Microbial combined inoculant and application thereof in promoting fermentation and acid production of garbage

Abstract

The invention relates to the technical field of garbage treatment, in particular to a combined microbial agent and application thereof in promoting garbage fermentation to produce acid. The invention provides a microbial composition. The microbial composition comprises klebsiella oxytoca, acetobacter pasteurianus, clostridium butyricum and pediococcus pentosaceus. The microbial composition provided by the invention can quickly decompose complex components in organic garbage through the synergistic effect of four types of functional bacteria in a specific proportion, and directionally convert the complex components into volatile fatty acids mainly comprising butyric acid, and has the advantages of quick start, high acid production efficiency and short fermentation period. No chemical reagent needs to be added in the treatment process, efficient conversion is achieved through microorganism cooperation, and the treatment cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of waste treatment technology, and in particular to a microbial composite agent and its application in promoting waste fermentation and acid production. Background Technology

[0002] With the acceleration of urbanization, the amount of organic waste such as kitchen waste and municipal sludge has increased dramatically. Traditional disposal methods such as landfill and incineration not only have low resource utilization rates but also easily lead to environmental problems such as soil pollution and greenhouse gas emissions. Anaerobic fermentation acid production technology, as one of the core technologies for the resource utilization of organic waste, decomposes organic waste into volatile fatty acids through microbial metabolism. The latter can be used as chemical raw materials, carbon sources for sewage treatment, etc., to achieve high-value utilization, and has significant environmental and economic benefits.

[0003] However, existing waste fermentation acid production technologies generally suffer from the following bottlenecks: First, the microbial community structure in natural fermentation systems is unstable, and the activity of acid-producing bacteria is low, resulting in long fermentation start-up cycles and insufficient substrate hydrolysis efficiency; second, the volatile fatty acid composition is complex, with a low proportion of target acids (such as acetic acid and butyric acid), leading to high costs for subsequent separation and purification; third, organic acid accumulation during fermentation easily causes a sharp drop in pH, inhibiting microbial activity and disrupting system stability. To address these issues, researchers have attempted to enhance the fermentation process by adding exogenous microbial agents. However, existing agents are mostly single-function strains or simple mixed strains, making it difficult to form an efficient synergistic metabolic network. Furthermore, they have poor adaptability to complex waste substrates and cannot simultaneously meet the requirements for improving acid production efficiency, product directionality, and system stability.

[0004] The core advantage of microbial inoculants lies in the synergistic effect formed through metabolic interactions and niche complementarity among strains, regulating the "promoting-competitive" balance to adapt to specific environments. For example, the synergistic effect of acid-producing bacteria and methanogens can regulate the redox potential of the system. However, current technologies have not addressed the need for targeted acid production in waste fermentation by designing composite inoculant combinations that combine efficient hydrolysis, targeted acid production, and environmental adaptability. Therefore, screening functional strains with synergistic effects and constructing microbial composite inoculants that can adapt to complex waste substrates and enhance targeted acid production has become the key to overcoming the current technological bottlenecks. Summary of the Invention

[0005] The purpose of this invention is to provide a microbial composite inoculant and its application in promoting acid production from waste fermentation, thereby addressing the problems existing in the prior art. The microbial composition provided by this invention, through the synergistic effect of four types of functional bacteria in a specific ratio, can rapidly decompose complex components in organic waste and directionally convert them into volatile fatty acids, primarily butyric acid, resulting in high acid production efficiency and a short fermentation cycle.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] The present invention provides a microbial composition comprising Klebsiella oxytoca, Acetobacter pasteurianus, Clostridium butyricum, and Pediococcus pentosaceus.

[0008] Optionally, the ratio of viable Klebsiella acid-producing bacteria, Acetobacter pastoris, Clostridium butyricum, and Pediococcus pentosaceus in the microbial composition is (3-5):(1-2):(2-3):(2-4).

[0009] This invention provides the application of the above-described microbial composition in the preparation of microbial agents that promote acid production from waste fermentation.

[0010] The present invention provides a microbial preparation for promoting acid production from waste fermentation, characterized in that the microbial preparation comprises the above-mentioned microbial composition.

[0011] Optionally, the microbial preparation may also include excipients.

[0012] Optionally, the dosage form of the microbial preparation includes granules, powders, and suspensions.

[0013] The present invention provides the application of the above-mentioned microbial composition or the above-mentioned microbial agent in promoting the fermentation and acid production of waste.

[0014] The present invention provides a method for promoting the fermentation and acid production of waste, the method comprising the step of mixing the above-mentioned microbial composition or the above-mentioned microbial agent with waste and carrying out fermentation.

[0015] Optionally, the amount of the microbial composition or microbial preparation used is 1%-3% of the total mass of the waste.

[0016] Optionally, the fermentation temperature is 35-37℃, the time is 3-5 days, and the initial pH is 6.5-7.0.

[0017] The present invention discloses the following technical effects:

[0018] 1. Significant Synergistic Effects: The core role of *Klebsiella acidogenic* is to decompose complex carbohydrates and produce medium / short-chain organic acids. This strain can secrete various extracellular enzymes such as amylase and cellulase, degrading macromolecular polysaccharides such as starch and hemicellulose in waste into monosaccharides such as glucose and xylose, providing usable carbon sources for itself and other microbial communities. Simultaneously, this strain can convert monosaccharides into organic acids such as butyric acid, accompanied by the generation of a small amount of ethanol, making it one of the fundamental contributors of organic acids in the fermentation system. *Acetobacter pasteurellii* is a typical key bacterium in acetic acid fermentation. It cannot directly decompose macromolecular polysaccharides, mainly utilizing ethanol produced by other microorganisms (such as *Klebsiella acidogenic*) during waste fermentation as a substrate. *Clostridium butyricum*'s core role is to efficiently produce butyric acid and enhance the decomposition of recalcitrant substrates; it is a core functional bacterium in butyric acid fermentation, capable of directionally converting substrates to produce target volatile fatty acids such as butyric acid and acetic acid. *Pediococcus pentosaceus*'s core role is to rapidly produce lactic acid and regulate the pH of the fermentation system, making it a dominant bacterium in lactic acid fermentation. It can efficiently utilize various monosaccharides (including pentoses) such as glucose, xylose, and arabinose to convert carbon sources into large quantities of L-lactic acid through homolactic fermentation. The rapid accumulation of lactic acid can quickly lower the pH value of the fermentation system. The low pH environment can inhibit the growth of putrefactive bacteria and pathogens, reduce odors (such as ammonia and hydrogen sulfide) during waste fermentation, and provide suitable conditions for the growth of acidophilic bacteria. Its strong acid and salt tolerance allows it to continue to function in the middle and late stages of waste fermentation (in a lower pH environment), and its metabolic product, lactic acid, can serve as a co-metabolite substrate for other acid-producing bacteria (such as Clostridium butyricum), promoting the generation of complex organic acids. The combination of these four components produces a synergistic effect: Klebsiella acidophilus is responsible for the initial degradation of macromolecular substrates and the synthesis of basic organic acids; Pediococcus pentosaceus rapidly produces lactic acid to regulate pH and inhibit bacteria; Acetobacter pasteurellium converts the intermediate product ethanol into acetic acid to increase the proportion of the target acid; and Clostridium butyricum utilizes various substrates to generate butyric acid, increasing the added value of the product. Together, these four components construct a highly efficient and stable acid-producing fermentation microbial community structure.

[0019] 2. Strong product targeting: By optimizing the strain ratio, butyric acid production can be targeted and enhanced.

[0020] 3. High system stability: The addition of Pediococcus pentosaceus effectively alleviates the problem of sudden pH drop caused by the accumulation of organic acids during fermentation, keeping the system pH stable within the suitable range of 5.5-6.5 and preventing inhibition of microbial activity. At the same time, the compound microbial agent exhibits strong adaptability to fluctuations in the composition of the waste substrate and its shock resistance is significantly superior to existing microbial agents.

[0021] 4. Low application cost and environmentally friendly: The preparation process of the microbial agent of this invention is simple, the scale-up culture conditions are mild, and no complicated purification steps are required; the dosage is small, and it can be adapted to conventional waste fermentation equipment without additional modification; the fermentation process has no secondary pollution, realizing the reduction and resource utilization of waste, and has broad industrial application prospects.

[0022] 5. Quick start-up and short cycle: The microbial agent has strong adaptability and can quickly start the acid production process within 48 hours, shortening the fermentation cycle to 3-5 days.

[0023] 6. Wide range of applications: Applicable to organic waste from different sources, including high-oil kitchen waste and high-fiber agricultural waste.

[0024] 7. Environmentally friendly: No chemical reagents are required; efficient conversion is achieved through synergistic microbial action, reducing processing costs. Detailed Implementation

[0025] 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.

[0026] 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. Any stated value or intermediate value within a stated range, as well as each smaller range between 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.

[0027] 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.

[0028] 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 obvious to those skilled in the art. This specification and embodiments are merely exemplary.

[0029] 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.

[0030] Chinese patent application number "201310499963.6" entitled "A Method for Promoting the Production of Volatile Fatty Acids from Anaerobic Fermentation of Kitchen Waste" discloses a method for promoting the production of volatile fatty acids from anaerobic fermentation of kitchen waste. The method involves first crushing the kitchen waste to a particle size of 1-5 mm, then adjusting the solid content to 100 mg / L, and then placing it in an anaerobic fermentation reactor. 10-40 g / L of commercially available zero-valent iron (800 mesh) is added, and fermentation is carried out at 15-40℃ and 120 r / min for 4-17 days. After centrifugation, the zero-valent iron in the filter residue is recycled, and the remaining organic components are taken out for composting or as liquid fertilizer. The yield of volatile fatty acids in the supernatant is 29.1-35.8 g / L. When the yield of volatile fatty acids in the supernatant is 29.1 g / L, the content of acetic acid is 32%, propionic acid is 17%, butyric acid is 27%, and valeric acid is 20%. Compared with conventional anaerobic fermentation of kitchen waste, this invention increases the content of volatile fatty acids in the supernatant by 2.3 to 13 times, effectively realizing the resource utilization of kitchen waste. Moreover, it is low-cost, fast, and has good social, economic and environmental benefits.

[0031] Chinese patent application number "202211619856.8" entitled "A Method for Increasing the Production of Butyric Acid During Anaerobic Fermentation of Food Waste" discloses a method for increasing the production of butyric acid during the anaerobic fermentation of food waste. This method uses food waste, anaerobic activated sludge, and a buffer solution as raw materials to prepare a fermentation reaction substrate. Under continuous electrical stimulation, the substrate undergoes anaerobic fermentation to complete the treatment of food waste. This method utilizes a continuous supply of electrons provided by a micro-voltage to promote carbon chain elongation, enabling the acetic acid generated during the anaerobic fermentation of food waste to be converted into butyric acid through carbon chain elongation. This optimizes the acid production structure and enhances the value of fatty acid products. It has advantages such as low cost, simple operation, short fermentation cycle, high reaction efficiency, and high product value, and has excellent application prospects.

[0032] None of the aforementioned patents involve the use of microbial compositions to decompose waste.

[0033] Example 1: Preparation of Microbial Preparations

[0034] The strains were sourced as follows:

[0035] Klebsiella oxytoca was purchased from the China Industrial Microbial Culture Collection Center, strain number CICC 21518. The culture medium used for activation and fermentation of this strain was 0002 nutrient broth agar (5.0 g peptone, 3.0 g beef extract, 5.0 g NaCl, 15.0 g agar, and 1000.0 mL distilled water, pH 7.0), and the culture temperature was 36℃.

[0036] Acetobacter pasteurianus was purchased from the China Industrial Microbial Culture Collection Center, strain number CICC 20001. The culture medium used for activation and fermentation of this strain was 0001 acetic acid bacteria medium (100.0g glucose, ...).

[0037] The mixture consisted of 10.0g yeast extract, 20.0g CaCO3, 20.0mL anhydrous ethanol, 15.0g agar, and 1000.0mL distilled water (pH 6.8), and was cultured at 30℃.

[0038] Clostridium butyricum was purchased from the China Industrial Microbial Culture Collection Center, strain number CICC 23847. The activation and fermentation of this strain were performed using O786 medium (15.0 g tryptone, 5.0 g soybean peptone, 5.0 g NaCl, 50.0 mL defibrinated sheep blood (added after sterilization), 15.0 g agar, and 1000.0 mL distilled water, pH 7.3), at a temperature of 37℃.

[0039] Pediococcus pentosaceus was purchased from the China Industrial Microbial Culture Collection Center, strain number CICC 21862. The culture medium used for activation and fermentation of this strain was 0006 MRS medium (10.0 g casein (trypsin digestion) , 10.0 g beef extract, 5.0 g yeast extract, 20.0 g glucose, 1.0 g Tween 80, 5.0 g sodium acetate, 2.0 g triammonium citrate, 2.0 g K₂HPO₄, 0.2 g MgSO₄·7H₂O, 0.05 g MnSO₄·H₂O, 15.0 g agar, and 1000.0 mL distilled water, pH 6.2-6.5), and the culture temperature was 37℃.

[0040] The activated Klebsiella acidogenic bacteria were inoculated into 0002 nutrient broth agar medium at an inoculum rate of 5% (v / v) and fermented at 36°C for 24 h. The culture was then diluted to obtain 4 × 10⁻⁶ Klebsiella acidogenic bacteria. 9 CFU / mL Klebsiella acidogenic bacterial suspension;

[0041] The activated *Acetobacter pasteurellium* was inoculated into 0001 acetic acid bacteria medium at an inoculation rate of 5% (v / v) and fermented at 30°C for 24 hours. The culture was then diluted to obtain 2 × 10⁻⁶ samples. 9 CFU / mL of Acetobacter pasteurellium culture;

[0042] The activated Clostridium butyricum was inoculated into O786 medium at a rate of 5% (v / v) and fermented at 37°C for 24 hours. The culture was then diluted to obtain 3×10⁻⁶ cells / mL. 9 Clostridium butyricum bacterial suspension at CFU / mL;

[0043] The activated *Pediococcus pentosaceus* was inoculated into 0006 MRS medium at a rate of 5% (v / v) and fermented at 37°C for 24 hours. The culture was then diluted to obtain 3 × 10⁻⁶ cells / mL. 9 CFU / mL Pediococcus pentosaccharide bacterial suspension;

[0044] A microbial preparation was obtained by mixing Klebsiella acidogenic bacterial suspension, Acetobacter pasteurellii bacterial suspension, Clostridium butyricum bacterial suspension, and Pediococcus pentosaceus bacterial suspension in equal proportions.

[0045] Example 2: Experiment on the promotion of acid production by microbial agents in waste fermentation

[0046] 1. Experimental materials:

[0047] Waste substrate: Kitchen waste and municipal sludge are mixed at a volume ratio of 7:3, homogenized (particle size ≤5mm) and degreased (removal of floating oil), the dry weight of the waste has an organic matter content of 72%, and the initial C / N ratio is 22:1.

[0048] Experimental bacterial agents: microbial preparation (microbial preparation obtained in Example 1), single Klebsiella acidogenic bacterial suspension (Klebsiella acidogenic bacterial suspension obtained in Example 1), single Acetobacter pasteurellii bacterial suspension (Acetobacter pasteurellii bacterial suspension obtained in Example 1), single Clostridium butyricum bacterial suspension (Clostridium butyricum bacterial suspension obtained in Example 1), single Pediococcus pentosacchari bacterial suspension (Pediococcus pentosacchari bacterial suspension obtained in Example 1), and compound bacterial suspension (compared to the microbial preparation, lacking Klebsiella acidogenic bacterial suspension);

[0049] Experimental equipment: 5L anaerobic fermenter, temperature control device, pH meter, gas chromatograph (GC-TCD).

[0050] 2. Experimental Groups:

[0051] Experimental group: 2 kg of waste substrate was added, microbial preparation was added (the amount added was 2% of the dry weight of the waste), deionized water was added to adjust the solid-liquid ratio to 1:2, and the initial pH was adjusted to 6.8;

[0052] Control group 1: 2 kg of garbage substrate was added, and Klebsiella pneumoniae culture was added. Other conditions were the same as those in the experimental group.

[0053] Control group 2: 2 kg of garbage substrate was added, and a single Acetobacter pasteurization solution was added. Other conditions were the same as those in the experimental group.

[0054] Control group 3: 2 kg of garbage substrate was added, and Clostridium butyricum bacterial solution was added. Other conditions were the same as those in the experimental group.

[0055] Control group 4: 2 kg of garbage substrate was added, and Pediococcus monomorphus bacterial solution was added. Other conditions were the same as those in the experimental group.

[0056] Control group 5: 2 kg of garbage substrate was added, compound bacterial solution was added, and other conditions were the same as the experimental group;

[0057] Blank control group: 2 kg of garbage substrate was added, no bacterial agent was added, and other conditions were the same as those of the experimental group.

[0058] 3. Experimental conditions: All groups were fermented in a constant temperature anaerobic environment of 37℃ for 5 days, with stirring twice a day (10 min each time). pH changes were monitored regularly. After fermentation, the substrate hydrolysis rate and volatile fatty acid yield (total VFAs) were measured.

[0059] 4. Detection method:

[0060] Substrate hydrolysis rate: The change in dry weight of waste before and after fermentation was determined by gravimetric method. The formula for calculating the hydrolysis rate is shown below:

[0061] .

[0062] Volatile fatty acids (total VFAs): The fermentation broth was centrifuged at 8000 r / min for 10 min, and the supernatant was filtered through a 0.22 μm filter membrane. The contents of acetic acid, butyric acid and other components were determined by gas chromatography. The chromatographic column was an HP-FFAP capillary column (30 m × 0.32 mm × 0.25 μm), and the detector was FID. The column temperature program was: initial 60 °C for 2 min, increased to 180 °C at 10 °C / min, and held for 5 min; the injection port temperature was 200 °C, the detector temperature was 220 °C, and the carrier gas was nitrogen.

[0063] 5. Experimental Results:

[0064] Table 1. Results of substrate hydrolysis rate, total VFAs yield, butyric acid yield, and pH at the end of fermentation for different treatments.

[0065]

[0066] The experimental results are shown in Table 1. The results show that:

[0067] 1) Substrate hydrolysis capacity: The experimental group's microbial community significantly improved the degradation efficiency of organic substrates. The substrate hydrolysis rate of the experimental group reached 83.2%, significantly higher than all control groups and the blank group. Compared with the blank group (28.6%), the hydrolysis rate increased by about 2.9 times, indicating that the complex microbial community can efficiently secrete extracellular enzymes (amylase, cellulase, etc.) to decompose large molecular substrates such as polysaccharides and proteins in waste, providing sufficient carbon sources for subsequent acid production. The hydrolysis rate of control group 5 (67.9%) was second only to the experimental group, but it was still 15.3% lower than the experimental group, indicating that the substrate degradation capacity of its microbial community combination was weaker than that of the four-strain synergistic system of the experimental group. The hydrolysis rates of the remaining control groups (control groups 1-4) were concentrated between 35.7% and 42.3%, only about half that of the experimental group, further verifying the synergistic degradation advantage of the experimental group's microbial community.

[0068] 2) Total VFAs Production: The acid production efficiency of the experimental group was significantly higher than that of the control group. The total VFAs production of the experimental group was 15.6 g / L, which was 3.47 times that of the control group (4.5 g / L) and much higher than that of other control groups. The total VFAs production of control group 5 was 8.4 g / L, less than 54% of that of the experimental group; the production of control groups 1-4 was only 5.3-7.8 g / L, showing a significant difference in acid production capacity. Combined with the high hydrolysis rate, it can be seen that the experimental group of bacteria can not only efficiently degrade the substrate, but also fully convert the degradation products into volatile fatty acids, resulting in a smoother overall acid production metabolic pathway.

[0069] 3) Butyric acid production performance: The experimental group achieved highly efficient targeted synthesis of butyric acid, a high-value-added target product. The experimental group showed the best performance in butyric acid yield. The butyric acid yield of the experimental group reached 9.2 g / L, which is 6.13 times that of the blank group (1.5 g / L); the butyric acid yield of control group 5 was 6.8 g / L, which is 73.9% of that of the experimental group; and the butyric acid yield of control groups 1-4 was only 3.7-4.1 g / L, showing a significant difference.

[0070] This result directly reflects the core role of Clostridium butyricum in the complex microbial community. At the same time, the synergistic effect of other strains (such as Klebsiella acidogens providing substrates and Pediococcus pentosus regulating the environment) ensures the efficient synthesis and accumulation of butyric acid.

[0071] 4) pH stability of the fermentation system: The experimental group maintained a more suitable fermentation environment. At the end of fermentation, the pH of the experimental group was 6.2, which was higher than that of all control groups and blank groups (4.8-5.6). The pH of the blank group and most control groups was lower (<5.6), which may be due to the excessive accumulation of acidic substances such as lactic acid, which inhibited the activity of acid-producing bacteria (especially strict anaerobic bacteria such as Clostridium butyricum). The pH of the experimental group was maintained at around 6.2, which is within the suitable growth range of acid-producing bacteria. This indicates that the metabolic balance among the microbial community was better (for example, while Pediococcus pentosaceus produced lactic acid to regulate the pH, Acetobacter pasteurellum and Clostridium butyricum consumed some acidic substances), ensuring the continuous and efficient progress of the fermentation process.

[0072] It is evident that the four strains of the experimental group, through synergistic effects, achieved multiple advantages, including efficient substrate degradation, high total VFA production, targeted butyrate synthesis, and stable fermentation environment. Compared with single or other combinations of microorganisms, it has higher practical value in the application of waste fermentation for acid production.

[0073] Example 3: Experiment on co-fermentation of agricultural straw and kitchen waste

[0074] Experimental materials: Kitchen waste (70% moisture content, C / N=25) and crushed corn stalks (10% moisture content, C / N=45) were mixed at a wet weight ratio of 7:3, and the moisture content was adjusted to 60% and C / N=28.

[0075] Experimental method: Inoculate with 2.0 wt% microbial preparation (the microbial preparation obtained in Example 1), and the remaining conditions are the same as in Example 2. The fermentation period is 10 days. At the same time, the treatment without inoculation is used as a control group.

[0076] Experimental results: On day 5 of fermentation, the substrate hydrolysis rate was 85.2%, and the total VFAs yield reached 17.1 g / L, with butyric acid accounting for 61.1%. Compared with the control without added microbial agent, the substrate hydrolysis rate increased by 60.9%, the total VFAs yield increased by 142%, and the butyric acid ratio was only 33.2%. Therefore, the microbial agent provided by this invention also has a significant promoting effect on high-fiber waste.

[0077] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A microbial composition, characterized in that, The microbial composition includes Klebsiella oxytoca, Acetobacter pasteurianus, Clostridium butyricum, and Pediococcus pentosaceus.

2. The microbial composition according to claim 1, characterized in that, The ratio of viable Klebsiella acid-producing bacteria, Acetobacter pastoris, Clostridium butyricum, and Pediococcus pentosaceus in the microbial composition is (3-5):(1-2):(2-3):(2-4).

3. The use of the microbial composition according to claim 1 or 2 in the preparation of microbial agents that promote acid production from waste fermentation.

4. A microbial preparation for promoting acid production by garbage fermentation, characterized by, The microbial preparation includes the microbial composition according to claim 1 or 2.

5. The microbial preparation according to claim 4, characterized in that, The microbial preparation also includes excipients.

6. The microbial preparation according to claim 5, characterized in that, The dosage forms of the microbial preparations include granules, powders, and suspensions.

7. The use of the microbial composition according to claim 1 or 2 or the microbial agent according to any one of claims 4-6 in promoting the fermentation and acid production of waste.

8. A method of promoting acid production from waste fermentation, characterized by, The method includes the step of mixing the microbial composition of claim 1 or 2 or the microbial agent of any one of claims 4-6 with waste and carrying out fermentation.

9. The method of claim 8, wherein, The amount of the microbial composition or microbial preparation used is 1%-3% of the total mass of the waste.

10. The method of claim 8, wherein, The fermentation temperature is 35-37℃, the time is 3-5 days, and the initial pH is 6.5-7.0.

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