Method for preparing rice seedling-raising acid-regulating bacteria agent using fruit waste

Abstract

The application discloses a method for preparing rice seedling raising acid adjusting bacterial agent by using fruit garbage, and comprises the following steps: sequentially washing and disinfecting collected fruit garbage to obtain disinfected fruit garbage; inoculating aspergillus into liquid culture medium to culture aspergillus seed liquid; mixing the disinfected fruit garbage with glucose, corn syrup, FeSO4, K2HPO4, NaCl, MgSO4 and CaCO3, and then sterilizing to obtain fermentation culture medium; inoculating the aspergillus seed liquid into the fermentation culture medium and carrying out fermentation; obtaining fermentation liquor after the fermentation is completed; and centrifuging the fermentation liquor to extract supernatant, which is the rice seedling raising acid adjusting agent. The prepared rice seedling raising acid adjusting agent is a fermentation product and harmless to rice; the fermentation liquor acid and the acid secretion capacity of microorganisms can continuously maintain the pH of rice seedling raising soil.

Description

Technical Field

[0001] The invention relates to the technical field of rice seedling-growing acid-regulating agents, and in particular to a method for preparing a rice seedling-growing acid-regulating bacterial agent by utilizing fruit waste. Background Art

[0002] Rice damping-off disease, caused by Fusarium and Rhizoctonia, is a highly susceptible disease of rice seedlings, and in severe cases can lead to the death of large numbers of rice seedlings. When the pH of the rice seedling soil is greater than 6, rice damping-off disease is particularly prone to occur. Furthermore, rice itself is a slightly acid-loving crop, with an optimum pH of 4.5-5.5 for normal root growth. A slightly acidic seedbed environment improves the effectiveness of nutrients such as minerals, and is beneficial for digestion, oxidation, and the activity of probiotics. Therefore, rice farmers typically adjust the acidity of the seedling soil to prevent and control damping-off disease and promote the growth of rice seedlings.

[0003] Sulfuric acid is the most commonly used acidifier for rice seedlings. Rice farmers typically dilute concentrated sulfuric acid to adjust the pH of the seedling soil. Improper use and uneven mixing of sulfuric acid, as a strong inorganic acid, can easily damage rice roots. Using sulfuric acid as an acidifier also has the problem of poor long-term effectiveness. Seedling soil has inherent acid-base buffering capacity, and watering, spraying pesticides, and fertilizing during the seedling cultivation process continuously increase the soil pH.

[0004] Therefore, there is a need for a rice seedling raising acidifier that is harmless to rice and can continuously produce acidity and can be used throughout the rice seedling raising period to continuously adjust the pH of the rice seedling raising soil. Summary of the Invention

[0005] In response to the above-mentioned prior art, the present invention aims to provide a method for preparing an acid-regulating agent for rice seedling cultivation using fruit waste. This method utilizes fruit waste to prepare an acid-regulating agent for rice seedling cultivation, representing waste recycling. Furthermore, the resulting acid-regulating agent is a fermented product and harmless to rice. The acidity of the fermentation liquid and the acid-secreting ability of microorganisms are utilized to continuously maintain the pH of the rice seedling soil.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A first aspect of the present invention provides a method for preparing an acid-regulating bacterial agent for rice seedling cultivation using fruit waste, comprising the following steps:

[0008] The Aspergillus seed liquid is inoculated into a fermentation medium containing fruit waste for fermentation, and a fermentation liquid is obtained after the fermentation is completed. The fermentation liquid is centrifuged to extract the supernatant to obtain an acidic liquid.

[0009] The fruit garbage in the present invention refers to discarded peels, cores, pulp, and rotten fruits, which belong to wet garbage in garbage classification.

[0010] Preferably, the fruit waste is cleaned and disinfected in sequence before fermentation; the disinfection is as follows: adding the cleaned fruit waste into a NaCl solution, heating it to 50-70° C., and keeping it warm for 24-48 hours.

[0011] Preferably, the mass ratio of the fruit waste to the NaCl solution is 1:(2-5); and the concentration of the NaCl solution is 0.1%-0.5wt%.

[0012] Preferably, the Aspergillus seed liquid comprises Aspergillus flavus seed liquid and Aspergillus niger seed liquid, and the mass ratio of the Aspergillus flavus seed liquid to the Aspergillus niger seed liquid is 1:1; the Aspergillus flavus seed liquid is inoculated into a liquid culture medium and cultured; the Aspergillus niger seed liquid is inoculated into a liquid culture medium and cultured; the inoculation amounts of the Aspergillus flavus and the Aspergillus niger are 7-10wt% respectively;

[0013] Preferably, the culture is carried out at 20-30°C for 48 hours.

[0014] The strain collection number of the Aspergillus flavus is CICC 2091, and it is deposited in the China Industrial Microbiology Culture Collection Center.

[0015] The strain collection number of the Aspergillus niger is ATCC9142, which is deposited in the American Type Culture Collection.

[0016] The Aspergillus flavus and Aspergillus niger used in the present invention can be purchased through commercial channels.

[0017] Preferably, the culture is carried out at 20-30°C for 48 hours.

[0018] Preferably, in step (2), the liquid culture medium is prepared by adding distilled water to 1 L, peptone 2-3 g / L, glucose 1-2 g / L, K2HPO4 0.1-0.2 g / L, MgSO4 0.05-0.1 g / L, chloramphenicol 0.01-0.02 g / L.

[0019] Preferably, in step (3), the fermentation medium is composed of the following raw materials in parts by weight:

[0020] 50-70 parts of fruit waste, 10-20 parts of glucose, 5-10 parts of corn pulp, 0.1-0.3 parts of FeSO4, 0.3-0.5 parts of K2HPO4, 0.01-0.05 parts of NaCl, 0.1-0.3 parts of MgSO4, and 30-50 parts of CaCO3.

[0021] Preferably, in step (3), the inoculation amount of the Aspergillus seed liquid is 5-7 wt% of the fermentation medium;

[0022] Preferably, the sterilization treatment is carried out at 100°C for 10-15 minutes.

[0023] Preferably, in step (3), the fermentation is carried out at 25-30° C. with aeration and stirring for 48 hours;

[0024] Preferably, the ventilation volume is 0.3-0.5 L / (min·L);

[0025] Preferably, the stirring speed is 300-400 r / min;

[0026] Preferably, the centrifugal speed is 8000-10000 r / min.

[0027] The second aspect of the present invention provides the use of an acidic liquid in preparing an acid-regulating bacterial agent for rice seedling cultivation.

[0028] The third aspect of the present invention provides an acid-regulating bacterial agent for rice seedlings, wherein the acid-regulating bacterial agent for rice seedlings contains an acidic liquid as an active ingredient; the acid-regulating bacterial agent for rice seedlings is mixed with soil before rice seedlings are grown or is used by flushing, spraying or atomizing during the rice seedling cultivation process.

[0029] Preferably, the amount used for soil mixing is 1%-20% of the amount of soil mixing; the amount used for flushing, spraying or spraying is 1-20mL / m 2 .

[0030] Beneficial effects of the present invention:

[0031] 1. The present invention utilizes fruit waste to prepare a rice seedling-raising acidifier, which is a waste recycling method, improves the utilization rate of waste, and is green and environmentally friendly.

[0032] 2. The rice seedling acidifier prepared by the present invention is a fermentation product and is harmless to rice. It utilizes the acidity of the fermentation liquid obtained by fermentation and the acid secretion ability of microorganisms to achieve the function of continuously maintaining the pH of the rice seedling soil; and can also prevent the occurrence of rice diseases.

[0033] 3. The preparation method of the present invention is simple, the raw materials are easily available, and the prepared rice seedling acidifier is low in cost and easy to use. DETAILED DESCRIPTION

[0034] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0035] As described in the background technology section, improper use of acid for rice seedling soil acidification can damage rice roots and result in poor long-term acidification. Based on this, the present invention aims to provide a method for preparing an acidification agent for rice seedlings using fruit waste. This method utilizes fruit waste as the primary raw material for a fermentation medium, inoculates it with Aspergillus niger, and ferments it. The resulting fermentation broth is centrifuged to obtain a supernatant, which serves as the rice seedling soil acidification agent. This rice seedling soil acidification agent is a fermented product that is harmless to rice; it utilizes the acidity of the fermentation broth and the acid-secreting capacity of the microorganisms to continuously maintain the pH of the rice seedling soil. The acidic substances in the fermentation broth obtained after fermentation must not damage the rice roots while effectively regulating and sustaining the pH of the rice seedling soil. The inventors have discovered that the optimal acidification effect of the fermentation broth is achieved when Aspergillus niger and Aspergillus flavus are inoculated in a 1:1 mass ratio.

[0036] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the technical solution of the present application will be described in detail below with reference to specific embodiments.

[0037] The test materials used in the examples of the present invention are all conventional test materials in the art and can be purchased through commercial channels.

[0038] Note: The strain collection number of Lactobacillus delbrueckii used in the comparative example is CICC 6045; the strain collection number of Acetobacter pasteurianus is CICC 20001; both Lactobacillus delbrueckii and Acetobacter pasteurianus can be purchased through commercial channels.

[0039] Example

[0040] A method for preparing an acid regulator for rice seedling cultivation using fruit waste, the production method comprising:

[0041] Step (1): 10 kg of fruit waste was washed to remove sediment and placed in a stainless steel tank, 35 kg of 0.3 wt% NaCl solution was added, the temperature was maintained at 60° C., and the solution was allowed to stand for 24 hours to obtain sterilized fruit waste.

[0042] Step (2): Aspergillus niger was inoculated into 7 L of liquid culture medium at an inoculum size of 8 wt% of the mass of the liquid culture medium. The liquid culture medium components were: 2.5 g / L peptone, 1.5 g / L glucose, 0.15 g / L K2HPO4, 0.075 g / L MgSO4, and 0.015 g / L chloramphenicol. Distilled water was added to 7 L. The mixture was maintained at 25° C. and allowed to stand for 48 hours to obtain an Aspergillus niger seed solution.

[0043] Aspergillus flavus was inoculated into 7L liquid medium, and the inoculation amount of Aspergillus flavus was 8wt% of the mass of the liquid medium. The components of the liquid medium were as follows: 2.5g / L of proteose peptone, 1.5g / L of glucose, 0.15g / L of K2HPO4, 0.075g / L of MgSO4, 0.015g / L of chloramphenicol, and 7L of distilled water. The temperature was kept at 25℃, and the seed solution of Aspergillus flavus was obtained after 48 hours of standing.

[0044] Step (3): 10kg of sterilized fruit waste, 4kg of glucose, 1.5kg of corn syrup, 0.02kg of FeSO4, 0.08kg of K2HPO4, 0.006kg of NaCl, 0.06kg of MgSO4, and 10kg of CaCO3 were added into a 100L fermentation tank to obtain a fermentation medium.

[0045] Step (4): The fermentation tank was heated to 100℃ and kept for 20 minutes for sterilization.

[0046] Step (5): The seed solution of Aspergillus flavus and the seed solution of Aspergillus niger prepared in step (2) were added into the sterilized fermentation tank in step (4), and the addition amount of the seed solution of Aspergillus flavus and the seed solution of Aspergillus niger was 3.5wt% of the total mass of the fermentation medium. The temperature was kept at 30℃, the ventilation was 0.5L / (min·L), and the stirring speed was 350r / min. After 48 hours, the fermentation liquid was obtained.

[0047] Step (6): The fermentation liquid prepared in step (5) was centrifuged at 9000r / min to obtain the supernatant, which was filled to obtain the rice seedling growth and acid adjusting agent.

[0048] Comparative Example 1

[0049] Step (1): 10kg of fruit waste was washed to remove sand and placed in a stainless steel tank. 35kg of 0.3% NaCl solution was added, and the temperature was kept at 60℃ for 24 hours to obtain sterilized fruit waste.

[0050] Step (2): Lactobacillus delbrueckii was inoculated into 7L liquid medium, and the inoculation amount of Lactobacillus delbrueckii was 8wt% of the mass of the liquid medium. The components of the liquid medium were as follows: 2.5g / L of proteose peptone, 1.5g / L of glucose, 0.15g / L of K2HPO4, 0.075g / L of MgSO4, 0.015g / L of chloramphenicol, and 7L of distilled water. The temperature was kept at 25℃, and the seed solution of Lactobacillus delbrueckii was obtained after 48 hours of standing.

[0051] Step (3): 10 kg of sterilized fruit waste, 4 kg of glucose, 1.5 kg of corn steep liquor, 0.02 kg of FeSO4, 0.08 kg of K2HPO4, 0.006 kg of NaCl, 0.06 kg of MgSO4, and 10 kg of CaCO3 were added to a 100 L fermentation tank to obtain a fermentation medium.

[0052] Step (4): Heat the fermenter to 100°C and keep it for 15 minutes for sterilization.

[0053] Step (5): Add the Lactobacillus delbrueckii seed solution prepared in step (2) to the sterilized fermentation tank in step (4) in an amount of 7 wt% of the total mass of the fermentation medium. Maintain the temperature at 30° C., aerate at 0.5 L / (min·L), and stir at 350 r / min for 48 hours to obtain a fermentation broth.

[0054] Step (6): centrifuging the fermentation liquid obtained in step (5) at 9000 r / min to extract the supernatant, and filling the obtained rice seedling raising acidifier.

[0055] Comparative Example 2

[0056] Step (1): 10 kg of fruit waste was washed to remove the sediment and placed in a stainless steel tank, 35 kg of 0.3% NaCl solution was added, the mixture was kept at 60° C., and allowed to stand for 24 hours to obtain sterilized fruit waste.

[0057] Step (2): Inoculate 7 L of liquid culture medium with Acetobacter pasteurianus at an inoculum size of 8 wt% of the mass of the liquid culture medium. The liquid culture medium comprises 2.5 g / L peptone, 1.5 g / L glucose, 0.15 g / L K₂HPO₄, 0.075 g / L MgSO₄, and 0.015 g / L chloramphenicol. Add distilled water to a volume of 7 L. Maintain the medium at 25°C and allow it to stand for 48 hours to obtain a seed solution of Acetobacter pasteurianus.

[0058] Step (3): 10 kg of sterilized fruit waste, 4 kg of glucose, 1.5 kg of corn steep liquor, 0.02 kg of FeSO4, 0.08 kg of K2HPO4, 0.006 kg of NaCl, 0.06 kg of MgSO4, and 10 kg of CaCO3 were added to a 100 L fermentation tank to obtain a fermentation medium.

[0059] Step (4): Heat the fermenter to 100°C and keep it for 15 minutes for sterilization.

[0060] Step (5): Add the Acetobacter pasteurianus seed solution obtained in step (2) to the sterilized fermentation tank in step (4) in an amount of 7 wt% of the total mass of the fermentation medium. Maintain the temperature at 30° C., aerate at 0.5 L / (min·L), and stir at 350 r / min for 48 hours to obtain a fermentation broth.

[0061] Step (6): centrifuging the fermentation liquid obtained in step (5) at 9000 r / min to extract the supernatant, and filling the obtained rice seedling raising acidifier.

[0062] Comparative Example 3

[0063] Step (1): 10 kg of fruit waste was washed to remove the sediment and placed in a stainless steel tank, 35 kg of 0.3% NaCl solution was added, the mixture was kept at 60° C., and allowed to stand for 24 hours to obtain sterilized fruit waste.

[0064] Step (2): Lactobacillus delbrueckii was inoculated into 7 L of liquid culture medium at an inoculum size of 8 wt% of the mass of the liquid culture medium. The liquid culture medium components were: 2.5 g / L peptone, 1.5 g / L glucose, 0.15 g / L K₂HPO₄, 0.075 g / L MgSO₄, and 0.015 g / L chloramphenicol. Distilled water was added to 7 L. The culture medium was maintained at 25°C and allowed to stand for 48 hours to obtain a Lactobacillus delbrueckii seed solution.

[0065] An equal mass of Acetobacter pasteurianus to that of Lactobacillus delbrueckii was inoculated into 7 L of liquid culture medium, at an inoculum size of 8 wt% of the total mass of the liquid culture medium. The liquid culture medium consisted of 2.5 g / L peptone, 1.5 g / L glucose, 0.15 g / L K₂HPO₄, 0.075 g / L MgSO₄, and 0.015 g / L chloramphenicol. Distilled water was added to the volume to 7 L. The culture medium was maintained at 25°C and allowed to stand for 48 hours to obtain an Acetobacter pasteurianus seed solution.

[0066] Step (3): 10 kg of sterilized fruit waste, 4 kg of glucose, 1.5 kg of corn steep liquor, 0.02 kg of FeSO4, 0.08 kg of K2HPO4, 0.006 kg of NaCl, 0.06 kg of MgSO4, and 10 kg of CaCO3 were added to a 100 L fermentation tank to obtain a fermentation medium.

[0067] Step (4): Heat the fermenter to 100°C and keep it for 15 minutes for sterilization.

[0068] Step (5): adding the Lactobacillus delbrueckii seed liquid and the Acetobacter pasteurian seed liquid obtained in step (2) to the sterilized fermentation tank in step (4), wherein the amount of the Lactobacillus delbrueckii seed liquid and the Acetobacter pasteurian seed liquid added each accounts for 3.5wt% of the total mass of the fermentation medium, maintaining 30°C, aerating 0.5L / (min·L), and stirring at a speed of 350r / min for 48 hours to obtain a fermentation liquid.

[0069] Step (6): centrifuging the fermentation liquid obtained in step (5) at 9000 r / min to extract the supernatant, and filling the obtained rice seedling raising acidifier.

[0070] Comparative Example 4

[0071] Step (1): 10 kg of fruit waste was washed to remove the sediment and placed in a stainless steel tank, 35 kg of 0.3% NaCl solution was added, the mixture was kept at 60° C., and allowed to stand for 24 hours to obtain sterilized fruit waste.

[0072] Step (2): Inoculate Aspergillus flavus into 7 L of liquid culture medium at an inoculum size of 8 wt% of the mass of the liquid culture medium. The liquid culture medium comprises 2.5 g / L peptone, 1.5 g / L glucose, 0.15 g / L K₂HPO₄, 0.075 g / L MgSO₄, and 0.015 g / L chloramphenicol. Add distilled water to 7 L. Maintain the medium at 25°C and allow to stand for 48 hours to obtain an Aspergillus flavus seed solution.

[0073] Step (3): 10 kg of sterilized fruit waste, 4 kg of glucose, 1.5 kg of corn steep liquor, 0.02 kg of FeSO4, 0.08 kg of K2HPO4, 0.006 kg of NaCl, 0.06 kg of MgSO4, and 10 kg of CaCO3 were added to a 100 L fermentation tank to obtain a fermentation medium.

[0074] Step (4): Heat the fermenter to 100°C and keep it for 15 minutes for sterilization.

[0075] Step (5): Add the Aspergillus flavus seed solution prepared in step (2) to the sterilized fermentation tank in step (4) in an amount of 7 wt% of the total mass of the fermentation medium. Maintain the temperature at 30° C., aerate at 0.5 L / (min·L), and stir at 350 r / min for 48 hours to obtain a fermentation broth.

[0076] Step (6): centrifuging the fermentation liquid obtained in step (5) at 9000 r / min to extract the supernatant, and filling the obtained rice seedling raising acidifier.

[0077] Comparative Example 5

[0078] Step (1): Put 10 kg of fruit waste washed to remove the sand into a stainless steel tank, add 35 kg of 0.3% NaCl solution, keep 60℃, and stand for 24 hours to obtain the disinfected fruit waste.

[0079] Step (2): Inoculate the Aspergillus niger into 7 L of liquid culture medium, and the inoculation amount is 8 wt% of the mass of the liquid culture medium. The components of the liquid culture medium are: 2.5 g / L of proteose peptone, 1.5 g / L of glucose, 0.15 g / L of K2HPO4, 0.075 g / L of MgSO4, 0.015 g / L of chloramphenicol, and 7 L of distilled water. Keep 25℃, and stand for 48 hours to obtain the Aspergillus niger seed liquid.

[0080] Step (3): Add 10 kg of disinfected fruit waste, 4 kg of glucose, 1.5 kg of corn syrup, 0.02 kg of FeSO4, 0.08 kg of K2HPO4, 0.006 kg of NaCl, 0.06 kg of MgSO4, and 10 kg of CaCO3 into a 100 L fermentation tank to obtain the fermentation culture medium.

[0081] Step (4): Heat the fermentation tank to 100℃ and keep for 20 minutes for sterilization.

[0082] Step (5): Add the Aspergillus niger seed liquid prepared in step (2) into the sterilized fermentation tank in step (4), and the addition amount is 7 wt% of the total mass of the fermentation culture medium. Keep 30℃, ventilate 0.5 L / (min·L), and stir at a speed of 350 r / min for 48 hours to obtain the fermentation liquid.

[0083] Step (6): Centrifuge the fermentation liquid prepared in step (5) at 9000 r / min to extract the supernatant, and fill to obtain the rice seedling raising acid adjusting agent.

[0084] Utility test:

[0085] In order to verify the acid adjusting and disease preventing effect of the rice seedling raising acid adjusting agent, field tests are carried out, and the tested rice variety is Longjing 46. The seedling raising tray is used for seedling raising, the seedling raising soil is a mixture of 1:1 of paddy field soil and seedling raising substrate, the pH is 6.76, the organic matter is 4.83%, the total nitrogen is 1.2 mg / kg, the available phosphorus is 14.63 mg / kg, and the available potassium is 113 mg / kg.

[0086] 1. Test method:

[0087] The experiment set up 10 treatments in total, blank control (CK), sulfuric acid (CK0), acid regulator prepared in Example (T1), acid regulator prepared in Comparative Example 1 (CK1), acid regulator prepared in Comparative Example 2 (CK2), acid regulator prepared in Comparative Example 3 (CK3), acid regulator prepared in Comparative Example 1 and acid regulator prepared in Comparative Example 2 mixed at a mass ratio of 1:1 (CK4). Acid regulator prepared in Comparative Example 4 (CK5), acid regulator prepared in Comparative Example 5 (CK6), acid regulator prepared in Comparative Example 4 and acid regulator prepared in Comparative Example 5 mixed at a mass ratio of 1:1 (CK7). 10 seedling trays were adjusted for each treatment and mixed with soil for use, and the amount used in each treatment was the same. Before raising the seedlings, the CK treatment was sprayed with an equal amount of tap water, and the other treatments adjusted the pH of the seedling soil to 5.5. Other daily management of each treatment was the same.

[0088] The pH change data of the seedling soil under each treatment are shown in Table 1.

[0089] Table 1 pH of seedling raising soil under different treatments

[0090]

[0091]

[0092] As shown in Table 1, the liquid acidifier prepared by fermenting Aspergillus flavus and Aspergillus niger resulted in the least pH change in the rice seedling soil within 28 days of application. Compared to other treatments, it has a longer-lasting effect and can meet the acidification needs throughout the rice seedling raising period.

[0093] The incidence of rice seedling damping-off disease is shown in Table 2.

[0094] Table 2 Incidence of damping-off disease in rice seedlings under different treatments (%)

[0095] experimental group 7 days after treatment 14 days after treatment 28 days after treatment CK 5.63％ 26.58％ 56.73％ CK0 0 5.63％ 18.35％ T1 0 0.02％ 0.22％ CK1 0.01 5.32％ 8.25％ CK2 0.01 6.21％ 10.32％ CK3 0 5.12％ 6.93％ CK4 0.02 6.03％ 12.54％ CK5 0 1.03％ 1.52％ CK6 0 1.13％ 2.62％ CK7 0 0.09％ 0.67％

[0096] As shown in Table 2, adjusting the acidity of rice seedling soil effectively inhibits damping-off. The liquid acidifier prepared by fermenting Aspergillus flavus and Aspergillus niger effectively controlled damping-off 28 days after use. The liquid acidifier prepared by the present invention significantly reduces the incidence of damping-off by continuously adjusting the pH.

[0097] In summary, the liquid microbial agent for regulating acidity and preventing diseases in rice seedling cultivation provided by the present invention can effectively and continuously adjust the pH of the rice seedling cultivation soil, significantly inhibiting the occurrence of damping-off disease, and has important practical significance for rice seedling cultivation production.

[0098] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method for preparing an acidifier for rice seedling cultivation using fruit waste, characterized in that: The method is: The Aspergillus seed liquid is inoculated into a fermentation medium containing fruit waste for fermentation, and fermentation is completed to obtain a fermentation liquid, and the fermentation liquid is centrifuged to extract the supernatant to obtain a rice seedling acidifier; The Aspergillus seed liquid includes Aspergillus flavus seed liquid and Aspergillus niger seed liquid, and the mass ratio of the Aspergillus flavus seed liquid to the Aspergillus niger seed liquid is 1:1; the Aspergillus flavus seed liquid is inoculated into a liquid culture medium and cultured; the Aspergillus niger seed liquid is inoculated into a liquid culture medium and cultured; the inoculation amount of the Aspergillus flavus and the Aspergillus niger is 8wt% of the mass of the liquid culture medium; and the culture is both cultured at 20-30° C. for 48 hours; The strain collection number of the Aspergillus flavus is CICC 2091; the strain collection number of the Aspergillus niger is ATCC 9142; The fruit garbage refers to discarded peels, cores, pulp, and rotten fruits, which are classified as wet garbage in garbage classification.

2. The method according to claim 1, characterized in that The fruit waste is cleaned and disinfected in sequence before fermentation; the disinfection is as follows: the cleaned fruit waste is added to a NaCl solution, heated to 50-70° C., and kept warm for 24-48 hours.

3. The method according to claim 2, characterized in that The mass ratio of the fruit waste to the NaCl solution is 1:(2-5); the concentration of the NaCl solution is 0.1%-0.5wt%.

4. The method according to claim 1, wherein The liquid culture medium is prepared by adding 2-3 g / L of peptone, 1-2 g / L of glucose, 0.1-0.2 g / L of K2HPO4, 0.05-0.1 g / L of MgSO4, and 0.01-0.02 g / L of chloramphenicol to 1 L of distilled water.

5. The method according to claim 1, wherein The fermentation medium is composed of the following raw materials in parts by weight: 50-70 parts of fruit waste, 10-20 parts of glucose, 5-10 parts of corn steep liquor, 0.1-0.3 parts of FeSO4, 0.3-0.5 parts of K2HPO4, 0.01-0.05 parts of NaCl, 0.1-0.3 parts of MgSO4, 30-50 parts of CaCO3; The inoculation amount of the Aspergillus seed liquid is 5-7 wt % of the fermentation medium.

6. The method according to claim 1, characterized in that The fermentation is carried out at 25-30° C. with aeration and stirring for 48 hours; the aeration volume is 0.3-0.5 L / (min·L); and the stirring speed is 300-400 r / min.

7. Use of the method according to any one of claims 1 to 6 in preparing an acid-regulating bacterial agent for rice seedling cultivation.

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