CN110066746B - High-temperature-resistant bacillus bacterium NJAU-ND8 for accelerating compost maturity and application thereof - Google Patents

Abstract

The invention provides a high-temperature-resistant bacillus bacterium NJAU-ND8 for accelerating compost maturity and application thereof. The preservation number of the bacillus bacteria NJAU-ND8 is CGMCC No.16737, and the application of the strain is to accelerate composting fermentation. The method comprises the following steps: mixing livestock and fowl feces and adjuvants according to a certain C/N, inoculating liquid strain, building into strip pile, and fermenting by turning over and throwing. Compared with the control without adding strains, the addition of the strains effectively promotes the temperature rise of the compost at the initial stage of composting, promotes the compost to enter a cooling period in advance, promotes the germination index of compost products to be improved, and promotes the C/N of the compost to be reduced to a thoroughly decomposed range in advance.

Description

A strain of thermostable Bacillus bacterium NJAU-ND8 that accelerates compost maturity and its application

technical field

The invention belongs to the field of agricultural microorganisms, and provides a strain of Bacillus sp. NJAU-ND8 for accelerating compost maturity and application thereof.

Background technique

my country's livestock and poultry breeding industry has entered a stage of large-scale and vigorous development, and large-scale intensive breeding enterprises have emerged rapidly. This ensures the people's demand for meat, eggs and other products, and also produces a large amount of breeding waste. These If the breeding waste cannot be treated effectively, it will become a potential environmental pollution. However, in the "weight loss and drug reduction" action launched by the Ministry of Agriculture, the fertilization of waste from these farms can also provide a large amount of high-quality organic fertilizers that can replace chemical fertilizers on the premise of ensuring the healthy development of the aquaculture industry. Therefore, improving the production technology of organic fertilizers and developing industrialized and commercialized refined organic fertilizers and organic-inorganic compound fertilizers have become the guarantee for effectively solving the pollution caused by breeding. However, the traditional composting methods and technologies can no longer adapt to the development of commercial organic fertilizers. At the same time, the existing modern composting technologies all need the assistance of high-efficiency composting bacteria to improve fermentation efficiency, reduce production costs, and increase the added value of composting.

In order to speed up the degradation rate of organic materials and improve the degree of humification of compost, scholars at home and abroad have conducted a series of studies on the microbial process in the composting process in recent years. Since composting is a series of complex processes dominated by microbial activities, with physical, chemical, and biological changes, and microbial activities will affect the time of composting and the quality of composting products, microbial agents are added to the composting process. Increasing the number of microorganisms and adjusting the structure of the flora is an effective method to promote the rapid decomposition of compost. However, in the entire composting industry, there are still some shortcomings such as unstable composting strains and weak promotion effect of composting effect. Therefore, it is necessary to develop more high-temperature or high-temperature-resistant strains, and use industrialized actual composting to evaluate the promotion effect of the strains. is extraordinarily important.

CN 105524858 A discloses a high-temperature-resistant decomposing bacteria agent for decomposing organic waste, Bacillus subtilis H1-7. The H1-7 bacterial agent grows well in an environment of 55°C. At 55°C, the α-amylase activity can reach 62.1U/mL, the protease activity is 673.2U/mL, and the cellulase activity is 6.75U/mL . By inoculating the high-temperature-resistant H1-7 bacterial agent in the initial stage of composting, the temperature of the compost can be rapidly increased. The high-temperature-resistant bacterial agent can maintain a good degradation effect in a high-temperature environment, has stronger environmental adaptability, and accelerated the composting process. CN 106957807A A kind of Bacillus licheniformis strain TA65 and its application in promoting compost maturity. CN 106978367A discloses a kind of urea bacillus strain TB42 and its application in promoting compost maturity. These two strains are resistant to high temperature, fast in growth and reproduction, and can produce lignocellulose degrading enzymes; their bacterial agents can increase the compost temperature, accelerate the degradation of organic matter and water-soluble organic matter (DOM), increase the content of Kjeldahl nitrogen, and promote compost maturity; It has the function of producing biosurfactant. CN 104560817B discloses a phytase-producing Bacillus licheniformis UTM102 strain and its application. The UTM102 strain can perform aerobic composting fermentation in organic solid waste such as sewage sludge, domestic garbage, animal carcasses, livestock and poultry manure, crop straw, etc., can adapt to high temperature environment, and can proliferate in large quantities in organic solid waste The heating speed is fast, the temperature is high, the decomposition is fast, and it can accelerate the degradation of organic matter, and the reduction and harmlessness are more thorough. It can convert organic solid waste into biological fertilizer. The large amount of Bacillus licheniformis contained in this fertilizer can inhibit plant Pathogenic bacteria can promote plant growth and increase crop yield.

Contents of the invention

The object of the present invention is to provide a strain of Bacillus amyloliquefaciens with accelerated compost maturity aimed at practical problems and demands in production practice.

The invention provides the application of the strain in promoting compost maturity.

In the present invention, the ability to produce various enzyme activities of the provided bacillus bacteria is measured at a high temperature of 50 DEG C for 1 day.

A high-temperature bacillus bacterium (Bacillus sp.) NJAU-ND8 with accelerated compost maturity, characterized in that the strain is preserved in the General Microbiology Center of China Microbiological Culture Collection Management Committee, and the preservation date is November 12, 2018. The deposit number is CGMCC No.16737.

The physiological characteristics of the high temperature-resistant Bacillus subtilis NJAU-ND8 are:

(1) The number of effective viable bacteria of the strain is high, and the liquid inoculum is used, and the concentration is greater than 10 ⁹ cfu/ml;

(2) High temperature resistance, able to grow at a high temperature of 55 degrees;

(3) Salt tolerance, able to produce in medium containing 15% salt;

(4) The strain NJAU-ND8 was identified as a bacterium of the genus Bacillus, harmless to crops, and non-pathogenic to humans and animals.

(5) The strain was cultured in LB liquid medium at 55°C with horizontal shaking at 170r/min for 1 day to measure the enzyme production value. The activity of exo-β-1,4-glucanase reached 1.2813U, and the activity of endo-β-1,4 - Glucanase activity reaches 1.2326U, β-glucanase activity reaches 4.4221U, neutral xylanase activity reaches 1265.4149U, filter paper enzyme activity reaches 0.012494U, neutral protease activity reaches 2.2983U, β -Amylase activity reaches 0.08242U.

Application of the high-temperature bacteria NJAU-ND8 described in the present invention in high-temperature composting to produce organic fertilizer.

The method for producing organic fertilizer using the described Bacillus bacterium NJAU-ND8 comprises: inoculating the Bacillus bacterium NJAU-ND8 according to claim 1 into the heap and mixing to obtain the organic fertilizer fermentation base material, and the fermentation process is carried out every Throwing once every 2 days, the fermentation ends after 30 days, and finally the water content of the organic fertilizer is evaporated to less than 30% under the condition that the temperature does not exceed 50°C, and the finished organic fertilizer is packaged and shipped.

The method preferably comprises the steps of:

(1) Raw material mixing: Pig manure, sawdust and mushroom slag are mixed according to the ratio of heap C/N 24:1-26:1, the initial moisture content is adjusted to 55-65%, and the liquid inoculum is used with an inoculum size of 9.5 -10.5mg/kg, after inoculation, mix the pile materials evenly, and then build them into strips. The width of the pile base material is 1.1-1.2m, the height is 1.4-1.5m, and the length is not limited;

(2) Composting fermentation: After the organic fertilizer fermentation base material is piled up in the fermentation shed in strips, it is manually turned over for fermentation. When the core temperature of the pile reaches above 40°C, turn over once every two days. After 10 days, the compost begins to cool down, and the compost temperature remains above 50°C for more than 10 days during the entire composting process;

The method of the present invention preferably controls the compost fermentation temperature in the composting process, the fermentation time, the number of times of turning over, and when the composting ends, the water content of the compost is lower than 30%, and the color is black.

Wherein, described liquid inoculum is preferably realized by following production process:

Streak the NJAU-ND8 strains stored in glycerol tubes at -80°C on LB solid medium plates for activation, and cultivate them in a 37°C incubator for 1 hour. Pick a single colony of NJAU-ND8 and place them in a 3ml liquid test tube at 37°C, shaking at 170r/min for 10 After 1 hour, the bacterial solution was used as the seed solution, and a seed solution was transferred to an LB liquid shake flask with an inoculation amount of 1% (v/v), cultivated at 37°C and 170r/min to the mid-logarithmic phase, and collected by centrifugation at 4°C , the cells were washed 3 times with distilled water, and resuspended in an equal volume of distilled water for later use.

In the method of the present invention, the C/N ratio of the preferred inoculated heap is reduced from 25 to 15-17 after 9 days of fermentation; the germination rate is ≥ 60% after 9 days of fermentation, and ≥ 90% after 30 days; the temperature of the heap After 10 days of fermentation, it enters the cooling period.

During the fermentation process, the heap naturally heats up and keeps above 50°C for 10 days. On the 10th day, the temperature of the heap body began to decrease, the germination index was greater than 60%, and the C/N was less than 17, which indicated that the heap body with added bacteria had become decomposed. It indicated that the addition of the strain significantly drove the composting and improved the composting efficiency.

According to the organic fertilizer produced by the above-mentioned method.

Beneficial effect:

The present invention mainly utilizes the Bacillus bacterium NJAU-ND8 which is separated and screened and can accelerate compost maturity to produce organic fertilizer. The strain is resistant to high temperature, fast in growth and reproduction, and has high-efficiency production of lignocellulosic enzyme activity. Compared with the control pile without bacteria, the C/N ratio of the pile inoculated with NJAU-ND8 decreased from 25 to about 16 after 9 days of fermentation; the germination rate was ≥60% after 9 days of fermentation, and ≥90% after 30 days ; The heap body temperature enters the cooling period after 10 days of fermentation. The composting efficiency after inoculation with liquid inoculum was greatly improved.

Description of drawings

Figure 1 is a phylogenetic tree based on the 16S rDNA gene sequence of strain NJAU-ND8 using the neighbor-joining method

Figure 2 is the change curve of temperature with composting time. Room temperature, blank group (CK), test group (NJAU-ND8)

Figure 3 is the change curve of pH with composting time. Blank group (CK), test group (NJAU-ND8)

Figure 4 is the change curve of C/N with composting time. Blank group (CK), test group (NJAU-ND8)

Fig. 5 is the change curve of germination index with composting time. Blank group (CK), test group (NJAU-ND8)

Biological Material Deposit Information

NJAU-ND8, classified as Bacillus sp. bacteria, is preserved in the General Microbiology Center of the China Committee for the Collection of Microbial Cultures, and the preservation address is the Institute of Microbiology, Chinese Academy of Sciences, No. 1, No. 1 Beichen West Road, Chaoyang District, Beijing , the date of deposit is November 12, 2018, and the deposit number is CGMCC No.16737.

Detailed ways

Embodiment 1, isolation and identification of functional strains

Put the samples in the high temperature phase of composting into a 250ml Erlenmeyer flask with glass beads and 100ml of sterile water, shake at 25°C and 170r/min for 20min to form a soil suspension, and absorb 10 ^-2 , 10 ^-3 , 10 ^-4 , 0.1ml of fertilizer suspension with a dilution factor of ^10-5 , spread it on a lignocellulose culture plate, repeat each concentration 3 times, after 5 days of culture at 28°C, pick and purify the colony growing on the plate for more than 5 times, and the selection is still possible The grown colonies were transferred to slant cultures and stored at 4°C for future use.

Through qualitative and quantitative screening, a bacterial strain named NJAU-ND8 was finally obtained. The colony of the bacterial strain NJAU-ND8 on the LB plate was large, pale white, and the edges were scattered. The bacteria were soft and sticky to a certain extent. provoke. The starch decomposition is positive and the tryptophan decomposition is negative, and it is cultured in LB liquid medium, and still has strong activity in the environment of 3%-15% NaCl and 25-55°C. The 16S rDNA sequence accession number (MK450453) of the NJAU-ND8 strain was used to construct a developmental tree, which showed that NJAU-ND8 had 99% homology with Bacillus amyloliquefaciens (CP000560), and it had 99% homology with Bacillus subtilis, Bacillus licheniformis, urea Bacillus and Bacillus licheniformis do not belong to the same kind of microorganisms. Based on the morphological characteristics, physical and chemical characteristics and 16S rDNA sequence analysis of the strain, the strain NJAU-ND8 was preliminarily identified as a Bacillus bacterium. It was deposited in the General Microorganism Center of China Committee for Culture Collection of Microorganisms with the preservation number CGMCC No.16737.

Table 1 Bacillus bacterium NJAU-ND8 cultivation situation (5%NaCl) under different temperatures

(++: good growth; +: can grow; —: cannot grow; the same as the following table)

Table 2 Bacillus bacteria NJAU-ND8 under different salt concentrations of culture (37 ℃)

This patent also compares the difference between the patented bacterial strain NJAU-N30 and other published strains. According to the morphology and physiological and biochemical characteristics, the patented bacterial strain is obviously different from the published strains (Table 3).

Table 3 Differences between strain NJAU-N30 and other published strains

Embodiment 2, NJAU-ND8 produces the determination of various enzyme activities

Use LB medium as NJAU-ND8 enzyme production medium: 10g peptone, 5g yeast powder, 10g NaCl, 1000ml deionized water, pH 7.0, sterilized at 121°C for 20min. Use 3ml of sterile water to make the bacterial suspension into bacterial suspension, take 0.5ml and inoculate them in the enzyme-producing medium respectively, and culture on a shaking table at 170r/min at 50°C. After 24 hours, the bacterial solution was taken, and after adding the extract solution for extraction, the cell membrane was broken to form a stock solution by using an ultrasonic breaker (300W, ultrasonic for 3s, with an interval of 7s, for 3min).

Cellulase activity was determined according to the method of Albrecht et al. (2008). The stock solution was mixed with acetate buffer (50mM, pH 5) at a ratio of 1:5 (W/V), shaken on a horizontal shaker for 1h, and then centrifuged at 10000r/min at 4°C for 10min to obtain a crude enzyme solution. The enzyme activity was measured using the dinitrosalicylic acid method (DNS), based on the amount of reducing sugar produced in the system after 1 hour of reaction at 50°C. The reaction system is 0.5ml crude enzyme solution, 0.5ml 1% carboxymethyl cellulose acetate (50mM, pH 6) solution. The absorbance of the reaction solution was measured at 520 nm. Definition of enzyme activity unit: 1U is defined as catalyzing 1 μg of glucose per minute per milliliter of sample, which is defined as an enzyme activity unit (μg/min/ml).

The determination of neutral protease activity refers to the method of Albrecht et al. (2008). The stock solution was mixed with phosphate buffer (50mM, pH 7.5) at a ratio of 1:15 (W/V), shaken on a horizontal shaker for 1 hour, and then centrifuged at 10000r/min at 4°C for 10 minutes to obtain a crude enzyme solution. The enzymatic reaction system was 0.5ml of crude enzyme solution, 0.5ml of Azoll phosphate (2.5mg/ml) buffer solution (50mM, pH7.5), incubated at 37°C for 1h, and then 0.5ml of 5% trichloroacetic acid was added to terminate the enzymatic reaction. The content of the azo dye produced by the enzymatic reaction at 520nm was determined. Definition of NP activity unit: 1U is defined as 1 nmol of tyrosine produced by hydrolysis per milliliter of sample per minute at 30°C, which is 1 enzyme activity unit (nmol/min/ml).

The enzyme activity of neutral xylanase was determined according to the method of Liu et al. (2011). The stock solution was mixed with acetic acid buffer (0.2M pH 5.5) at a ratio of 1:10 (W/V), shaken on a shaker for 1 hour, and then centrifuged at 10,000 r/min at 4°C for 10 minutes to obtain a crude enzyme solution. The enzymatic reaction is 0.2ml of crude enzyme solution, 1.8ml of 1.7% xylan solution, in a water bath at 50°C for 30min. After cooling, the amount of reducing sugar produced was measured by DNS method at 550 nm. Enzyme activity definition: 1U is defined as 50°C, pH 6.0, the amount of enzyme needed to decompose xylan per milliliter of liquid sample to produce 1nmol reducing sugar per minute is the activity unit of a neutral xylanase (nmol/min /ml).

The enzyme activity of β-glucosidase was determined according to the method of Liu et al. (2011). The stock solution was mixed with citrate buffer (0.05M, pH 6.0) and p-nitro β-D-glucoside (25mM) at a ratio of 1:4:1 (W/V/V), incubated at 37°C for 1h, and then added 1ml CaCl ₂ solution (0.5M) and 4ml Tris solution (0.2M), adjust the pH to 12.0 with NaOH, centrifuge at 10000r/min at 4°C for 10min to collect the supernatant, and measure the absorbance at 410nm. Definition of unit: 1U is defined as 1 nmol of p-nitrophenol produced per milliliter of sample per minute, which is defined as an enzyme activity unit (nmol/min/ml).

Determination of enzyme activity of filter paper: Put 50mg of Xinhua No. 1 filter paper into a colorimetric tube, add 0.5mL of 10-fold diluted stock solution, add 2.0mL of HAc-NaAc buffer solution, place in a constant temperature water bath at 50°C for 60min, add 3.0mL of DNS Solution, boiled water bath for 10min, after cooling, the volume was adjusted to 25.0mL, and the OD value was measured at 540nm. After measuring the OD value, refer to the glucose standard curve, calculate the glucose content obtained by enzymatic hydrolysis, and convert it into the corresponding enzyme activity value. Unit definition: 1U is defined as an enzyme activity unit (mg/min/ml) which is the amount of enzyme needed to decompose filter paper to produce 1 mg of glucose per milliliter of culture solution per minute at 50°C and pH 4.6.

The enzyme activity of β-amylase was determined by DNS method: reaction system 2.05mL, 1mL 0.05mol/L pH 5.6 citrate buffer, 0.5mL 1% soluble starch, 50μL stock solution, 37°C for 3min, 0.5mL stop solution DNS, boiling water Bath for 5min, cool to room temperature, add 15mL deionized water, mix well, measure OD ₅₄₀ nm absorbance value. In the control group, DNS was added first, followed by enzyme solution. Enzyme activity unit: 1U is defined as an enzyme activity unit (mg/min/ml) that catalyzes the substrate (starch) to produce 1 mg of reducing sugar per minute under the experimental conditions (37C, pH 5.6).

LB liquid medium 50℃, 170r/min horizontal shaking culture for 1d to measure the enzyme production value, the cellulase activity reached 2.514U, the β-glucosidase enzyme activity reached 4.4221U, and the neutral xylanase activity reached 1265.4149U , the filter paper enzyme activity reached 0.012494U, the neutral protease activity reached 2.2983U, and the β-amylase activity reached 0.08242U. The strain has a high enzyme-producing ability at a higher culture temperature, and it has advantages in the production of biomass solid waste composting and edible fungus culture medium compared with normal temperature bacteria.

Embodiment 3, the generation of liquid inoculum

Streak the NJAU-ND8 strains stored in glycerol tubes at -80°C on LB solid medium plates for activation, and cultivate them in a 37°C incubator for one hour. Pick a single colony of NJAU-ND8 and culture it in a 3ml liquid test tube at 37°C with shaking at 170r/min for 10 hours, and the bacterial solution is used as the seed solution. Transfer a seed liquid to an LB liquid shake flask with an inoculation amount of 1% (v/v), culture at 37°C and 170r/min until mid-logarithmic phase (OD ₆₀₀ =1.0), and collect the bacteria by centrifugation at 4°C. The body was washed 3 times with distilled water, and resuspended in an equal volume of distilled water for later use.

The preparation method of the LB culture medium used is as follows, taking the preparation of 1L medium as an example: protein building 10g, yeast powder 5g, NaCl 10g agar 20g, constant volume to 1000ml, pH natural, sterilized at 121°C for 20min.

Embodiment 4, solid fermented organic fertilizer

Pig manure, sawdust and mushroom slag are mixed according to the ratio of C/N 24:1-26:1 to form a stack (45 tons, wet weight), and the initial moisture content is adjusted to 55-65%. Two treatments were set up, the experimental group was inoculated with liquid inoculum, and the inoculation amount was 10mg/kg; , 3, 4, 5, 6, 9, 30 days sampling (in case of dumping, sampling after dumping). Use a mercury thermometer to randomly measure 3 points at the same height (50cm) in the middle of the pile at 9:00 a.m. (such as flipping, collect samples before flipping) and 3:00 p.m., and take the average temperature as the actual temperature of the pile. There are three main stages of compost temperature change, which are heating stage, high temperature stage and post-ripening cooling stage. It can be seen from Figure 1 that the temperature of the pile body reached 50°C within 6 days of NJAU-ND8 treatment, the highest temperature was 55°C, and the holding time of the pile body temperature above 50°C was 26 days. The temperature is higher than 50°C and the holding time is 14 days. Studies have shown that when the temperature of the compost is higher than 50°C and maintained for more than 7 days, the pathogens in the compost can be killed, which can ensure the harmless hygienic quality of the compost (Deportes I, 1995). Therefore, although it is speculated that the 30-day compost of the treatment and control results can all be decomposed, but the addition of bacteria significantly promotes the temperature rise of the compost during the compost heating period, and the compost enters the cooling period ahead of time (about 10 days, while the control needs 15 days), indicating that the addition of the strain significantly drove the composting and improved the composting efficiency.

After the air-dried and ground sample is filtered through a 100-mesh sieve, the potassium dichromate oxidation-water bath heating method is used to oxidize the organic matter in an acidic solution with potassium dichromate, and the excess potassium dichromate is reduced with ferrous sulfate , the amount of carbon obtained from the consumed potassium dichromate, and then multiplied by a constant to obtain the organic matter content. The content of total nitrogen in the sample was measured by the semi-micro Kelvin method. Nitrogen-containing compounds in the sample are digested and decomposed with concentrated sulfuric acid in a digestion furnace with the participation of accelerators such as copper sulfate, potassium sulfate and selenium powder, so that the nitrogen contained in it is converted into ammonia, and combined with sulfuric acid to form ammonium sulfate , and then use sodium hydroxide to basify and distill ammonia in a micro-nitrogen distiller, absorb it in boric acid, titrate it with standard acid, and calculate its content. C/N = total carbon content/total nitrogen content. The C/N ratio is an important indicator for judging whether the composting reaction has reached maturity, and it also plays an important role in the growth and metabolism of microorganisms. For compost raw materials with an initial C/N ratio of 25, when the value drops to about 16, the compost can be considered to be basically decomposed (Qiu Ruizong, 1991). The C/N of the heap after adding bacteria was less than 17 on the 9th day, and it was basically decomposed. The C/N of the control group was greater than 20 in the same period, indicating that the addition of strains significantly accelerated the process of compost maturity.

The air-dried sample was ground through a 20-mesh sieve and mixed with deionized water at a ratio of 1:10 (w/v), placed on a horizontal shaker at 2000r/min for 2h, left to stand for 30min and then filtered. Get 8ml of filtrate and add in the petri dish that is covered with filter paper, place 20 lentil seeds in each petri dish, and the blank control is deionized water. After the culture dish was placed in a constant temperature incubator at 25°C for 2 days in the dark, the number of germinated seeds and root length were measured. The germination index is an important index used to evaluate the toxicity and maturity of organic fertilizers. Calculate the germination index GI by seed germination and root length. When the GI value>50%, the compost has basically no toxicity to the plants, and the compost is basically decomposed. When the GI value>80%, the compost is completely decomposed. Therefore, at 30 days, add Bacteria treatment and control fertilizers all meet the requirements. However, it can be seen from Figure 5 that the germination index of CK and the test treatment were 45% and 60% respectively on the 9th day, and the germination index of the bacteria-added treatment was always higher than that of the control, especially in the early stage of composting. It is inferred that the bacteria-added treatment improved the maturity of compost process.

Conclusion: Bacillus bacterium NJAU-ND8 has the ability to produce various degradative enzymes related to the degradation of compost materials under high temperature conditions. After inoculation of this strain, it can drive the compost to enter the heating period quickly and enter the cooling period in advance (after 10 days), which can effectively Drive composting to improve composting efficiency.

Claims (6)

1. A high-temperature Bacillus (Bacillus sp.) NJAU-ND8 with compost maturity acceleration function is characterized in that the strain is preserved in the China general microbiological culture Collection center of the China Committee for culture Collection of microorganisms, the preservation date is 2018, 11 and 12 days, and the preservation number is CGMCC No. 16737.

2. The use of the high temperature bacterium NJAU-ND8 of claim 1 in high temperature composting for producing organic fertilizer.

3. The method for producing an organic fertilizer by using the bacillus bacterium NJAU-ND8 as described in claim 1, which comprises: inoculating the bacillus bacteria NJAU-ND8 of claim 1 into a pile, uniformly mixing to obtain an organic fertilizer fermentation base material, turning and throwing once every 2 days in the fermentation process, ending the fermentation after 30 days, finally evaporating the water content of the organic fertilizer to be below 30% under the condition that the temperature is not more than 50 ℃, and packaging and leaving the factory to obtain the finished organic fertilizer.

4. The method of claim 3, wherein the temperature, time and frequency of compost fermentation are controlled during composting to reduce the water content of the compost to less than 30% and to darken the color of the compost.

5. The method of claim 3, wherein: the C/N ratio of the pile is reduced from 25 to 15-17 after 9 days of fermentation; the germination rate is more than or equal to 60 percent after 9 days of fermentation and more than or equal to 90 percent after 30 days; the temperature of the stack body enters a temperature reduction period after fermenting for 10 days.

6. An organic fertilizer produced by the method of any one of claims 3 to 5.