Method for efficiently converting livestock and poultry manure into fermented protein feed based on biotechnology

Abstract

The invention provides a method for efficiently converting livestock and poultry manure into a fermented protein feed based on a biotechnology, and belongs to the technical field of agricultural waste resource utilization. According to the method for converting the livestock and poultry manure into the fermented protein feed, the livestock and poultry manure is fermented through the bacillus subtilis and the bacillus amyloliquefaciens, the bacillus subtilis and the bacillus amyloliquefaciens can efficiently utilize small molecular substances in the livestock and poultry manure to synthesize protein, and the protein conversion rate of the livestock and poultry manure is increased. The livestock and poultry manure subjected to fermentation treatment can be used as a fermented protein feed. Furthermore, according to the method provided by the invention, the livestock and poultry manure treatment time can be remarkably shortened, and the livestock and poultry manure treatment efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of agricultural waste resource utilization, and specifically relates to a method for efficiently converting livestock and poultry manure into fermented protein feed based on biotechnology. Background Art

[0002] Livestock and poultry manure, as waste from the aquaculture industry, is complex in composition, easily decomposes, and contains numerous harmful pathogens, posing serious risks to livestock and poultry, as well as humans. Therefore, the proper disposal of livestock and poultry manure is directly related to issues such as livestock and poultry disease prevention, food hygiene and safety, public health, and the sustainable development of the aquaculture industry.

[0003] Currently, the methods for treating livestock and poultry manure are relatively simple, and the process of treating livestock and poultry manure often takes a long time, making it difficult to quickly treat a large amount of livestock and poultry manure. At the same time, it is usually not conducive to the full utilization of the substances in livestock and poultry manure. Summary of the Invention

[0004] In view of the defects in the prior art, the purpose of the present invention is to provide a method for converting livestock and poultry manure into fermented protein feed, which can achieve rapid processing of livestock and poultry manure and use livestock and poultry manure as protein feed, which is conducive to improving the utilization efficiency of livestock and poultry manure.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] The present invention provides a method for converting livestock and poultry manure into fermented protein feed, comprising the following steps:

[0007] The moisture content and pH value of the livestock and poultry manure are adjusted and then sterilized to obtain pretreated livestock and poultry manure; the moisture content of the livestock and poultry manure is adjusted to 55% to 65%; and the pH value is adjusted to 6.0 to 7.5;

[0008] The pretreated livestock and poultry manure is mixed with a microbial agent for fermentation to obtain a fermented protein feed;

[0009] The microbial agent includes Bacillus subtilis and Bacillus amyloliquefaciens; the bacterial activity of Bacillus subtilis is 1×10 8 ~2×10 10 CFU / g; the bacterial activity of Bacillus amyloliquefaciens is 1×10 8 ~2×10 10 CFU / g; the mass ratio of Bacillus subtilis to Bacillus amyloliquefaciens is (1-3): (1-3).

[0010] Preferably, when mixing, the mass of the microbial agent accounts for 0.5% to 1.5% of the mass of livestock and poultry manure.

[0011] Preferably, the method for adjusting the moisture content of livestock and poultry manure comprises mixing the livestock and poultry manure with bran and / or straw.

[0012] Preferably, glucose is used as feed during the fermentation process, and the amount of glucose added is such that its mass concentration in the fermentation system is 1% to 3%.

[0013] Preferably, the feeding time is once every 4 to 7 hours.

[0014] Preferably, the temperature before fermentation for 24 hours is 35-39°C; and the temperature after fermentation for 24 hours is 40-44°C.

[0015] Preferably, the fermentation process is accompanied by stirring, and the stirring speed is 200-400 rpm.

[0016] Preferably, after the fermentation is completed, the fermentation product is further dehydrated, dried, sterilized and granulated.

[0017] Preferably, the sterilization method includes irradiation sterilization; the irradiation sterilization includes irradiation sterilization using cobalt 60 gamma rays.

[0018] The present invention provides application of the method described in the above technical solution in resource utilization of livestock and poultry manure.

[0019] Beneficial effects of the present invention:

[0020] The present invention provides a method for converting livestock and poultry manure into fermented protein feed, comprising the following steps: adjusting the moisture content and pH value of the livestock and poultry manure and sterilizing to obtain pretreated livestock and poultry manure; adjusting the moisture content of the livestock and poultry manure to 55% to 65%; and adjusting the pH value to 6.0 to 7.5; mixing the pretreated livestock and poultry manure with a microbial agent for fermentation to obtain a fermented protein feed; the microbial agent comprises Bacillus subtilis and Bacillus amyloliquefaciens; and the bacterial activity of the Bacillus subtilis is 1×10 8 ~2×10 10 CFU / g; the bacterial activity of Bacillus amyloliquefaciens is 1×10 8 ~2×10 10 CFU / g; the mass ratio of Bacillus subtilis and Bacillus amyloliquefaciens is (1-3): (1-3). The present invention adopts Bacillus subtilis and Bacillus amyloliquefaciens to ferment livestock and poultry manure. The Bacillus subtilis and Bacillus amyloliquefaciens can efficiently utilize small molecules in livestock and poultry manure to synthesize protein, thereby improving the protein conversion rate of livestock and poultry manure. The fermented livestock and poultry manure can be used as fermented protein feed. Furthermore, the method provided by the present invention can significantly shorten the time for livestock and poultry manure treatment and improve the treatment efficiency of livestock and poultry manure. DETAILED DESCRIPTION

[0021] The present invention provides a method for converting livestock and poultry manure into fermented protein feed, comprising the following steps:

[0022] The moisture content and pH value of the livestock and poultry manure are adjusted and then sterilized to obtain pretreated livestock and poultry manure; the moisture content of the livestock and poultry manure is adjusted to 55% to 65%; and the pH value is adjusted to 6.0 to 7.5;

[0023] The pretreated livestock and poultry manure is mixed with a microbial agent for fermentation to obtain a fermented protein feed;

[0024] The microbial agent includes Bacillus subtilis and Bacillus amyloliquefaciens; the bacterial activity of Bacillus subtilis is 1×10 8 ~2×10 10 CFU / g; the bacterial activity of Bacillus amyloliquefaciens is 1×10 8 ~2×10 10 CFU / g; the mass ratio of Bacillus subtilis to Bacillus amyloliquefaciens is (1-3): (1-3).

[0025] The present invention has no particular limitation on the source of the livestock and poultry manure, and any conventional livestock and poultry manure in the art can be used. As an optional embodiment of the present invention, the livestock and poultry manure can be fresh livestock and poultry manure.

[0026] After obtaining the livestock and poultry manure, the present invention preferably sieves the obtained livestock and poultry manure; the aperture of the sieve can be 2 mm; the sieving method can be vibration screening. The present invention mainly removes macromolecular substances such as sand and gravel from the livestock and poultry manure by sieving the livestock and poultry manure.

[0027] After obtaining the sieved livestock and poultry manure, the present invention preferably adjusts the moisture content and pH of the manure. In the present invention, the moisture content of the manure can be adjusted to 55% to 65%, or can be adjusted to 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, or 65%. As an optional embodiment of the present invention, the method for adjusting the moisture content of the manure includes mixing the manure with bran and / or straw. The present invention does not specifically limit the sources of the bran and straw; any conventional source in the art can be used. As an optional embodiment of the present invention, when using straw to adjust the moisture content of the manure, the straw can be pulverized straw. The present invention does not specifically limit the particle size of the pulverized straw; any conventional pulverized particle size in the art can be used. The present invention preferably adjusts the pH of the manure after adjusting the moisture content. The present invention does not specifically limit the method for adjusting the pH of the manure; any conventional pH adjustment method in the art can be used. As an optional embodiment of the present invention, the pH adjustment method may be the addition of calcium carbonate, ammonia water, and / or lactic acid. After adjusting the moisture content and pH of the livestock and poultry manure, the present invention preferably sterilizes the manure. The present invention does not specifically limit the sterilization method; conventional sterilization methods in the art may be employed. As an optional embodiment of the present invention, the sterilization may be high-temperature sterilization; the high-temperature sterilization temperature may be 85°C; and the high-temperature sterilization time may be 30 minutes. After sterilization, the present invention obtains pretreated livestock and poultry manure.

[0028] After obtaining the pretreated livestock and poultry manure, the present invention mixes the pretreated livestock and poultry manure with a microbial agent for fermentation to obtain a fermented protein feed. As an optional embodiment of the present invention, the microbial agent includes Bacillus subtilis and Bacillus amyloliquefaciens; the bacterial activity of the Bacillus subtilis can be 1×10 8 ~2×10 10 CFU / g, or 1×10 9 ~1×10 10 CFU / g; the bacterial activity of Bacillus amyloliquefaciens can be 1×10 8 ~2×10 10 CFU / g, or 1×10 9 ~1×10 10CFU / g; the mass ratio of Bacillus subtilis and Bacillus amyloliquefaciens is (1-3): (1-3), or it can be 1:1, 1:2, 2:1, 1:3 or 3:1. The present invention has no special restrictions on the sources of Bacillus subtilis and Bacillus amyloliquefaciens, and conventional products in the field can be used. In the embodiments of the present invention, Bacillus subtilis and Bacillus amyloliquefaciens purchased from Hubei Qiming Bioengineering Co., Ltd. are used as examples to specifically illustrate the method. The present invention has no special restrictions on the mixing method, and conventional mixing methods in the field can be used. When mixing in the present invention, the mass of the microbial agent preferably accounts for 0.5% to 1.5% of the mass of livestock and poultry manure, and can also be 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4% or 1.5%. The present invention adopts two composite bacteria, Bacillus subtilis and Bacillus amyloliquefaciens, to ferment livestock and poultry manure. The two bacteria are compounded synergistically to optimize the fermentation effect, efficiently utilize small molecules in livestock and poultry manure to synthesize protein, improve protein conversion rate, and at the same time significantly shorten the processing time and improve processing efficiency.

[0029] As a preferred embodiment of the present invention, while mixing livestock and poultry manure with microbial agents, it is preferred to add ferrous sulfate and manganese sulfate simultaneously in the fermentation system. As an optional embodiment of the present invention, the ferrous sulfate and manganese sulfate can be added in the form of a solution; the mass concentration of ferrous sulfate in the ferrous sulfate solution can be 1% to 5%, or 1%, 2%, 3%, 4% or 5%; the mass concentration of manganese sulfate in the manganese sulfate solution can be 1% to 5%, or 1%, 2%, 3%, 4% or 5%. As an optional embodiment of the present invention, the amount of ferrous sulfate added is preferably such that Fe 2+ The mass of the pre-treated livestock and poultry manure is 0.5% to 1%, which can be 0.5%, 0.6%, 0.7%, 0.8%, 0.9% or 1%. As an optional embodiment of the present invention, the amount of manganese sulfate added is preferably Mn 2+ The mass of the ferrous sulfate and manganese sulfate accounts for 0.2% to 0.5% of the mass of the pretreated livestock and poultry manure, and can be 0.2%, 0.3%, 0.4% or 0.5%. After adding ferrous sulfate and manganese sulfate, the fermentation system is preferably stirred to fully mix the materials.

[0030] The present invention combines the microbial agent, ferrous sulfate, and manganese sulfate with livestock and poultry manure, and then ferments the manure. As an optional embodiment of the present invention, the temperature for the first 24 hours of fermentation can be 35-39°C, or 35°C, 36°C, 37°C, 38°C, or 39°C; and the temperature after 24 hours of fermentation can be 40-44°C, or 40°C, 41°C, 42°C, 43°C, or 44°C. The present invention preferably incorporates stirring during the fermentation process, and the stirring speed can be 200-400 rpm, or 300 rpm. The stirring during the fermentation process is primarily used to control the dissolved oxygen level in the fermentation system, maintaining it at 30% to 50%. As an optional embodiment of the present invention, the fermentation time can be 48-72 hours, or 48, 49, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, or 72 hours. As an optional embodiment of the present invention, a carbohydrate is used for feeding during the fermentation process; the carbohydrate includes any one or more of glucose, sucrose, maltose, lactose, and fructose; the carbohydrate is added in an amount such that its mass concentration in the fermentation system can be 1% to 3%, or 1%, 2%, or 3%. As an optional embodiment of the present invention, the feeding time is once every 4 to 7 hours, or once every 6 hours. The present invention uses glucose for feeding to provide a carbon source for the microorganisms, promote their growth and protein synthesis, and improve fermentation efficiency.

[0031] After fermentation is complete, the present invention produces a fermentation product of livestock and poultry manure. As an optional embodiment of the present invention, the resulting fermentation product can be used directly as a fermented protein feed; alternatively, the resulting fermentation product can be dehydrated, dried, sterilized, and pelletized before being used as a fermented protein feed. The present invention does not specifically limit the methods for dehydration, drying, sterilization, and pelletization; conventional methods in the art may be employed. As an optional embodiment of the present invention, the dehydration method includes plate and frame filter pressing. The present invention preferably obtains a fermentation product having a moisture content of ≤40% through dehydration, which can also be referred to as a filter cake. After dehydration, the present invention preferably performs drying. The drying method includes fluidized bed drying; the fluidized bed drying temperature can be 80°C; and the fluidized bed drying time can be 2 hours. After drying, the present invention preferably sterilizes the resulting fermentation product. The sterilization method preferably includes irradiation sterilization; the irradiation sterilization preferably includes sterilization using cobalt-60 gamma rays. After sterilization, the present invention preferably pelletizes the fermentation product. As an optional embodiment of the present invention, the size of the granules can be 2-4 mm, or 2, 3 or 4 mm.

[0032] The present invention treats livestock and poultry manure through the method, which can improve the treatment efficiency of livestock and poultry manure. At the same time, the method significantly improves the protein conversion rate in livestock and poultry manure, and the obtained fermented protein feed has a high protein content, thereby improving the resource utilization effect of protein and other substances in livestock and poultry manure.

[0033] The present invention provides an application of the method described in the above technical solution in the resource utilization of livestock and poultry manure. The method provided by the present invention can prepare livestock and poultry manure into fermented protein feed, and the method is conducive to improving the utilization efficiency of livestock and poultry manure.

[0034] In order to further illustrate the present invention, the technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0035] The Bacillus subtilis and Bacillus amyloliquefaciens used in the following technical scheme were purchased from Hubei Qiming Bioengineering Co., Ltd. The product name of Bacillus subtilis is Bacillus subtilis, and the bacterial activity is 1×10 8 ~2×10 10 CFU / g; Registration number of Bacillus amyloliquefaciens: Microbial Fertilizer (2018) No. (3446), bacterial activity is 1×10 8 ~2×10 10 CFU / g.

[0036] In the following technical scheme, three parallel experiments were performed in each experimental group.

[0037] Example 1

[0038] A method for converting livestock and poultry manure into fermented protein feed, comprising the following steps:

[0039] 1. Collect fresh pig manure and perform vibration screening with an aperture of 2mm to remove large particles including sand and gravel to obtain screened pig manure.

[0040] 2. Add bran to the sieved pig manure to adjust the moisture content of the pig manure to 55% to 65%, and then add CaCO3 to adjust the pH to 6.5 to obtain tempered pig manure.

[0041] 3. The conditioned pig manure is sterilized at high temperature. The temperature of high temperature sterilization is 85°C and the time of high temperature sterilization is 30 minutes. High temperature sterilization is mainly used to kill pathogens in pig manure to obtain sterilized pig manure, which is the pretreated pig manure.

[0042] 4. Bacillus subtilis and Bacillus amyloliquefaciens were inoculated into the pretreated pig manure at a ratio of 0.8 wt. %, with Bacillus subtilis and Bacillus amyloliquefaciens added at a mass ratio of 1:1. At the same time, ferrous sulfate solution and manganese sulfate solution were added to the pretreated pig manure, wherein the mass concentration of ferrous sulfate in the ferrous sulfate solution was 1%, the mass concentration of manganese sulfate in the manganese sulfate solution was 1%, and the amount of ferrous sulfate solution added was such that Fe 2+ The mass of the pretreated pig manure is 0.5% of the mass, and the amount of manganese sulfate solution added is Mn 2+ The mass of the pretreated pig manure is 0.2%. The ferrous sulfate solution and the manganese sulfate solution are added by spraying. After the addition is completed, the fermentation system is stirred to mix the materials evenly.

[0043] 5. After step 4, the following parameters were used for the fermentation process: stirring was performed during the fermentation process to increase the dissolved oxygen content in the fermentation system. The stirring speed was set at 300 rpm, the temperature was controlled at 37°C for the first 24 hours of fermentation, and the fermentation temperature was controlled at 42°C after 24 hours of fermentation. Glucose was added every 6 hours during the fermentation process, and the amount of glucose added was 2 wt.% of the pretreated pig manure. After 60 hours of fermentation, the fermented pig manure was fully decomposed.

[0044] 6. After obtaining the decomposed pig manure, the decomposed pig manure is sequentially dehydrated, dried, sterilized, and formed to obtain a fermented protein feed. The dehydration is performed by filter press dehydration using a plate and frame filter press with operating parameters: a pressure of 0.4-0.6 MPa and a holding time of 30 minutes. The filter cake obtained after filter press dehydration has a moisture content of ≤40%. After obtaining a filter cake with a moisture content of ≤40%, the filter cake is subjected to fluidized bed drying using an internally heated fluidized bed dryer with operating parameters: a hot air temperature of 80-85°C and a drying time of 2 hours, resulting in a filter cake with a moisture content reduced to below 12%. The filter cake with a moisture content reduced to below 12% is sterilized by irradiation. Irradiation sterilization is performed using a cobalt-60 gamma ray irradiator with operating parameters: a dose of 5 kGy (dose rate of 5 kGy / h) and a double-sided irradiation time of 60 minutes. After sterilization, the sterilized filter cake is granulated using a φ300 ring die granulator (die hole diameter 3.0 mm). Operating parameters: temperature 75-80°C, steam addition 3%-5% of the filter cake mass, compression ratio 1:8; particle specifications: particle size 2-4 mm, hardness ≥4 kg / cm 2 After pelleting, the pellets are cooled to a temperature of ≤40°C and the moisture content of the fermented protein feed is ≤10%.

[0045] The crude protein, amino acid composition and heavy metal content in the fermented protein feed were tested, and the test results are shown in Table 1.

[0046] Table 1 Test results of crude protein, amino acid composition and heavy metal content in fermented protein feed

[0047]

[0048] As shown in Table 1, the crude protein content of the protein prepared in Example 1 is 48.2% (dry basis), the amino acid composition is 52% of essential amino acids, which meets the feed standards, and the heavy metal content is Cu <10 mg / kg, As <2 mg / kg, which meets GB 13078-2017.

[0049] The protein content in the fresh pig manure is tested before processing, and the protein content in the fermented protein feed is tested after obtaining the fermented protein feed. It is found that the protein conversion rate of the fermented protein feed obtained from fresh pig manure by the corresponding method of the present invention is increased to 20-30%.

[0050] Comparative Example 1

[0051] The method is the same as that of Example 1, with the only difference being that only Bacillus subtilis is used as the microbial agent, and the microbial agent is inoculated into the pretreated pig manure at a ratio of 0.8 wt.%.

[0052] The resulting fermented protein feed contained: crude protein content of 35.8% dry basis, a 12.4% decrease compared to Example 1; essential amino acid content of 46%, a 6% decrease compared to Example 1; and residual heavy metals Cu and As, respectively, less than 10 mg / kg and 2 mg / kg, respectively. This indicates that Bacillus subtilis alone, when used for pig manure fermentation, has limited ability to decompose macromolecular organic matter in the manure, resulting in low protein conversion and poor amino acid balance.

[0053] Comparative Example 2

[0054] The method is the same as that of Example 1, with the only difference being that only Bacillus amyloliquefaciens is used as the microbial agent, and the microbial agent is inoculated into the pretreated pig manure at a ratio of 0.8 wt.%.

[0055] The resulting fermented protein feed had a crude protein content of 38.2% dry basis, a 10% decrease compared to Example 1; essential amino acids accounted for 48%, a 4% decrease compared to Example 1; and heavy metal Cu / As residues were <10 mg / kg / <2 mg / kg, respectively, consistent with Example 1. Note: Bacillus amyloliquefaciens has a strong ability to degrade cellulose, but a weaker effect on promoting protein synthesis, resulting in a limited increase in overall crude protein.

[0056] Comparative Example 3

[0057] The method is the same as that in Example 1, except that Bacillus subtilis and Lactobacillus plantarum (with a bacterial activity of 1×10 8CFU / g) as the microbial agent, the mass ratio of Bacillus subtilis and Lactobacillus plantarum was 1:1. The microbial agent was inoculated into the pretreated pig manure at a ratio of 0.8 wt.%.

[0058] The resulting fermented protein feed had a crude protein content of 32.1% dry matter, a 16.1% decrease compared to Example 1; essential amino acids accounted for 43%, a 9% decrease compared to Example 1; and heavy metal Cu / As residues were <10 mg / kg / <2 mg / kg, respectively. This suggests that Lactobacillus plantarum primarily produces acid, inhibiting the protease activity of Bacillus subtilis, resulting in decreased protein degradation efficiency. Furthermore, the acidic environment is not conducive to amino acid synthesis.

[0059] Comparative Example 4

[0060] The method is the same as that of Example 1, with the only difference being that the temperature of the entire fermentation process is controlled at 37°C.

[0061] The resulting fermented protein feed contained: crude protein content of 40.5% dry matter, a 7.7% decrease compared to Example 1; essential amino acid content of 49%, a 3% decrease compared to Example 1; and a fermentation period extended to 72 hours, compared to 60 hours in Example 1. Explanation: A constant temperature of 37°C resulted in insufficient activity of thermophilic bacteria (such as Bacillus amyloliquefaciens), slowing the decomposition rate of organic matter.

[0062] Comparative Example 5

[0063] A traditional fermentation method for livestock and poultry manure, comprising the following steps:

[0064] After collecting the pig manure, it is piled up naturally and the moisture content is adjusted to 60% without adding any bacterial agents.

[0065] The pile is turned over every 7 days, and the fermentation cycle is 45 days.

[0066] No high temperature sterilization and glucose feeding were performed.

[0067] Effect data:

[0068] The resulting fermented protein feed had a crude protein content of 28.7% dry matter, a 19.5% decrease compared to Example 1; an essential amino acid content of 40%, a 12% decrease compared to Example 1; and heavy metal Cu / As residues of 15 mg / kg and 5 mg / kg, respectively (exceeding national standards). This indicates that traditional composting lacks microbial regulation, resulting in low protein conversion rates and ineffective heavy metal degradation, posing a risk of secondary pollution.

[0069] Application Example 1

[0070] The results of relevant indicators in the fermented protein feed prepared in Example 1 and Comparative Examples 1 to 5 are shown in Table 2.

[0071] Table 2 Results of relevant indicators in fermented protein feed prepared in Example 1 and Comparative Examples 1 to 5

[0072] Test items Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Crude protein content (dry basis) 48.2％ 35.8％ 38.2％ 32.1％ 40.5％ 28.7％ Essential amino acids ratio 52％ 46％ 48％ 43％ 49％ 40％ Heavy metal Cu (mg / kg) <10 <10 <10 <10 <10 15 Heavy metal As (mg / kg) <2 <2 <2 <2 <2 5 Fermentation cycle 60h 60h 60h 60h 72h 45 days

[0073] The combination of Bacillus subtilis and Bacillus amyloliquefaciens in Example 1 improves the effect in the following ways: Enzyme system complementarity: Bacillus subtilis secretes protease, and Bacillus amyloliquefaciens secretes amylase, which jointly promote the decomposition of organic matter. Metabolic product synergy: The surfactant produced by Bacillus amyloliquefaciens can enhance the inhibitory ability of Bacillus subtilis against pathogens. The key role of temperature control: 37°C in the first 24 hours of fermentation promotes the reproduction of mesophilic bacteria (such as Bacillus subtilis), and fermentation at 42°C after 24 hours activates Bacillus amyloliquefaciens, thereby achieving efficient degradation of pig manure. The constant temperature of 37°C in Comparative Example 4 leads to insufficient activity of thermophilic bacteria and a decrease in protein conversion rate. Limitations of traditional composting: Natural composting relies on environmental microorganisms and lacks directional regulation. The crude protein improvement effect is poor, which is far lower than the crude protein content of the fermented protein feed obtained in Example 1. At the same time, heavy metals are not effectively degraded in traditional fermentation.

[0074] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A method for converting livestock and poultry manure into fermented protein feed, characterized in that: The following steps are involved: The moisture content and pH value of the livestock and poultry manure are adjusted and then sterilized to obtain pretreated livestock and poultry manure; the moisture content of the livestock and poultry manure is adjusted to 55% to 65%; and the pH value is adjusted to 6.0 to 7.5; The pretreated livestock and poultry manure is mixed with a microbial agent for fermentation to obtain a fermented protein feed; The microbial agent includes Bacillus subtilis and Bacillus amyloliquefaciens; the bacterial activity of Bacillus subtilis is 1×10 8 ~2×10 10 CFU / g; the bacterial activity of Bacillus amyloliquefaciens is 1×10 8 ~2×10 10 CFU / g; the mass ratio of Bacillus subtilis to Bacillus amyloliquefaciens is (1-3): (1-3).

2. The method according to claim 1, characterized in that When mixing, the mass of the microbial agent accounts for 0.5% to 1.5% of the mass of livestock and poultry manure.

3. The method according to claim 1, characterized in that The method for adjusting the moisture content of livestock and poultry manure includes mixing the livestock and poultry manure with bran and / or straw.

4. The method according to claim 1, characterized in that During the fermentation process, sugar substances are used for feeding, and the added amount of the sugar substances is such that the mass concentration in the fermentation system is 1% to 3%.

5. The method according to claim 4, characterized in that: The feeding time is once every 4 to 7 hours.

6. The method according to claim 1, characterized in that The temperature before fermentation for 24 hours is 35-39°C; the temperature after fermentation for 24 hours is 40-44°C.

7. The method according to claim 1, characterized in that: The fermentation process is accompanied by stirring, and the stirring speed is 200-400 rpm.

8. The method according to claim 1, characterized in that: After fermentation is completed, the fermentation product is also dehydrated, dried, sterilized and granulated.

9. The method according to claim 8, characterized in that The sterilization method includes irradiation sterilization; the irradiation sterilization includes irradiation sterilization using cobalt 60 gamma rays.

10. Use of the method according to any one of claims 1 to 9 in resource utilization of livestock and poultry manure.

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