyster mushrooms is increased, reaching a maximum of 38.66%, which is 44.09% higher than that of conventional culture, and is closer to the ideal protein essential amino acid ratio of about 40% proposed by FAO / WHO.
[0025] (2) After adding a certain concentration and combination of trace elements to the culture medium and treating it with a magnetic field, the content of functional polysaccharides in oyster mushrooms increased by 27.52%, which is beneficial to improving the edible and medicinal value of oyster mushrooms.
[0026] (3) The magnetic field combined with the trace elements in the culture medium is beneficial to promoting the growth and metabolism of oyster mushrooms. It not only increases the proportion of essential amino acids in oyster mushrooms, but also increases the mycelial biomass under the same culture time, with the maximum biomass increasing by up to 56.16%.
[0027] (4) The magnetic field treatment selected in this invention is an emerging physical field-assisted processing technology. It has the characteristics of strong penetration ability, no secondary pollution, convenient operation and relatively low operating cost, which provides technical feasibility for industrial processing and production. Attached Figure Description
[0028] Figure 1 The growth of oyster mushroom mycelium under different external magnetic field interventions at different times. Detailed Implementation
[0029] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.
[0030] The strain information involved in the following examples is as follows:
[0031] The oyster mushroom disease-resistant strain No. 3 was donated to the Chinese Academy of Agricultural Sciences.
[0032] The culture media involved in the following examples are as follows:
[0033] PDA agar medium: 20 g / L agar, 15 g / L glucose or sucrose, 200 g / L potato.
[0034] The detection methods involved in the following embodiments are as follows:
[0035] Biomass detection: Collect mycelium, observe its morphology, and weigh its wet weight.
[0036] The determination of hydrolyzed amino acid content should refer to the "National Food Safety Standard - Determination of Amino Acids in Food" (GB5009.124-2016).
[0037] The ratio of essential amino acids = total essential amino acid content in hydrolyzed amino acids (g / 100g) / total amount of hydrolyzed amino acids (g / 100g) × 100%.
[0038] Polysaccharide detection: Polysaccharide content was determined according to the NY / T 1676—2008 standard.
[0039] Example 1
[0040] A method for cultivating oyster mushroom mycelium rich in essential amino acids and polysaccharides, the specific steps of which are as follows:
[0041] (1) Cut small pieces of the low-temperature preserved oyster mushroom disease-resistant No. 3 slant culture and inoculate them into the center of a PDA agar medium plate for culture activation. The culture conditions are room temperature culture for 7-8 days until the mycelium covers the entire plate.
[0042] (2) Using a 0.5cm diameter punch, take oyster mushroom blocks of uniform size from the oyster mushroom mycelium plate that has been cultured for 7-8 days, and inoculate them into the center of a PDA agar medium plate containing 0.8mmol / L manganese sulfate.
[0043] (3) Eight parallel inoculated plates were placed in a 50Hz, 10mT magnetic field incubator for 24h, 48h, 72h, 96h, 108h, 132h, 156h, and 180h. A control plate was set up without magnetic field treatment, and other culture conditions were the same as those for the experimental groups. The incubator temperature was 23℃, and the total culture time was 180h.
[0044] After cultivation, mycelia were collected, their morphology was observed, and their wet weight was measured. After drying, the polysaccharide content and hydrolyzed amino acid content were measured, and the proportion of essential amino acids was calculated. The results are shown in Table 1.
[0045] Table 1
[0046]
[0047]
[0048] Table 1 shows that the duration of magnetic field treatment within the experimental range promoted the accumulation of oyster mushroom mycelial biomass. Specifically, a magnetic field treatment time of 132 h resulted in relatively high levels of biomass, essential amino acid ratios, and polysaccharide content in oyster mushrooms. It was also observed that, compared to the control group, the mycelium obtained through magnetic field treatment had a looser surface morphology and some wrinkles. Static magnetic field treatment may have increased the fluidity of mycelial cell membranes and promoted the exchange of substances between intracellular and extracellular spaces by affecting cell structure. It may also have promoted cell metabolism by enhancing the expression of genes related to amino acid metabolism, signal transduction, citric acid cycling, and cell division. Furthermore, as an external physical stimulus, magnetic field treatment of a certain intensity and duration may lead to the self-protective synthesis and secretion of extracellular polysaccharides by oyster mushroom mycelia.
[0049] Example 2
[0050] The specific implementation method is the same as that in Example 1, except that:
[0051] The PDA agar medium used for extended culture contained manganese sulfate concentrations of 0.6 mmol / L, 0.8 mmol / L, 1.0 mmol / L, and 1.2 mmol / L. After inoculation, the plates were cultured in a 50 Hz, 10 mT magnetic field incubator for 132 h, followed by culture under non-magnetic field conditions for 180 h. A control plate was set up without magnetic field treatment, and other culture conditions were the same as those for the experimental groups.
[0052] After cultivation, mycelia were collected, their morphology was observed, and their wet weight was measured. After drying, the polysaccharide content and hydrolyzed amino acid content were measured, and the proportion of essential amino acids was calculated. The results are shown in Table 2.
[0053] Table 2
[0054]
[0055] Table 2 shows that adding different concentrations of manganese sulfate to the culture medium promoted the growth and metabolism of *Pleurotus ostreatus* mycelium to varying degrees. The most significant promoting effect was observed when 0.8 mmol / L manganese sulfate was added. Some enzymes with manganese ions as their active sites (such as oxidases and catalases) are affected by a magnetic field, leading to changes in enzyme activity and consequently affecting the mycelium's antioxidant capacity and free radical scavenging ability. Furthermore, the magnetic field promotes mycelial growth and the synthesis of amino acids and polysaccharides by influencing the transfer and transport of electrons or ions in mycelial anabolic reactions.
[0056] Example 3
[0057] The specific implementation method is the same as that in Example 1, except that:
[0058] The micronutrient composition added to the PDA agar medium used for extended culture includes: Mg 2+ Zn 2+ Mn 2+ Mg 2+ +Zn 2+ Mg 2+ +Mn 2+ Zn 2+ +Mn 2+ Mg 2+ +Zn 2+ +Mn 2+ The concentration of each element was 0.8 mmol / L in the single-element treatment, 0.4 mmol / L in the two-element treatment, and 0.27 mmol / L in the three-element treatment.
[0059] Seven batches of samples were inoculated and cultured in a 50Hz, 10mT magnetic field incubator for 132 hours, followed by further culture under non-magnetic field conditions for 180 hours. A control plate was set up, which was not treated with a magnetic field, and all other culture conditions were the same as those of the experimental groups.
[0060] After cultivation, mycelium was collected, its morphology was observed, and its wet weight was measured. After drying, the polysaccharide content was measured, and the proportion of essential amino acids was calculated by determining the content of hydrolyzed amino acids. The results are shown in Table 3.
[0061] Table 3
[0062]
[0063] Table 3 shows that different micronutrient combinations, compared with the control group, all promoted the growth of oyster mushroom mycelium and the synthesis of nutrients. Among them, the addition of 0.4 mmol / L Zn to the culture medium... 2+ +0.4mmol / L Mn2+ It can maximize the promoting effect. Trace elements are important mediators for important catalytic enzymes and macromolecules. The magnetic field affects the trace metal ions in the culture medium, thereby changing the biomembrane potential and its permeability to ions, affecting the metabolic process of microorganisms, and thus increasing mycelial biomass and the synthesis of related nutrients.
[0064] The tables and figures above illustrate that in different embodiments and batches of *Pleurotus ostreatus* mycelium cultivation, different magnetic field treatment times, different micronutrient concentrations in the culture medium, and different formulations all affect the accumulation of *Pleurotus ostreatus* mycelium biomass and the synthesis of essential amino acids and polysaccharides. From Figure 1 It can be seen that magnetic field treatment can promote mycelial growth to varying degrees, manifested in more uniform and denser mycelia and larger mycelial growth radius. Tables 1-3 show that the optimal magnetic field treatment time is 132 h, the optimal micronutrient concentration in the culture medium is 0.8 mmol / L, and the optimal micronutrient composition in the culture medium is Zn. 2+ and Mn 2 + Especially in the presence of 0.8 mmol / L Zn 2+ and Mn 2+ After 132 hours of magnetic field treatment, the mycelial weight, essential amino acid ratio, and polysaccharide content of the culture medium increased by 56.16%, 44.09%, and 27.52%, respectively, compared to the control group. The essential amino acid ratio reached 38.66%, which is closer to the FAO / WHO standard of approximately 40% for ideal proteins.
[0065] Comparative Example 1:
[0066] Mycelial culture was conducted under single magnetic field treatment, single trace element treatment, and simultaneous magnetic field and trace element treatment. A comparative experiment was also conducted under the condition of no magnetic field treatment and no trace elements added to the culture medium, but other culture conditions were the same. The results are shown in Table 4.
[0067] Table 4 Comparative comparisons using magnetic field treatment and trace elements as key parameters
[0068]
[0069] As shown in Table 4, applying a suitable magnetic field during the growth of oyster mushroom mycelium and adding a certain ratio and concentration of trace elements to the culture medium can produce a better growth and metabolism promotion effect than a single treatment method.
[0070] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.
Claims
1. A cultivation method for increasing the proportion of essential amino acids and polysaccharide content in Pleurotus ostreatus mycelium, characterized in that, Includes the following steps: (1) Activation of microbial strains: Small pieces of the low-temperature preserved oyster mushroom slant culture were inoculated into PDA agar medium for culturing and activation of the culture at room temperature for 7-8 days. (2) Expanded cultivation: The activated oyster mushroom spawn blocks were inoculated into PDA agar medium supplemented with trace elements, namely 0.4 mmol / L Zn. 2+ and 0.4 mmol / L Mn 2+ The system is composed of a continuous static magnetic field, the intensity of which is 8-10 mT, the frequency of which is 50 Hz, and the duration of which is 132 h.
2. The method according to claim 1, characterized in that, The activation and expansion cultures were both conducted at temperatures of 22-25℃.
3. The application of the method according to any one of claims 1 to 2 in the preparation of products containing oyster mushroom mycelium.
4. The application according to claim 3, characterized in that, The product in question is a food or health supplement.