A composite lignocellulose nutrition regulation type special fruiting medium for Chinese saprobic boletus and a preparation and use method thereof

Abstract

This invention discloses a composite lignocellulose nutrient-regulated culture medium for the fruiting of *Boletus chinensis*, along with its preparation and application methods, belonging to the field of edible mushroom cultivation technology. The culture medium comprises, by weight, 27.0–30.0 parts eucalyptus sawdust, 9.0–11.0 parts bamboo fiber powder, 17.0–19.0 ​​parts cottonseed hulls, 11.0–13.0 parts rice hulls, 16.0–18.0 parts wheat grains, 2.5–4.0 parts silkworm pupa protein powder, 0.5–1.0 parts humic acid, 0.8–1.2 parts white sugar, and 1.0–1.5 parts gypsum. This culture medium improves the substrate structure through the composite lignocellulose material, provides continuous carbon and nitrogen nutrition through the wheat grains and silkworm pupa protein powder, and regulates the microenvironment through humic acid, providing suitable conditions for mycelial growth and fruiting body formation. This invention also discloses the preparation and application methods of the culture medium. Using the culture medium of this invention, mycelium fills the bag after 30-35 days of cultivation, primordia form after 4-5 days of covering with soil, and fruiting bodies are formed after 7-8 days. It has the characteristics of stable fruiting, high yield and suitability for large-scale application.

Description

Technical Field

[0001] This invention belongs to the field of artificial cultivation technology of large fungi, specifically relating to a composite substrate culture technology suitable for the fruiting body formation of the saprophytic Boletus xylophilus, and particularly to a fruiting culture medium based on the synergistic effect of lignocellulose carbon source, slow-release nutrient components and humic environment regulating components, as well as its preparation and application method. Background Technology

[0002] *Boletus chinensis*, commonly known as "Jianshouqing" in folk terms, is a typical wood-rotting macrofungus with high edible value and industrial development potential. Unlike common wood-rotting edible fungi such as shiitake and oyster mushrooms, its natural growth relies on a complex process of lignocellulose degradation and humification. Mycelial growth, nutrient accumulation, and fruiting body formation require not only a suitable carbon-nitrogen ratio but also a continuous and stable carbon source release, a favorable substrate structure, and microenvironmental conditions close to its natural habitat. Current macrofungus production commonly uses culture media composed of sawdust, cottonseed hulls, wheat bran, and corn flour. These media are designed to improve readily available nutrient supply and promote rapid mycelial expansion, suitable for conventional wood-rotting edible fungi with relatively fast growth rates and simple nutrient requirements. However, the high proportion of readily available nutrients in these media leads to a mismatch between the nutrient release process and the long-term saprophytic growth characteristics of *Boletus chinensis*, easily resulting in insufficient mycelial nutrient accumulation and maturation during cultivation. This can cause a series of production problems, such as large-scale contamination of the culture medium and unstable fruiting body formation.

[0003] To address the unique ecological requirements of Boletus fungi, existing technologies have attempted to improve the culture environment by adding materials such as soil, kudzu root residue, *Spatholobus suberectus* residue, sawdust, wheat bran, corn cobs, magnesium sulfate, and potassium dihydrogen phosphate to simulate their natural habitat. However, these solutions primarily focus on increasing organic nutrient sources or supplementing mineral elements, remaining traditional nutrient-enhanced culture medium construction methods. They do not fully consider the specific needs of *Boletus saprophyticus* for a humus environment, the continuous degradation process of lignocellulose, and the ecological stability of the culture medium. Although sawdust and cereal-based nutrient sources are widely used in edible fungi cultivation, current technologies mainly focus on selecting and optimizing the proportions of raw materials for the nutritional needs of conventional edible fungi. They lack a systematic culture medium construction strategy tailored to the growth and development characteristics of *Boletus saprophyticus*, and cannot directly provide insights into achieving full mycelial maturation and stable fruiting body formation through a multi-factor synergistic approach involving lignocellulose carbon source optimization, nutrient slow-release regulation, substrate structure improvement, and the construction of a humus-rich ecological environment. Therefore, current technologies still lack a specific culture medium for *Boletus chinensis* that does not rely on natural soil, has a stable source of raw materials, a controllable production process, and can balance nutrient supply, substrate structure, and humic ecological environment regulation. Developing an eco-friendly culture medium suitable for the growth and development characteristics of *Boletus chinensis* is of great significance for improving the stability of its artificial cultivation, promoting continuous fruiting, and advancing the industrial utilization of this rare boletus resource. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the first technical problem solved by the present invention is to provide a culture medium for fruiting of *Boletus chinensis*, characterized in that the culture medium comprises, by weight, the following components: 27.0-30.0 parts eucalyptus wood chips, 9.0-11.0 parts bamboo fiber powder, 17.0-19.0 parts cottonseed hulls, 11.0-13.0 parts rice hulls, 16.0-18.0 parts wheat grains, 2.5-4.0 parts silkworm pupa protein powder, 0.5-1.0 parts humic acid, 0.8-1.2 parts white sugar, and 1.0-1.5 parts gypsum.

[0005] Furthermore, the culture medium is adjusted to a water content of 55%–60% by adding water.

[0006] The eucalyptus wood chips are wood fiber materials obtained by crushing eucalyptus processing residues, with a particle size ≤2 mm, and serve as the main wood fiber carbon source for the culture medium.

[0007] The bamboo fiber powder is selected from moso bamboo (Phyllostachys edulis). The bamboo material is pulverized to obtain fibrous plant material, preferably with a particle size of 0.5-2 mm. It is used to increase the proportion of structural carbon sources in the culture medium, improve the pore structure of the culture medium, and has a certain buffering and slow regulation effect on pH, which is conducive to maintaining the stable acidic environment required for mycelial growth.

[0008] The cottonseed hulls and rice hulls are used to adjust the particle structure of the culture medium, provide the carbon source, nitrogen source, and mineral elements required by the mycelium, and improve the aeration and water retention capacity of the culture medium.

[0009] The wheat grains are soaked and then added to a culture medium to provide a slow-release carbon source and nutrients.

[0010] The silkworm pupa protein powder is obtained by drying and pulverizing defatted silkworm pupae and is used to provide animal-derived protein, amino acids and organic nitrogen nutrition.

[0011] The humic acid, as an active component of humic substances, improves the humic environment of the culture medium, enhances the acid-base buffering capacity and nutrient slow-release capacity, and improves the stability of the culture system, which is conducive to the mycelial maturation and fruiting body formation of Boletus sinensis.

[0012] The sugar is a fast-acting carbon source used to meet the rapid nutritional needs of mycelial growth in the early stages.

[0013] The gypsum is used as an auxiliary regulating component of the culture medium to improve the structural stability of the culture medium and supplement the mineral elements required during the culture process.

[0014] The second technical problem to be solved by the present invention is to provide a method for preparing and using the above-mentioned culture medium for fruiting of *Boletus chinensis*, comprising the following steps:

[0015] A. Raw material pretreatment: Weigh out eucalyptus wood chips, bamboo fiber powder, cottonseed hulls, rice hulls, wheat grains, silkworm pupa protein powder, humic acid, white sugar and gypsum according to the above weight proportions.

[0016] The eucalyptus wood chips are crushed to a particle size of ≤2 mm and left to stand naturally for 6-12 months.

[0017] The preferred particle size of the bamboo fiber powder is 0.5–2 mm, and it is naturally stored for 3–6 months.

[0018] The wheat grains are dried, whole wheat kernels, which are soaked before use. The soaking accumulated temperature is controlled at 720–800℃•h, that is, the product of the soaking water temperature and the soaking time is 720–800℃•h. The grains are turned twice a day during soaking to ensure that they absorb water evenly.

[0019] The rice husks should be soaked in water for 10-12 hours before use, until thoroughly soaked.

[0020] B. Culture medium preparation: Mix the pretreated components evenly according to the proportions to fully combine the lignocellulosic raw materials, plant-derived nutrients, animal-derived nitrogen sources, and humic active components to form a composite culture medium system suitable for the growth and development of Boletus sinicus.

[0021] C. Moisture content adjustment: Add water to the mixed culture medium to adjust the moisture content to 55% to 60% to obtain the culture medium for fruiting of Boletus chinensis saprophyticus.

[0022] D. Sterilization by bagging: The culture medium with adjusted moisture content is packed into culture bags.

[0023] The culture bags are preferably polyethylene or polypropylene culture bags, with the following specifications: length 33 cm; folded diameter 17 cm; thickness 0.003 cm. The wet weight of the culture medium is 1.2–1.5 kg / bag. After bagging, the bags are sterilized according to the edible mushroom substrate production process and then cooled before use.

[0024] The method of using the culture medium includes the following steps:

[0025] E. Inoculation: Inoculate the sterilized and cooled culture bags with Boletus chinensis strain.

[0026] Furthermore, the strain is a liquid culture medium, formulated with 20 g glucose, 3 g beef extract, 2 g yeast extract, 3 g peptone, 1-2 vitamin B1 tablets, 1 L water, and 0.01% (v / v) antifoaming agent. After mixing and dissolving the above components, the initial pH of the culture medium is adjusted to 5.0-5.5. After sterilization, the *Boletus spp.* strain is inoculated and cultured at 28-32℃ and 170 r / min for 9-12 days to obtain the liquid strain for inoculation. The inoculation volume is 15-20 mL / bag.

[0027] F. Mycelial Culture: After inoculation, the culture bags are placed in a suitable environment for mycelial culture. The temperature for mycelial growth is controlled at 28–32℃, the relative humidity is 60%–65%, and the environment is dark and well-ventilated. After 30–35 days of culture, the mycelium will have completely filled the bag.

[0028] G. Inducing fruiting by covering with soil: When the mycelium fills the bag, fruiting should be induced by covering the bag with soil or by completely removing the bag and covering with soil.

[0029] Furthermore, the method of covering the bag with soil for mushroom cultivation is as follows: after the mycelium has filled the bag, an opening is made at the top or side of the cultivation bag, and the film at the bag opening or side is removed to expose the surface of the culture medium. The sterilized covering soil material is then placed on the surface of the culture medium to form a covering soil layer.

[0030] The complete bag removal and soil covering method for fruiting involves: after the mycelium has filled the bag, removing the entire substrate from the bag while maintaining the integrity of the substrate block, and transferring it to a fruiting area such as a foam box or cultivation bed. The substrate blocks are then arranged according to production needs, and the surface and surrounding area of ​​the substrate blocks are covered with treated soil material.

[0031] Preferably, the casing soil thickness is 1.5–2.5 cm. This ensures full contact between the culture medium and the casing soil, creating a stable environment for moisture, temperature, and microorganisms.

[0032] The covering material should be sterilized, disinfected, or pretreated humus, peat, garden soil, or composite covering material.

[0033] H. Mushroom Management: After covering with soil, adjust the temperature, humidity, ventilation and light conditions in the cultivation environment to promote the formation of Boletus sinensis primordia and the development of fruiting bodies.

[0034] The optimal temperatures are 28℃–30℃, relative humidity 78%–90%, light intensity 350–550 lux, and CO2 concentration 0.10%–0.15%. Under suitable conditions, primordia form after approximately 4–5 days of soil covering, fruiting bodies develop in approximately 7–8 days, and are harvested at their optimal marketability in approximately 9–12 days. Using the culture medium and cultivation method of this invention, 1–2 flushes of fruiting bodies can be harvested, achieving a biological efficiency of 36%–39%.

[0035] I. Post-harvest Management: After each flush of fruiting bodies is harvested, the surface of the substrate casing soil should be maintained. Dead fruiting bodies, rotten fruiting bodies, residual mushroom stems, and immature fruiting bodies that have stopped developing should be removed promptly from the surface of the substrate casing soil to reduce ineffective nutrient consumption and the risk of contamination. Small fruiting bodies that are still growing and have the potential to continue developing should be retained, avoiding excessive disturbance to the substrate structure.

[0036] The beneficial effects of this invention are:

[0037] Compared with existing technologies, the culture medium for fruiting *Boletus chinensis* provided in this invention does not use the conventional wood-rotting edible mushroom culture medium formula. Instead, based on the saprophytic characteristics of *Boletus chinensis*, it constructs a composite wood fiber structure system composed of eucalyptus wood chips and bamboo fiber powder, and a nutrient slow-release and environmental regulation system composed of wheat grains, silkworm pupa protein powder, and potassium humate. The composite wood fiber component improves the culture medium structure and provides a stable carbon source; wheat grains and silkworm pupa protein powder provide continuous carbon and nitrogen nutrition; and potassium humate improves the humic environment of the culture medium, enhancing its acid-base buffering capacity and nutrient release stability. Through the synergistic effect of the above components, this invention makes the culture medium more suitable for the mycelial growth, casing induction, and fruiting body formation of *Boletus chinensis*. When using the culture medium of this invention, the mycelial culture cycle is 30–35 days, primordia form in about 4–5 days after casing, and fruiting body morphology is completed in about 7–8 days. The first flush yield reaches 160–200 g / bag, with a biological efficiency of 30–36%. This invention solves the problems of insufficient culture medium adaptability and low fruiting stability in the artificial cultivation of Boletus chinensis, and provides technical support for its large-scale and standardized cultivation. Attached Figure Description

[0038] Figure 1 Example 1: Fruiting was carried out in bags in a factory-style facility, and the fruiting period was 9 days.

[0039] Figure 2 Example 3: The mushrooms were fully unpacked and cultivated in a factory-style facility for 9 days. Detailed Implementation

[0040] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the following embodiments.

[0041] The strain used in this embodiment is *Boletus sinensis*. Evaluation indicators for cultivation effectiveness included: time to full mycelial coverage, mycelial growth rate, pH change in the culture medium, primordia formation time, fruiting body formation time, yield per bag, and biological efficiency. Six replicates were performed for each indicator.

[0042] Example 1: Culture medium for fruiting of *Boletus edulis* of the present invention, its preparation and application.

[0043] (1) Preparation of culture medium: Weigh out 28.0 parts by weight of eucalyptus wood chips, 10.0 parts of bamboo fiber powder, 18.0 parts of cottonseed hulls, 12.0 parts of rice hulls, 17.0 parts of wheat grains, 3.0 parts of silkworm pupa protein powder, 0.8 parts of humic acid, 1.0 part of white sugar, and 1.2 parts of gypsum. Among them, the eucalyptus wood chips are crushed and passed through a 2 mm sieve; the bamboo fiber powder is crushed and the particle size is controlled to be 0.5-2 mm; the wheat grains are soaked for 10 h before use. Mix the raw materials thoroughly and add water to adjust the moisture content of the culture medium to 56.3%±1.2%.

[0044] (2) Bagging and sterilization: Polyethylene culture bags with a length of 33 cm, a folded diameter of 17 cm, and a thickness of 0.003 cm are used. The wet weight of the culture medium is 1.25 ± 0.3 kg / bag. Sterilize at 121℃ for 2 h using conventional edible mushroom cooked material production process. Cool to a core temperature of 25-30℃ for later use.

[0045] (3) Inoculation and culture: The liquid culture formula described in this invention was used for culture production, namely 20g glucose, 3g beef extract, 2g yeast extract, 3g peptone, 1 vitamin B1 tablet, water to 1L, and 0.01% (v / v) antifoaming agent. The initial pH of the culture medium was adjusted to 5.5. The culture temperature was 30℃, and the rotation speed was 170 r / min. The culture was cultured for 10 days, and the inoculation amount was 15mL / bag.

[0046] (4) After inoculation, culture in the dark at a temperature of 30°C until the mycelium fills the bag.

[0047] (5) After the mycelium has filled the bag, cover it with soil inside the bag. Open the top of the cultivation bag and cover the surface of the culture medium with the treated soil material. Soil thickness: 2 cm. Fruiting environment: temperature 20-23℃, air humidity 85%-90%, CO2 concentration 0.10%-0.15%.

[0048] The experimental results are shown in Table 1 below.

[0049] Table 1. Experimental data record table of culture medium for fruiting of Boletus chinensis, its preparation and application examples.

[0050] Mycelial growth rate (mm / d) 7.3±0.7 Time to primordia formation after backfilling (d) 4.2±0.3 Time to form young mushrooms (d) 6.5±0.5 Harvestable time of fruiting bodies (d) 9.2±0.3 Average number of product sub-entities per bag (units) 5.6±0.8 Highest yield of first flush mushrooms (g / bag) 168.1±3.4 Minimum yield of first flush mushrooms (g / bag) 160.3±2.7 Biological efficiency (%) 32.2±0.9

[0051] The fruiting situation in the above embodiments is shown in the figure. Figure 1 The first flush of mushrooms was uniform in size, intact in shape, with typical cap color and distinct flushes, indicating that the constructed culture medium can meet the nutritional supply, physicochemical environment and water conditions required for the formation of Boletus sinensis fruiting bodies, and has good cultivation adaptability and fruiting promotion effect.

[0052] Example 2: Culture medium for fruiting of *Boletus saprophyticus* of the present invention, its preparation and application.

[0053] Another formulation within the scope of this invention is used: 30 parts eucalyptus wood chips, 11.0 parts bamboo fiber powder, 19.0 parts cottonseed hulls, 13.0 parts rice hulls, 18.0 parts wheat grains, 4.0 parts silkworm pupa protein powder, 1 part humic acid, 1.2 parts white sugar, and 1.5 parts gypsum.

[0054] The preparation and use of the culture medium are the same as in Example 1.

[0055] The experimental results are shown in Table 2 below.

[0056] Table 2. Experimental Data Recording Table for Fruiting Culture Medium of *Boletus saprophyticus* and its Preparation and Application Examples Mycelial growth rate (mm / d) 7.7±0.3 Time to primordia formation after backfilling (d) 4.5±0.4 Time to form young mushrooms (d) 7.0±0.5 Harvestable time of fruiting bodies (d) 9.7±0.3 Average number of product sub-entities per bag (units) 5.1±0.5 Highest yield of first flush mushrooms (g / bag) 170.2±1.7 Minimum yield of first flush mushrooms (g / bag) 163.7±2.1 Biological efficiency (%) 32.6±1.1

[0057] Compared with Example 1, the mycelium grows faster in this example, shortening the time to full bag by about 3 days, and slightly prolonging the time for primordia and young mushroom formation. This is beneficial to increasing the number of fruits per bag and the yield, indicating that the formula within the scope of protection of this invention can meet the cultivation requirements of Boletus saprophyticus.

[0058] Example 3: Culture medium for fruiting of *Boletus saprophyticus* of the present invention, its preparation and application.

[0059] The culture medium formulation and usage method were the same as in Example 1. After the mycelium filled the bag, the entire bag was removed and the mushrooms were covered with soil for fruiting. The results are shown in Table 3.

[0060] Table 3. Recording Table of Fruiting Data for *Boletus edulis* after Complete Bag Removal Time to form young mushrooms (d) 7.5±0.5 Harvestable time of fruiting bodies (d) 9.3±0.2 Average number of product sub-entities per bag (units) 9.3±0.4 Average yield of first flush mushrooms (g / bag) 194.7±1.1 Biological efficiency (%) 34.7±0.9

[0061] The results show that the culture medium of the present invention is suitable for production without bags and covered with soil, and this method is beneficial to improving biological efficiency.

[0062] Example 4: Culture medium for fruiting of *Boletus saprophyticus* of the present invention, its preparation and application.

[0063] This embodiment conducts a gradient screening experiment for humic acid addition. Other components are kept constant, while the amount of humic acid added is varied. The culture medium is prepared and used according to the technical method of this invention. Six replicates are set for each treatment of 60 bags. The experimental results are shown in Table 4 below.

[0064] Table 4. Experimental Data Recording of Humic Acid Addition Gradients in Culture Medium for Fruiting of *Boletus chinensis* A1 0 5.8±0.2 39 5.2±0.1 147.8±3.2 23.7±0.8 A2 0.3 5.7±0.1 36 5.0±0.2 156.2±2.6 25.1±1.2 A3 0.5 5.5±0.1 32 5.0±0.1 163.3±2.3 30.1±0.9 A4 0.8 5.4±0.2 32 4.9±0.1 166.4±1.8 33.1±0.9 A5 1.0 5.3±0.1 33 4.7±0.2 169.1±2.2 30.1±1.0 A6 1.5 5.1±0.1 34 4.7±0.2 164.5±3.3 29.7±1.2

[0065] The results showed that when the amount of humic acid added was 0.5 to 1.0 parts, the number of days for mycelium to fill the bag was short and the yield was high, with a biological efficiency of 30% to 33%. This indicates that humic acid has the functions of improving the humic composition of the culture medium, enhancing the nutrient buffering capacity, and optimizing the substrate microenvironment.

[0066] Comparative Example 1: Effects of conventional edible fungi culture medium on the growth and fruiting effect of Boletus sinensis.

[0067] A traditional and common formula was used: 78 parts broadleaf sawdust, 20 parts wheat bran, and 2 parts gypsum. The water content of the culture medium was [not specified]. This was used to produce *Boletus sinensis*, a saprophytic fungus. Inoculation and culture conditions were the same as in Example 1. The results showed that mycelial growth was very slow, and no fruiting was observed.

[0068] Comparative Example 2: Effect of bamboo fiber powder addition on the growth and fruiting effect of *Boletus chinensis*.

[0069] The bamboo fiber powder in Example 1 was removed and replaced with an equal amount of eucalyptus wood chips. The culture medium formula was 38 parts eucalyptus wood chips, 18 parts cottonseed hulls, 12 parts rice hulls, 17 parts wheat grains, 3 parts silkworm pupa protein powder, 0.8 parts humic acid, 1 part white sugar, and 1.2 parts gypsum. The preparation and use of the culture medium were the same as in Example 1.

[0070] The experimental results are shown in Table 5 below.

[0071] Table 5. Data Record of the Effects of Lack of Bamboo Fiber Powder Culture Medium on Boletus sinensis Mycelial growth rate (mm / d) 4.2±0.6 Time to primordia formation after backfilling (d) 5.0±0.5 Time to form young mushrooms (d) 7.5±0.5 Harvestable time of fruiting bodies (d) 10.5±0.5 Average number of product sub-entities per bag (units) 3.1±0.4 Highest yield of first flush mushrooms (g / bag) 104.3±6.8 Minimum yield of first flush mushrooms (g / bag) 86.7±8.2 Biological efficiency (%) 25.4±2.7

[0072] Compared with Example 1, the lack of bamboo fiber powder reduced the pore structure of the culture medium and the continuous carbon source supply capacity, resulting in a slower mycelial expansion rate, a longer fruiting time, and a significant decrease in biological efficiency.

[0073] Comparative Example 3: Effect of wheat grain addition method on the growth and fruiting effect of Boletus chinensis.

[0074] To verify the role of wheat grains in the culture medium of this invention, based on the culture medium described in Example 1, the amounts of eucalyptus wood chips, bamboo fiber powder, cottonseed hulls, rice hulls, silkworm pupa protein powder, potassium humate, white sugar, and gypsum were kept constant, only the method of adding wheat grains was adjusted, and different treatment groups were set up. Each treatment consisted of 60 bags, with 6 replicates. The treatments are shown in Table 6 below.

[0075] Table 6 Different wheat grain treatment methods M1 Instead of wheat grains, use an equal amount of eucalyptus wood chips. M2 Add wheat grains soaked at 720℃•h accumulated temperature M3 Add crushed dry wheat flour (sieved through a 2 mm sieve).

[0076] The culture medium was prepared and used according to Example 1 of this invention. The experimental results are shown in Table 7 below.

[0077] Table 7. Effects of different wheat grain treatments on mycelial growth and fruiting bodies of *Boletus spp.* M1 1 56.3±0.5 3.3% ++ 4.8±0.5 4.1±0.5 158.5±3.5 22.7±1.3 M2 1 33.0±1.0 1.7% ++++ 4.5±0.2 5.5±0.5 172.1±4.2 34.1±0.9 M3 1 41.5±0.5 6.6% +++ 4.5±0.3 5.2±0.3 167.5±6.7 26.5±1.1

[0078] Note: "+" indicates sparse hyphae. "++" indicates relatively sparse hyphae. "++++" indicates dense hyphae. "++++" indicates very dense hyphae.

[0079] The results show that without the addition of wheat grains (M1), the mycelial growth rate of *Boletus spp.* decreased, the time to full coverage of the bag was prolonged, and the yield of the first flush of mushrooms decreased significantly. While the treatment with crushed wheat flour (M3) promoted early mycelial growth, the stability of the substrate structure decreased after the first flush was harvested, making it susceptible to contamination by other microorganisms and affecting subsequent fruiting. Using whole wheat grains soaked at 720℃·h (M2), the mycelial growth rate was the fastest, the time to full coverage of the bag was 33 days, the yield of the first flush of mushrooms reached 172.1 g / bag, and the biological efficiency reached 34.1%. These results indicate that the use of pretreated whole wheat grains as a nutrient component in this invention can achieve slow-release of nutrients, improving the cultivation and continuous fruiting effect of *Boletus spp.*

[0080] In summary, this invention utilizes the synergistic effect of specific proportions of lignocellulose carbon source, structure-regulating components, slow-release nutrient components, and humic substance-regulating components to construct a specialized fruiting medium suitable for the artificial cultivation of *Boletus chinensis*. This medium improves the substrate structure and nutrient supply pattern, increases mycelial growth rate, promotes fruiting body formation, and enhances yield and substrate utilization efficiency. It solves the problems of poor substrate compatibility, unstable fruiting, and low yield in existing artificial cultivation methods for *Boletus chinensis*.

Claims

1. A composite lignocellulose nutrient-regulated culture medium for fruiting of *Boletus sinensis*, characterized in that, By weight, it comprises the following components: 27.0–30.0 parts eucalyptus wood chips, 9.0–11.0 parts bamboo fiber powder, 17.0–19.0 ​​parts cottonseed hulls, 11.0–13.0 parts rice hulls, 16.0–18.0 parts whole wheat grains, 2.5–4.0 parts silkworm pupa protein powder, 0.5–1.0 parts humic acid, 0.8–1.2 parts white sugar, and 1.0–1.5 parts gypsum; The culture medium consists of a composite lignocellulose matrix composed of eucalyptus wood chips and bamboo fiber powder, a slow-release nutrient component composed of wheat grains and silkworm pupa protein powder, and a humic acid component as a conditioning component. The water content of the culture medium is 55%–60%.

2. The culture medium for fruiting of *Boletus chinensis* according to claim 1, characterized in that: The eucalyptus wood chips are wood fiber materials produced during the processing of eucalyptus wood, obtained by crushing, with a particle size ≤2 mm.

3. The culture medium for fruiting of *Boletus chinensis* according to claim 1, characterized in that: The bamboo fiber powder is a plant fiber material obtained by crushing bamboo, with a particle size of 0.5 to 2 mm.

4. The culture medium for fruiting of *Boletus chinensis* according to claim 1, characterized in that: The weight ratio of eucalyptus wood chips to bamboo fiber powder is (27-30):(9-11).

5. The culture medium for fruiting of *Boletus chinensis* according to claim 1, characterized in that: The wheat grains are whole wheat kernels, which are soaked and then added to the culture medium.

6. The culture medium for fruiting of *Boletus chinensis* according to claim 4, characterized in that: The wheat grain soaking treatment is carried out using a temperature accumulation control method, with a soaking temperature accumulation of 700–750℃·h.

7. The culture medium for fruiting of *Boletus chinensis* according to claim 1, characterized in that: The silkworm pupa protein powder is an animal-derived protein powder obtained by drying and pulverizing defatted silkworm pupae.

8. The culture medium for fruiting of *Boletus chinensis* according to claim 1, characterized in that: The humic acid is a natural humic acid substance.

9. A method for preparing a culture medium for fruiting *Boletus chinensis* as described in any one of claims 1 to 8, characterized in that, Includes the following steps: (1) Raw material pretreatment: crush eucalyptus wood chips to a particle size ≤ 2 mm, adjust bamboo fiber powder to a particle size of 0.5-2 mm, and soak wheat grains; (2) Preparation of culture medium: Weigh each component according to the weight parts described in claim 1, mix eucalyptus wood chips, bamboo fiber powder, cottonseed hulls, rice hulls, soaked wheat grains, silkworm pupa protein powder, humic acid, white sugar and gypsum evenly, add water to adjust the moisture content of the culture medium to 55% to 60%, and obtain the culture medium. (3) Sterilization treatment: After the obtained culture medium is bagged, it is sterilized to obtain the culture medium for fruiting of Boletus chinensis.

10. The method for preparing the culture medium for fruiting of *Boletus chinensis* according to claim 9, characterized in that: The sterilization process is carried out using the edible mushroom cooked substrate production process, and the sterilized culture medium is cooled to a suitable inoculation temperature for later use.

11. A method for cultivating *Boletus chinensis* using the fruiting culture medium of *Boletus chinensis* as described in any one of claims 1 to 8, characterized in that, Includes the following steps: (1) Inoculation and culture: The Boletus saprophyticus strain was inoculated into a sterilized culture medium; (2) Mycelial culture: Cultivate under suitable culture conditions to allow the mycelium to grow fully in the culture medium and reach the state of filling the bag; (3) Soil induction: After the mycelium fills the bag, soil is used to induce the formation of fruiting bodies of Boletus sinensis.

12. The method for cultivating *Boletus chinensis* according to claim 11, characterized in that: The mycelial culture temperature was 28–32℃, and the culture was carried out in the dark for 30–35 days.

13. The method for cultivating *Boletus chinensis* according to claim 11, characterized in that: The soil covering treatment includes soil covering inside the bag for mushroom cultivation and soil covering after removing the bag for mushroom cultivation. Among them: "covering soil inside the bag for mushroom cultivation" means covering the culture material at the opening of the culture bag with soil to keep the culture bag intact; "removing the bag and covering soil for mushroom cultivation" means covering the entire culture material with soil after removing the culture bag.

14. The method for cultivating *Boletus chinensis* according to claim 11, characterized in that: After covering with soil, primordia are formed after 4-5 days of cultivation, and fruiting bodies of Boletus sinensis are formed after 7-8 days of further cultivation.

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