A degradation bacteria for liquefying degradation of kitchen waste and a bacterial agent containing the same and application thereof

Abstract

The present application relates to the field of kitchen waste treatment, and particularly relates to a degradation bacteria compound for liquefying and degrading kitchen waste and application thereof. The compound comprises six bacteria, which are Pseudogulbenkiania indica, Alcaligenes faecalis, Bacillus amyloliquefaciens, Serratia marcescens, Sphingobium yanoikmois, Bacillus subtilis. The kitchen waste is treated by the compound bacteria of the present application, which can effectively degrade the protein, starch, cellulose and oil in the kitchen waste, and the degradation rates are 35.31%, 92.64%, 72.55% and 43.90% respectively. In addition, the compound bacteria can liquefy part of the kitchen waste, effectively reduce the volume and weight, and achieve a garbage reduction rate of 99.78%. In summary, the culture conditions of the compound bacteria are easy to realize and control, the compound bacteria can effectively degrade and liquefy the kitchen waste, and the compound bacteria have great significance for efficient treatment of kitchen waste.

Description

Technical Field

[0001] This invention relates to the field of microbial technology, and in particular to a compound of degrading bacteria for liquefying and degrading kitchen waste and its application. Background Technology

[0002] Due to the rapid development of the catering industry, the amount of food waste generated has increased rapidly in recent years. Food waste is characterized by its large volume and high concentration of pollutants. If not properly treated, it will cause serious environmental pollution and affect the normal life of some organisms. Traditional methods of food waste treatment include composting, landfilling, incineration, and use as animal feed, but all of these have some drawbacks. Biological treatment methods are characterized by low cost and high efficiency, but microorganisms often cannot directly utilize the large molecules in food waste. Liquefying food waste can significantly improve the utilization rate of nutrients in wastewater by microorganisms, which is beneficial for subsequent purification and resource utilization. Therefore, developing methods that can rapidly degrade and liquefy food waste is key to the efficient treatment of food waste. Summary of the Invention

[0003] The purpose of this invention is to provide a degrading bacterium for liquefying and degrading kitchen waste, a bacterial agent containing the bacterium, and its application.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] This invention provides a compound bacteria for liquefying and degrading kitchen waste, the compound bacteria including Serratia marcescens.

[0006] Furthermore, the compound bacteria include Serratia marcescens and Sphingobacterium mizutaii.

[0007] Furthermore, the compound bacteria include *Pseudochrobactrum asaccharolyticum*, *Alcaligenes faecalis*, *Paenibacillus amylolyticus*, *Serratia marcescens*, *Sphingobacterium mizutaii*, and *Bacillus subtilis*.

[0008] The present invention also provides a microbial agent for liquefying and degrading kitchen waste, wherein the active ingredient of the microbial agent is the above-mentioned compound bacteria.

[0009] Furthermore, the bacterial agent is composed of a mixture of single-strain enrichment solutions of *Pseudomonas aeruginosa*, *Alcaligenes faecalis*, *Bacillus amyloliquefaciens*, *Serratia marcescens*, *Sphingospora hydrophila*, and *Bacillus subtilis*.

[0010] Furthermore, the biomass of *Pseudomonas aeruginosa*, *Alcaligenes faecalis*, *Bacillus amyloliquefaciens*, *Serratia marcescens*, *Sphingomyelinus hydrate*, and *Bacillus subtilis* in the bacterial agent is 1:1:1:1:1:1.

[0011] The application of the aforementioned compound bacteria or the aforementioned bacterial agents in the liquefaction and degradation of kitchen waste should also be within the scope of protection of this invention.

[0012] The present invention also provides a method for liquefying and degrading kitchen waste, wherein the above-mentioned compound bacteria or the above-mentioned bacterial agent is inoculated into the kitchen waste mixture.

[0013] Furthermore, the food waste mixture is a mixture of solid waste and tap water, wherein the mass ratio of solid waste to tap water is 3:10 to 1:1.

[0014] Furthermore, after inoculation into the mixed liquid of kitchen waste, the initial biomass of single bacteria of *Pseudomonas aeruginosa*, *Alcaligenes faecalis*, *Bacillus amyloliquefaciens*, *Serratia marcescens*, *Sphingomyelinus hydrate*, and *Bacillus subtilis* was 0.01–0.03 g / L, and the total biomass in the mixed liquid of kitchen waste was 0.06–0.18 g / L.

[0015] This invention provides a compound bacterial strain for the degradation and liquefaction of food waste and its application. The compound bacterial strain includes *Pseudochrobactrum asaccharolyticum*, *Alcaligenes faecalis*, *Paenibacillus amylolyticus*, *Serratia marcescens*, *Sphingobacterium mizutaii*, and *Bacillus subtilis*, with Latin names Pseudochrobactrum asaccharolyticum, *Alcaligenes faecalis*, *Paenibacillus amylolyticus*, *Serratia marcescens*, *Sphingobacterium mizutaii*, and *Bacillus subtilis*. Using this compound bacterial strain, proteins, starches, cellulose, and oils in food waste can be effectively degraded, reducing the weight and volume of food waste and liquefying it. This has significant implications for the subsequent resource utilization of food waste.

[0016] Preservation Instructions

[0017] Biomaterial 1

[0018] Classification and nomenclature of biological materials: Pseudochrobactrum asaccharolyticum).

[0019] The strain number of the biological material is HL-1.

[0020] Name of the institution that preserves the biological materials: China General Microbiological Culture Collection Center, China Microbiological Culture Collection Committee.

[0021] The abbreviation for the depository of biological materials is CGMCC.

[0022] Address of the depository for biological materials: No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences Research Institute, Postal Code: 100101.

[0023] Preservation date of biological material: May 23, 2023.

[0024] Biological material depository registration number: CGMCC No. 27442.

[0025] Biomaterial 2

[0026] Classification and nomenclature of biological material: Alcaligenes faecalis.

[0027] The strain number of the biomaterial is HL-2.

[0028] Name of the institution that preserves the biological materials: China General Microbiological Culture Collection Center, China Microbiological Culture Collection Committee.

[0029] The abbreviation for the depository of biological materials is CGMCC.

[0030] Address of the depository for biological materials: No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences Research Institute, Postal Code: 100101.

[0031] Preservation date of biological material: May 23, 2023.

[0032] Biological materials depository registration number: CGMCC No. 27443.

[0033] Biomaterials 3

[0034] Classification and nomenclature of biological materials: Paenibacillus amylolyticus.

[0035] The strain number of the biological material is HL-4.

[0036] Name of the institution that preserves the biological materials: China General Microbiological Culture Collection Center, China Microbiological Culture Collection Committee.

[0037] The abbreviation for the depository of biological materials is CGMCC.

[0038] Address of the depository for biological materials: No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences Research Institute, Postal Code: 100101.

[0039] Preservation date of biological material: May 23, 2023.

[0040] Biological materials depository registration number: CGMCC No. 27445.

[0041] Biomaterials 4

[0042] Classification and nomenclature of biological material: Serratia marcescens.

[0043] The strain number of the biological material is HL-18.

[0044] Name of the institution that preserves the biological materials: China General Microbiological Culture Collection Center, China Microbiological Culture Collection Committee.

[0045] The abbreviation for the depository of biological materials is CGMCC.

[0046] Address of the depository for biological materials: No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences Research Institute, Postal Code: 100101.

[0047] Preservation date of biological material: May 23, 2023.

[0048] Biological materials depository registration number: CGMCC No. 27448.

[0049] Biomaterials 5

[0050] Classification and nomenclature of biological material: Sphingobacterium mizutaii.

[0051] The strain number of the biological material is HL-26.

[0052] Name of the institution that preserves the biological materials: China General Microbiological Culture Collection Center, China Microbiological Culture Collection Committee.

[0053] The abbreviation for the depository of biological materials is CGMCC.

[0054] Address of the depository for biological materials: No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences Research Institute, Postal Code: 100101.

[0055] Preservation date of biological material: May 23, 2023.

[0056] Biological materials depository registration number: CGMCC No. 27451.

[0057] Biomaterials 6

[0058] Classification and nomenclature of biological materials: Bacillus subtilis.

[0059] The strain number of the biomaterial is HL-27.

[0060] Name of the institution that preserves the biological materials: China General Microbiological Culture Collection Center, China Microbiological Culture Collection Committee.

[0061] The abbreviation for the depository of biological materials is CGMCC.

[0062] Address of the depository for biological materials: No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences Research Institute, Postal Code: 100101.

[0063] Preservation date of biological material: May 23, 2023.

[0064] Biological materials depository registration number: CGMCC No. 27452. Attached Figure Description

[0065] Figure 1 Example 2 shows the maximum degradation rate of a single bacterial strain on protein (a), cellulose (b), oil (c), and starch (d).

[0066] Figure 2The degradation rates of protein, starch, cellulose, and oil in Example 2 are given.

[0067] Figure 3 The reduction rate of the weight and volume of kitchen waste in Example 2.

[0068] Figure 4 The figure shows the reduction rate of kitchen waste height after it has been degraded by compound bacteria overnight (14 hours) in Example 3 (the horizontal axis 1-6 in the figure are the time points for comparing the height of the waste).

[0069] Figure 5 The figure shows the COD removal rate of the liquefied liquid effluent from the kitchen waste after it has been degraded by compound bacteria overnight (14 hours) in Example 3 (the horizontal axis 1-6 in the figure represents the comparison time of COD removal rate). Detailed Implementation

[0070] The present invention will now be described in further detail with reference to specific embodiments. The given embodiments are merely illustrative of the invention and not intended to limit its scope. The embodiments provided below can serve as a guide for further improvements by those skilled in the art and do not constitute a limitation on the invention in any way.

[0071] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0072] This invention provides a compound bacteria for the degradation and liquefaction of kitchen waste and its application. The compound bacteria include *Pseudochrobactrum asaccharolyticum*, *Alcaligenes faecalis*, *Paenibacillus amylolyticus*, *Serratia marcescens*, *Sphingobacterium mizutaii*, and *Bacillus subtilis*, with Latin names Pseudochrobactrum asaccharolyticum, *Alcaligenes faecalis*, *Paenibacillus amylolyticus*, *Serratia marcescens*, *Sphingobacterium mizutaii*, and *Bacillus subtilis*.

[0073] The strains described in this invention can be obtained through conventional isolation and screening methods.

[0074] The present invention also provides the application of the compound bacteria in the degradation of liquefied kitchen waste.

[0075] In this invention, the compound bacteria are inoculated into the mixed liquid of kitchen waste.

[0076] In this invention, the initial biomass of the six bacteria in the compound bacteria is the same, preferably 0.01-0.03 g / L, more preferably 0.02 g / L, and the total initial biomass is 0.06-0.18 g / L, more preferably 0.12 g / L.

[0077] In this invention, the mass ratio of solid waste to tap water in the kitchen waste mixture is preferably 3:10 to 1:1, and more preferably 3:5.

[0078] In this invention, the degradation process is carried out in a 100mL conical flask, which is placed in a constant temperature shaker, preferably at a speed of 125-135 r / min, more preferably 130 r / min.

[0079] In this invention, the degradation temperature is preferably 25-35°C, and more preferably 30°C.

[0080] In this invention, the degradation time is preferably 5 to 7 days, and more preferably 6 days.

[0081] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0082] The materials used in the embodiments are as follows:

[0083] 1. Enrichment medium: 3.0g beef extract, 10.0g peptone, 5.0g NaCl, 1000mL distilled water, pH 7.2-7.4.

[0084] 2. Food waste mixture: The food waste was taken from a university canteen. After removing large pieces of solid waste, the food waste and tap water were mixed in a ratio of 3:5 (by mass) to obtain the food waste mixture.

[0085] Example 1

[0086] The selected bacterial strains exhibiting degradation effects on proteins, starches, cellulose, and lipids were sequenced on the HiSeq 2500 platform. The 16S rRNA gene sequence of each well was then compared using BLAST at NCBI to obtain the compared bacterial species, which were then deposited using a patented procedure. Specific information is as follows.

[0087] The 16S rRNA gene sequence of bacterium HL-1 is shown in Sequence 1, and it was identified as *Pseudochrobactrum asaccharolyticum*. The bacteria are rod-shaped and dispersed. Colonies are white, small, round, moist, raised, transparent, oily, and glossy with regular edges. The bacteria are non-capsulated, non-spore-forming, and Gram-negative. *Pseudochrobactrum asaccharolyticum* HL-1 has the registration number CGMCC No. 27442 at the China General Microbiological Culture Collection Center (CGMCC). This strain was deposited at CGMCC on May 23, 2023, at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing. Hereinafter referred to as *Pseudochrobactrum asaccharolyticum* HL-1.

[0088] The 16S rRNA gene sequence of bacterium HL-2 is shown in Sequence 2, and it has been identified as *Alcaligenes faecalis*. It is a Gram-negative bacillus, approximately 0.7-1.0 μm in diameter, with peritrichous motility. When cultured for 5 days at 30°C on nitrogen-free agar plates using benzoate as the carbon source, colonies are round, smooth, raised, with regular edges, and 1-1.5 mm in diameter, producing melanin. It exhibits respiratory metabolism, is oxidase-positive, and does not utilize carbohydrates for growth.

[0089] Alcaligenes faecalis HL-2, with the registration number CGMCC No. 27443 at the China General Microbiological Culture Collection Center (CGMCC), was deposited on May 23, 2023, at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing. Hereinafter referred to as Alcaligenes faecalis HL-2.

[0090] The 16S rRNA gene sequence of bacterium HL-4 is shown in Sequence 4, and it was identified as *Bacillus amyloliquefaciens*. It is a Gram-positive bacterium with pale yellow, smooth, non-moistened colonies, irregular edges, and a semi-transparent appearance. The colony diameter is approximately 1 mm.

[0091] Paenibacillus amylolyticus HL-4, with the registration number CGMCC No. 27445, was deposited at the China General Microbiological Culture Collection Center (CGMCC) on May 23, 2023, at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing. Hereinafter referred to as Paenibacillus amylolyticus HL-4.

[0092] The 16S rRNA gene sequence of bacterium HL-18 is shown in Sequence 7, and it was identified as *Serratia marcescens*. The colonies of this strain are generally raised, opaque in the center, and irregular in edge, ranging in size from 1 to 2.5 mm, and all produce red pigment (Plate I-3). On nutrient agar plates, it can produce distinctive dendritic, left-handed colonies (Plate I-1); under special conditions, it can produce double-row colonies that gradually increase in size and are arranged in a continuous, orderly fashion (Plate I-2). The bacteria are Gram-negative short rods, measuring (1–1.3) μm × (0.7–1.0) μm, with peritrichous flagella, motile, without capsules, and without spores.

[0093] Serratia marcescens HL-18, with the China General Microbiological Culture Collection Center (CGMCC) registration number CGMCC No. 27448, was deposited at the CGMCC on May 23, 2023, at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing. Hereinafter referred to as Serratia marcescens HL-18.

[0094] The 16S rRNA gene sequence of bacterium HL-26 is shown in Sequence 10, and it was identified as *Sphingomonas hydrate*. It presents as a pale yellow, smooth, raised, single colony with neat edges; the cells are short rod-shaped, 0.2-0.7 μm wide and 1.0-2.5 μm long; it is a Gram-negative bacterium, non-motile, and does not produce spores.

[0095] Sphingobacterium mizutaii HL-26, with the China General Microbiological Culture Collection Center (CGMCC) registration number CGMCC No. 27451, was deposited at the CGMCC on May 23, 2023, at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing. Hereinafter referred to as Sphingobacterium mizutaii HL-26.

[0096] The 16S rRNA gene sequence of bacterium HL-27 is shown in Sequence 11, and it has been identified as Bacillus subtilis. Individual cells are 0.7–0.8 × 2–3 μm in size and uniformly stained. They lack capsules, have peritrichous flagella, and are motile. Gram-positive, they can form endophytic, stress-resistant spores. Spores are 0.6–0.9 × 1.0–1.5 μm in size, elliptical to columnar, located centrally or slightly off-center from the cell body; the cell body does not swell after spore formation. They grow and reproduce rapidly, and the colony surface is rough, opaque, and dirty white or slightly yellow. When grown in liquid culture media, they often form a wrinkled appearance. They are an aerobic bacterium.

[0097] Bacillus subtilis HL-27, with the registration number CGMCC No. 27452 at the China General Microbiological Culture Collection Center (CGMCC), was deposited on May 23, 2023, at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing. Hereinafter referred to as Bacillus subtilis HL-27.

[0098] Example 2

[0099] 1. Degradation effect of a single bacterial strain

[0100] The six bacterial strains from Example 1 were cultured separately in liquid culture medium. They were then inoculated into protein, starch, cellulose, and lipid selection media at an initial biomass of 0.05 g / L. The contents of cellulose, protein, starch, and lipid were measured on days 0 and 6, and the degradation rates of these substances by different bacterial strains were calculated. The results are as follows: Figure 1 As shown. Figure 1 Table 1 shows the bacterial species corresponding to different numbers on the horizontal axis.

[0101] Combination Figure 1 According to Table 1, the maximum degradation rates of protein, cellulose, oil, and starch by a single bacterial species were 35.59%, 45.50%, 94.34%, and 99.71%, respectively, corresponding to Serratia marcescens, Sphingobacterium mizutaii, Paenibacillus amylolyticus, and Paenibacillus amylolyticus, respectively.

[0102] Table 1. Strain Numbers and Names

[0103]

[0104]

[0105] 2. Degradation effect of compound microbial strains

[0106] 30g of kitchen waste and 50g of tap water were mixed in a 100mL Erlenmeyer flask to obtain the desired solution. Single-strain enrichment solutions of six bacteria—*Pseudomonas aeruginosa* HL-1, *Alcaligenes faecalis* HL-2, *Bacillus amyloliquefaciens* HL-4, *Serratia marcescens* HL-18, *Sphingomyelinus hydrate* HL-26, and *Bacillus subtilis* HL-27—were added to the kitchen waste mixture at an initial biomass of 0.02g / L. This means that 1L of kitchen waste mixture inoculated with the bacterial agent contained 0.02g each of *Pseudomonas aeruginosa*, *Alcaligenes faecalis*, *Bacillus amyloliquefaciens*, *Serratia marcescens*, *Sphingomyelinus hydrate*, and *Bacillus subtilis*. The Erlenmeyer flask was placed in a constant-temperature water bath shaker at 30℃ and 130 rpm for 6 days.

[0107] Samples were taken on day 0 (before the reaction began) and day 6 to determine the protein, starch, cellulose, and fat content, respectively. The results are as follows: Figure 2 As shown, from Figure 2 It can be seen that the compound bacteria can effectively remove protein, starch, cellulose and oil from the mixed liquid of kitchen waste, with removal rates of 35.31%, 92.64%, 72.55% and 43.90±3.55%, respectively.

[0108] On day 0 (before the reaction started) and day 6, samples were taken and the weight and volume of solid waste 2 in the mixed liquid of food waste 2 were measured. The results are as follows. Figure 3 As shown, from Figure 3 It can be seen that the compound bacteria can effectively liquefy kitchen waste, effectively reduce volume and weight, with weight reduction rate and volume reduction rate of 54.95% and 63.99% before and after liquefaction, respectively.

[0109] Example 3

[0110] This invention addresses the problem of the difficulty in degrading food waste by providing a pilot-scale process and method for applying a compound microbial agent (composed of six microbial agents described in Example 2) to the degradation of food waste. The compound microbial agent was applied to an aerobic fermentation equipment for the biochemical treatment of food waste, treating food waste from the staff canteen of a municipal company in Beijing. This system achieved significant degradation of the food waste. The operating parameters of the equipment were adjusted to maximize the effect of the compound microbial agent. The equipment could process 469.18 kg of food waste over 7 days. After entering the equipment, the waste underwent degradation by the compound microbial agent (each liter of the mixed liquid was inoculated with 0.02 g each of *Pseudomonas aeruginosa*, *Alcaligenes faecalis*, *Bacillus amyloliquefaciens*, *Serratia marcescens*, *Sphingomyelinus*, and *Bacillus subtilis*), achieving a waste reduction rate of 99.78%. The formula for calculating the reduction rate of food waste is as follows: Food waste reduction rate = 1 - (1.05 / 469.18) = 99.78% (Note: parameter 1.05 is the mass of undegraded cellulose in the waste treatment equipment after 7 days).

[0111] The compound bacteria of this invention were applied in a pilot-scale process for one week. The specific operating steps are as follows:

[0112] (1) First, the compound bacterial solution is cultured in the laboratory stage and then applied to the pilot-scale process equipment;

[0113] (2) Add the compound bacterial solution to the waste treatment equipment, add bacterial attachment materials, and adjust and optimize the equipment parameters (e.g., spraying time, etc.);

[0114] (3) Measure the amount of garbage fed each time, observe the change in the height of kitchen waste in the equipment, collect the effluent before and after garbage feeding and test the effluent quality.

[0115] The results are as follows Figure 4 and Figure 5 As shown, after one night of degradation (14 hours), the height of the waste was significantly reduced, with a maximum reduction rate of 21.40%. The waste height exhibited a stable fluctuation trend within the same day, achieving effective reduction of kitchen waste. Simultaneously, the COD removal rate of the effluent liquefied from the compound bacteria of this invention after degrading kitchen waste reached a maximum of 93.26%. Optimization of the waste treatment equipment parameters significantly improved the performance of the compound bacterial solution, reflected in the viscosity change of the liquefied waste, and consequently, its degradation performance.

[0116] In conclusion, the compound bacteria can effectively degrade liquefied kitchen waste.

[0117] As shown in the above embodiments, the present invention provides a compound bacteria for degrading liquefied kitchen waste and its application. The compound bacteria include six bacteria: *Pseudochrobactrum asaccharolyticum*, *Alcaligenes faecalis*, *Paenibacillus amylolyticus*, *Serratia marcescens*, *Sphingobacterium mizutaii*, and *Bacillus subtilis*. Using the compound bacteria of the present invention to treat kitchen waste can effectively degrade proteins, starches, cellulose, and oils in the kitchen waste, with degradation rates of 35.31%, 92.64%, 72.55%, and 43.90%, respectively. Furthermore, it can also liquefy a portion of the kitchen waste, effectively reducing volume and weight, with weight reduction and volume reduction rates of 54.95% and 63.99% before and after liquefaction, respectively. In practical pilot applications, the compound bacteria still achieved good and sustained degradation effects on kitchen waste, with a waste reduction rate of 99.78% within one week. The culture conditions of this compound bacteria are easy to achieve and control, and it can effectively degrade and liquefy kitchen waste, which is of great significance for the efficient treatment of kitchen waste.

[0118] The present invention has been described in detail above. For those skilled in the art, the invention can be practiced in a wide range of ways with equivalent parameters, concentrations, and conditions without departing from its spirit and scope, and without requiring unnecessary experiments. Although specific embodiments have been given, it should be understood that further modifications can be made to the invention. In summary, according to the principles of the invention, this application is intended to include any changes, uses, or improvements to the invention, including changes made using conventional techniques known in the art that depart from the scope disclosed herein. Some of the essential features can be applied within the scope of the following appended claims.

Claims

1. A compound microbial agent for the liquefaction and degradation of kitchen waste, characterized in that, The compound bacteria consist of *Pseudomonas aeruginosa* in an equibioscale ratio (…). Pseudochrobactrum asaccharolyticum ), Alcaligenes faecalis ( Alcaligenes faecalis ), Amylolytic Bacillus ( Paenibacillus amylolyticus Serratia marcescens ( ), Serratia marcescens ), Sphingomyelin bacillus ( Sphingobacterium mizutaii ) and Bacillus subtilis ( Bacillus subtilis )composition; Among them, Pseudochrobactrum asaccharolyticum is HL-1, and its registration number at the China General Microbiological Culture Collection Center is CGMCC No. 27442; Alcaligenes faecalis is HL-2, and its registration number at the China General Microbiological Culture Collection Center is CGMCC No. 27443. The amylolytic bacillus is HL-4, and its registration number at the China General Microbiological Culture Collection Center is CGMCC No. 27445. Serratia marcescens is HL-18, and its registration number at the China General Microbiological Culture Collection Center is CGMCC No. 27448. Sphingobacterium mizutaii is HL-26, and its registration number at the China General Microbiological Culture Collection Center is CGMCC No. 27451. Bacillus subtilis is HL-27, and its registration number at the China General Microbiological Culture Collection Center is CGMCC No. 27452.

2. A microbial agent for the liquefaction and degradation of kitchen waste, characterized in that, The active ingredient of the bacterial agent is the compound bacteria described in claim 1.

3. The microbial agent according to claim 2, characterized in that, The bacterial agent is a mixture of single-strain enrichment solutions of *Pseudomonas aeruginosa*, *Alcaligenes faecalis*, *Bacillus amyloliquefaciens*, *Serratia marcescens*, *Sphingospora hydrophila*, and *Bacillus subtilis*.

4. The application of the compound bacteria as described in claim 1 or the bacterial agent as described in any one of claims 2-3 in the liquefaction and degradation of kitchen waste.

5. A method for liquefying and degrading kitchen waste, characterized in that, The compound bacteria as described in claim 1 or the bacterial agent as described in any one of claims 2-3 are inoculated into the mixed liquid of kitchen waste.

6. The method according to claim 5, characterized in that, The kitchen waste mixture is a mixture of solid waste and tap water, wherein the mass ratio of solid waste to tap water is 3:10 to 1:

1.

7. The method according to claim 6, characterized in that, After inoculation into the mixed liquid of kitchen waste, the initial biomass of single bacteria of *Pseudomonas aeruginosa*, *Alcaligenes faecalis*, *Bacillus amyloliquefaciens*, *Serratia marcescens*, *Sphingomyelinus hydrate*, and *Bacillus subtilis* was 0.01–0.03 g / L, and the total biomass in the mixed liquid of kitchen waste was 0.06–0.18 g / L.

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