A Taiwan copper-greedy bacteria, its microbial agent and application

Abstract

The present invention relates to the field of microbial technology, and in particular to a Taiwan cupriavidus, a liquid microbial agent and an application thereof. The Taiwan cupriavidus (Cupriavidus) NKK10 has a deposit number of CCTCC No. M 2024729. The Taiwan cupriavidus NKK10 provided by the present invention and the microbial agent prepared therefrom have excellent potassium-solubilizing performance, can convert stable potassium-containing minerals in rocks into an effective form that can be absorbed by plants, and provide an effective solution to the potassium deficiency problem in my country. The present invention effectively solves the problems of instability of industrial potassium-solubilizing bacteria and unsatisfactory potassium-solubilizing effect of wild potassium-solubilizing bacteria in the prior art.

Description

Technical Field

[0001] The present invention relates to the field of microbial technology, and in particular to a Taiwan copper-grabbing bacterium, a microbial agent thereof and applications. Background Art

[0002] Most of the land in my country is deficient in potassium, because most of the potassium in the soil exists in the form of insoluble potassium salts, and the main reason for this is the low utilization rate of chemical fertilizers. According to statistics, when soluble potassium fertilizers are applied to the soil, the utilization rate in the season is only 10%-25%. The residual potassium element is easily chelated and fixed in the soil to form a chelate that is insoluble in water, making it difficult for plants to absorb and utilize it. Moreover, my country has abundant potassium-rich rocks, but they also exist in the form of insoluble potassium and cannot be used in agricultural production. Plant growth cannot be separated from potassium. Although my country is rich in potassium resources, it is not easily absorbed and utilized by plants. Based on this, how to convert insoluble potassium into an effective form that can be absorbed by plants has become an important research topic for scientific researchers.

[0003] In the prior art, chemical methods are mostly used to convert insoluble potassium into soluble potassium, but the chemical agents used are not conducive to environmental protection. Therefore, some people have proposed a bioconversion method, which uses microbial strains to dissociate insoluble potassium, convert insoluble mineral potassium into soluble potassium, and improve the absorption efficiency of potassium elements by plants. Furthermore, some potassium-solubilizing bacteria can secrete plant hormones, which have the effect of promoting plant growth and have a beneficial effect on agricultural development. However, the potassium-solubilizing bacteria in industrial production are currently single, mostly bacteria, and the strong spontaneous mutation of bacteria may lead to the weakening or disappearance of functional characteristics during the passage process. Although there are wild potassium-solubilizing bacteria isolated from nature, it is often encountered that crops have a good potassium-solubilizing effect but the yield of crops has not been significantly improved, and the inoculation of functional bacteria for consecutive years cannot increase production year by year. More importantly, the current research on potassium-solubilizing bacteria in the field of agricultural microorganisms is not comprehensive enough, and there is more research on a certain type of strain, such as rhizobia, and there is a lack of basic research on other functional strains.

[0004] Based on this, the development of a biological agent with efficient potassium-dissolving effect is of great significance for the resource utilization of insoluble potassium and agricultural production. Summary of the invention

[0005] In view of the problems in the prior art that industrial potassium-solubilizing bacteria are unstable and wild potassium-solubilizing bacteria have unsatisfactory potassium-solubilizing effects, the present invention provides a Taiwan copper-sucking bacteria, a microbial agent and an application thereof. The Taiwan copper-sucking bacteria NKK10 provided by the present invention and the microbial agent prepared therefrom have excellent potassium-solubilizing performance, can convert stable potassium-containing minerals in rocks into an effective form that can be absorbed by plants, and provide an effective solution to the potassium deficiency problem in my country.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The first aspect of the present invention provides a Cupriavidus NKK10, whose deposit number is CCTCC No.M 2024729.

[0008] Cupriavidus formosanus NKK10 was screened out from the rhizosphere soil of Lespedeza floribunda during the vegetative growth period in Limutai Scenic Area, Jizhou District, Tianjin City. It was classified and named Cupriavidus formosanus (Cupriavidus). It was deposited in the China Center for Type Culture Collection, abbreviated as CCTCC, on April 26, 2024. The strain collection number is CCTCC No.M 2024729. The collection address is: Wuhan University, No. 299, Bayi Road, Luojiashan Street, Wuchang District, Wuhan City.

[0009] Compared with the prior art, the Taiwan copper-greedy bacteria NKK10 provided by the present invention has an extremely high potassium feldspar adsorption capacity, and can form a biofilm on the surface of potassium feldspar, thereby achieving the purpose of efficiently degrading potassium feldspar and dissociating and releasing potassium ions. The Taiwan copper-greedy bacteria NKK10 provided by the present invention can convert stable potassium-containing minerals in rocks into an effective form that can be absorbed by plants, which can become an effective method for solving the problem of potassium deficiency in my country and has a high practical value. Furthermore, the Taiwan copper-greedy bacteria NKK10 strain provided by the present invention has strong stability and excellent potassium-solubilizing effect, which can effectively solve the problems of instability of industrial potassium-solubilizing bacteria and unsatisfactory potassium-solubilizing effect of wild potassium-solubilizing bacteria in the prior art, and provides a theoretical basis for the utilization of insoluble potassium-containing minerals.

[0010] A second aspect of the present invention provides an application of the Taiwan Cupric Bacteria NKK10 in rock potassium dissolution.

[0011] The third aspect of the present invention provides a liquid microbial agent, comprising the Cuproplastis taiwanensis NKK10 and fungal polysaccharides.

[0012] The present invention also mixes the Taiwan copper-greedy bacteria NKK10 and fungal polysaccharides to prepare a liquid microbial agent. The addition of fungal polysaccharides can help the Taiwan copper-greedy bacteria NKK10 to effectively adhere to the mineral surface, form a bacteria-mineral complex, change and maintain the microenvironment inside the complex, and thus improve the potassium-degrading ability of the Taiwan copper-greedy bacteria NKK10 to potassium feldspar, thereby achieving efficient potassium degrading in a short time.

[0013] Preferably, the mass ratio of Cupriais formosanus NKK10 and fungal polysaccharide in the microbial agent is 10000:1-10000:1.5.

[0014] Preferably, the number of viable bacteria of Taiwan Cupricobacterium NKK10 in the microbial agent is 1×10 3CFU / g-1×10 4 CFU / g.

[0015] Preferably, the fungal polysaccharide is Cordyceps militaris polysaccharide.

[0016] A fourth aspect of the present invention provides an application of the microbial agent in potassium dissolution from rocks.

[0017] A fifth aspect of the present invention provides a method for applying the microbial agent to rock potassium dissolution, comprising the following steps:

[0018] S1, activating the Taiwan copper-grabbing bacteria NKK10 to obtain an activated bacterial solution;

[0019] S2. Inoculate the activated bacterial solution into a liquid culture medium, add crushed potassium-containing rock and fungal polysaccharide, and culture with shaking to obtain treated potassium-dissolving rock.

[0020] Preferably, in S1, the culture medium used for activation is LB liquid culture medium.

[0021] Further preferably, the LB liquid culture medium is composed of: 10 g of tryptone, 5 g of yeast extract powder, 10 g of NaCl, and distilled water to 1000 mL; pH 7.0; 121° C., 0.1 MPa, and sterilization for 30 min before use.

[0022] Preferably, in S1, the activation culture time is 10h-14h.

[0023] Preferably, in S2, the particle size of the crushed potassium-containing rock is 0.3 mm-1.0 mm.

[0024] Further preferably, in S2, the particle size of the crushed potassium-containing rock is 0.5 mm.

[0025] Preferably, in S2, the shaking culture temperature is 28-32°C, and the shaking culture time is 10d-14d.

[0026] Further preferably, in S2, the shaking culture temperature is 30° C., and the shaking culture time is 12 days.

[0027] Preferably, in S2, the added amount of the sample to be tested is 0.3%-0.5% of the mass of the liquid culture medium.

[0028] Preferably, in S2, the liquid culture medium comprises the following raw materials in parts by weight: 8-12 parts of sucrose, 0.3-0.5 parts of Na2HPO4, 0.8-1.2 parts of (NH4)2SO4, 0.1-0.3 parts of MgSO4, 1-3 parts of yeast extract, 0.01-0.03 parts of FeCl3 and 980-1020 parts of distilled water, and the pH of the culture medium is adjusted to 7.1-7.3.

[0029] In summary, in view of the problems of instability of industrial potassium-solubilizing bacteria and unsatisfactory potassium-solubilizing effect of wild potassium-solubilizing bacteria in the prior art, the present invention provides a Taiwan copper-sucking bacteria, its microbial agent and application. The Taiwan copper-sucking bacteria NKK10 and the microbial agent prepared therefrom have excellent potassium-solubilizing performance and stability, can convert stable potassium-containing minerals in rocks into effective forms that can be absorbed by plants, have huge application potential in mineral element conversion, and provide an effective solution to the potassium deficiency problem in my country. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a phylogenetic tree constructed based on the 16SrDNA of Taiwan Cupricobacterium NKK10 in the present invention;

[0031] Figure 2 This is a comparison diagram of the effects of releasing potassium ions from the NKK1-NKK15 strains provided by the present invention;

[0032] Figure 3 This is a scanning electron microscope image of the effect of Taiwan copper-grabbing bacteria NKK10 on the surface of granite; Figure 3 (a) is a scanning electron micrograph of the granite surface that has not been treated with Taiwan Cupricobacterium NKK10; Figure 3 (b) is a scanning electron micrograph of the granite surface of NKK10 treated with Taiwan copper-grabbing bacteria;

[0033] Figure 4 This is a comparison chart of the absorbance of the culture of Taiwan Cupricobacterium NKK10, Cordyceps militaris polysaccharide (FPS) and microbial inoculant after being cultured on liquid potassium feldspar medium for 10 minutes;

[0034] Figure 5 This is a comparison of the number of live bacteria on the surface of feldspar samples in liquid potassium feldspar culture medium under different time points of Taiwan copper-grabbing bacteria NKK10, Cordyceps militaris polysaccharide (FPS) and microbial inoculants;

[0035] Figure 6 This is a comparison chart of the effects of Taiwan copper-greedy bacteria NKK10, Cordyceps militaris polysaccharide (FPS) and microbial agents in releasing potassium ions.

[0036] Figure 7 This is a comparison of the effects of potassium ion release by Taiwan Cupricobacterium NKK10 and Pseudomonas putida strain KT2440;

[0037] Figure 8 The microscope and scanning electron microscope comparison pictures of potassium solubilization of Taiwan Cupricobacterium NKK10 and Pseudomonas putida strain KT2440 are shown; Figure 8 (a) is a microscope image of the blank control, Pseudomonas putida strain KT2440 and Taiwan copper-grabbing bacteria NKK10 cultured in liquid potassium feldspar medium for 7 days, and the feldspar samples in the culture medium were sampled and stained with safranin; Figure 8 (b) is the scanning electron micrograph of the feldspar samples taken from the culture medium after the blank control, Pseudomonas putida strain KT2440 and Taiwan copper-grabbing bacteria NKK10 were cultured in liquid potassium feldspar medium for 7 days;

[0038] Fig. 9 is the absorbance of the blank control, Pseudomonas putida strain KT2440 and Cupriavidae taiwanensis NKK10 after being cultured on liquid potassium feldspar medium for 10 min;

[0039] Fig.10 The number of live bacteria on the surface of feldspar samples in liquid potassium feldspar culture medium at different time points for the blank control, Pseudomonas putida strain KT2440 and Taiwan copper-greedy bacteria NKK10. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Each experiment of the present invention was repeated three times (n=3). The values ​​are expressed with the mean value as the standard error. The differences between the groups were compared using the t-Student test (P<0.05), and all statistical tests were performed using the SPSS.20 software package.

[0042] Culture medium used in the examples:

[0043] Liquid culture medium: sucrose 10g, Na2HPO4 0.4g, (NH4)2SO4 1g, MgSO4 0.2g, yeast extract 2g, FeCl3 0.02g, distilled water 1000mL; pH 7.2; sterilize at 121℃, 0.1MPa for 30min before use.

[0044] Liquid potassium feldspar culture medium: sucrose 10g, Na2HPO4 0.4g, (NH4)2SO4 1g, MgSO40.2g, yeast extract 2g, FeCl3 0.02g, potassium feldspar 5g (washed 5 times with distilled water and air-dried naturally), distilled water 1000mL; pH 7.2; 121℃, 0.1MPa sterilization for 30min before use.

[0045] Solid potassium feldspar culture medium: sucrose 10g, Na2HPO4 0.4g, (NH4)2SO4 1g, MgSO40.2g, yeast extract 2g, FeCl3 0.02g, potassium feldspar 5g (washed 5 times with distilled water and air-dried naturally), agar 15g, distilled water 1000mL; pH 7.2; sterilize at 121℃, 0.1MPa for 30min before use.

[0046] LB solid culture medium: 10 g of tryptone, 5 g of yeast extract powder, 10 g of NaCl, 17 g of agar, add distilled water to 1000 mL; pH 7.0; sterilize at 121°C, 0.1 MPa for 30 min before use.

[0047] LB liquid culture medium: 10 g of tryptone, 5 g of yeast extract powder, 10 g of NaCl, add distilled water to 1000 mL; pH 7.0; sterilize at 121°C, 0.1 MPa for 30 min before use.

[0048] Example 1

[0049] 1.1 Screening of Taiwan copper-grasping bacteria

[0050] Five rhizosphere soil samples of Lespedeza multiflora during the vegetative growth period were collected at Limutai Scenic Area, Jizhou District, Tianjin (39°45N, 117°05E, 997m above sea level). The collection depth of each sample was 0-15cm, 2mm around the roots. The physical and chemical properties of the rhizosphere soil were tested, and the results showed that the organic carbon was 45g / kg, the total nitrogen was 1.8g / kg, the total phosphorus was 1.6g / kg, and the pH was 7.5. The five-point mixed samples were placed in sterile sampling bags, and after the grass chips, stones and other debris were picked out, they were stored in a 4℃ refrigerator for later use.

[0051] Potassium-solubilizing bacteria were isolated by dilution plate separation method. 10 g of wild Lespedeza multiflora rhizosphere soil sample was taken and 90 mL of sterile water was added. The mixture was shaken vigorously to prepare a uniform soil suspension, and then the suspension was spread on a liquid potassium feldspar medium plate with a 10-fold dilution. The diluted solution was added to a solid potassium feldspar medium plate, and then cultured at 30 ° C for 56 hours. The single colony was further purified on the LB solid medium plate to obtain potassium-solubilizing strains NKK1-NKK15.

[0052] The purified strain was cultured in LB liquid medium for 12 hours, and then centrifuged at 12000 rpm for 2 minutes to collect the bacteria; the bacteria were then suspended in sterile water and added to 50 mL of liquid potassium feldspar medium to a cell concentration of 107 cells / mL, and the mixture was then shaken and cultured at 30°C for 7 days. 5 mL of the sample was taken every day and centrifuged at 12000 rpm for 5 minutes. The potassium concentration in the obtained supernatant was measured using an ICP mass spectrometer to evaluate the strain's ability to release potassium from potassium feldspar. The results are shown in Figure 2. Figure 2 After 7 days of culture in liquid potassium feldspar medium, 15 strains were able to release 0.02-0.35 mg / mL of K from potassium feldspar. + Among them, strain NKK10 showed the highest potassium release capacity, with the potassium released reaching 0.35 mg / mL. According to statistics, NKK10 has the most efficient potassium release performance.

[0053] 1.2 Scanning electron microscope observation of granite surface changes

[0054] The Taiwan copper-grabbing bacteria NKK10 was applied to the granite surface, and then left to stand. The surface changes of the granite were observed using a scanning electron microscope. The results are as follows: Figure 3 shown.

[0055] according to Figure 3 It can be seen that the granite surface that has not been in contact with the Taiwan Cupric Bacteria NKK10 is smoother and has sharp edges and corners due to the lack of the Taiwan Cupric Bacteria NKK10. The surface of the granite that has been cultured with the Taiwan Cupric Bacteria NKK10 for 14 days has the distribution of NKK10 strains, a large amount of granular substances, and even the presence of fungal secretions. This shows that the granite has undergone varying degrees of weathering under the action of the Taiwan Cupric Bacteria NKK10.

[0056] 1.3 Construction of phylogenetic tree

[0057] NKK10 cells were cultured in K-rich + The cells were cultured in a liquid medium (sucrose 10 g, K2HPO4 0.3 g, NaCl 0.1 g, (NH4) 2SO4 1 g, MgSO4 0.2 g, yeast extract 2 g, FeCl3 0.02 g, distilled water 1000 mL, pH = 7.2) for 3 days, and then genomic DNA was extracted from the cells using a soil DNA extraction kit (Biomarker Technologies, Beijing, China). The 16S rDNA of the cells was amplified from the genomic DNA by primers 27F (5'-agagtttgatcctgtgctcag-3') and 1492R (5'-ggttacctttgttacgactt-3') as shown in SEQ ID NO.1, specifically:

[0058] GAACTGAAGAGTTTGATCCTGGCTCAGATTGAACGCTGGCGGCATGCCTTACACATGCAAGTCGAACGGCAGCGCGGGCTTCGGCCTGGCGGCGAGTGGCGAACGGGTGAGTAATACATCGGAACGTGCCCTGTCGTGGGGGATAACTAGTCGAAAGATTAGCTAATACCGCATACGACCTGAGGGTGAAAGCGGGGGACCGCAAGGCCTCGCGCGATAGGAGCGGCCGATGTCTGATTAGCTAGTTGGTGGGGTAAAGGCCTACCAAGGCGACGATCAGTAGCTGGTCTGAGAGGACGATCAGCCACACTGGGACTGAGACACGGCCCAGACTCCTACGGGAGGCAGCAGTGGGGAATTTTGGACAATGGGGGCAACCCTGATCCAGCAATGCCGCGTGTGTGAAGAAGGCCTTCGGGTTGTAAAGCACTTTTGTCCGGAAAGAAATGGCTCTGGCTAATACCCGGGGTCGATGACGGTACCGGAAGAATAAGCACCGGCTAACTACGTGCCAGCAGCCGCGGTAATACGTAGGGTGCGAGCGTTAATCGGAATTACTGGGCGTAAAGCGTGCGCAGGCGGTTTGATAAGACAGGCGTGAAATCCCCGGGCTCAACCTGGGAATGGCGCTTGTGACTGTCAGGCTAGAGTGCGTCAGAGGGGGGTAGAATTCCACGTGTAGCAGTGAAATGCGTAGAGATGTGGAGGAATACCGATGGCGAAGGCAGCCCCCTGGGACGTGACTGACGCTCATGCACGAAAGCGTGGGGAGCAAACAGGATTAGATACCCTGGTAGTCCACGCCCTAAACGATGTCAACTAGTTGTTGGGGATTCATTTCTTCAGTAACGTAGCTAACG

[0059] The obtained PCR products were sequenced by China Qingke Biotechnology Co., Ltd. The sequence of NKK10 16SrDNA (accession number OR53494) was input into the NCBI BLAST system. Similar sequences were downloaded using the neighbor-joining method through MEGA11.0 software to construct the phylogenetic tree of NKK10. The results are shown in Figure 1 According to the 16S rDNA sequence similarity analysis, the NKK10 strain has the highest similarity (99%) with Cupriavidus taiwanensis CD3, and the NKK10 strain is determined to be Cupriavidus taiwanensis.

[0060] The Taiwan copper-greedy bacteria NKK10 was deposited in the China Center for Type Culture Collection, abbreviated as CCTCC, on April 26, 2024. The strain collection number is CCTCC No.M 2024729, and the collection address is: Wuhan University, No. 299, Bayi Road, Luojiashan Street, Wuchang District, Wuhan City.

[0061] Example 2

[0062] This embodiment provides a method for applying a liquid microbial agent to potassium feldspar to decompose potassium, wherein the liquid microbial agent is prepared using Copperbacillus taiwanensis NKK10 and Cordyceps militaris polysaccharide as raw materials, and specifically includes the following contents:

[0063] S1. The Taiwan Cupribothrium NKK10 was inoculated into LB liquid culture medium and activated at 25°C for 12 hours to obtain a live bacterial concentration of 2.8×10 3 CFU / g of activated bacterial solution;

[0064] S2. The potassium feldspar-containing rock is crushed into a powder with a particle size of 0.5 mm, washed with distilled water for 5 times, and naturally air-dried to obtain the crushed potassium-containing rock;

[0065] S3. Inoculate the activated bacterial solution into a liquid culture medium, add crushed potassium-containing rock and 0.0001 g of Cordyceps militaris polysaccharide, and culture at 30° C. with shaking for 14 days to obtain treated potassium-dissolving rock.

[0066] The present invention verifies the potassium-dissolving effect of Taiwan Cupric Bacteria NKK10 obtained in Example 1 and the liquid microbial agent obtained in Example 2. 5 mL of the culture medium containing the treated potassium-dissolving rock is taken and high-speed centrifuged at a speed of 12000 rpm for 5 minutes to measure the potassium ion content in the supernatant. The results are as follows: Figure 4-6 And as shown in Table 1.

[0067] according to Figure 4It can be seen that the addition of Cordyceps militaris polysaccharide (FPS) can significantly enhance the adsorption capacity of strain NKK10 on potassium feldspar. The absorbance at 600nm (OD600) and colony forming unit (CFU) determination showed that the NKK10+FPS group showed higher OD600 value and CFU than the control group.

[0068] Table 1 Statistical table of potassium dissolving effect of NKK10 and microbial agent (NKK10+FPS)

[0069]

[0070] according to Figure 5 As can be seen from Table 1, the addition of Cordyceps militaris polysaccharide (FPS) can help bacteria effectively adhere to the mineral surface, form a bacteria-mineral complex, and change and maintain the microenvironment inside the complex, thereby improving its ability to depotassium feldspar. The potassium ion release reached 810 mg / L at 14 days, confirming that the liquid microbial agent containing Cordyceps militaris polysaccharide has better potassium depotassium depotassium capacity than Taiwan copper-greedy bacteria NKK10.

[0071] Comparative Example 1

[0072] In this comparative example, Pseudomonas putida strain KT2440 was used as a comparative strain, and the Pseudomonas putida strain KT2440 was obtained from the ATCC Biological Standard Resource Center in the United States.

[0073] In order to further reflect the technical effect of the present invention, the present invention cultured the Taiwan copper-greedy bacteria NKK10 and the Pseudomonas putida strain KT2440 obtained in Example 1 in LB liquid culture medium for 12 hours, and then centrifuged at 12000 rpm for 2 minutes to collect the bacteria; then the bacteria were suspended in sterile water and added to 50 mL of liquid potassium feldspar culture medium to make the cell concentration reach 107 cells / mL. The mixture was then shaken and cultured at 30°C for 14 days; 5 mL was sampled every day and centrifuged at 12000 rpm for 5 minutes. The potassium concentration in the obtained supernatant was determined using an ICP mass spectrometer to evaluate the ability of the two strains to release potassium from potassium feldspar. The results are shown in Table 2 or Figure 7 shown.

[0074] Table 2 Statistical results of the ability of two strains to release potassium from potassium feldspar

[0075] project NKK10 KT2440 blank 0 0 0 0 2d 0.050 0.005 0.005 4d 0.180 0.008 0.006 6d 0.290 0.012 0.008 8d 0.397 0.026 0.009 10d 0.490 0.033 0.009 12d 0.540 0.041 0.009 14d 0.565 0.045 0.010

[0076] According to Table 2 or Figure 7 It can be seen that the potassium release experiment of the two strains over time showed that the sterile control group and the Pseudomonas putida KT2440 group could only slightly release 0.045 mg / mL of K even after 14 days. +In contrast, the C. formosanus NKK10 group had significant potassium release from the 2nd to the 10th day, reaching 0.565 mg / mL after 14 days.

[0077] Bacterial staining and microscopic observation

[0078] Cupricobacterium formosanum NKK10 and Pseudomonas putida strain KT2440 were inoculated into liquid potassium feldspar medium and cultured for 7 days. The two cultures were allowed to stand for 10 minutes, and then samples were taken and the feldspar with bacterial cells adsorbed was separated; the particles were suspended in distilled water and safranin reagent was added to a final concentration of 100 mg / L. After filtering for 10 minutes, the feldspar was gently washed twice with distilled water and then observed under an optical microscope. The treated feldspar was also sampled and fixed with 3% glutaraldehyde, dried in a vacuum dessicator, and observed with a scanning electron microscope. To evaluate the growth of bacteria in liquid potassium feldspar medium, the cells were cultured in the medium for 14 days. After standing at room temperature for 10 minutes, the absorbance of the culture was measured using a UV-visible spectrophotometer. The number of viable bacterial cells on potassium feldspar at different time points was determined by the colony forming unit (CFU) method. The cultures at different time points were diluted with distilled water, and the dilutions were then added to K-rich medium. + The colonies were counted after culturing on a culture medium plate at 30°C for 3 days. Figure 8-10 shown.

[0079] according to Figure 8 It can be seen that the control group Pseudomonas putida KT2440 showed a small number of bacterial cells on potassium feldspar, and the surface of the feldspar was smooth. However, the Formosan Cuprix NKK10 showed a higher bacterial growth biomass, and the cells formed a dense biofilm on potassium feldspar. In addition, according to Figure 9-10 It can be seen that the absorbance at 600nm (OD600) and colony forming unit (CFU) determinations showed that the Taiwan Cupric Bacteria NKK10 group showed much higher OD600 values ​​and CFU than the control group and the Pseudomonas putida KT2440 treatment group. For example, on day 8, the Taiwan Cupric Bacteria NKK10 group had an OD600 value of 0.88 and 109.1CFU / g of live bacterial cells, while the control group and the Pseudomonas putida KT2440 treatment group only had an OD600 value of <0.16 and <102.8CFU / g of live cells. These results indicate that Taiwan Cupric Bacteria NKK110 can grow stably in a culture medium with potassium feldspar as the only potassium source, and its ability to release potassium from feldspar is very strong, which can provide effective potassium to maintain bacterial cell growth.

[0080] In summary, Taiwan copper-greedy bacteria NKK10 can form a dense biofilm on the surface of potassium feldspar to dissolve potassium, thus having a strong potassium-releasing ability. It is a potential plant growth-promoting microorganism and can be used to develop microbial agents to optimize soil quality and promote plant growth.

[0081] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A microbial agent, characterized in that: It includes Copperbacillus taiwanensis NKK10 and fungal polysaccharide, wherein the deposit number of Copperbacillus taiwanensis NKK10 is CCTCC No.M 2024729; The fungal polysaccharide is Cordyceps militaris polysaccharide.

2. The microbial agent according to claim 1, characterized in that: The mass ratio of Cupric bacteria Taiwania NKK10 and fungal polysaccharide in the microbial agent is 10000:1-10000:1.

5.

3. The microbial agent according to claim 1 or 2, characterized in that: The number of viable bacteria of Taiwan Cupricobacterium NKK10 in the microbial agent is 1×10 3 CFU / g-1×10 4 CFU / g.

4. Use of the microbial agent as described in any one of claims 1 to 3 in rock potassium solution.

5. The method for applying the microbial agent as described in any one of claims 1 to 3 to depotassium in rocks, characterized in that: The steps include: S1, activating the Cupric Bacterium Taiwanense NKK10 to obtain an activated bacterial solution; S2. Inoculate the activated bacterial solution into a liquid culture medium, add crushed potassium-containing rock and fungal polysaccharide, and culture with shaking to obtain treated potassium-dissolving rock.

6. The method for applying the microbial agent to rock potassium solution as claimed in claim 5, characterized in that: In S1, the culture medium used for activation is LB liquid culture medium; and / or In S1, the activation culture time is 10h-14h.

7. The method of using the microbial agent in rock potassium solution as claimed in claim 5, characterized in that: In S2, the amount of the crushed potassium-containing rock added is 0.3%-0.5% of the mass of the liquid culture medium.

8. The method of using the microbial agent in rock potassium solution as claimed in claim 5, characterized in that: In S2, the liquid culture medium includes the following raw materials in parts by weight: 8-12 parts of sucrose, 0.3-0.5 parts of Na2HPO4, 0.8-1.2 parts of (NH4)2SO4, 0.1-0.3 parts of MgSO4, 1-3 parts of yeast extract, 0.01-0.03 parts of FeCl3 and 980-1020 parts of distilled water, and the pH of the culture medium is adjusted to 7.1-7.3.

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