Composting method for synchronously reducing antibiotics and malodorous gas

Abstract

The invention discloses a composting method for synchronously reducing antibiotics and malodorous gas, and relates to the technical field of solid waste treatment. The composting method comprises the following steps: (1) mixing solid waste materials; (2) adding a cladosporium camphora agent into the material, and carrying out conventional aerobic composting; the method provided by the invention not only can reduce the residual quantity of various antibiotics in the compost, but also can reduce the emission of odor such as ammonia gas and hydrogen sulfide in the composting process, is simple in composting process and low in cost, can realize synergistic reduction of toxic and harmful substances such as antibiotics and odor in the compost, is beneficial to environmental protection and improvement of compost product quality, and is suitable for industrial production. The method has a good application prospect in the field of solid waste treatment.

Description

Technical Field

[0001] The invention belongs to the technical field of solid waste treatment, and in particular relates to a composting method for simultaneously reducing antibiotics and malodorous gases. Background Art

[0002] Aerobic composting is one of the main measures for treating and utilizing solid waste, and it has the advantages of low cost and wide application range. However, the traditional solid waste composting method has the disadvantage of serious pollution during the composting process, which is mainly reflected in the high residual amount of organic pollutants such as antibiotics and the large emission of malodorous gases such as ammonia and hydrogen sulfide, which not only pollute the ecological environment, but also may have adverse effects on humans and animals. Disadvantages such as incomplete harmlessness and serious odor pollution restrict the promotion and application of aerobic composting technology. Adding microbial agents is an important treatment method to promote the degradation of antibiotics and the reduction of malodorous gas emissions in composting.

[0003] At present, the method to reduce antibiotic residues in compost is mainly to directly degrade antibiotics in compost by adding antibiotic degrading bacteria. For example, patent 202311652078.7 discloses a strain of Bacillus thuringiensis for degrading sulfonamide antibiotics and its application, which has a strong degradation ability for sulfonamide antibiotics in livestock and poultry manure or its compost, and the maximum degradation rate can reach 96% after 7 days of treatment; however, the antibiotic degrading bacteria added by this method only have a degradation effect on specific types of antibiotics, but have no degradation effect on other types of antibiotics in compost, so the effect is relatively limited. The existing method of reducing the emission of malodorous gases from compost is mainly to add extremely thermophilic bacterial agents (optimum growth temperature>65°C) to decompose organic matter to produce heat, increase the compost temperature, and use high temperature to inhibit the ammoniation reaction of compost to reduce ammonia production. For example, patent 2023111850422 discloses a method for simultaneously reducing nitrogen loss and odor emissions in kitchen waste composting, using extreme thermophilic bacteria with thermophilic Bacillus as the core to metabolize and produce heat for ultra-high temperature composting, so that the compost temperature is raised to above 80°C, accelerating the composting process while inhibiting the ammoniation process, reducing ammonia emission and nitrogen loss. The shortcomings of this method are that the screening and culture conditions of extreme thermophilic bacteria are strict, the cost of strain expansion is high, and it is difficult to colonize in compost. The composting temperature can only reach above 80°C when the pile scale is above ton level, and ventilation and oxygen supply are required during the composting process to maintain the high temperature of the compost, which increases the equipment investment cost and energy consumption.

[0004] In summary, although there are methods to reduce antibiotic residues and malodorous gas emissions in compost, there are disadvantages such as complex preparation process, strict use conditions and single effect of microbial agents. Composite microbial agents are usually composed of a variety of different microbial strains, and the compounding process is cumbersome. It is difficult to keep the composition and proportion of the agents stable during the composting process, and the existing methods only have a reduction effect on specific types of antibiotics or malodorous gases. Therefore, it is urgent to develop an efficient and simple method that can simultaneously remove multiple antibiotics in compost and reduce malodorous gas emissions.

[0005] Malbranchea cinnamomea is a heat-resistant filamentous fungus with an optimal growth temperature of 45°C. According to existing reports, the main application of this strain is to produce hemicellulase and cellulase to degrade lignocellulose. For example, the document "Optimization of fermentation conditions for solid fermentation of xylanase by Malbranchea cinnamomea" (Yan Ye, et al. Microbiology Bulletin. 2013, 40(8):1339-1346) discloses a method for producing xylanase by solid fermentation of agricultural waste using Malbranchea cinnamomea; the document "Improving the fermentable sugar yields of wheat straw by high-temperature pre-hydrolysis with thermophilic enzymes of Malbranchea cinnamomea" (Ning Zhu, et al. Microbial Cell Factories.2020,19:149) discloses a method for hydrolyzing wheat straw to produce glucose and xylose using xylanase from C. camphorata and commercial cellulase. At present, the application of C. camphorata in composting to degrade antibiotics and inhibit malodorous gases has not been reported. Summary of the invention

[0006] In view of the pollution problems of antibiotics and malodorous gases in the composting process of solid waste, the present invention provides a composting method based on Cladosporium camphora for simultaneously reducing antibiotics and malodorous gases.

[0007] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is as follows:

[0008] First, the present application provides a composting method for simultaneously reducing antibiotics and malodorous gases, comprising the following steps:

[0009] (1) Mixing materials: mixing the compost raw materials and auxiliary materials evenly to obtain compost materials;

[0010] The above-mentioned composting raw materials include at least one of livestock and poultry manure, sludge, and kitchen waste; the auxiliary materials include at least one of crop straw (such as wheat straw, rice straw, corn straw, soybean straw), garden waste, and edible fungus residue.

[0011] Furthermore, the mass ratio of the above raw materials to auxiliary materials is controlled at 3:1 to 6:1.

[0012] Furthermore, the length of the above composting auxiliary material is less than 5 cm.

[0013] Furthermore, the moisture content of the mixed material is adjusted to 50-65%.

[0014] (2) Adding bacterial agents: Adding Malbranchea cinnamomea to the compost material and mixing them evenly; performing conventional aerobic composting and ending the composting after the compost temperature returns to room temperature, thereby achieving the simultaneous reduction of antibiotics and malodorous gases during composting.

[0015] The addition amount of the above-mentioned camphor velvet mulberry agent is 1-3% (v / w, mL / g) of the dry weight of the compost material, and the bacterial content in the camphor velvet mulberry agent is not less than 1×10 8 CFU / mL.

[0016] Furthermore, the preparation method of the above-mentioned camphor velvet fungus agent is as follows: inoculate camphor velvet fungus into PDA solid culture medium and culture it at 45°C for 3 days; after the mycelium has grown all over the plate, scrape the spores on the surface of the culture and add 1×10 8 ~1×10 9 The inoculum was added to the PDB liquid culture medium at an inoculum amount of 1000 g / mL, and cultured at 45°C and 150 rpm for 1 to 2 days to obtain the seed solution; the seed solution was inoculated into the inorganic salt culture medium at an inoculum amount of 2 to 5% (v / v), and cultured at 45°C and 150 rpm for 3 to 5 days to obtain the liquid inoculum of C. cinnamomi, with a bacterial count of not less than 1×10 8 CFU / mL.

[0017] The above-mentioned aerobic composting is a conventional composting method in the art, such as windrow composting, trough composting, silo composting, and film composting. The addition of C. camphorata did not increase the composting temperature.

[0018] Furthermore, the above-mentioned antibiotics include at least one of tetracycline, sulfonamide, and fluoroquinolone antibiotics; and the above-mentioned malodorous gas includes at least one of ammonia and hydrogen sulfide.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) The present application first discovered that C. camphorata has a degradation effect on multiple types of antibiotics and can quickly degrade the main antibiotics in compost; and C. camphorata has an antagonistic effect on odor-producing bacteria such as Bacillus, which can reduce the content of odor-producing bacteria and the abundance of urease and sulfate reductase genes in compost, reduce the ammoniation activity and sulfate reduction activity of compost, and reduce the production of ammonia and hydrogen sulfide, thereby achieving a simultaneous reduction of antibiotics and odor in compost.

[0021] In addition, C. camphorata is a saprophytic fungus with strong environmental adaptability, a wide range of substrates, and the ability to tolerate higher antibiotic concentrations and temperatures. It can colonize well in compost and thus play a role in degrading antibiotics and deodorizing.

[0022] (2) The method of the present application is simple, easy to operate, and low in cost. The addition of a single bacterial agent can achieve significant reductions in major antibiotics and malodorous gases in compost. In the examples, the residual amounts of tetracyclines, sulfonamides, and quinolone antibiotics are 64-82%, 55-69%, and 66-91% lower than those in conventional composting, respectively, and the cumulative emissions of ammonia and hydrogen sulfide are 48% and 34% lower than those in conventional composting, respectively. The composting method can achieve safe disposal of solid waste and has good application prospects and environmental benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A photograph of the colonies of Cladosporium camphorata on PDA culture medium in Example 1 of the present invention.

[0024] Figure 2 Comparative results of the degradation effects of different microorganisms on antibiotics in Example 1 of the present invention.

[0025] Figure 3 Comparative results of the removal effects of different microorganisms on ammonia and hydrogen sulfide in simulated composting in Example 2 of the present invention.

[0026] Figure 4 Schematic diagram of temperature change of compost with different bacterial agents added in Example 3 of the present invention. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0028] The strain sources and culture media involved in the following examples are:

[0029] Malbranchea cinnamomea is an existing strain. The strain used in the embodiment is the strain disclosed in the document "Improving the fermentable sugar yields of wheat straw by high-temperature pre-hydrolysis with thermophilic enzymes of Malbranchea cinnamomea" (Zhu et al., Microbial Cell Factories, 2020, 19: 149), which is preserved and provided by Jiangsu Academy of Agricultural Sciences.

[0030] Thermus thermophilus is a conventional strain. The strain used in the example is the strain disclosed in the document "Degradation of fluoroquinolone antibiotics by Thermus thermophilus" (Pan Lanjia et al., Journal of Environmental Engineering, 2020, 14(4): 1092-1102), which is preserved and provided by Jiangsu Academy of Agricultural Sciences.

[0031] Thermodenitrificans Geobacillus thermodenitrificans is a conventional strain. The strain used in the examples is the strain disclosed in the document “Study on Factors Affecting the Production of α-galactosidase by Thermodenitrificans Bacillus” (Wei Yangdao et al., China Brewing, 2015, 34(11): 113-118), which is provided by Jiangsu Academy of Agricultural Sciences.

[0032] Geobacillus stearothermophilus is a conventional strain. The strain used in the example is the strain disclosed in the document "Study on the Effect of NaCl on the Heat Resistance of Bacillus stearothermophilus" (Zhao Yue et al., Modern Food Science and Technology, 2017, 33(4): 229-235), which is preserved and provided by Jiangsu Academy of Agricultural Sciences.

[0033] Bacillus subtilis is a conventional strain. The strain used in the embodiment is the strain disclosed in the document "Study on inoculation of thermophilic Bacillus to promote compost maturity" (Xu Yan et al., Soil Bulletin, 2020, 51(5): 1134-1141), which is preserved and provided by Jiangsu Academy of Agricultural Sciences.

[0034] The culture medium involved in the following examples:

[0035] PDA solid medium: 200 g / L potato, 20 g / L glucose, 15 g / L agar, natural pH. PDB liquid medium: 200 g / L potato, 20 g / L glucose, natural pH.

[0036] LB liquid medium: tryptone 10g / L, yeast extract 5g / L, NaCl 10g / L, pH 7.2-7.4. LB solid medium: add agar with a final concentration of 10g / L and gellan gum with a final concentration of 10g / L to LB liquid medium.

[0037] Inorganic salt culture medium: KH2PO4 1.0 g / L, MgSO4·7H2O 0.5 g / L, CaCl2·2H2O 0.5 g / L, FeSO4·7H2O 0.013 g / L, NaCl 2.5 g / L, (NH4)2SO4 1.0 g / L, pH 6.0.

[0038] The above culture media were all steam sterilized at 121°C for 15 min and used after cooling.

[0039] Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0040] Example 1 Degradation effect of Cladosporium camphorata on different antibiotics

[0041] In this example, tetracycline, sulfadiazine and norfloxacin were used as target antibiotics, respectively, and the degradation performance of C. camphora on tetracycline, sulfonamide and fluoroquinolone antibiotics was detected and compared with that of thermophilic bacteria.

[0042] C. camphorata was inoculated into PDA solid culture medium and cultured at 45°C for 3 days. The culture dish photo is shown in Figure 1 Scrape the spores from the culture surface and add them to sterile water. Shake thoroughly to make a spore suspension. 8 The spore suspension was inoculated into PDB liquid culture medium containing 100 mg / L target antibiotic and cultured at 45°C and 150 rpm in the dark for 3 days; the supernatant was collected by centrifugation every 24 hours, and the residual antibiotic concentration in the supernatant was determined by HPLC.

[0043] Single colonies of Thermus thermophilus, Geobacillus thermodenitrificans, Geobacillus stearothermophilus, and Bacillus subtilis were selected and inoculated into 5 mL LB liquid medium, respectively, and cultured at 70°C and 150 rpm overnight to prepare seed solution; 1×10 8The seed liquid was inoculated into LB liquid containing 100 mg / L of the target antibiotic at a final concentration of CFU / mL, and cultured in the dark at 70°C and 150 rpm with shaking for 3 days; the supernatant was collected by centrifugation every 24 hours, and the residual antibiotic concentration in the supernatant was determined by HPLC. The HPLC detection method is a conventional method in the art, such as the method disclosed in the document "Simultaneous determination of 25 antibiotics in water, soil and feces by ultra-high performance liquid chromatography / tandem mass spectrometry" (Guo Xinyan et al., Analytical Chemistry. 2015, 43(1): 13-20).

[0044] Test results such as Figure 2 As shown, Figure 2 In the data, AC are the residual rates of tetracycline, sulfadiazine and norfloxacin in each treatment group. It can be seen that during the culture process, the residual rates of tetracycline, sulfadiazine and norfloxacin in the group treated with C. camphora were continuously reduced. On the third day, the residual rates of tetracycline, sulfadiazine and norfloxacin in the group treated with C. camphora were 36%, 30% and 33%, respectively, which were significantly lower than the residual rates of antibiotics in the groups treated with other strains (55-69%, 51-68%, 58-64%). This shows that C. camphora has a good degradation effect on tetracyclines, sulfonamides and fluoroquinolones.

[0045] Example 2 Deodorizing effect of Cladosporium camphorense on simulated compost

[0046] The cinnamomum cyperus was inoculated into PDB liquid culture medium and cultured at 45℃ and 150rpm for 3-5 days. Single colonies of Thermus thermophilus, Geobacillus thermodenitrificans, Geobacillus stearothermophilus and Bacillus subtilis were picked and inoculated into LB liquid culture medium respectively and cultured at 70℃ and 150rpm for 1-3 days. The cinnamomum cyperus and thermophilic bacteria were collected by centrifugation at 8000rpm for 10min, and the cells were resuspended with sterile water and the concentration of the bacterial solution was adjusted to 1×10 8 CFU / mL; each bacterial solution was added at a 5% addition amount (v / v) to a small tank simulated compost (material weight 1 kg, pig manure: wheat straw = 3:1, adjusted to 60%), and the compost added with an equal amount of sterile water was used as a control.

[0047] The composting temperature was controlled by an incubator in a simulated composting manner. The specific temperature changes were as follows: at the beginning of composting, the incubator temperature was 25°C; the temperature was linearly increased to 60°C within 3 days and maintained for 2 days; the temperature was increased to 70°C within 1 day and maintained for 5 days; the temperature was reduced to 60°C within 2 days and maintained for 3 days; the temperature was reduced to 50°C within 2 days; the temperature was reduced to 40°C within 2 days and maintained for 2 days; the temperature was reduced to 30°C within 2 days and maintained for 1 day; the temperature was reduced to 25°C within 1 day, and the composting was completed. The whole process lasted for 25 days. A portable gas detector (WOST, Shenzhen WOST Technology Co., Ltd.) was used to measure the concentrations of ammonia and hydrogen sulfide in the tank every day.

[0048] Test results such as Figure 3 As shown, Figure 3 In the figure, A and B are the average emissions of ammonia and hydrogen sulfide, respectively. It can be seen that C. camphora has a significant reduction effect on the emission of ammonia and hydrogen sulfide, and the average emissions of ammonia and hydrogen sulfide are 66% and 87% lower than the control, respectively, while the average ammonia emissions of Bacillus subtilis, Thermus thermophilus, Geobacillus thermodenitrificans, and Geobacillus stearothermophilus are reduced by 16-51%, and the average hydrogen sulfide emissions are reduced by 42-64%. The results show that C. camphora has a better deodorization effect on ammonia and hydrogen sulfide than other test strains.

[0049] Example 3 Experiment on the reduction effect of C. camphorata on antibiotics and malodorous gases in compost

[0050] This embodiment provides a composting method for simultaneously reducing antibiotics and malodorous gases, which specifically includes the following steps:

[0051] (1) Mixing material: chicken manure and wheat straw are mixed evenly in a mass ratio of 4:1, and the moisture content is adjusted to 60%. The wheat straw is pre-crushed to less than 3 cm;

[0052] (2) Adding microbial agents: Add the fungus Cladosporium camphorata to the compost material, with a bacterial content of 5×10 8 CFU / mL, the addition amount is 1% (v / w, mL / g) of the dry weight of the mixed material, and it is mixed evenly with the material;

[0053] (3) Aerobic composting: Aerobic composting is carried out in a 60L reactor, and 20kg of mixed materials are placed in each reactor. Depending on the temperature of the pile, the pile is turned every 3 to 5 days during the warming period and high temperature period, and every 7 to 10 days during the cooling period and mature period to ensure aerobic fermentation. The composting time is 35 days in total. HPLC was used to detect the antibiotic content in the compost solid sample; gas chromatography was used to detect the emissions of ammonia and hydrogen sulfide during the composting process, and the cumulative emissions of ammonia and hydrogen sulfide during the composting period were calculated. The gas chromatography detection method was a conventional method in the art, such as the method disclosed in the document "Effects of thermophilic bacteria inoculation on maturity, gaseous emission and bacterial community succession in hyperthermophilic composting" (Jing Zhang et al. Science of the Total Environment, 2024, 927: 172304); 16S high-throughput sequencing technology was used to detect the content of odor-producing bacteria in the compost of each treatment group, and quantitative PCR technology was used to detect the relative abundance of odor-related genes in the compost of each treatment group.

[0054] In this embodiment, in addition to the above-mentioned composting treatment group (F) with the addition of C. camphorata, a composting treatment group (B) with the addition of an extreme thermophilic bacterial agent was set up at the same time. The extreme thermophilic bacterial agent was composed of Bacillus subtilis, Thermus thermophilus, Geobacillus thermodenitrificans, and Geobacillus stearothermophilus mixed in equal volumes, and the addition amount was 1% (v / w, mL / g) of the dry weight of the mixed material. Conventional compost without any bacterial agent was used as a control group (CK).

[0055] In this embodiment, the preparation steps of the extreme thermophilic bacterial agent are as follows:

[0056] Each thermophilic bacterium was streaked onto an LB solid plate and cultured at 70°C for 48 h; a single colony was picked and inoculated into 10 mL of LB liquid culture medium, and cultured overnight at 70°C with shaking at 160 rpm to prepare a seed solution; fresh seed solution was taken at 5% inoculum (v / v) and inoculated into 200 mL of LB liquid culture medium, and cultured at 70°C with shaking at 160 rpm for 24 h; the bacteria were then collected by centrifugation at 8000 rpm, and the bacterial solution was resuspended in an inorganic salt culture medium to adjust the bacterial count to 5×10 8 CFU / mL, and then the thermophilic bacterial solutions were mixed evenly according to equal volumes to obtain the extremely thermophilic bacterial agent.

[0057] In this embodiment, the temperature change curves of the compost with different bacterial agents added are as follows: Figure 4As shown in the figure, during the high temperature period and the cooling and mature period of composting, the temperature of the composting group (B) with the addition of extreme thermophilic bacteria was significantly higher than that of the control group (CK) and the composting group (F) with the addition of C. camphorata. The highest temperature of the composting group with extreme thermophilic bacteria reached 75°C. There was no significant difference in temperature between the control group and the C. camphorata composting group, with the highest temperature being around 70°C, indicating that the addition of C. camphorata had no significant effect on the composting temperature.

[0058] Table 1 Removal effect of tetracycline antibiotics in different composting treatments

[0059]

[0060] The initial contents of tetracycline, chlortetracycline and oxytetracycline in the compost raw materials were 29.1, 70.6 and 38.2 μg / kg, respectively. As shown in Table 1, at the end of composting, the contents of the three tetracycline antibiotics in the composting treatment group of the present invention and the thermophilic bacteria were lower than those in the control group. The residual amounts of tetracycline, chlortetracycline and oxytetracycline in the composting treatment group of the present invention were 64%, 77% and 82% lower than those in the control group, respectively, while the residual amounts of tetracycline, chlortetracycline and oxytetracycline in the composting treatment group of the thermophilic bacteria were 8%, 38% and 34% lower than those in the control group, respectively. The degradation rates of tetracycline in the composting of the control group, thermophilic bacteria and camphor velvet were 83%, 84% and 94%, respectively, the degradation rates of chlortetracycline were 56%, 73% and 90%, respectively, and the degradation rates of oxytetracycline were 85%, 90% and 97%, respectively.

[0061] Table 2 Comparison of sulfonamide antibiotics content in different composting treatments

[0062]

[0063] The initial contents of sulfadiazine, sulfamethazine, sulfamethoxazole and sulfathiazole in the compost raw materials were 13.5, 21.6, 169.5 and 408.1 μg / kg, respectively. As shown in Table 2, at the end of composting, the residual amounts of sulfadiazine, sulfamethazine, sulfamethoxazole and sulfathiazole in the method of the present invention were 87%, 91%, 91% and 66% lower than those in the control group, respectively, while the residual amounts of sulfadiazine, sulfamethazine, sulfamethoxazole and sulfathiazole in the thermophilic bacteria composting treatment group were 50%, 67%, 34% and 38% lower than those in the control group, respectively. The degradation rates of sulfadiazine in the control group, thermophilic bacteria and C. cinnamomea composts were 76%, 88% and 97%, respectively; the degradation rates of sulfamethoxazole were 48%, 83% and 95%, respectively; the degradation rates of sulfamethoxazole were 85%, 90% and 99%, respectively; and the degradation rates of sulfathiazole were 91%, 95% and 97%, respectively.

[0064] Table 3 Removal effect of fluoroquinolone antibiotics in different composting treatments

[0065]

[0066] The initial enrofloxacin, ciprofloxacin, ofloxacin and norfloxacin contents of the compost raw materials were 11.3, 242.4, 63.8 and 87.5 μg / kg, respectively. As shown in Table 3, at the end of composting, the residual amounts of enrofloxacin, ciprofloxacin, ofloxacin and norfloxacin in the method of the present invention were 55%, 62%, 69% and 57% lower than those in the control group, respectively, while the residual amounts of enrofloxacin, ciprofloxacin, ofloxacin and norfloxacin in the thermophilic bacteria composting treatment group were 27%, 13%, 24% and 6% lower than those in the control group, respectively. The degradation rates of enrofloxacin in the control group, thermophilic bacteria and camphor velvet were 93%, 95% and 97%, respectively, the degradation rates of ciprofloxacin were 82%, 84% and 93%, respectively, the degradation rates of ofloxacin were 43%, 57% and 82%, respectively, and the degradation rates of norfloxacin were 80%, 81% and 91%, respectively. The above results show that the removal effect of the method of the present invention on tetracyclines, sulfonamides and fluoroquinolone antibiotics is better than that of the thermophilic bacteria agent treatment group and conventional composting.

[0067] Table 4 Cumulative emissions of malodorous gases from different composting treatments

[0068]

[0069] As can be seen from Table 4, both the method of the present invention and the thermophilic bacteria composting treatment group can reduce the odor emission during the composting process, and the effect of the method of the present invention is more significant. The cumulative emission of ammonia in the composting of the method of the present invention is 48% and 36% lower than that of the control group and the thermophilic bacteria composting treatment group, respectively, and the cumulative emission of hydrogen sulfide is 34% and 12% lower than that of the control group and the thermophilic bacteria composting treatment group, respectively, which shows that the method of the present invention can effectively reduce the emission of ammonia and hydrogen sulfide during the composting process.

[0070] Table 5 Ammonia producing bacteria content in different composting treatments

[0071]

[0072] Table 6 Content of hydrogen sulfide producing bacteria in different composting treatments

[0073]

[0074] Table 7 Abundance of genes related to odor production in different composting treatments (10 -3 Copy number / 16S rRNA copy number)

[0075]

[0076] As shown in Tables 5, 6 and 7, compared with the control group (CK) and the thermophilic bacterial agent composting group (B), the camphor velvet worm composting group (F) can significantly reduce the content of ammonia-producing bacteria such as Bacillus, Sinibacillus, and Ammoniibacillus, as well as the content of hydrogen sulfide-producing bacteria such as Lactobacillus and Limosilactobacillus, and reduce the relative abundance of urease gene (ureC) and sulfate reduction gene (dsrB). The above results show that the addition of camphor velvet worm can reduce the emission of ammonia and hydrogen sulfide during composting by inhibiting bacteria and functional genes related to the production of ammonia and hydrogen sulfide.

[0077] Although the above embodiments have been described in detail with general explanations and specific implementations of the present invention, it is obvious to those skilled in the art that some modifications or improvements can be made thereto based on the present invention. Therefore, these modifications or improvements made on the basis of not departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A composting method for simultaneously reducing antibiotics and malodorous gases, characterized in that: The specific steps are as follows: 1) Mix the compost raw materials and auxiliary materials evenly to obtain compost materials; The composting raw material includes at least one of livestock and poultry excrement, sludge, and kitchen waste; the auxiliary material includes at least one of crop straw, garden waste, and edible fungus residue; 2) Add the fungus of Cinnamomum camphora to the compost material and mix well; carry out conventional aerobic composting and end the composting after the compost temperature returns to room temperature, thereby achieving the simultaneous reduction of antibiotics and malodorous gases during composting.

2. The composting method for simultaneously reducing antibiotics and malodorous gases according to claim 1, characterized in that: Step 1) The mass ratio of the compost raw material to the auxiliary material is 3:1 to 6:

1.

3. The composting method for simultaneously reducing antibiotics and malodorous gases according to claim 1, characterized in that: Step 1) The auxiliary material is less than 5 cm in length.

4. The composting method for simultaneously reducing antibiotics and malodorous gases according to claim 1, characterized in that: Step 1) The moisture content of the compost material is 50-65%.

5. The composting method for simultaneously reducing antibiotics and malodorous gases according to claim 1, characterized in that: In step 2), the volume mass ratio of the added camphor velvet fungus agent to the dry weight of the compost material is 1-3%, and the unit of volume mass ratio is mL / g; the bacterial content of the camphor velvet fungus agent is not less than 1×10 8 CFU / mL.

6. The composting method for simultaneously reducing antibiotics and malodorous gases according to claim 1, characterized in that: In step 2), the camphor velvet cladodes fungal agent is prepared by the following method: inoculating camphor velvet cladodes into PDA solid culture medium and culturing at 45°C for 3 days; after the mycelium has grown all over the plate, scraping the spores on the surface of the culture and adding them to PDB liquid culture medium, culturing at 45°C and 150 rpm for 1 to 2 days to obtain seed liquid; inoculating the seed liquid into an inorganic salt culture medium at an inoculation rate of 2 to 5%, culturing at 45°C and 150 rpm until the bacterial content in the fungal agent is not less than 1×10 8 CFU / mL.

7. The composting method for simultaneously reducing antibiotics and malodorous gases according to claim 1, characterized in that: In step 2), the antibiotics include at least one of tetracycline, sulfonamide and fluoroquinolone antibiotics.

8. The composting method for simultaneously reducing antibiotics and malodorous gases according to claim 1, characterized in that: In step 2), the malodorous gas includes at least one of ammonia and hydrogen sulfide.

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