Aspergillus niger composition and use thereof

Abstract

The present application belongs to the field of agricultural microorganism technology, and particularly relates to a composition of Aspergillus niger and application thereof.The composition of the present application combines Aspergillus niger and fertilizer synergist, and has a synergistic effect, wherein the Aspergillus niger has high lead tolerance and lead repair capacity.The composition of the present application not only has the functions of dissolving phosphorus and degrading straw, but also can effectively improve soil fertility and reduce the availability of heavy metal lead.The composition of the present application plays an important role in promoting the reuse of phosphorus-containing solid waste, promoting straw rot, reducing industrial and agricultural waste emissions, reducing the biological availability of lead and maintaining the safety of ecological environment.

Description

Technical Field

[0001] This invention relates to the field of agricultural microbial technology, specifically to a composition of Aspergillus niger and its application. Background Technology

[0002] Phosphorus-solubilizing microorganisms can effectively promote the conversion of insoluble phosphorus in the soil into forms that can be absorbed and utilized by plants. The low-molecular-weight organic acids they secrete can not only significantly reduce the environmental pH value, but also react with calcium... 2+ Fe 3+ It can complex with metal ions, promoting the release of phosphorus from insoluble phosphates. Aspergillus niger is a typical phosphorus-solubilizing microorganism in soil, possessing cellulase activity.

[0003] In existing technologies, there are techniques that utilize Aspergillus niger to degrade straw, increase the accumulation of soil organic matter, and achieve carbon sequestration and emission reduction. However, in the application of straw degradation and lead pollution remediation, simply using Aspergillus niger in planting is not ideal. The growth of Aspergillus niger and the secretion of its organic acids are easily affected by various environmental factors, which in turn affects its application effect.

[0004] Therefore, how to provide a substance that can effectively improve the degradation, phosphorus dissolution and lead fixation effects of Aspergillus niger in straw has become an urgent problem to be solved in this field. Summary of the Invention

[0005] In order to provide a solution that can effectively achieve phosphorus dissolution, promote straw degradation and lead fixation, this invention provides a Aspergillus niger composition, which has the advantages of simple preparation method, high efficiency and environmental protection.

[0006] A composition of Aspergillus niger, the composition comprising the following components: Aspergillus niger and a fertilizer synergist;

[0007] The ratio of fertilizer synergist to Aspergillus niger in liquid solution is 0.1–0.5 g: 1 mL;

[0008] The concentration of Aspergillus niger in the composition is 2–3 × 10⁻⁶. 8 CFU / mL.

[0009] Preferably, the Aspergillus niger includes Aspergillus niger AH-F-1-2, and the preservation number of Aspergillus niger AH-F-1-2 is CGMCC No. 23272.

[0010] Preferably, the fertilizer synergist includes any one or more of fulvic acid, alginic acid, and glutamic acid.

[0011] The present invention also provides a method for preparing the Aspergillus niger composition as described above, comprising the following steps:

[0012] The Aspergillus niger suspension was inoculated into PVK medium to obtain PVK medium inoculated with the Aspergillus niger suspension;

[0013] A fertilizer enhancer was added to the PVK medium inoculated with Aspergillus niger, and the medium was shaken and cultured to obtain the Aspergillus niger composition.

[0014] Preferably, the volume ratio of the Aspergillus niger suspension to PVK medium is 1:100; the pH of the PVK medium is 7.0–7.2; and the inoculation concentration of the Aspergillus niger suspension is (1–9) × 10⁻⁶. 7 CFU / mL.

[0015] Preferably, the mass ratio of the fertilizer synergist to the volume ratio of the PVK culture medium is 0.1–0.5 g: 100 mL.

[0016] Preferably, the temperature for the shaking culture is 28–30°C, and the shaking speed is 160–180 rpm.

[0017] The present invention also provides the application of the Aspergillus niger composition or the Aspergillus niger composition prepared by the above-described preparation method in any one or more of phosphorus solubilization, straw degradation promotion and lead fixation.

[0018] Preferably, when the Aspergillus niger composition is used to dissolve phosphorus and / or promote straw degradation, the ratio of the Aspergillus niger suspension, fertilizer synergist, and phosphorus-containing substances and / or straw is 1 mL: 0.1-0.5 g: 0.5 g.

[0019] Preferably, the lead fixation includes: fixing the lead by combining the Aspergillus niger composition with phosphorus-containing substances and / or straw.

[0020] The beneficial effects of this invention are as follows:

[0021] This invention provides a *Aspergillus niger* composition comprising *Aspergillus niger* and a fertilizer synergist; the ratio of the fertilizer synergist to *Aspergillus niger* in the liquid solution is 0.1–0.5 g: 1 mL; and the concentration of *Aspergillus niger* in the composition is 2–3 × 10⁻⁶. 8 CFU / mL. This invention combines Aspergillus niger with a fertilizer synergist. The fertilizer synergist can promote the growth of Aspergillus niger or stimulate its metabolic activity, and can stimulate the secretion of organic acids, especially oxalic acid, by Aspergillus niger. In this way, it can promote the degradation of straw or the release of phosphorus through acidification and chelation. In lead fixation, this process can not only promote the formation of lead oxalate minerals, but also generate more and more stable lead phosphate ore, thereby enhancing the remediation effect of Aspergillus niger on lead pollution.

[0022] This invention provides an effective way to enhance phosphorus resource utilization and improve lead pollution remediation by combining Aspergillus niger with fertilizer synergists. It plays an important role in promoting the reuse of phosphorus-containing solid waste, promoting straw decomposition, reducing industrial and agricultural waste emissions, reducing the bioavailability of lead, and maintaining ecological and environmental security. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the embodiments will be briefly described below.

[0024] Figure 1 This is a colony diagram of the phosphate-solubilizing fungi in Example 2;

[0025] Figure 2 The figure shows the effect of fertilizer synergist combined with Aspergillus niger on phosphorus release from apatite in Example 8.

[0026] Figure 3 The graph shows the effect of fertilizer synergist combined with Aspergillus niger on phosphorus release from straw in Example 9.

[0027] Figure 4 This is a graph showing the effect of fertilizer synergist combined with Aspergillus niger on microbial biomass in straw degradation in Example 9;

[0028] Figure 5 This is a graph showing the effect of fertilizer synergist combined with Aspergillus niger on oxalic acid release during straw degradation in Example 9;

[0029] Figure 6 This is a graph showing the effect of fertilizer synergist combined with Aspergillus niger on straw degradation rate in Example 9;

[0030] Figure 7 The diagram shows the effect of fertilizer synergist combined with Aspergillus niger compound apatite or straw lead fixation in Example 10.

[0031] Biological Preservation Information

[0032] The strain of Aspergillus niger, AH-F-1-2, was deposited on September 30, 2021, at the China General Microbiological Culture Collection Center (CGMCC), Institute of Microbiology, Chinese Academy of Sciences, No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing, with accession number CGMCCNo. 23272. Detailed Implementation

[0033] The specific embodiments of the present invention will be described in further detail below with reference to the examples. These examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0034] This invention provides a *Aspergillus niger* composition comprising the following components: *Aspergillus niger* and a fertilizer synergist; the ratio of the fertilizer synergist to *Aspergillus niger* in the liquid solution is 0.1–0.5 g: 1 mL; the concentration of *Aspergillus niger* in the composition is 2–3 × 10⁻⁶. 8 CFU / mL.

[0035] In one embodiment, the ratio of fertilizer synergist to Aspergillus niger in the liquid solution is 0.1–0.5 g:1 mL; in another embodiment, the ratio of fertilizer synergist to Aspergillus niger in the liquid solution can be any one of 0.1 g:1 mL, 0.2 g:1 mL, 0.3 g:1 mL, 0.4 g:1 mL, and 0.5 g:1 mL; in yet another embodiment, the concentration of Aspergillus niger in the composition can be 2 × 10⁻⁶. 8 CFU / mL, 2.1×10 8 CFU / mL, 2.2×10 8 CFU / mL, 2.3×10 8 CFU / mL, 2.4×10 8 CFU / mL, 2.58×10 8 CFU / mL, 2.6×10 8 CFU / mL, 2.7×10 8 CFU / mL, 2.8×10 8 CFU / mL, 2.9×10 8 CFU / mL and 3.0×10 8 Any one of CFU / mL; in a specific embodiment, the fertilizer synergist to Aspergillus niger liquid ratio is 0.4g:1mL, and the concentration of Aspergillus niger in the composition is 2.58×10⁻⁶. 8 CFU / mL.

[0036] In one embodiment, the *Aspergillus niger* of this invention includes *Aspergillus niger* AH-F-1-2; *Aspergillus niger* AH-F-1-2 was screened from the rhizosphere soil of wheat at the Wanbei Comprehensive Experimental Station of Anhui Agricultural University, as disclosed in patent CN116285999A. The colonies of *Aspergillus niger* AH-F-1-2 are charcoal black, flat, and granular with concentric rings on the colony surface.

[0037] In one embodiment, the fertilizer synergist includes any one, two, or three of fulvic acid, alginic acid, and glutamic acid; in a specific embodiment, the fertilizer synergist is fulvic acid, and the weight fraction of the fertilizer synergist is 0.4 parts.

[0038] The present invention also provides a method for preparing the Aspergillus niger composition described in the above technical solution, comprising the following steps: inoculating Aspergillus niger suspension into PVK medium to obtain PVK medium inoculated with Aspergillus niger suspension; adding a fertilizer synergist to the PVK medium inoculated with Aspergillus niger suspension, shaking and culturing to obtain the Aspergillus niger composition.

[0039] This invention involves inoculating a suspension of *Aspergillus niger* into PVK medium to obtain PVK medium inoculated with the *Aspergillus niger* suspension. As one embodiment, the volume ratio of the *Aspergillus niger* suspension to PVK medium is 1:100; as another embodiment, the inoculation concentration of the *Aspergillus niger* suspension is (1–9) × 10⁻⁶. 7 CFU / mL; as one embodiment, the inoculation concentration of the Aspergillus niger suspension includes 1×10⁻⁶ CFU / mL. 7 CFU / mL, 2×10 7 CFU / mL, 3×10 7 CFU / mL, 4×10 7 CFU / mL, 5×10 7 CFU / mL, 6×10 7 CFU / mL, 7×10 7 CFU / mL, 8×10 7 CFU / mL and 9×10 7 Any of the following concentrations (CFU / mL). As one embodiment, the PVK medium comprises the following raw materials in parts by weight: 10 parts glucose, 0.5 parts ammonium sulfate, 0.2 parts sodium chloride, 0.25 parts magnesium sulfate heptahydrate, 0.03 parts ferric sulfate heptahydrate, 0.2 parts potassium chloride, 0.03 parts manganese sulfate tetrahydrate, and 1000 parts deionized water; in a specific embodiment, the volume ratio of the Aspergillus niger suspension to the PVK medium is 1:100; the pH of the PVK medium is 7.1, and the PVK medium comprises the following raw materials: 10 g glucose, 0.5 g ammonium sulfate, 0.2 g sodium chloride, 0.25 g magnesium sulfate heptahydrate, 0.03 g ferric sulfate heptahydrate, 0.2 g potassium chloride, 0.03 g manganese sulfate tetrahydrate, and 1000 mL deionized water; the pH of the PVK medium is 7.0–7.2; as one embodiment, the pH of the PVK medium can be any of 7.0, 7.1, and 7.2.

[0040] After obtaining the PVK medium inoculated with Aspergillus niger suspension, the present invention adds a fertilizer synergist to the PVK medium inoculated with Aspergillus niger suspension, and then shakes and cultures to obtain the Aspergillus niger composition. As one embodiment, the mass ratio of the fertilizer synergist to the volume of the PVK medium is 0.1–0.5 g:100 mL; as another embodiment, the mass ratio of the fertilizer synergist to the volume of the PVK medium can be any one of 0.1 g:100 mL, 0.2 g:100 mL, 0.3 g:100 mL, 0.4 g:100 mL, and 0.5 g:100 mL; as one embodiment, the shaking culture temperature is 28°C–30°C, and the shaking speed is 160–180 rpm. m; as another embodiment, the temperature of the shaking culture can be any one of 28℃, 29℃ and 30℃; as another embodiment, the shaking speed of the shaking culture can be any one of 160rpm, 170rpm and 180rpm; in a specific embodiment, the present invention adds a fertilizer synergist to PVK medium and shakes the culture, the inoculation ratio of the fertilizer synergist to PVK medium is 0.4g:100mL, the shaking culture temperature is 29℃ and the shaking speed is 170rpm.

[0041] The present invention also provides the use of the composition as described in any one of the preceding claims or the composition prepared by any one of the preceding methods in one or more of the following: phosphorus dissolution, promoting straw degradation and lead fixation.

[0042] In one embodiment, the application of the Aspergillus niger composition in phosphorus solubilization includes the following steps: mixing the Aspergillus niger composition with a phosphorus-containing substance, followed by shaking and incubation, thereby achieving the phosphorus solubilization effect; in one embodiment, the phosphorus-containing substance includes apatite. In one embodiment, when applied to phosphorus solubilization, the ratio of the Aspergillus niger suspension to the fertilizer synergist and the phosphorus-containing substance is 1 mL: 0.1–0.5 g: 0.5 g. In another embodiment, the ratio of the Aspergillus niger suspension to the fertilizer synergist and the phosphorus-containing substance can be any one of 1 mL: 0.1 g: 0.5 g, 1 mL: 0.2 g: 0.5 g, 1 mL: 0.3 g: 0.5 g, 1 mL: 0.4 g: 0.5 g, and 1 mL: 0.5 g: 0.5 g. As one implementation method, the shaking culture conditions are 160-180 rpm shaking culture for 5 days; in a specific embodiment, the application of the Aspergillus niger composition in phosphorus solubilization includes the following steps: after mixing the Aspergillus niger composition with apatite evenly, shaking culture at 170 rpm for 5 days to achieve phosphorus solubilization effect; the ratio of the Aspergillus niger suspension to fertilizer synergist and phosphorus-containing substances is 1 mL: 0.4 g: 0.5 g.

[0043] As another embodiment, the application of the Aspergillus niger composition in phosphorus solubilization can be combined with the preparation of the Aspergillus niger composition and the application of phosphorus solubilization, including the following steps: mixing Aspergillus niger, fertilizer synergist, PVK medium and phosphorus-containing substances and then shaking and culturing to achieve the phosphorus solubilization effect; as one embodiment, the shaking and culturing conditions are 160-180 rpm for 5 days; in a specific embodiment, the application of the Aspergillus niger composition in phosphorus solubilization includes the following steps: mixing Aspergillus niger, fertilizer synergist, PVK medium and apatite evenly and then shaking and culturing at 170 rpm for 5 days to achieve the phosphorus solubilization effect.

[0044] In one embodiment, the application of the Aspergillus niger composition in promoting straw degradation includes the following steps: mixing the Aspergillus niger composition with straw achieves the effect of promoting straw degradation; in one embodiment, the shaking culture conditions are 160-180 rpm for 5 days; in one embodiment, the straw can be rice straw; in one embodiment, when applied to promote straw degradation, the ratio of the Aspergillus niger suspension to the fertilizer synergist and straw is 1 mL:0.1-0.5 g:0.5 g. In another embodiment, the ratio of the Aspergillus niger suspension to the fertilizer synergist and straw can be any one of 1 mL:0.1 g:0.5 g, 1 mL:0.2 g:0.5 g, 1 mL:0.3 g:0.5 g, 1 mL:0.4 g:0.5 g, and 1 mL:0.5 g:0.5 g. In a specific embodiment, the application of the Aspergillus niger composition in promoting straw degradation includes the following steps: after mixing the Aspergillus niger composition with rice straw evenly, it is shaken and cultured at 170 rpm for 5 days to achieve the effect of promoting straw degradation; the ratio of the Aspergillus niger suspension to fertilizer synergist and rice straw is 1 mL: 0.4 g: 0.5 g.

[0045] As another embodiment, the application of the Aspergillus niger composition in promoting straw degradation can be combined with the preparation of the Aspergillus niger composition and its application in promoting straw degradation, including the following steps: mixing Aspergillus niger, fertilizer synergist, PVK medium and straw, and then shaking and culturing to achieve the effect of promoting straw degradation; as one embodiment, the shaking and culturing conditions are 160-180 rpm for 5 days; in a specific embodiment, the application of the Aspergillus niger composition in promoting straw degradation includes the following steps: mixing Aspergillus niger, fertilizer synergist, PVK medium and straw evenly, and then shaking and culturing at 170 rpm for 5 days to achieve the effect of promoting straw degradation.

[0046] In one embodiment, the application of the Aspergillus niger composition in lead fixation includes the following steps: mixing the Aspergillus niger composition with phosphorus-containing substances and / or straw to obtain a mixture, and then mixing the mixture with lead-containing substances to achieve lead fixation; in one embodiment, the lead-containing substances include lead nitrate; in a specific embodiment, the application of the Aspergillus niger composition in lead fixation includes the following steps: mixing Aspergillus niger, fertilizer synergist, and straw evenly, and then mixing the straw with lead nitrate after it has degraded to achieve lead fixation; in another specific embodiment, the application of the Aspergillus niger composition in lead fixation includes the following steps: mixing the Aspergillus niger composition with apatite evenly, and then mixing the apatite with lead nitrate after it has dissolved to achieve lead fixation.

[0047] In another embodiment, the application of the Aspergillus niger composition in lead fixation includes the following steps: mixing Aspergillus niger, fertilizer synergist, phosphorus-containing substances, and lead-containing substances. The phosphorus-containing substances can increase the stability of lead fixation, and Aspergillus niger can promote the release of phosphorus from the phosphorus-containing substances. The released phosphorus can further react with lead to form very stable lead-containing minerals, thus achieving the lead fixation effect. In another embodiment, the application of the Aspergillus niger composition in lead fixation includes the following steps: mixing Aspergillus niger, fertilizer synergist, straw, and lead-containing substances to achieve the lead fixation effect. In a specific embodiment, the application of the Aspergillus niger composition in lead fixation includes the following steps: mixing Aspergillus niger, fertilizer synergist, apatite, and lead nitrate to achieve the lead fixation effect. In yet another specific embodiment, the application of the Aspergillus niger composition in lead fixation includes the following steps: mixing Aspergillus niger, fertilizer synergist, crop straw, and lead nitrate to achieve the lead fixation effect.

[0048] In summary, the purpose of this invention is to provide a composition of Aspergillus niger prepared by combining different fertilizer synergists with Aspergillus niger, and the application of the composition in promoting phosphorus release from apatite, promoting straw degradation, and using compound phosphates and straw for lead fixation. Aspergillus niger can secrete large amounts of oxalic acid (H₂C₂O₄), which promotes phosphorus dissolution in phosphate rock or increases cellulose degradation rate through acidification media, promotes straw decomposition and degradation, and can also reduce the bioavailability of lead in the environment in conjunction with straw.

[0049] To further illustrate the present invention, the following detailed description, in conjunction with the accompanying drawings and embodiments, provides an anti-wrinkle, firming, and repairing composition containing sturgeon caviar extract and its application, but these descriptions should not be construed as limiting the scope of protection of the present invention.

[0050] Example 1: Preparation of Culture Medium

[0051] Prepare Monkina (PVK) medium, PDA medium and PDB medium according to the raw material components shown below;

[0052] PVK medium: 10g glucose, 0.5g ammonium sulfate, 0.2g sodium chloride, 0.25g magnesium sulfate heptahydrate, 0.03g ferric sulfate heptahydrate, 0.2g potassium chloride, 0.03g manganese sulfate tetrahydrate, 1000mL deionized water, pH 7.1.

[0053] PDA medium: Wash and peel fresh potatoes, weigh 200g, cut into small pieces, boil in water for 25 minutes, filter through eight layers of gauze, add 20g glucose and 15-20g agar powder while hot, stir well, and after the medium cools, add water to 1000mL.

[0054] PDB medium: 46g potato glucose medium, 1000mL deionized water, pH 7.0.

[0055] The preparation methods for all culture media are as follows: dissolve the raw materials in deionized water and mix well.

[0056] Example 2: Preparation of Spore Suspension

[0057] The Aspergillus niger strain AH-F-1-2 disclosed in patent CN116285999A was inoculated onto PDA medium and cultured in an incubator at 28°C for 5 days to form spores.

[0058] Remove the PDA medium containing Aspergillus niger spores. Wash the medium with sterile water under sterile conditions. Then, scrape the fungal spores from the PDA medium with a sterile inoculation loop and mix them with the sterile water from the washing medium to obtain a spore suspension. Filter the spore suspension through three layers of gauze to remove broken hyphal fragments, obtaining a spore solution. Measure the spore concentration in the spore solution using a hemocytometer. Dilute the spore solution to 9 × 10⁻⁶ with sterile water. 7 CFU / mL was used to obtain a suspension of Aspergillus niger.

[0059] Example 4: A composition of Aspergillus niger

[0060] The composition comprises 1 part Aspergillus niger and 0.1 part fertilizer synergist;

[0061] The Aspergillus niger suspension was prepared according to the method described in Example 2, except that the final concentration of the Aspergillus niger suspension was 1×10⁻⁶. 7 CFU / mL;

[0062] The fertilizer synergist is fulvic acid, and the inoculation concentration of fulvic acid is 1 g / L.

[0063] Example 5: A composition of Aspergillus niger

[0064] The composition comprises 1 part Aspergillus niger and 0.3 parts fertilizer synergist;

[0065] The Aspergillus niger suspension was prepared according to the method described in Example 2, except that the final concentration of the Aspergillus niger suspension was 5 × 10⁻⁶. 7 CFU / mL;

[0066] The fertilizer enhancer is glutamic acid, and the concentration of glutamic acid in the inoculation is 3 g / L.

[0067] Example 6: A composition of Aspergillus niger

[0068] The composition comprises 1 part Aspergillus niger and 0.5 parts fertilizer synergist;

[0069] The Aspergillus niger was prepared into a suspension according to the method described in Example 2;

[0070] The fertilizer synergist is alginic acid, and the inoculation concentration of alginic acid is 5 g / L.

[0071] Example 7: A method for preparing an Aspergillus niger composition

[0072] The preparation method includes the following steps:

[0073] Weigh out Aspergillus niger and fertilizer enhancer according to the specified ratio and set aside.

[0074] The Aspergillus niger was inoculated into PVK medium at a volume ratio of 1:100, and the pH of the PVK medium was 7.1.

[0075] A fertilizer synergist was added to the PVK medium at an inoculation ratio of 0.3 g to 100 mL, and the mixture was cultured under shaking conditions at 29 °C and 170 rpm to obtain the composition.

[0076] Example 8: Application of fertilizer synergist combined with Aspergillus niger in promoting phosphorus release from apatite.

[0077] In this embodiment, the concentration of Aspergillus niger in the composition was 2.58 × 10⁻⁶. 8 CFU / mL; the inoculum volume of Aspergillus niger was 1% of the volume of PVK medium; ammonium sulfate was the sole nitrogen source in PVK medium.

[0078] Apatite sample processing: After the apatite is collected, it is first crushed, then ground into powder by ball milling, and then stored for later use after passing through a 100-mesh sieve.

[0079] The experimental method is as follows: 100 mL of PVK medium was added to a 250 mL Erlenmeyer flask and sterilized at 121 °C for 20 min; Aspergillus niger and 0.5 g of apatite powder were added, and then the mixture was divided into 18 groups, with three replicates for each group. The following were added respectively: 0 g fulvic acid, 0.1 g fulvic acid, 0.2 g fulvic acid, 0.3 g fulvic acid, 0.4 g fulvic acid, 0.5 g fulvic acid; 0 g alginic acid, 0.1 g alginic acid, 0.2 g alginic acid, 0.3 g alginic acid, 0.4 g alginic acid, 0.5 g alginic acid; 0 g glutamic acid, 0.1 g glutamic acid, 0.2 g glutamic acid, 0.3 g glutamic acid, 0.4 g glutamic acid, 0.5 g glutamic acid.

[0080] The above cultures were incubated on a shaker at 28℃ and 180rpm for 5 days. Samples were taken on day 5 to observe and measure the growth of the strains. The available phosphorus content in each treatment culture medium was determined by ICP-OES. The results are as follows: Figure 2 As shown in Table 1.

[0081] Table 1. Phosphorus solubility in apatite by different fertilizer synergists combined with Aspergillus niger.

[0082]

[0083] Note: The letters after the numbers indicate the differences in phosphorus solubility between different concentrations of fertilizer synergists; the same letter indicates that they are at the same level.

[0084] From Table 1 and Figure 2 As can be seen from the results, compared with the group without fertilizer synergists, the group with fertilizer synergists was able to promote the release of phosphorus from phosphate rock by Aspergillus niger, and the effects were significantly different. Among them, after 5 days of cultivation, the group containing 4 g / L glutamic acid in combination with Aspergillus niger had the best effect on promoting phosphorus release from apatite, and the solution of this group had the highest phosphorus content.

[0085] Example 9: Effects of fertilizer synergist combined with Aspergillus niger on the degradation of rice straw

[0086] In this embodiment, the concentration of Aspergillus niger in the composition was 2.58 × 10⁻⁶. 8 CFU / mL; the inoculum volume of Aspergillus niger was 1% of the volume of PVK medium; ammonium sulfate was the sole nitrogen source in PVK medium.

[0087] Rice straw sample processing: After drying the rice straw, cut it into 2cm sections for later use.

[0088] The experimental method is as follows: 100 mL of PVK medium was added to a 250 mL Erlenmeyer flask and sterilized at 121 °C for 20 min; Aspergillus niger solution was added, and 0.5 g of rice straw was added. Then, the mixture was divided into 18 groups, with three replicates for each group. The following were added respectively: 0 g fulvic acid, 0.1 g fulvic acid, 0.2 g fulvic acid, 0.3 g fulvic acid, 0.4 g fulvic acid, 0.5 g fulvic acid; 0 g alginic acid, 0.1 g alginic acid, 0.2 g alginic acid, 0.3 g alginic acid, 0.4 g alginic acid, 0.5 g alginic acid; 0 g glutamic acid, 0.1 g glutamic acid, 0.2 g glutamic acid, 0.3 g glutamic acid, 0.4 g glutamic acid, 0.5 g glutamic acid.

[0089] The above cultures were incubated on a shaker at 28℃ and 180rpm for 5 days. Samples were taken on day 5 to observe and measure the growth of the strains. The available phosphorus content in each treatment culture medium was determined by ICP-OES. The results are as follows: Figure 3 As shown in Table 2; the straw degradation rate was observed and measured, and the results are as follows. Figure 4 As shown in Table 3; the biomass of Aspergillus niger in different groups was measured, and the results are as follows. Figure 5 As shown in Table 4; the oxalic acid secretion of straw was measured, and the results are as follows. Figure 6 As shown in Table 5.

[0090] Table 2. Effects of fertilizer synergists combined with Aspergillus niger on phosphorus release from straw.

[0091]

[0092] Note: The letters after the numbers indicate the differences in phosphorus release from straw between different concentrations of fertilizer enhancers; the same letter indicates that they are at the same level.

[0093] From Table 2 and Figure 3 It is evident that, compared to the group without fertilizer synergists, the group with added fertilizer synergists (alginic acid / humic acid / glutamic acid) was able to promote the release of phosphorus from straw by Aspergillus niger, and the effects were significantly different.

[0094] Table 3. Degradation rate of straw by fertilizer synergist combined with Aspergillus niger.

[0095]

[0096] Note: The letters after the numbers indicate the differences in the straw degradation promotion effects of different concentrations of fertilizer synergists combined with Aspergillus niger; the same letters indicate that they are at the same level.

[0097] From Table 3 and Figure 4 It is evident that, compared to the group without fertilizer synergists, the group with added fertilizer synergists (alginic acid / humic acid / glutamic acid) was able to promote the degradation of straw by Aspergillus niger, and the effects were significantly different.

[0098] Table 4. Effects of fertilizer synergists combined with Aspergillus niger on Aspergillus niger biomass in straw degradation.

[0099]

[0100] Note: The letters after the numbers indicate the differences in the effect of different concentrations of fertilizer synergists combined with Aspergillus niger on increasing Aspergillus niger biomass; the same letters indicate that they are at the same level.

[0101] From Table 4 and Figure 5 It is evident that, except for the group with 0.5g of glutamic acid, all other groups with added fertilizer enhancers were able to promote the growth of Aspergillus niger and increase its biomass.

[0102] Table 5. Oxalic acid secretion from straw degraded by fertilizer synergist combined with Aspergillus niger.

[0103]

[0104] Note: The letters after the numbers indicate the differences in oxalic acid secretion during the degradation of straw by different concentrations of fertilizer synergists combined with Aspergillus niger; the same letters indicate that they are at the same level.

[0105] From Table 5 and Figure 6 It is evident that the addition of glutamic acid promotes oxalic acid secretion from *Aspergillus niger*, while the addition of fulvic acid inhibits it. Alginic acid has little effect on oxalic acid secretion. This is because *Aspergillus niger* secretes a variety of organic acids, with oxalic acid being the primary organic acid leading to straw degradation and phosphorus release. The reduction in oxalic acid secretion after the addition of fulvic acid indicates that it is less effective than glutamic acid and alginic acid in promoting oxalic acid secretion. However, fulvic acid may also stimulate the secretion of other organic acids, resulting in increased straw degradation. Overall, however, the effect of fulvic acid is weaker than that of glutamic acid and alginic acid. The highest oxalic acid release was observed when 5 g / L of glutamic acid was added.

[0106] Example 10: The effect of fertilizer synergist combined with Aspergillus niger compound phosphate for lead fixation

[0107] Based on the results of Examples 8 and 9, the amount of fertilizer synergist added in this experiment was limited to 0.4g; the concentration of Aspergillus niger in the composition in this example was 2.58 × 10⁻⁶. 8 CFU / mL; the inoculum amount of Aspergillus niger was 1% of the volume of PVK medium; in PVK medium, ammonium sulfate was the only nitrogen source, and PVK medium with an initial lead concentration of 1000 mg / L was obtained by adding 0.16 g of lead nitrate to 100 mL of PVK medium.

[0108] The experimental method is as follows: 100 mL of PVK medium was added to a 250 mL Erlenmeyer flask and sterilized at 121 °C for 20 min; Aspergillus niger was added, and then the mixture was divided into 8 groups, with three replicates for each group: no fertilizer synergist + 0.5 g apatite, 0.4 g fulvic acid + 0.5 g apatite, 0.4 g alginic acid + 0.5 g apatite, 0.4 g glutamic acid + 0.5 g apatite, no fertilizer synergist + 0.5 g rice straw, 0.4 g fulvic acid + 0.5 g rice straw, 0.4 g alginic acid + 0.5 g rice straw, and 0.4 g glutamic acid + 0.5 g rice straw.

[0109] The above culture was carried out on a shaker at 28℃ and 180rpm for 5 days. Samples were taken on day 5, and the lead content in the filtrate of each treatment was determined by ICP-OES. The results are shown in Table 6. Figure 7 As shown.

[0110] Table 6. Effects of fertilizer synergists combined with Aspergillus niger, specifically compounded with apatite and rice straw for lead fixation.

[0111]

[0112] Note: The letters after the numbers indicate the differences in lead content between different fertilizer synergists combined with Aspergillus niger to remove lead; the same letters indicate that they are at the same level.

[0113] From Table 6 and Figure 7 It is evident that adding fertilizer synergists can significantly reduce the lead content in the solution compared to not adding them. Among these, the combination of alginate and apatite with Aspergillus niger shows the best effect on lead fixation.

[0114] As demonstrated by the above embodiments, the Aspergillus niger composition of the present invention, by combining Aspergillus niger with a fertilizer synergist, produces a synergistic effect, promoting the release of phosphorus from phosphorus-containing substances and accelerating straw degradation. Furthermore, the Aspergillus niger composition, when used with phosphorus-containing substances and / or straw, also has a lead-fixing effect. The present invention provides a method for enhancing phosphorus resource utilization and improving lead pollution remediation by combining Aspergillus niger with a fertilizer synergist. It plays a crucial role in promoting the reuse of phosphorus-containing solid waste, accelerating straw decomposition, reducing industrial and agricultural waste emissions, decreasing lead bioavailability, and maintaining ecological and environmental safety.

[0115] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements without departing from the principle of the present invention, and these improvements should also be considered within the scope of protection of the present invention.

Claims

1. An Aspergillus niger composition, characterized in that, The Aspergillus niger composition comprises the following components: Aspergillus niger and a fertilizer synergist; The Aspergillus niger comprises Aspergillus niger AH-F-1-2, and the preservation number of the Aspergillus niger AH-F-1-2 is CGMCC No. 23272; The fertilizer synergist is any one of fulvic acid, alginic acid and glutamic acid; The ratio of the fertilizer synergist and the Aspergillus niger is 0.1-0.5 g: 1 mL; The concentration of the A. niger in the composition is 2-3 x 10 8 CFU / mL.

2. The process for the preparation of Aspergillus niger composition as claimed in claim 1, wherein, The method comprises the following steps: Inoculating the Aspergillus niger suspension into the PVK culture medium to obtain the PVK culture medium inoculated with the Aspergillus niger suspension; Adding the fertilizer synergist into the PVK culture medium inoculated with the Aspergillus niger, and oscillating the culture to obtain the Aspergillus niger composition.

3. The production method according to claim 2, wherein The volume ratio of the Aspergillus niger suspension to the PVK medium is 1:100; the pH of the PVK medium is 7.0-7.2; the inoculation concentration of the Aspergillus niger suspension is (1-9)×10 7 CFU / mL.

4. The production method according to claim 2, wherein The ratio of the mass of the fertilizer synergist and the volume of the PVK culture medium is 0.1-0.5 g: 100 mL.

5. The production method according to claim 2, wherein The oscillating culture is carried out at a temperature of 28-30 °C and an oscillating speed of 160-180 rpm.

6. The Aspergillus niger composition of claim 1 is used for any one or more of the following purposes: dissolving phosphorus, promoting straw degradation and fixing lead.

7. The Aspergillus niger composition prepared by the method of any one of claims 2-5 is used for any one or more of the following purposes: dissolving phosphorus, promoting straw degradation and fixing lead.

8. Use according to claim 7, wherein the compound is ###0002### When the Aspergillus niger composition is used for dissolving phosphorus, the ratio of the Aspergillus niger suspension, the fertilizer synergist and the phosphorus-containing substance is 1 mL: 0.1-0.5 g: 0.5 g.

9. The use according to claim 7, wherein the compound is ###00003### 8 or ###00004### 9. When the Aspergillus niger composition is used for promoting straw degradation, the ratio of the Aspergillus niger suspension, the fertilizer synergist and the straw is 1 mL: 0.1-0.5 g: 0.5 g.

10. The use according to any one of claims 6 to 9, characterized in that, The fixing lead comprises: fixing lead after the Aspergillus niger composition is combined with the phosphorus-containing substance or the straw.

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