Liquid phosphate solubilizing bacterial agent as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of biological bacterial agents, and particularly relates to a liquid phosphate solubilizing bacterial agent as well as a preparation method and application thereof. In order to realize resource utilization of yellow water bottom pot water and improve absorption of available phosphorus in soil by plants, acinetobacter S-1 (the preservation number is CGMCC No.31164) with a phosphorus-dissolving function is taken as an active ingredient of the microbial agent, and a fermentation culture medium added with yellow water bottom pot water is taken as a strain culture solution, so that the liquid-state phosphorus-dissolving microbial agent with the available phosphorus content of 60-95 mg / L is obtained. The liquid phosphate solubilizing bacterial agent prepared by the invention is used for planting a main raw material required by wine brewing, such as sorghum, and can convert solidified phosphorus in soil into unstable phosphorus which can be absorbed and utilized by plants, promote growth and production of the sorghum and improve the production efficiency; and the yellow water bottom pot water can be recycled, the cost of a winery is reduced, and the economic benefit is increased.

Description

Technical Field

[0001] The invention belongs to the technical field of biological microbial agents, and particularly relates to a liquid phosphate-dissolving microbial agent and a preparation method and application thereof. Background Art

[0002] Bottom pot water is the distillation water produced during the distillation of wine. The water vapor generated by grain gelatinization and mash distillation condenses on the mash, then falls back and mixes with the original bottom pot water. Although this bottom pot water is a wastewater from the brewing process, it is rich in usable nutrients, such as reducing sugars, organic acids, esters, alcohols, hydroxylated compounds, and phenolic compounds. Bottom pot water is generally divided into: tail bottom pot water, yellow bottom pot water, and clear bottom pot water. Yellow bottom pot water is typically yellowish-brown or brown in color and is added to the pot during the brewing process to increase wine production. Wineries generally treat this water as wastewater and then discharge it, which not only wastes resources and increases treatment costs, but also causes environmental pollution. While many wineries have been developing its potential, such as producing esterification liquid, continuous distillation liquid, and fermentation liquid, its extraction efficiency is low, and product quality improvement is inconsistent.

[0003] Phosphorus is an essential nutrient for crop growth and development and is also a non-renewable resource. Soil is the primary source of phosphorus for plants, and plants primarily absorb phosphorus in unstable forms. However, excessive application of phosphorus fertilizers can disrupt the metabolism of trace elements in plants, resulting in reduced crop yields and agricultural product quality. At the same time, excess phosphorus can be transferred from farmland to adjacent water bodies through erosion, runoff, and leaching, leading to eutrophication and environmental pollution. Therefore, how to promote the conversion of stable phosphorus in the soil to unstable phosphorus, thereby increasing plant absorption of available phosphorus in the soil and promoting plant growth, is also a technical problem that needs to be solved urgently. Summary of the Invention

[0004] In order to utilize the water from the bottom of the yellow water pot as a resource and improve the absorption of available phosphorus in the soil by plants, the present invention uses the water from the bottom of the yellow water pot as a matrix to produce a liquid phosphate-solubilizing bacterial agent. The prepared bacterial agent can not only convert the solidified phosphorus in the soil into unstable phosphorus that can be absorbed and utilized by plants, thereby promoting plant growth; it can also utilize the water from the bottom of the yellow water pot as a resource, reduce the cost of the winery, and protect the environment.

[0005] To achieve the above application objectives, the technical solutions adopted in this application are as follows: In a first aspect, the present invention provides a method for preparing a liquid phosphate-solubilizing bacteria agent, comprising the following steps: A liquid phosphate-solubilizing bacteria agent is obtained by inoculating a seed liquid containing Acinetobacter S-1 into a fermentation medium for cultivation; wherein the preservation number of the Acinetobacter S-1 is CGMCC No. 31164; the fermentation medium uses yellow water bottom pot water as a solvent and comprises, by mass ratio to the yellow water bottom pot water, 22-28 g / L of honey, 1.2-2.0 g / L of ammonium sulfate, 3-8 g / L of calcium phosphate, 0.1-0.3 g / L of potassium chloride, 0.1-0.5 g / L of sodium chloride, 0.1-0.5 g / L of magnesium sulfate, 0.01-0.05 g / L of ferrous sulfate, and 0.01-0.05 g / L of manganese sulfate.

[0006] Furthermore, the seed liquid is obtained by inoculating Acinetobacter S-1 into a seed culture medium and culturing at 32-37° C. and 120-160 rpm for 12-24 hours.

[0007] Furthermore, the seed culture medium includes 2-3 g / L beef powder, 7-15 g / L peptone and 3-8 g / L sodium chloride.

[0008] Preferably, the seed culture medium comprises 3 g / L beef powder, 10 g / L peptone and 5 g / L sodium chloride.

[0009] Furthermore, the pH of the yellow water bottom pot water is adjusted to 7.0-7.5 before use.

[0010] Furthermore, after the fermentation medium is sterilized, its pH value is adjusted to 7.0-7.5.

[0011] Furthermore, the seed liquid inoculation amount is 3 to 8%.

[0012] Furthermore, the seed liquid is inoculated into a fermentation medium and cultured at 32-37° C. for 24-48 h.

[0013] Furthermore, the Acinetobacter S-1 ( Acinetobacter geminorum ) The deposit number is CGMCC No.31164. It was deposited on July 4, 2024, at the General Microbiology Center of China Culture Collection Administration (CGMCC), Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, Postal Code: 100101, and the classification name is: Acinetobacter geminorum .

[0014] Preferably, the 16S rDNA nucleotide sequence of the Acinetobacter S-1 is shown in SEQ ID NO: 1.

[0015] In a second aspect, the present invention provides the above-mentioned liquid phosphate-solubilizing bacteria agent.

[0016] Further, the effective phosphorus of the liquid phosphorus solubilizing bacterial agent is 60-95 mg / L.

[0017] In a third aspect, the present application provides a microbial phosphorus solubilizing bacterial agent containing Acinetobacter S-1, with a preservation number of CGMCC No. 31164.

[0018] In a fourth aspect, the present application provides the use of the above-mentioned liquid phosphorus solubilizing bacterial agent or microbial phosphorus solubilizing bacterial agent in promoting plant growth.

[0019] Further, the promoting effect is adding the liquid phosphorus solubilizing bacterial agent into the soil in which the plant is cultivated, so as to convert the solidified phosphorus in the soil into unstable phosphorus that can be absorbed and utilized by the plant, thereby promoting the growth and production of the plant.

[0020] Beneficial effects: the present application uses Acinetobacter S-1 (with a preservation number of CGMCC No. 31164) having the function of solubilizing phosphorus as the active ingredient of the bacterial agent, and uses the fermentation medium added with yellow water at the bottom of the pot as the strain culture solution, thereby obtaining a liquid phosphorus solubilizing bacterial agent with effective phosphorus of 60-95 mg / L. The liquid phosphorus solubilizing bacterial agent prepared by the present application is used for planting the main raw material required for brewing wine, such as sorghum, so as to convert the solidified phosphorus in the soil into unstable phosphorus that can be absorbed and utilized by the plant, thereby promoting the growth and production of sorghum and improving the production efficiency; and the yellow water at the bottom of the pot can also be resourcefully utilized, thereby reducing the cost of the winery and increasing the economic benefits.

[0021] Preservation instruction of Acinetobacter S-1 of the present application: Acinetobacter S-1 (CGMCC No. 31164) Acinetobacter geminorum ) with a preservation number of CGMCC No. 31164, which was preserved in the China General Microbiological Culture Collection Center (CGMCC) on July 4, 2024, and the address of the preservation is No. 1, Beichen West Road, Yard 3, Beijing City, Chaoyang District, Institute of Microbiology of Chinese Academy of Sciences, with a postal code of 100101, and is classified and named as: Acinetobacter geminorum . DETAILED DESCRIPTION

[0022] In order to make the technical problems, technical solutions and beneficial effects of the present application more clearly understood, the present application will be further described in detail below in combination with the embodiments. Unless otherwise defined, all technical terms used in the present application have the same meanings as understood by those skilled in the art.

[0023] In an embodiment of the present application, a preparation method of a liquid phosphorus solubilizing bacterial agent is provided, which comprises the following steps: A liquid phosphate-solubilizing bacteria agent is obtained by inoculating a seed liquid containing Acinetobacter S-1 into a fermentation medium for cultivation; wherein the preservation number of the Acinetobacter S-1 is CGMCC No. 31164; the fermentation medium uses yellow water bottom pot water as a solvent and comprises, by mass ratio to the yellow water bottom pot water, 22-28 g / L of honey, 1.2-2.0 g / L of ammonium sulfate, 3-8 g / L of calcium phosphate, 0.1-0.3 g / L of potassium chloride, 0.1-0.5 g / L of sodium chloride, 0.1-0.5 g / L of magnesium sulfate, 0.01-0.05 g / L of ferrous sulfate, and 0.01-0.05 g / L of manganese sulfate.

[0024] In the present invention, the fermentation medium contains calcium phosphate, which mainly drives the metabolic regulation, nutrient supply and environmental buffering of phosphate-solubilizing bacteria. Calcium phosphate mainly exists in crystalline or amorphous form. Crystalline calcium phosphate has a dense structure and is difficult to decompose. It can induce phosphate-solubilizing bacteria to secrete more organic acids such as citric acid, acetic acid and phosphatase, promoting dissolution through the dual effects of acidification and enzymolysis. Amorphous calcium phosphate has relatively high solubility, and phosphate-solubilizing bacteria can achieve this through simple proton exchange (H + Replacement of Ca 2+ ) releases phosphate. Calcium phosphate can also be used as a phosphorus source in the fermentation medium, providing the necessary phosphorus element for the growth of phosphate-solubilizing bacteria and promoting the synthesis of cellular nucleic acids, phospholipids and other substances; the Ca in calcium phosphate 2+ It can neutralize the organic acids produced by microbial metabolism, maintain the pH stability of the culture medium, and avoid excessive acidity that inhibits bacterial activity.

[0025] During the fermentation process, fermentation time is closely related to microbial growth activity. The effect of time on available phosphorus content follows the laws of microbial growth and metabolism: during the logarithmic growth phase, the activity of phosphate-solubilizing bacteria reaches its peak, and the secretion of organic acids and phosphatase surges, driving the maximum efficiency of calcium phosphate decomposition. As the culture time continues, the microorganisms enter the decline phase, with a significant decrease in metabolites and enzyme activity. Combined with the influence of factors such as phosphate re-fixation, the available phosphorus content shows a downward trend. Therefore, accurately controlling the fermentation time window between 24 and 48 hours is key to ensuring the effectiveness of liquid inoculant phosphorus.

[0026] In the present invention, Acinetobacter S-1 (CGMCC No. 31164) is used as the active ingredient of the bacterial agent. The strain was screened and isolated in an inorganic phosphate-dissolving liquid culture medium and deposited in the General Microbiology Center of the China Culture Collection of Microorganisms (CGMCC) on July 4, 2024, with the deposit number CGMCC No. 31164. The deposit address is Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, Postal Code: 100101, and the classification name is: Acinetobacter geminorum .

[0027] In one embodiment of the present application, the liquid phosphorus solubilizing bacterial agent is provided. The effective phosphorus of the liquid phosphorus solubilizing bacterial agent is 60-95 mg / L.

[0028] In one embodiment of the present application, the microorganism phosphorus solubilizing bacterial agent containing Acinetobacter S-1 with the preservation number of CGMCC No. 31164 is also provided.

[0029] In one embodiment of the present application, the application of the liquid phosphorus solubilizing bacterial agent or the microorganism phosphorus solubilizing bacterial agent in promoting plant growth is provided.

[0030] The following specific examples will be listed to explain the scheme of the present application. The person skilled in the art will understand that the following examples are only used to illustrate the present application, and should not be regarded as limiting the scope of the present application. The specific technology or condition not noted in the examples is carried out according to the technology or condition described in the literature in the art or according to the product instruction. The reagent or instrument not noted by the manufacturer is a conventional product that can be obtained by market purchase.

[0031] The culture medium used in the examples is as follows: Inorganic phosphorus solubilizing solid medium: glucose 10 g / L, ammonium phosphate 0.5 g / L, yeast powder 0.5 g / L, sodium chloride 0.3 g / L, potassium chloride 0.3 g / L, magnesium sulfate 0.3 g / L, ferrous sulfate 0.03 g / L, manganese sulfate 0.03 g / L, calcium carbonate 1 g / L, lecithin 0.2 g / L and agar 2%.

[0032] Inorganic phosphorus solubilizing liquid medium: glucose 10 g / L, ammonium phosphate 0.5 g / L, yeast powder 0.5 g / L, sodium chloride 0.3 g / L, potassium chloride 0.3 g / L, magnesium sulfate 0.3 g / L, ferrous sulfate 0.03 g / L, manganese sulfate 0.03 g / L, calcium carbonate 1 g / L and lecithin 0.2 g / L.

[0033] Beef extract protein peptone liquid medium or NB liquid medium: beef powder 3 g, protein peptone 10 g, sodium chloride 5 g and water 1 L; pH is 7.4-7.6.

[0034] (I) The determination method of the liquid effective phosphorus is as follows: NaOH (100 g / L): 10 g NaOH + 100 mL H2O; H2SO4 (5%): 5 mL concentrated H2SO4 + 90 mL H2O, constant volume to 100 mL.

[0035] The bacterial agent of the test example was inoculated at a 5% inoculum size into 50 mL of beef extract peptone liquid culture medium and cultured at 37°C and 150 r / min for 24 h. 2 mL of the bacteria was inoculated into sterilized inorganic phosphate-dissolving liquid culture medium (100 / 250 mL) respectively. No bacteria were used as the control. The culture was repeated three times at 37°C and 150 r / min. The content of available phosphorus in the fermentation broth was determined by molybdenum blue colorimetry at 0, 24, 48, and 72 h, respectively.

[0036] Determination of available phosphorus content in fermentation broth by molybdenum blue colorimetry: Molybdenum-antimony stock solution: Weigh 0.5 g of potassium antimony tartrate and dissolve it in 100 mL of deionized water. Weigh 10 g of ammonium molybdate and dissolve it in 450 mL of deionized water. Slowly pour 153 mL of concentrated sulfuric acid into the solution and allow it to cool. Combine the two solutions and dilute to 1 L to obtain the molybdenum-antimony stock solution.

[0037] Molybdenum antimony anti-coloring agent: 1.5 g L-ascorbic acid + 100 mL molybdenum antimony stock solution (prepare and use immediately); The cultured fermentation broth was centrifuged at 10,000 r / min for 10 min, 0.8 mL of the supernatant was aspirated, and the volume was made up to 15 mL with water. Two drops of dinitrophenol indicator were added, and the color of the solution was adjusted to slightly yellow by adjusting the pH. Then 4 mL of molybdenum antimony anti-colorant was added and the volume was made up to 25 mL. The solution was thoroughly mixed and allowed to stand for 30 min before colorimetry at 700 nm.

[0038] To construct a phosphorus standard curve: Pipette 0, 0.5, 1, 2, 3, 4, and 5 mL of the phosphorus standard stock solution into a 25 mL volumetric flask, add water to 15 mL, add two drops of dinitrophenol indicator, adjust the pH to a slightly yellowish color, add 4 mL of molybdenum antimony anticolorimeter, and dose to volume to obtain phosphorus standard solutions with phosphorus concentrations of 0, 0.1, 0.2, 0.4, 0.6, 0.8, and 1.0 mg / L, respectively. Let the solution stand for 30 minutes. Measure the absorbance of the phosphorus standard solutions at 700 nm using the zero-concentration solution as a reference, and then construct a standard curve.

[0039] The phosphorus content was calculated according to the following formula: Where: X is the phosphorus content in the culture medium (mg / L); P is the mass concentration of phosphorus obtained from the working curve (mg / L); V1 is the volume of the color developing solution (mL); K is the dilution factor; V2 is the volume of the supernatant (mL).

[0040] (II) The methods for screening, isolating and identifying Acinetobacter S-1 used in the examples are as follows: (1) Screening and isolation of Acinetobacter S-1 Weigh 10 g of soil sample into a flask filled with 90 mL of sterile water and shake at 160 rpm / min for 20 min at room temperature to prepare a uniform soil suspension. -1 ~10 -6 The concentration gradient sample solution was selected from 10 -4 , 10 -5 , 10 -6 Samples were prepared at three different concentration gradients. To isolate phosphate-solubilizing bacteria, 0.1 mL of each sample was aspirated and spread onto a plate containing solid inorganic phosphate-solubilizing medium. Three replicates were set for each dilution. After incubation in an inverted position at 37°C, the size of the clearing zone was observed over time. Colonies with clearing zones were selected from the plates at each gradient, and the clearing zone diameter (D) and colony diameter (d) were measured. The presence of clearing zones and the D / d ratio were used to preliminarily determine the phosphate-solubilizing ability of the strain. Using the molybdenum blue colorimetric method, the strain with the best phosphate-solubilizing effect was selected based on the color depth and designated S-1.

[0041] (2) Identification Morphological Observation: 1. Colony Morphology Observation: Preliminary isolation and identification of selected strains is performed based on the appearance of the colonies on the plate culture medium, including sensory indicators such as the degree of central ridge, color, edge shape, transparency, and shape. 2. Bacterial Morphology Observation: Single colonies are selected and inoculated into NB liquid culture medium. Culture fluid obtained after reaching the stationary phase or late logarithmic growth phase is subjected to Gram staining and scanning electron microscopy to observe bacterial morphology.

[0042] Identification of physiological and biochemical characteristics: gelatin liquefaction test, amylase hydrolysis test, VP determination, indole test, catalase test, nitrate reduction test, H2S production test, and sugar fermentation test were all performed with reference to the "Common Bacterial System Identification Manual" and "Bergey's Bacterial Identification Manual" compiled by Dong Xiuzhu and Cai Miaoying, and physiological and biochemical tests were performed on the strains.

[0043] Molecular Biological Identification: 1. Strain Cultivation: The activated strain seed solution was cultured in NB liquid medium at 37°C, shaking at 180 rpm for 12 hours. 2. Sequencing: Genomic DNA of strain S-1 was extracted using a bacterial DNA extraction kit. The DNA was then sent to Beijing Qingke Biotechnology Co., Ltd. (Chengdu) for sequencing.

[0044] (3) Identification results 1. Morphological observation revealed that a single colony of strain S-1 on NB medium appeared milky white, with rounded protrusions, smooth, regular edges, a moist surface, and a viscous texture. Gram staining revealed a negative bacterium. After 12 hours of constant temperature culture in NB medium, followed by fixation, rinsing, dehydration, drying, gold spraying, and electron microscopic observation, strain S-1 exhibited a typical rod-shaped bacterium with a smooth, well-defined surface and edges, lacking flagella or capsules, and arranged singly without branches.

[0045] 2. Physiological and biochemical characteristics are shown in Table 1.

[0046] Table 1 Results of physiological and biochemical tests on strains Note: + indicates a positive reaction, - indicates a negative reaction 3. 16S rDNA Identification The molecular identification sequence is shown in SEQ ID NO: 1.

[0047] SEQ ID NO: 1: Combined with the morphological characteristics, physiological and biochemical characteristics and 16S rDNA comparison results of the strain, the strain S-1 was identified as Acinetobacter Acinetobacter geminorum , and was preserved in the China General Microbiological Culture Collection Center (CGMCC) on July 4, 2024, with a preservation number of CGMCC No. 31164 and a preservation address of No. 3, Yikuangli, Beichenxi Road, Beijing, China Institute of Microbiology, Chinese Academy of Sciences, with a postcode of 100101.

[0048] (III) The seed liquid preparation method used in the following examples is as follows: Seed culture medium: beef powder 3 g / L, peptone 10 g / L, sodium chloride 5 g / L. The seed culture medium was filled into a triangular flask with a liquid volume of 50 mL / 250 mL, sterilized at 121°C for 30 min, and then inoculated with a loop of Acinetobacter S-1 (preservation number: CGMCC No. 31164) under sterile operation, cultured at 37°C and 160 rpm for 12 h to obtain the seed liquid.

[0049] Example 1: Preparation of liquid phosphorus-solubilizing bacterial agent Fermentation medium: honey 25 g, ammonium sulfate 1.7 g, calcium phosphate 6 g, potassium chloride 0.2 g, sodium chloride 0.3 g, magnesium sulfate 0.3 g, ferrous sulfate 0.03 g, manganese sulfate 0.03 g, and 1 L of bottom pot water of strong-flavor brewing yellow water (pH adjusted to 7.5 with 50% NaOH solution) was used for dissolution.

[0050] After sterilizing the fermentation medium at 121°C for 30 min, the pH value was adjusted to 7.0 by adding 1:1 diluted hydrochloric acid solution under sterile operation, inoculating the seed liquid at a 5% inoculation amount, and culturing at 37°C and 150 rpm for 24 h to obtain the liquid microbial agent with phosphorus-solubilizing function.

[0051] The number of viable bacteria was determined to be 5.2×10 9 CFU / mL, the effective phosphorus was 94.94 mg / L, the alkaline phosphatase activity was 8105.16 μmol / L·h, and the acid phosphatase activity was 1009.93 μmol / L·h.

[0052] Example 2: Preparation of liquid phosphorus-solubilizing bacterial agent The difference from Example 1 is that the calcium phosphate used in the fermentation medium is 7 g, and after inoculating the seed liquid, the culture is carried out for 36 h, and the rest of the operation steps are consistent with Example 1 to obtain the liquid microbial agent with phosphorus-solubilizing function.

[0053] The number of viable bacteria was determined to be 7.8×10 9CFU / mL, available phosphorus was 86.84 mg / L, alkaline phosphatase activity was 7169.18 μmol / L·h, and acid phosphatase activity was 1953.63 μmol / L·h.

[0054] Example 3: Preparation of liquid phosphorus solubilizing bacterial agent The difference from Example 1 is that after inoculating the seed liquid, the culture is cultured for 48 h, and the remaining operation steps are consistent with those of Example 1, thereby obtaining a liquid microbial agent with phosphorus solubilizing function.

[0055] It is determined that the viable bacterial count is 4.8×10 9 CFU / mL, available phosphorus was 60.76 mg / L, alkaline phosphatase activity was 10292.93 μmol / L·h, and acid phosphatase activity was 3000.10 μmol / L·h.

[0056] Comparative Example 1 The difference from Example 1 is that the composition of the fermentation medium is different, and 5 g of lecithin is used instead of 6 g of calcium phosphate in Example 1, and after inoculating the seed liquid, the culture is cultured for 36 h, and the remaining operation steps are consistent with those of Example 1, thereby obtaining a liquid microbial agent with phosphorus solubilizing function.

[0057] It is determined that the viable bacterial count is 4.8×10 8 CFU / mL, available phosphorus was 49.85 mg / L, alkaline phosphatase activity was 545.65 μmol / L·h, and acid phosphatase activity was 943.98 μmol / L·h.

[0058] Comparative Example 2 The difference from Example 1 is that the composition of the fermentation medium is different, and deionized water is used instead of yellow water in Example 1, and the remaining operation steps are consistent with those of Example 1, thereby obtaining a liquid microbial agent with phosphorus solubilizing function.

[0059] It is determined that the viable bacterial count is 5.2×10 8 CFU / mL, available phosphorus was 55.47 mg / L, alkaline phosphatase activity was 8713.35 μmol / L·h, and acid phosphatase activity was 1465.36 μmol / L·h.

[0060] Table 2: Performance of liquid microbial agents prepared in different test groups As can be seen from the examples and comparative examples, the composition of the fermentation medium and the fermentation time have a great influence on the available phosphorus content of the phosphorus solubilizing agent. When the fermentation medium contains calcium phosphate and yellow water, the available phosphorus content is as high as 94 mg / L or more.

[0061] Test Example 1: Liquid phosphate-dissolving bacteria agent used in growing sorghum The effects of different treatment groups, including clean water, commercial microbial agent (commercially available), 10% S-1 liquid phosphate-solubilizing agent (Example 1), and 20% S-1 liquid phosphate-solubilizing agent (Example 1), on sorghum growth and rhizosphere soil nutrients were compared.

[0062] The results showed that the application of 10% S-1 liquid microbial agent significantly promoted the growth of sorghum compared with the clear water group. Its leaf area, plant height, stem diameter and ear length increased by 10.8%, 9.6%, 5.1% and 6.1% respectively compared with the clear water group, and the yield increased by 52.58%; for rhizosphere soil nutrients, the soil available phosphorus content of the 20% S-1 liquid microbial agent group was 39.85 mg / kg and the total nitrogen content was 1.97 g / kg. Compared with the clear water group, its available phosphorus, total nitrogen and available potassium contents increased by 96.21%, 13.22% and 12.09% respectively. Compared with the commercial microbial agent, the leaf area, plant height, stem diameter and ear length of the group applying 10% S-1 inoculant increased by 8.0%, 8.4%, 5.0% and 14.1% respectively, and the yield increased by 31.47%; for rhizosphere soil nutrients, the soil available phosphorus, total nitrogen and available potassium contents of the group applying 10% S-1 liquid inoculant increased by 12.33%, 2.18% and 15.41% respectively; the soil available phosphorus content of the group applying 20% ​​S-1 liquid inoculant increased by 18.12%.

Claims

1. A method for preparing a liquid phosphate-dissolving bacteria agent, characterized in that: The following steps are involved: A liquid phosphate-solubilizing bacteria agent is obtained by inoculating a seed liquid containing Acinetobacter S-1 into a fermentation medium for cultivation; wherein the preservation number of the Acinetobacter S-1 is CGMCC No. 31164; the fermentation medium uses yellow water bottom pot water as a solvent and comprises, by mass ratio to the yellow water bottom pot water, 22-28 g / L of honey, 1.2-2.0 g / L of ammonium sulfate, 3-8 g / L of calcium phosphate, 0.1-0.3 g / L of potassium chloride, 0.1-0.5 g / L of sodium chloride, 0.1-0.5 g / L of magnesium sulfate, 0.01-0.05 g / L of ferrous sulfate, and 0.01-0.05 g / L of manganese sulfate.

2. The method for preparing the liquid phosphate-solubilizing bacteria agent according to claim 1, wherein: The seed liquid is obtained by inoculating Acinetobacter S-1 into a seed culture medium and culturing at 32-37° C. and 120-160 rpm for 12-24 hours.

3. The preparation method of the liquid phosphate-solubilizing bacteria agent according to claim 1, wherein: The seed culture medium comprises 2-3 g / L beef powder, 7-15 g / L peptone and 3-8 g / L sodium chloride.

4. The method for preparing the liquid phosphate-solubilizing bacteria agent according to claim 1, wherein: The pH of the yellow water bottom pot water is adjusted to 7.0-7.5 before use.

5. The method for preparing the liquid phosphate-solubilizing bacteria agent according to claim 1, wherein: After the fermentation medium is sterilized, its pH value is adjusted to 7.0-7.

5.

6. The method for preparing the liquid phosphate-solubilizing bacteria agent according to claim 1, wherein: The seed liquid inoculation amount is 3-8%.

7. The method for preparing the liquid phosphate-solubilizing bacteria agent according to claim 1, wherein: The seed liquid was inoculated into the fermentation medium and cultured at 32-37°C for 24-48 h.

8. The liquid phosphate-solubilizing bacteria agent according to any one of claims 1 to 7.

9. A microbial phosphate-solubilizing agent, characterized in that: It contains Acinetobacter S-1, and its deposit number is CGMCC No.31164.

10. Use of the phosphate-solubilizing bacteria agent according to claim 8 or 9 in promoting plant growth.

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