Dual-purpose composite microbial preparation for straw comprehensive treatment and straw fermentation method

Abstract

The invention discloses a dual-purpose composite microbial preparation for straw comprehensive treatment and a straw fermentation method.According to the preparation, a composite microbial system is formed by a core bacterial group and an auxiliary bacterial group, the adaptability to the environment temperature is high, and the preparation can be applied to high-temperature composting or straw returning as required; the preparation utilizes the comprehensive decomposition effect of microorganisms and functional enzymes to destroy the compact cellulose structure on the surface layer of the straw, so that the sugar and nutrients in the straw are released, the composting decomposition, field decomposition and the like of the straw are efficiently promoted, the problems of low decomposition speed, difficulty in temperature control and the like in the straw treatment process are effectively solved, and the quality of the straw is improved. Therefore, efficient and green treatment and resource utilization of the straws are realized, and meanwhile, a new technical path is provided for green and environment-friendly treatment of agricultural wastes.

Description

Technical Field

[0001] This invention relates to the field of microbial technology, specifically to a dual-purpose compound microbial preparation for comprehensive straw treatment and a straw fermentation method.

[0002] This application claims priority to Chinese Patent Application No. 2025103895789, filed on March 31, 2025, the contents of which are incorporated herein by reference in their entirety. Background Technology

[0003] Straw is a significant waste product in agricultural production, with annual yields of materials such as rice straw and wheat straw being enormous. If not effectively managed, it not only wastes resources but can also cause environmental pollution. Traditionally, straw disposal methods include burning, composting, and returning it to the field.

[0004] Composting technology uses microorganisms to convert organic matter in straw into organic fertilizer, improving soil structure and fertility. However, traditional composting often suffers from problems such as long decomposition cycles, slow temperature rise, and difficulty in completely eliminating pests and diseases, which seriously affect composting efficiency and product quality.

[0005] Returning straw to the field is an environmentally friendly treatment method. By directly returning straw to the soil, it can increase soil organic matter content, promote the reproduction of soil microorganisms, and improve soil structure. However, the process of returning straw to the field often faces challenges such as slow decomposition and incomplete straw decomposition. Especially under low-temperature conditions, the decomposition rate of straw is slow, and undecomposed straw may have adverse effects on the soil, leading to unsatisfactory agricultural production results.

[0006] To overcome these problems, microbial agents have been increasingly applied to straw treatment processes in recent years. By introducing microbial communities with the ability to decompose cellulose and lignin, the decomposition and maturation of straw can be effectively accelerated, composting efficiency improved, and the maturation cycle shortened. However, most microbial agents currently on the market are targeted at a specific treatment method, such as being only suitable for high-temperature composting or only suitable for straw return to the field, lacking a composite microbial community that can flexibly adapt to different temperature conditions. Summary of the Invention

[0007] To address at least one of the aforementioned technical deficiencies, the present invention provides the following technical solution: This application discloses a dual-purpose compound microbial preparation for comprehensive straw treatment, comprising a core microbial group and an auxiliary microbial group.

[0008] The core microbial group includes Bacillus subtilis with accession number CGMCC.No.32063. Bacillus subtilisThe bacterial group consisted of Bacillus licheniformis, Aspergillus fumigatus, Trichoderma longipes, Bacillus pasteurellii, mesophilic pectinase, and ligninase, in a volume ratio of 2-3:1-1.5:1.5-3:2-2.5:0.5-2.5:2-2.5:1-2; the auxiliary bacterial group included Bacillus amyloliquefaciens, Bacillus belye, and Bacillus argentea with accession number CGMCC.No.32065. Bacillus aryabhattai ), and the volume ratio is 1-2:1-2:1-3; The mass ratio of the core bacterial group to the auxiliary bacterial group was 7-8:2-3. (Bacillus subtilis) Bacillus subtilis Both *Bacillus licheniformis* (accession number CGMCC.No.32063) and *Bacillus licheniformis* can function normally during the high-temperature composting process (above 55℃). *Bacillus licheniformis* is an obligate thermophile (30-65℃), while *Bacillus subtilis* (…)… Bacillus subtilis (Accession number CGMCC.No.32063) possesses a wider biological activity temperature range (10℃-60℃). It can synergize with Bacillus licheniformis during the high-temperature phase of composting, while also ensuring the secretion of highly efficient cellulase and hemicellulase during the low-temperature winter straw return to the field (5-15℃). It can randomly cleave β-1,4-glycosidic bonds within the cellulose molecular chain, breaking the orderly arranged long-chain cellulose into scattered, irregular short-chain oligosaccharide fragments, thereby disrupting the compact and solid cellulose backbone. With the overall disintegration of the primary cell wall structure, not only are various forms of cellulose chains released, but hemicellulose and lignin inside the cell wall are also exposed. Numerous target sites and reaction sites are recognized and acted upon by subsequent hemicellulases and other microorganisms, accelerating the degradation process of straw lignocellulose.

[0009] Lignin is composed of multiple aromatic rings cross-linked by carbon-carbon and ether bonds, forming a complex and dense three-dimensional network structure, making it one of the most difficult components to degrade in plant cell walls. *Aspergillus fumigatus* and *Trichoderma longipes* possess rich and diverse cellulase and lignin enzyme systems (such as laccase and manganese peroxidase). After the primary cell wall structure is disrupted, *Aspergillus fumigatus*, *Trichoderma longipes*, and their lignin enzymes can rapidly penetrate and recognize their sites of action. The cellulases (exonucleases) of *Aspergillus fumigatus* and *Trichoderma longipes* are similar to those of *Bacillus subtilis* (…). Bacillus subtilis The cellulase (endopeptidase) of this study (accession number CGMCC.No.32063) exhibits functional complementarity, enabling it to orderly cleave β-1,4-glycosidic bonds at both ends of the cellulose molecular chain, thoroughly clearing any incompletely decomposed cellulose chains and improving cellulose degradation efficiency. Simultaneously, *Aspergillus fumigatus*, *Trichoderma longiflora*, and ligninase synergistically participate in the oxidative degradation of lignin, gradually breaking down its complex three-dimensional network structure, thus degrading and releasing diverse small-molecule nutrients and enriching the organic nutrients in the environment.

[0010] Straw contains low levels of nitrogen, insufficient to supply the large amounts of nutrients required by the complex microbial community during its rapid reproduction. Bacillus pasteurellii possesses a superior nitrogen conversion system and temperature adaptability (5-40℃). Whether during the warming or cooling phases of composting or in cold field conditions, it can secrete urease to convert environmental nitrogen nutrients (such as urea initially applied to compost) into ammonia or nitrate nitrogen, carbon dioxide, etc., which can be utilized by microorganisms. This rapidly diffuses into the surrounding environment, making environmental nitrogen more readily absorbed by microorganisms and crop roots, thereby promoting the stable growth and metabolic activity of the microbial community and ensuring the continuous and efficient operation of the straw degradation process.

[0011] The core microbial community dominates the destruction and transformation of lignocellulose inside the straw during high-temperature composting (above 55℃), efficiently decomposing complex polysaccharides such as pectin, cellulose, hemicellulose and lignin. These sugars provide a rich source of nutrients for other microorganisms in the soil, further improving the microbial activity and fertility of the soil, accelerating the fermentation and maturation process of straw compost, and improving the maturity and biosafety of straw compost products.

[0012] Bacillus argentea ( Bacillus aryabhattai (Accession number CGMCC.No.32065) can exhibit excellent lignocellulose degradation activity in low-to-medium temperature environments (5℃-30℃), and can secrete various enzymes, including cellulase, hemicellulase, and pectinase. It can synergistically work with mesophilic pectinase to further enhance the pectin decomposition rate, breaking down pectin into soluble small-molecule sugars such as xylose and arabinose. Furthermore, in winter low-temperature straw return to the field (5-15℃), it can efficiently promote the decomposition of other complex lignocellulose in straw, and synergistically promote straw decomposition in the field with the core microbial community, providing abundant carbon sources for soil microorganisms. Bacillus amyloliquefaciens and Bacillus belye can activate and release soil nutrients, making soil conditions more conducive to microbial survival and reproduction. Their synergistic effect significantly improves the straw decomposition treatment effect of the compound microbial agent, thus breaking the limitations of low temperature on microbial cellulose decomposition.

[0013] Furthermore, the volumes of the core bacterial group and the auxiliary bacterial group are measured in liquid form.

[0014] Furthermore, in the core bacterial group, Bacillus subtilis ( Bacillus subtilis The bacterial concentrations of Bacillus licheniformis, Aspergillus fumigatus, Trichoderma longipes, and Bacillus pasteurellium were 6 × 10⁻⁶. 10 cfu / ml - 9×10 10 cfu / ml, medium-temperature pectinase activity is 2×10 4 U / ml - 5×10 4U / ml, the ligninase enzyme activity is 1×10 3 U / ml- 3×10 3 U / ml.

[0015] Further, in the auxiliary bacteria group, the bacterial solution concentration of Bacillus amyloliquefaciens, Bacillus velezensis and Bacillus aryabhattai (Bacillus aryabhattai) Bacillus aryabhattai 10 cfu / ml- 8×10 10 cfu / ml.

[0016] The present application discloses a straw fermentation method, which uses the above-mentioned compound microbial preparation in a proportion of 1.5-6 kg / ton or 1.5-6 kg / acre in straw treatment.

[0017] The compound microbial preparation is used in the compost fermentation treatment of straw, or the compound microbial preparation is used in the in-situ treatment of straw returning to field.

[0018] Compared with the prior art, the present application has the following beneficial effects: 1、The present application forms a compound microbial system with a core bacteria group and an auxiliary bacteria group, has strong environmental temperature adaptability, can be applied to high-temperature composting or straw returning to field according to requirements, and uses the comprehensive decomposition of microorganisms and functional enzymes to destroy the tight cellulose structure of the surface layer of straw, thereby releasing the sugar and nutrients in the interior of the straw, thereby efficiently promoting the composting of straw, field decomposition and the like, effectively solving the problems of slow composting speed and difficult temperature control in the straw treatment process, thereby realizing efficient and green treatment and resource utilization of straw, and simultaneously providing a new technical path for green and environmentally-friendly treatment of agricultural waste. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0020] Figure 1 is a functional cooperation schematic diagram of the present compound microbial agent; Figure 2 is an implementation schematic diagram of the functional components of the present compound microbial agent; Figure 3 is a cellulose degradation rate graph; Figure 4 is a hemicellulose degradation rate graph; Figure 5 is a lignin degradation rate graph; Figure 6 is a straw dry matter degradation rate graph;​ Figure 7 This is a diagram illustrating composting temperature. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0022] Medium-temperature pectinase: Purchased from Xiasheng Industrial Group Co., Ltd., model Xiasheng FDG-2259 and CAS number CAS: 9032-75-1. Ligninase: Purchased from Hangzhou Haoxin Biotechnology Co., Ltd., model HY-E70387 and CAS number 42613-30-9.

[0023] Example 1 A compound microbial preparation for straw return to the field and composting. S1, Core bacterial group: Bacillus subtilis ( Bacillus subtilis The following bacteria were cultured to a concentration of 8 × 10⁻⁶ (CGMCC No. 32063): Bacillus licheniformis (BNCC186161), Aspergillus fumigatus (BNCC238133), Trichoderma longiflora (BNCC187865), and Bacillus pasteurellii (ATCC 11859). 10 The bacterial suspension at CFU / ml showed mesophilic pectinase and ligninase activities of 2.33 × 10⁻⁶ CFU / ml. 4 U / ml and 1.15×10 2 The core bacterial group was obtained by mixing U / ml at a volume ratio of 2:1:2:2:1:1:1.

[0024] Bacillus subtilis ( Bacillus subtilis The sample (accession number CGMCC.No.32063) was selected from high-temperature samples of bamboo shavings and rice straw compost. It was expanded using a dedicated liquid fermentation medium A, which consisted of: 15 g / L tryptone, 5 g / L yeast extract, 4 g / L dipotassium hydrogen phosphate, 2 g / L ammonium sulfate, 1 g / L magnesium sulfate, and trace amounts of ferrous sulfate, manganese sulfate, zinc chloride, and cobalt chloride (in a 1:1:1:1 ratio, totaling 0.1 g / L), with a pH of 6.8. The medium was sterilized at 121℃ for 25 minutes and then cooled. Bacillus subtilis (…) was then… Bacillus subtilis After inoculating the seed culture at 1%, the culture temperature was set at 37℃ and cultured for 12 hours. (Bacillus subtilis) Bacillus subtilis On September 25, 2024, it was deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC.No.32063 and address: No.3, No.1 Beichen West Road, Chaoyang District, Beijing.

[0025] Bacillus licheniformis (BNCC186161), Aspergillus fumigatus (BNCC238133), Trichoderma longiflorum (BNCC187865), Bacillus pasteurellii (ATCC 11859), mesophilic pectinase, and ligninase can be cultured using conventional methods.

[0026] S2, Supporting bacterial group: Bacillus amyloliquefaciens, Bacillus belye (BNCC188043), and Bacillus argentea (… Bacillus aryabhattai (Accession number CGMCC.No.32065) were cultured to a concentration of 5×10⁻⁶. 10 The auxiliary bacterial group was obtained by mixing bacterial suspensions of CFU / ml at a volume ratio of 1:1:2.

[0027] Bacillus aryabhattai (accession number CGMCC.No.32065) was screened from the rhizosphere soil of field-grown lettuce and propagated using liquid fermentation medium B. The composition of liquid fermentation medium B was as follows: yeast extract 4 g / L, glucose 4 g / L, ammonium sulfate 2 g / L, dipotassium hydrogen phosphate 2 g / L, magnesium chloride 0.5 g / L, pH 7.2. The medium was sterilized by moist heat at 121℃ for 30 min and then cooled. A 5% seed culture of Bacillus aryabhattai was inoculated, and the culture temperature was set at 20℃ for 48 h. Bacillus abhattai (accession number CGMCC.No.32065) was deposited at the China General Microbiological Culture Collection Center (CGMCC) on September 25, 2024, with accession number CGMCC.No.32065 and deposit address: No.3, No.1 Beichen West Road, Chaoyang District, Beijing.

[0028] Bacillus amyloliquefaciens (BNCC132867) and Bacillus vesiculosus (BNCC188043) were purchased directly from the market.

[0029] S3. Mix the core bacterial group and the auxiliary bacterial group prepared above at a mass ratio of 7:3 to obtain a composite microbial agent.

[0030] Example 2 The difference from Example 1 is that: Bacillus subtilis ( Bacillus subtilis The concentrations of *Bacillus licheniformis* (BNCC186161), *Aspergillus fumigatus* (BNCC238133), *Trichoderma longiflora* (BNCC187865), *Bacillus pasteurellii* (ATCC 11859), mesophilic pectinase, and ligninase were 7.22 × 10⁻⁶. 10 cfu / ml, 7.41×10 10cfu / ml, 7.53×10 10 cfu / ml, 6.24×10 10 cfu / ml, 4.25×10 4 U / ml and 2.31×10 2 U / ml, with a volume ratio of 2:1:3:2:2:2:2.

[0031] Bacillus amyloliquefaciens, Bacillus belye (BNCC188043), and Bacillus argentea ( Bacillus aryabhattai The concentrations of (accession number CGMCC.No.32065) were 6.22×10⁻⁶. 10 cfu / ml, 6.83×10 10 cfu / ml, 6.24×10 10 cfu / ml, volume ratio 2:2:3.

[0032] The field test is as follows: In Zhejiang province, a region with a long-standing three-crop rotation system of wheat-rice-rice was selected. Experimental plots were divided into 20m × 20m sections, with each treatment replicated three times in a randomized block design. A 1m buffer zone was maintained between each experimental plot to prevent contamination from the microbial agent. Before the experiment, all straw residues were removed to ensure consistent soil conditions.

[0033] Treatment 1: Natural decomposition of straw (control group, no inoculant added).

[0034] Treatment 2: The compound microbial agent of Example 1 has both a core microbial group and an auxiliary microbial group.

[0035] Treatment 3: The compound microbial agent of Example 1 contains only the core bacterial group.

[0036] Treatment 4: The compound microbial agent of Example 1 contains only Bacillus subtilis ( Bacillus subtilis Treatment 5: The compound microbial agent of Example 1. Treatment 6: The compound microbial agent of Example 1, except that it does not contain Bacillus aureus (accession number CGMCC.No.32063) and auxiliary bacterial groups. Bacillus aryabhattai (Accession number CGMCC.No.32065). Treatment 7: The compound microbial agent of Example 1, except that it does not contain Bacillus argentea (…). Bacillus aryabhattai (Accession number CGMCC.No.32065) and core bacterial group. Treatment 8: Shandong Zuotian's straw treatment microbial agent Bacillus aureus. Treatment 9: Tonghua Wanying straw treatment microbial agent Bacillus aureus.

[0037] Straw return to field test 1 When harvesting rice, the straw is simultaneously crushed and evenly spread in deep pits or open areas at the edge of the field.

[0038] Take straw (moisture content 40%-50%) and spray it evenly with the corresponding microbial agent for each treatment to make the straw material moisture content 60%-70%. The dosage for treatments 2-8 is 4 kg / mu.

[0039] After treatment, the straw was packed into nylon mesh bags (1-2mm aperture) at a rate of 100g per bag. The initial weight was recorded, and the bags were manually buried in the topsoil layer of each corresponding experimental plot (3*9=27 replicates) at a depth of 5cm-10cm to simulate the working depth of a rotary tiller in the field. The daytime soil surface temperature was 7-13℃. The nylon bags were removed after 30, 60, and 90 days to measure the parameters.

[0040] like Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown, treatment 1 (control group) exhibited the worst degradation of lignocellulose and straw dry matter, especially lignin. Treatment 2 (compound microbial agent) showed the best degradation of lignocellulose and straw dry matter. Treatments 3, 4, 5, 6, 8, and 9 were all more effective than treatment 1 (control group) in all aspects; treatment 7 showed no difference from treatment 1 in terms of lignin and straw dry matter degradation.

[0041] These findings indicate that, except for treatment 7, the addition of microbial agents in the other groups promoted the degradation of lignocellulose and straw dry matter in the soil to varying degrees. The Bacillus subtilis strain cultured by the inventors (…) Bacillus subtilis (Accession number CGMCC.No.32063), Bacillus argentea ( Bacillus aryabhattai The *Bacillus subtilis* (CGMCC.No.32065) exhibits higher efficacy compared to conventional commercially available microbial agents. Simultaneously, Treatment 2, the combined use of the core and auxiliary microbial groups, achieves the best straw return-to-field effect. Further comparison of Treatments 2, 3, and 5 revealed that, in terms of degradation effects on lignocellulose and straw dry matter, Treatment 2 > Treatment 3 > Treatment 5. This not only confirms the necessity of the core and auxiliary microbial groups for straw return-to-field efficacy but also demonstrates their synergistic effect in promoting straw decomposition. Comparison of Treatments 3, 4, 6, and 7 revealed that, in terms of degradation effects on lignocellulose and straw dry matter, Treatment 3 > Treatment 4, and Treatment 6 > Treatment 7. Furthermore, the average effect of Treatments 6 and 7 was greater than that of Treatments 3 and 4. This not only confirms the effectiveness of *Bacillus subtilis* (CGMCC.No.32065) in achieving optimal straw return-to-field effect but also demonstrates the synergistic effect of these microbial groups. Bacillus subtilis, and the preservation number is CGMCC. No. 32063) has a synergistic effect on the quality upgrading of the core bacteria group, and Bacillus amyloliquefaciens, Bacillus velezensis (BNCC188043) can activate the soil and promote the decomposition of straw by the core bacteria group. Comparing treatments 2, 5, 6 and 7, it is found that the degradation effect of lignocellulose and straw dry matter is treatment 2 > treatment 6, treatment 5 > treatment 7, which proves that Bacillus amyloliquefaciens (BNCC188043) has a synergistic effect on the quality upgrading of the core bacteria group. Bacillus aryabhattai , and the preservation number is CGMCC. No. 32065) has a synergistic effect on the quality upgrading of the core bacteria group, and Bacillus amyloliquefaciens, Bacillus velezensis (BNCC188043) can activate the soil and promote the decomposition of straw by the core bacteria group. Comparing treatments 2, 5, 6 and 7, it is found that the degradation effect of lignocellulose and straw dry matter is treatment 2 > treatment 6, treatment 5 > treatment 7, which proves that Bacillus amyloliquefaciens (BNCC188043) has a synergistic effect on the quality upgrading of the core bacteria group.

[0042] The foregoing results prove that the compound microbial inoculant of the present application can promote the decomposition of straw in the field under cold winter conditions, and the combined use of the core bacteria group and the auxiliary bacteria group has a better effect than the commercial microbial inoculant.

[0043] Straw return test two When the harvester harvests wheat, the crushed straw is uniformly sprayed with the following treatment microbial inoculant (4 kg / ton), so that the moisture of the straw material is about 65%. The treated straw is manually buried in the plough layer of 5-10 cm of the corresponding test plot (3*7=21 repeats) to simulate the working depth of the field rotary cultivator. The field environment is 24-33℃, and the soil samples are taken on the 0th day and the 45th day in each plot to measure the parameters, as shown in Table 1.

[0044] Treatment 1: natural decomposition of straw (control group, without microbial inoculant).

[0045] Treatment 2: the compound microbial inoculant of Example 2, which has a core bacteria group + an auxiliary bacteria group.

[0046] Treatment 3: the compound microbial inoculant of Example 2, in which Bacillus subtilis is directly purchased.

[0047] Treatment 4: the compound microbial inoculant of Example 2, which does not contain Bacillus licheniformis (BNCC186161).

[0048] Treatment 5: the compound microbial inoculant of Example 2, which does not contain Aspergillus fumigatus and Trichoderma longibrachiatum (BNCC187865).

[0049] Treatment 6: The composite microbial inoculant of Example 2, wherein Bacillus aryabhattai is directly purchased from the market. Treatment 7: The composite microbial inoculant of Example 2, containing only the core bacterial group.

[0050] Table 1

[0051] It can be seen that the cellulase, xylanase and peroxidase of treatment 2 are significantly higher than those of other treatments, and the polyphenol oxidase of treatments 2, 3 and 4 is significantly higher than that of other groups, which confirms the synergistic effect of each component in treatment 2, and improves the activity and metabolic level of each lignocellulose enzyme in the soil. In the comparison of the soil treatment effects of treatment 2 and treatments 3, 4, 5, 6 and 7, it can be confirmed that each component in the core bacterial group and the auxiliary bacterial group is necessary for the function of the composite microbial inoculant. In particular, the comparison of treatments 1, 2 and 7 confirms that the auxiliary bacterial group and the core bacterial group have a synergistic effect, which is crucial for the improvement of soil cellulase. The comparison of treatments 1, 2 and 5 confirms that Aspergillus fumigatus and Trichoderma longibrachiatum (BNCC187865) cooperate with the core bacterial group, which is crucial for the improvement of xylanase and polyphenol oxidase activity, and these two enzymes are key active substances in the lignin degradation process in nature. From the comparison of treatment 2 and treatment 4, it can be seen that the Bacillus subtilis and Bacillus aryabhattai screened and cultured by the present inventors have a significantly higher effect in straw fermentation than the commercially available models.

[0052] Compost test In a compost factory in Yuhang District, Zhejiang Province, after the completion of rice harvesting in the surrounding rural areas, the straw was crushed to 2-4 cm, and the straw, urea, potassium dihydrogen phosphate and water were mixed into a shaped pile. The size of the pile was 1 meter long, 1 meter wide and 1.2 meters high. Each ton of straw in the pile was mixed with 15 kg of urea and 2 kg of potassium dihydrogen phosphate to make the carbon-nitrogen ratio between 25-30:1, and the moisture content of the pile was 60%. The mass ratio of straw to microbial inoculant was 500:1, i.e. 2 kg of microbial inoculant was used per ton of straw compost. In the test, the pile was turned over once a week, and each treatment was repeated three times.

[0053] The place where the pile is located is well ventilated and well drained to avoid rain. The ground where the pile is located is covered with plastic cloth to reduce nutrient loss.

[0054] Treatment 1: Natural composting of straw (control group, no microbial inoculant added); Treatment 2: The composite microbial inoculant of Example 1, with both the core bacterial group and the auxiliary bacterial group, applied at the recommended dose of 2 kg / ton; Treatment 3: The composite microbial inoculant of Example 1, containing only the core bacterial group, applied at the recommended dose of 2 kg / ton; Treatment 4: The composite microbial inoculant of Example 1, not containing Bacillus subtilis; Bacillus subtilis(CGMCC No. 32063) and auxiliary bacterial groups, applied at the recommended dose of 2 kg / ton; Treatment 5: The compound microbial agent of Example 1, containing only auxiliary bacteria, was applied at the recommended dosage of 2 kg / ton; Treatment 6: Bacillus subtilis, a straw composting agent from Hubei Qiming Biotechnology (applied at the manufacturer's recommended dosage for comparison, 2 kg / ton); Treatment 7: Bacillus subtilis, a straw composting agent from Shandong Yihao Biotechnology (applied at the manufacturer's recommended dosage for comparison, 2 kg / ton).

[0055] During the composting process, the temperature was recorded daily for different treatments. The composting period was 48 days. 500g samples were taken from the top, center and bottom of the compost pile and mixed evenly to obtain a representative sample. Various parameters were then measured.

[0056] Table 2. Indicators of compost products under each treatment at the end of composting.

[0057] *National standard, namely the People's Republic of China agricultural industry standard "Organic Fertilizer NY525-2021".

[0058] like Figure 7 As shown in Table 2, compared to other groups, Treatment 2 reached the high-temperature period (above 59.8℃ on the second day) faster and maintained it until the 12th day, meeting the standard requirements for the high-temperature period of organic fertilizer (above 55℃ for at least 7 days), effectively killing weed seeds, insect eggs, and pathogens; it cooled to ambient temperature on the 32nd day, ending the composting process. Compared to other treatments, Treatment 2 can quickly initiate the high-temperature period, reach higher temperatures and maintain them for a longer time, entering the composting maturity stage earlier. This confirms that Treatment 2 can effectively promote the transformation of substances in straw compost and accelerate the composting process.

[0059] There was no significant difference in the content of organic matter in all treatments, which might be because the material conversion occurred in the internal system of composting during the straw composting process, and the carbon loss was basically consistent in all treatments. In all treatments, the total nitrogen content of treatment 2 was the highest and significantly different from other groups; the total nitrogen of treatments 2, 3 and 4 was significantly higher than that of treatment 5, which might be due to the nitrogen conversion of Bacillus pasteurii (ATCC11859), which promoted the nitrogen turnover in treatments 2, 3 and 4, activated nitrogen and fixed it in the microbial body or in a stable form in the compost, resulting in less nitrogen loss. The cellulose degradation rate, hemicellulose degradation rate and lignin degradation rate of treatment 2 were significantly higher than those of treatment 5, which confirmed that the core bacteria group could significantly improve the degradation and conversion of lignocellulose during the composting process. In treatments 2, 3 and 4, the total nitrogen content, hemicellulose degradation rate and lignin degradation rate of treatment 2 were significantly higher than those of treatment 3, which indicated that the auxiliary bacteria group could strengthen the effect of the core bacteria group in promoting the maturity of straw materials during the composting process. The cellulose degradation rate of treatment 3 was significantly higher than that of treatment 4, which confirmed that the addition of Bacillus subtilis (ATCC 6633) with a preservation number of CGMCC.No.32063 could significantly promote the cellulose degradation in straw composting. Bacillus subtilis

[0060] Only treatments 2 and 3 reached the national standard of organic fertilizer in all treatments, which confirmed that the use of the core bacteria group alone could basically meet the technical requirements and product standards of straw composting; within the cost range, the core bacteria group and the auxiliary bacteria group could be selected together for straw composting to achieve the optimal effect. The indicators of treatment 2 except for the organic matter content were significantly higher than those of treatment 1, and according to the national standard of organic fertilizer, the compost product of treatment 2 met the standard and was better than that of treatment 6 and 7.

[0061] In summary, the compound microbial agent composed of the core bacteria group and the auxiliary bacteria group can effectively promote the maturity of straw composting and improve the compost quality and biological safety.

[0062] The above is only a preferred embodiment of the present application, and the protection scope of the present application is not limited to the above-mentioned embodiments. Any technical solutions falling within the concept of the present application shall fall within the protection scope of the present application. It should be noted that for ordinary technical personnel in the technical field, some improvements and decorations without departing from the principles of the present application shall also be considered as the protection scope of the present application.​

Claims

1. A dual-purpose compound microbial preparation for comprehensive straw treatment, characterized in that, Includes core microbiota and auxiliary microbiota; The core microbial community includes Bacillus subtilis with accession number CGMCC.No.32063 ( Bacillus subtilis ), Bacillus licheniformis, Aspergillus fumigatus, Trichoderma longiflora, Bacillus pasteurellii, mesophilic pectinase and ligninase, in a volume ratio of 2-3:1-1.5:1.5-3:2-2.5:0.5-2.5:2-2.5:1-2; The auxiliary bacterial group includes *Bacillus amyloliquefaciens*, *Bacillus belyceae*, and *Bacillus argentea* with accession number CGMCC.No.32065. Bacillus aryabhattai ), and the volume ratio is 1-2:1-2:1-3; The mass ratio of the core bacterial group to the auxiliary bacterial group was 7-8:2-3.

2. The dual-purpose compound microbial preparation for comprehensive straw treatment as described in claim 1, characterized in that: The volumes of the core and auxiliary bacterial groups are measured in liquid form.

3. The dual-purpose compound microbial preparation for comprehensive straw treatment as described in claim 2, characterized in that: In the core bacterial group, the Bacillus subtilis ( Bacillus subtilis The bacterial concentrations of Bacillus licheniformis, Aspergillus fumigatus, Trichoderma longipes, and Bacillus pasteurellium were 6 × 10⁻⁶. 10 cfu / ml - 9×10 10 The cfu / ml concentration of the mesophilic pectinase indicates an enzyme activity of 2 × 10⁻⁶ cfu / ml. 4 U / ml - 5×10 4 U / ml, the enzyme activity of the ligninase is 1×10⁻⁶. 2 U / ml - 3×10 2 U / ml.

4. The dual-purpose compound microbial preparation for comprehensive straw treatment as described in claim 2, characterized in that: In the auxiliary bacterial group, the *Bacillus amyloliquefaciens*, *Bacillus belye*, and *Bacillus argentea* (… Bacillus aryabhattai The bacterial concentration was 3×10⁻⁶. 10 cfu / ml - 8×10 10 cfu / ml.

5. A method for fermenting straw, characterized in that: The compound microbial preparation described in any one of claims 1-4 is used in straw treatment at a ratio of 1.5-6 kg / ton or 1.5-6 kg / mu.

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