Pleurotus citrinopileatus culture medium compounded by reed and corncob and preparation method of pleurotus citrinopileatus culture medium

Abstract

The invention provides a Pleurotus citrinopileatus culture medium compounded by reeds and corncobs and a preparation method of the Pleurotus citrinopileatus culture medium, and belongs to the technical field of plant resource utilization. The Pleurotus citrinopileatus culture medium compounded by the reeds and the corncobs is prepared from the following dry material raw materials: the reeds and the corncobs are used as composite carbon sources, bean cakes and wheat bran are used as composite nitrogen sources, and gypsum and lime are used as mineral auxiliary materials; wherein the mass ratio of the reed to the corncob is (0.5-2): 1; the mass ratio of the composite nitrogen source in the total dry weight of the matrix is 17%, the mass ratio of the composite carbon source in the total dry weight of the matrix is 81%, and the balance is mineral auxiliary materials. According to the method, the regeneration characteristic of perennial herbaceous plant reed is fully utilized to serve as a high-quality carbon source, agricultural solid waste corncob and the like are mixed, a traditional cultivation wood chip matrix is effectively replaced, the reed and the corncob in a proper proportion are regulated and controlled to serve as a mixed carbon source, and therefore the yield and quality of pleurotus citrinopileatus are remarkably improved, and the biological conversion rate is remarkably increased.

Description

Technical Field

[0001] This invention belongs to the field of plant resource utilization technology, and in particular relates to a cultivation substrate for *Pleurotus ostreatus* composed of reeds and corn cobs and its preparation method. Background Technology

[0002] The raw materials for edible mushroom cultivation substrates have diversified, gradually transitioning from traditional sawdust substrates to cellulose raw materials such as agricultural by-products like straw and mushroom stalks. However, traditional sawdust substrates mainly rely on forest resources, which have long regeneration cycles, are subject to harvesting restrictions, and long-term large-scale use is detrimental to forest resource protection and ecological restoration. Meanwhile, agricultural by-products (such as corn cobs and rice straw), as solid wastes, are abundant and renewable, but their carbon-to-nitrogen ratios, physical structures, and degradation characteristics are often unstable. Using them alone can easily lead to problems such as low cultivation efficiency and uneven fruiting.

[0003] Reed, a perennial large herbaceous plant, is characterized by rapid growth, large biomass, and strong regeneration ability. Its high lignocellulose content and porous structure, combined with excellent air permeability and water retention, make it an ideal carbon source for edible fungi cultivation. Compared to sawdust, reeds do not require logging, ensuring resource sustainability. Furthermore, its hollow stems and suitable cellulose-to-hemicellulose ratio facilitate mycelial colonization and nutrient absorption. Compared to common agricultural wastes (such as corn cobs and cottonseed hulls), reeds have a more stable cellulose structure and a moderate carbon release rate, providing a continuous and balanced carbon source supply and preventing nutrient deficiencies caused by rapid carbon decomposition.

[0004] Currently, some studies have attempted to use reeds for edible mushroom cultivation. For example, patent publication number CN 106083394 A proposes a method for preparing enoki mushroom cultivation material using reed powder. It utilizes 10-35% reeds, along with sawdust, cotton hulls, bagasse, corn cobs, wheat bran, etc., totaling eight ingredients. However, its formula is complex, involving eight different raw materials, resulting in high preparation costs and cumbersome operation. An article published in 2000 by Li Pingping et al. (Li Pingping, Zhu Zhonggui, Hu Yongguang. 2000. Utilization Technology of Reed Powder in Edible Mushroom and Vegetable Cultivation. Journal of Nanjing Forestry University, 24:24-26) points out that reed debris produced after papermaking can be added to edible mushroom cultivation material for utilization. This method primarily utilizes reed waste from papermaking, accounting for approximately 5% of the raw reeds. It proposes a mixed fermentation process using reeds, cottonseed hulls, chicken manure, and urea. This fermentation process is difficult to control, complex, and not easy to operate, and the complex composition poses food safety risks. A 2018 article by Hultterg et al. (Hultberg M, Prade T, Bodin H, et al., 2018. Adding benefit to wetlands-Valorization of harvested common reed through mushroom production. Science of the Total Environment, 637-638: 1395-1399) clearly indicates that reeds enriched with N and P nutrients in constructed wetlands can be used to cultivate oyster mushrooms (100% concentration). However, this method uses reeds from constructed wetlands containing purified wastewater for oyster mushroom cultivation, posing potential food safety risks. Besides N and P nutrients, the polluted water may also contain pesticide residues and heavy metals. In their 2023 article (Li XY, Wang M, Wen BL, et al. 2023. Reed-mushroom-fertilizer ecological agriculture in wetlands: Harvesting reed to cultivate mushroom and returning waste substrates to restore saline-alkaline marshes. Science of the Total Environment, 878, 162987), Li et al. pointed out that a combination of 50% reeds and 38% corn cobs for cultivating *Gynostemma pentaphyllum* achieved a biological efficiency of 69.10%, demonstrating that reed cultivation of *Gynostemma pentaphyllum* yields a high output.*Pleurotus ostreatus* is a cultivated fungus with relatively low biological efficiency. Compared to the high-yielding *Pleurotus ostreatus* (which can reach 120-140%), its biological efficiency in artificial cultivation remains very low, indicating significant room for improvement. While existing technologies have achieved some success, the synergistic effects of reeds and other carbon sources, the optimization of the carbon-nitrogen ratio, and their impact on the quality of *Pleurotus ostreatus* have not been systematically studied. In particular, its potential in improving the biological efficiency, metabolite content, and nutritional components of *Pleurotus ostreatus* has not been fully realized.

[0005] Therefore, addressing the limitations of traditional sawdust resources and the unstable effects of cultivation using single agricultural waste, this invention develops a composite substrate with reeds as the core and an appropriate amount of agricultural waste (such as corn cobs). By optimizing the carbon-nitrogen ratio and raw material proportions, it achieves a simultaneous increase in the yield and quality of *Pleurotus ostreatus*, which has significant practical and resource utilization implications. This invention aims to fill this technological gap by providing a scientifically formulated, easy-to-operate, and highly effective reed substrate for improving the yield and quality of *Pleurotus ostreatus*, along with its preparation method. Summary of the Invention

[0006] To improve the yield and quality of *Pleurotus ostreatus* cultivation and address the limitations of existing sawdust cultivation substrates, this invention proposes a reed-corn cob composite cultivation substrate for *Pleurotus ostreatus* and its preparation method. By optimizing the ratio of reeds to corn cobs and pre-wetting them, bag cultivation of *Pleurotus ostreatus* can significantly improve its yield and organic nutrient content.

[0007] To achieve the above objectives, the present invention provides the following technical solution: This invention proposes a cultivation substrate for *Pleurotus ostreatus* composed of reeds and corn cobs, comprising the following dry matter raw materials: reeds and corn cobs as a composite carbon source, soybean meal and wheat bran as a composite nitrogen source, and gypsum and lime as mineral adjuvants; wherein, The mass ratio of reeds to corn cobs is (0.5-2):1; The composite nitrogen source accounts for 17% of the total dry weight of the matrix, the composite carbon source accounts for 81% of the total dry weight of the matrix, and the remainder is the mineral additives.

[0008] Furthermore, the mass ratio of the reeds to the corn cobs is 1:2, 1:1, or 2:1.

[0009] Furthermore, in the composite nitrogen source, soybean cake accounts for 2% of the total dry weight of the matrix, and wheat bran accounts for 15% of the total dry weight of the matrix.

[0010] Furthermore, in the mineral additives, gypsum accounts for 1% of the total dry weight of the matrix, and lime accounts for 1% of the total dry weight of the matrix.

[0011] This invention also proposes a method for preparing the above-mentioned reed and corn cob composite substrate for cultivating *Pleurotus ostreatus*, comprising the following steps: (1) Weigh out each dry material raw material according to the proportion; (2) Mix the weighed reeds, corn cobs, soybean cake and wheat bran, and pre-wet them with water for 16 hours or more to obtain wet material; (3) After mixing the wet material, bag and sterilize it to obtain the elm yellow mushroom cultivation substrate composed of reed and corn cob.

[0012] Furthermore, in step (2), during the pre-wetting process, the mass ratio of dry material to water is 1:(1.5-1.65), and the standard is that it can be formed into a ball by hand and will fall apart when dropped.

[0013] Furthermore, in step (3), the sterilization is performed continuously at atmospheric pressure (101.325 kPa) and 100°C for a period of not less than 10 hours.

[0014] This invention also proposes a method to increase the yield of *Pleurotus ostreatus*, which uses the aforementioned *Pleurotus ostreatus* cultivation substrate for cultivation, including the following steps: after cooling the sterilized *Pleurotus ostreatus* cultivation substrate, inoculate it with *Pleurotus ostreatus* spawn, and allow the mycelium to grow in the dark for 20 days at 25℃ and 60%-70% humidity; then manage the fruiting process at 25℃ and 75%-85% humidity.

[0015] Compared with the prior art, the present invention has the following advantages and technical effects: (1) The reed substrate of the present invention uses reeds and corn cobs as raw materials, making full use of the regeneration characteristics of perennial herbaceous plants reeds as a high-quality carbon source, and mixing agricultural solid waste such as corn cobs to effectively replace traditional cultivation sawdust substrates, solving the problem of slow growth and relatively weak regeneration function of woody plants, alleviating the over-exploitation of forest resources, and regulating an appropriate ratio of reeds and corn cobs as mixed carbon sources, thereby significantly improving the yield and quality of elm yellow mushrooms and the bioconversion rate.

[0016] (2) In the method for increasing the yield of *Pleurotus ostreatus* in this invention, the nitrogen source accounts for 17% of the total mass, the carbon source accounts for 81%, and by adjusting the ratio of reeds to corn cobs, the yield of *Pleurotus ostreatus* can be significantly increased, with its biological efficiency increasing to 78.10%-91.11%, an increase of 13.02%-31.85%. The content of metabolites such as total polyphenols, flavonoids, and triterpenes is relatively high, and the crude protein content increases from 279.11 mg / g to 332.86-345.13 mg / g. Compared with using corn cobs and reeds alone as carbon sources, the appropriate ratio of the two can promote the improvement of biological efficiency, increase crude protein, polysaccharides, total polyphenols, and total flavonoids, and reduce crude fat content. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 The biological efficiency of *Pleurotus ostreatus* under different treatments in Examples 1-3 and Comparative Examples 1-5; Figure 2 The changes in the content of total polyphenols (A), total flavonoids (B), and total triterpenes (C) in mushrooms under different treatments in Examples 1-3 and Comparative Examples 1-2 are shown. Figure 3 The changes in the content of crude protein (A), total free amino acids (B), crude polysaccharide (C), and crude fat (D) of mushrooms under different treatments in Examples 1-3 and Comparative Examples 1-3 are shown. Detailed Implementation

[0018] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0019] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0020] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0021] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0022] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0023] This invention proposes a composite substrate for cultivating *Pleurotus ostreatus* (elm mushroom) using reeds and corn cobs. The key feature of this substrate is increasing the proportion of nitrogen (N) source materials and decreasing the proportion of carbon (C) source materials. Specifically, it is composed of the following dry matter raw materials: reeds and corn cobs as a composite carbon source, soybean meal and wheat bran as a composite nitrogen source, and gypsum and lime as mineral adjuvants; wherein... The mass ratio of reeds to corn cobs is (0.5-2):1; The composite nitrogen source accounts for 17% of the total dry weight of the matrix, the composite carbon source accounts for 81% of the total dry weight of the matrix, and the remainder is mineral additives.

[0024] This invention uses reeds (a perennial herb with strong regeneration ability and high lignocellulose content) and corn cobs (agricultural solid waste) as a composite carbon source to replace traditional sawdust substrates, efficiently utilizing renewable resources. The composite carbon source is limited to 81%, and the composite nitrogen source (soybean cake + wheat bran) to 17%, matching the carbon-to-nitrogen ratio (C / N) required for the growth of *Pleurotus ostreatus*, ensuring a balanced nutrient supply. Mineral adjuvants (gypsum + lime) supplement minerals and regulate the substrate microenvironment, laying the foundation for mycelial growth and fruiting body development. The limited reed-to-corn cob mass ratio (0.5-2):1 is based on the synergistic optimization of the differences in lignocellulose structure between the two, avoiding the low nutrient utilization efficiency caused by a single carbon source. This effectively solves the problems of limited resources and weak regeneration of woody plants in traditional sawdust substrates. Through precise carbon-to-nitrogen source ratios and the synergistic effect of the composite carbon source, the yield, quality, and bioconversion rate of *Pleurotus ostreatus* are significantly improved.

[0025] In a preferred embodiment of the present invention, the mass ratio of reeds to corn cobs is 1:2, 1:1, or 2:1. Reeds have a high lignocellulose content but decompose slowly, while corn cobs have a loose structure and are easily degraded. Combining the two in different proportions can regulate the carbon source release rate, matching the nutritional needs of *Pleurotus ostreatus* during its mycelial growth and fruiting stages; and avoiding the problem of excessively fast / slow carbon source release caused by a single carbon source (whole reeds or whole corn cobs).

[0026] In the preferred embodiment of the present invention, the proportion of soybean cake in the total dry weight of the substrate is 2%, and the proportion of wheat bran in the total dry weight of the substrate is 15%. Soybean cake has a high nitrogen content and slow release, which can provide long-term stable nitrogen nutrition; wheat bran has a moderate nitrogen content and is rich in vitamins and minerals, which can be quickly absorbed and utilized by mycelia. The combination of the two achieves a synergistic supply of fast-acting nitrogen and long-acting nitrogen; limiting the proportion of soybean cake to 2% and wheat bran to 15% ensures the core requirement of 17% total nitrogen while avoiding uneven mycelial growth caused by a single nitrogen source.

[0027] In the preferred embodiment of the present invention, the proportion of gypsum in the total dry weight of the substrate is 1%, and the proportion of lime in the total dry weight of the substrate is 1%. Lime (1%) can adjust the pH value of the substrate to the suitable range of elm yellow mushroom (neutral to alkaline), inhibit the growth of acidic bacteria, and at the same time play an auxiliary role in disinfection. Gypsum (1%) provides calcium, promotes mycelial cell wall synthesis and fruiting body development, and enhances the toughness of the mushroom. The two together account for 2%, avoiding excessive mineral additives that may lead to decreased substrate permeability or nutritional imbalance.

[0028] This invention also proposes a method for preparing the above-mentioned reed and corn cob composite substrate for cultivating *Pleurotus ostreatus*, comprising the following steps: (1) Weigh out each dry material raw material according to the proportion; (2) Mix the weighed reeds, corn cobs, soybean cake and wheat bran, and pre-wet them with water for 16 hours or more to obtain wet material; (3) After mixing the wet materials, bag and sterilize them to obtain the elm yellow mushroom cultivation substrate (mushroom stick) composed of reed and corn cob.

[0029] In a preferred embodiment of the present invention, reeds and corn cobs are added in the form of reed stalk fragments and corn cob fragments, that is, the reeds and corn cobs are respectively crushed into 20-mesh reed stalk fragments and corn cob fragments.

[0030] In step (2) of the preferred embodiment of the present invention, during pre-wetting, the mass ratio of dry material to water is 1:1.65.

[0031] In step (3) of the preferred embodiment of the present invention, sterilization is performed continuously at atmospheric pressure (101.325 kPa) and 100°C for a sterilization time of not less than 10 hours.

[0032] This invention also proposes a method to increase the yield of *Pleurotus ostreatus*, which uses a reed substrate for cultivation and includes the following steps: after the sterilized reed substrate is cooled, *Pleurotus ostreatus* spawn is inoculated and the mycelium is grown in the dark for 20 days at 25°C and 60%-70% humidity; then, fruiting management is carried out at 25°C and 75%-85% humidity.

[0033] All raw materials used in the embodiments of this invention were purchased commercially, and the *Pleurotus ostreatus* spawn used was purchased from Liaoning Xingcheng Lihe Edible Fungus Co., Ltd.

[0034] In this embodiment of the invention, normal pressure refers to approximately 101.325 kPa, and normal temperature refers to 25 ± 3 °C.

[0035] The technical solution of the present invention will be further illustrated by the following embodiments.

[0036] Example 1 A method for preparing a cultivation substrate (mushroom stick) of *Pleurotus ostreatus* composed of reeds and corn cobs includes the following steps: (1) Based on the size of the cultivation bag, prepare the materials according to the mass ratio of LY2 in Table 1. Each cultivation stick weighs 1 kg. To make 10,000 sticks, 4,000 kg of dry material is required. Therefore, prepare the materials according to the following mass: 1,620 kg of reed straw fragments, 1,620 kg of corn cob fragments, 80 kg of soybean cake, 600 kg of wheat bran, and 40 kg each of gypsum and lime (i.e., the mass ratio of the composite nitrogen source in the total dry weight of the substrate is 17%, the mass ratio of the composite carbon source in the total dry weight of the substrate is 81%, and the mass ratio of mineral additives in the total dry weight of the substrate is 2%). (2) Mix the weighed reed straw fragments, corn cob fragments, soybean cake, and wheat bran in a pre-wetting area and manually mix them. Add water and pre-wet for 16 hours at a dry-to-wet ratio of 1:1.65. After 16 hours, transport the pre-wetted material to a mixer and mix thoroughly for 60 minutes. Then, transport the mixture to an automatic bagging machine for bagging. The polypropylene bags used in the bagging process are 17×34×0.05cm in size. Sterilize continuously at 100℃ under normal pressure for 10 hours. After cooling to room temperature, inoculate with *Pleurotus ostreatus*. Ensure the sterility of the inoculation room and inoculation tools. Then, carry out mycelium growth. The mycelium growth conditions are: mycelium growth temperature of 25℃, humidity of 60-70%, ventilation, and shading. Mycelium growth time is 20 days. Fruiting: temperature of 25℃, humidity of 75-85%. Ventilate 3-5 times a day for 1 hour each time, and shading. Fruiting period is about 45-60 days.

[0037] Example 2 Same as Example 1, except that the materials are prepared according to the mass ratio of LY1 in Table 1 (i.e., weigh 1080 kg of reed stalk fragments, 2160 kg of corn cob fragments, 80 kg of soybean cake, 600 kg of wheat bran, and 40 kg each of gypsum and lime).

[0038] Example 3 Same as Example 1, except that the materials are prepared according to the mass ratio of LY3 in Table 1 (i.e., weigh 2160 kg of reed stalk fragments, 1080 kg of corn cob fragments, 80 kg of soybean cake, 600 kg of wheat bran, and 40 kg each of gypsum and lime).

[0039] Comparative Example 1 Same as Example 1, except that the materials are prepared according to the mass ratio of LY0 in Table 1 (i.e., weigh 3240 kg of corn cob scraps, 80 kg of soybean cake, 600 kg of wheat bran, and 40 kg each of gypsum and lime).

[0040] Comparative Example 2 Same as Example 1, except that the materials are prepared according to the mass ratio of LY4 in Table 1 (i.e., weigh 3240 kg of reed straw fragments, 80 kg of soybean cake, 600 kg of wheat bran, and 40 kg each of gypsum and lime).

[0041] Comparative Example 3 Same as Example 1, except that the materials were prepared according to the mass ratio of CK in Table 1 (i.e., weigh 2000 kg of reed stalk fragments, 1520 kg of corn cob fragments, 400 kg of soybean cake, and 40 kg each of gypsum and lime).

[0042] Comparative Example 4 Same as Example 1, except that the reed stalk fragments are replaced with wood chips of equal mass.

[0043] Comparative Example 5 The following materials were prepared according to the following mass ratio: 30% reed stalk fragments, 11.3% sawdust, 11.1% cottonseed hulls, 11% bagasse, 9% corn cob fragments, 25% wheat bran, 1% light calcium carbonate, 1% lime, and 0.6% superphosphate, all by dry weight, with a total ratio of 100%. Based on this, the preparation was carried out according to the method in Example 1.

[0044] Table 1. Reed substrate formulation design for cultivating *Pleurotus ostreatus* (mass percentage) Performance testing With the same carbon source ratio, the biological efficiency of *Pleurotus ostreatus* cultivated in the 1:1 reed + corn cob composite substrate LY2 was 85.48±1.17%, while the biological efficiency of *Pleurotus ostreatus* cultivated in the 1:1 sawdust + corn cob composite substrate MY was 63.04±2.46%, with the former being 35.60% higher than the latter. Reeds significantly replaced sawdust.

[0045] Different carbon source ratios were observed: Treatment LY3, with 81% carbon source in the 2:1 reed + corn cob composite substrate, had a biological efficiency of 91.11±2.61%; Treatment CK, with 88% carbon source in the reed + corn cob substrate, had a biological efficiency of 68.99±1.16%; and Treatment LY3, with 72% carbon source in the reed + sawdust + corn cob composite substrate, had a biological efficiency of 55.21±1.65%. LY3 showed improvements of 32.06% and 65.02% compared to CK and LMY, respectively. This indicates that a suitable carbon source ratio is one of the important factors for high yield in the cultivation substrate of *Pleurotus ostreatus*.

[0046] In the examples and comparative examples, three flushes of mushrooms were harvested from different treatment groups to represent the total yield. The biological efficiency was calculated using the formula: Biological efficiency (%) = Total fresh weight of edible fungi fruiting bodies / Dry weight of cultivation substrate × 100%. All mushrooms under different treatments were dried to constant weight, ground, and sieved to test the content of metabolites such as total polyphenols, total flavonoids, and total triterpenes, as well as the content of organic nutrients such as fungal polysaccharides, crude fat, crude protein, and total amino acids. This was used to compare the yield and quality differences of *Pleurotus ostreatus* under different treatment ratios.

[0047] Figure 1 The biological efficiency of *Pleurotus ostreatus* under different treatments in Examples 1-3 and Comparative Examples 1-5 is shown (different lowercase letters indicate significant differences between treatments (P<0.05), the same below). It can be seen that the biological efficiency of *Pleurotus ostreatus* in Comparative Example 3 (CK) is approximately 69%. When the proportion of N source in the substrate is increased and the proportion of C source is appropriately decreased, the biological efficiency of *Pleurotus ostreatus* both increased and decreased: when the C source was entirely corn cob or reed (Comparative Example 1 or 2), the biological efficiency of *Pleurotus ostreatus* decreased significantly, below 60%, while when reed and corn cob were combined in different proportions (Examples 1-3), the biological efficiency increased to 78.10%-91.11%. Compared with Comparative Example 3 (CK), the increase was 13.02%-31.85%.

[0048] Figure 2 The changes in the content of total polyphenols (A), total flavonoids (B), and total triterpenes (C) in mushrooms under different treatments in Examples 1-3 and Comparative Examples 1-2 are shown. Figure 3 The changes in the content of crude protein (A), total free amino acids (B), crude polysaccharides (C), and crude fat (D) in mushrooms under different treatments in Examples 1-3 and Comparative Examples 1-3 are shown. Figure 2 It can be seen that the changes in nutrient content in Examples 1-3 are between those in Comparative Examples 1 and 2. Figure 3 The results show that when different combinations of reeds and corn cobs are used as C sources for the cultivation substrate of *Pleurotus ostreatus*, the contents of crude protein, total amino acids, and polysaccharides in the mushroom bodies of Examples 1-3 are relatively higher than those in Comparative Examples 1 and 2, while the content of crude fat shows the opposite trend. Taking crude protein as an example, the crude protein content of the mushroom bodies increased from 279.11 mg / g in the CK treatment to 332.86-345.13 mg / g.

[0049] The results above show that by fixing the nitrogen content of soybean cake, wheat bran and other sources at 17% and the carbon source matrix ratio at 81%, and by adjusting the ratio of reeds to corn cobs, the yield of *Pleurotus ostreatus* can be significantly increased. Compared with using corn cobs and reeds alone as carbon sources, the appropriate ratio of the two can promote improved biological efficiency, increase crude protein, polysaccharides, total polyphenols, and total flavonoids, and reduce crude fat content.

[0050] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A composite substrate of reeds and corn cobs for cultivating *Pleurotus ostreatus*, characterized in that, It is composed of the following dry matter raw materials: reeds and corn cobs as a composite carbon source, soybean meal and wheat bran as a composite nitrogen source, and gypsum and lime as mineral adjuvants; among which, The mass ratio of reeds to corn cobs is (0.5-2):1; The composite nitrogen source accounts for 17% of the total dry weight of the matrix, the composite carbon source accounts for 81% of the total dry weight of the matrix, and the remainder is the mineral additives.

2. The reed and corn cob composite substrate for cultivating *Pleurotus ostreatus* as described in claim 1, characterized in that, The mass ratio of reeds to corn cobs is 1:2, 1:1, or 2:

1.

3. The reed and corn cob composite substrate for cultivating *Pleurotus ostreatus* as described in claim 1, characterized in that, In the composite nitrogen source, soybean cake accounts for 2% of the total dry weight of the matrix, and wheat bran accounts for 15% of the total dry weight of the matrix.

4. The reed and corn cob composite substrate for cultivating *Pleurotus ostreatus* as described in claim 1, characterized in that, In the mineral additives, gypsum accounts for 1% of the total dry weight of the matrix, and lime accounts for 1% of the total dry weight of the matrix.

5. A method for preparing a cultivation substrate of *Pleurotus ostreatus* composed of reeds and corn cobs as described in any one of claims 1-4, characterized in that, Includes the following steps: (1) Weigh out each dry material raw material according to the proportion; (2) Mix the weighed reeds, corn cobs, soybean cake and wheat bran, and pre-wet them with water for 16 hours or more to obtain wet material; (3) After mixing the wet material, bag and sterilize it to obtain the elm mushroom cultivation substrate composed of reed and corn cob.

6. The preparation method according to claim 5, characterized in that, In step (2), during the pre-wetting process, the mass ratio of dry material to water is 1:(1.5-1.65).

7. The preparation method according to claim 5, characterized in that, In step (3), the sterilization is performed continuously at normal pressure and 100°C for a period of not less than 10 hours.

8. A method for increasing the yield of *Pleurotus ostreatus*, characterized in that, The mushroom was cultivated using the reed and corn cob composite substrate as described in any one of claims 1-4.

9. The method for increasing the yield of *Pleurotus ostreatus* according to claim 8, characterized in that, Includes the following steps: After the sterilized reed and corn cob composite elm yellow mushroom cultivation substrate was cooled, elm yellow mushroom spawn was inoculated and the mycelium was allowed to grow in the dark for 20 days at 25℃ and 60%-70% humidity. Then, the mushroom production management was carried out at 25℃ and 75%-85% humidity.

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