Burkholderia paradensis and application thereof

Abstract

The invention discloses Burkholderia paradensis and application thereof, and relates to the technical field of microorganisms, the Burkholderia paradensis S3-22L provided by the invention is preserved in China General Microbiological Culture Collection Center (CGMCC), the strain preservation number is GGMCC NO: 31325, the preservation date is July 16, 2024, the preservation number is CGMCC NO: 31325, the preservation number is CGMCC NO: 31325, the preservation number is CGMCC NO: 31325, the preservation number is CGMCC NO: 31325, the preservation number is CGMCC NO: 31325, the preservation number is CGMCC NO: 31325, the preservation number is CGMCC NO: 31325, and the preservation number is CGMCC NO: 31325. The 16S rDNA (ribosomal deoxyribonucleic acid) sequence of the Burkholderia paradensis S3-22L is as shown in SEQ ID NO. 1; the strain obtained through screening can dissolve insoluble inorganic phosphorus and mineralize organic phosphorus, can also produce IAA and siderophore and secrete hydrolytic enzymes such as phosphatase, has an inhibition effect on growth and reproduction of ralstonia solanacearum, has an important application effect on prevention and treatment of plant bacterial wilt, and is harmless to the environment and human beings.

Description

Technical Field

[0001] The present invention relates to the field of microbial technology, and in particular to Burkholderia parudis and applications thereof. Background Art

[0002] In recent years, the excessive use of fertilizers and pesticides has led to serious ecological problems, such as eutrophication of water bodies, soil compaction, and reduced quality of agricultural products. With the introduction of the "two mountains" concept and the "three rural issues", people are increasingly concerned about the pollution of soil caused by the application of fertilizers and pesticides, and limiting their application will be a social consensus that must be reached. Therefore, the ecological transformation of promoting fertilizer application under the "three rural" environment and the current widespread application of ecological fertilizers are an opportunity.

[0003] Phosphorus is an important component of plants and is involved in many physiological processes such as photosynthesis, cell division, and material transport. Most soils are rich in total phosphorus, but less than 0.1% of it is directly available for plants to absorb and utilize. Therefore, phosphorus has become an important limiting factor in the growth and development of plants and the formation of quality. Phosphorus-dissolving bacteria can convert insoluble inorganic phosphorus and organic phosphorus in the soil into forms that can be absorbed and utilized by plants by secreting protons, organic acids, hydrolases and other substances, thereby expanding the range of phosphorus sources for plants. Therefore, in addition to applying chemical phosphorus fertilizers, the activation of phosphorus by microorganisms is also an effective way to increase the soil's phosphorus supply capacity. Because it is green and environmentally friendly, and is not prone to chemical residues, environmental pollution and other problems, it is currently widely promoted and applied in the fields of biological pesticides and biological fertilizers.

[0004] Ralstonia solanacearum is a Gram-negative rod-shaped bacterium that can secrete a variety of degradative enzymes when infecting plants, degrading plant cell walls and destroying plant cell structures. It enters plant cells by infecting plant roots, grows in the intercellular spaces, and then enters the xylem to multiply throughout the plant, causing the plant to wilt and eventually die. At present, plant bacterial wilt is still a typical and extremely destructive soil-borne disease, and there is an urgent need to find a novel and effective strategy for the prevention and control of bacterial wilt, which is also a major problem that technicians in this field need to overcome. Therefore, screening microorganisms with good resistance to plant bacterial wilt is the key.

[0005] Therefore, screening out a microbial strain that can prevent and treat plant bacterial wilt and is harmless to the environment and humans can provide a solid foundation for subsequent plant protection, biological fertilizer and other related biological protection fields, and is of great significance for the prevention and treatment of plant bacterial wilt. Summary of the invention

[0006] In view of this, the present invention separates and purifies a Burkholderia paludis S3-22L from soil with specific properties. The strain is now deposited in the General Microbiological Center of the China Microbiological Culture Collection Administration Committee, with a strain deposit number of GGMCC NO:31325 and a deposit date of July 16, 2024. The strain can not only dissolve insoluble inorganic phosphorus and mineralize organic phosphorus, but also produce IAA, iron carriers and secrete hydrolases such as phosphatase. The strain has an inhibitory effect on the growth and reproduction of Ralstonia solanacearum and has an important application effect on the prevention and treatment of plant bacterial wilt. That is, one of the purposes of the present invention is to propose a Burkholderia paludis S3-22L.

[0007] Furthermore, the 16S rDNA sequence of the Burkholderia parudis S3-22L is shown as SEQ ID NO.1.

[0008] The second object of the present invention is to provide a bacterial agent containing the above-mentioned Burkholderia parudis S3-22L.

[0009] The third object of the present invention is to provide the use of the above-mentioned Burkholderia parudis S3-22L or a bacterial agent containing the above-mentioned Burkholderia parudis S3-22L in preventing and controlling Ralstonia solanacearum.

[0010] Furthermore, it is used to prevent and treat plant wilt caused by Ralstonia solanacearum.

[0011] A fourth object of the present invention is to provide the use of the above-mentioned Burkholderia parudis S3-22L or a bacterial agent containing the above-mentioned Burkholderia parudis S3-22L in decomposing insoluble inorganic phosphorus and organic phosphorus in soil into soluble phosphorus.

[0012] Specifically, the insoluble inorganic phosphorus includes Ca3(PO4)2, AlPO4 and FePO4; the organic phosphorus includes lecithin and sodium phytate.

[0013] The present invention also aims to provide use of the above-mentioned Burkholderia parudis S3-22L or a bacterial agent containing the above-mentioned Burkholderia parudis S3-22L in treating soil containing sparingly soluble phosphorus.

[0014] The present invention also aims to provide a use of the above-mentioned Burkholderia parudis S3-22L or a bacterial agent containing the above-mentioned Burkholderia parudis S3-22L in the preparation of a bacterial fertilizer for promoting plant growth.

[0015] The present invention also aims to provide the use of the above-mentioned Burkholderia parudis S3-22L or a bacterial agent containing the above-mentioned Burkholderia parudis S3-22L in the production of hydrolases.

[0016] Furthermore, the hydrolase comprises at least one of phosphatase, cellulase, lipase and β-1,3-glucanase.

[0017] The present invention also aims to provide a use of the above-mentioned Burkholderia parudis S3-22L or a bacterial agent containing the above-mentioned Burkholderia parudis S3-22L in secreting siderophores.

[0018] The present invention also aims to provide the use of the above-mentioned Burkholderia parudis S3-22L or a bacterial agent containing the above-mentioned Burkholderia parudis S3-22L in the production of indoleacetic acid.

[0019] Compared with the prior art, the present invention has the following advantages: The strain screened by the present invention can not only dissolve insoluble inorganic phosphorus and mineralize organic phosphorus but also produce IAA, iron carriers and secrete hydrolases such as phosphatase. The strain has an inhibitory effect on the growth and reproduction of Ralstonia solanacearum, has important application effects on the prevention and treatment of plant bacterial wilt, is harmless to the environment and humans, and can provide a solid foundation for subsequent plant protection, biological fertilizer and other related biological protection fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is the colony morphology of the Burkholderia paludis strain S3-22L provided in the embodiment of the present invention after being cultured on NA solid culture medium for 24 hours.

[0021] Figure 2 It is a phylogenetic tree of strain S3-22L constructed based on the 16S rRNA gene sequence provided in an embodiment of the present invention.

[0022] Figure 3 The ecological characteristics of the Burkholderia paludis strain S3-22L provided in the embodiments of the present invention are summarized as follows: a: siderophore; b: phosphatase; c: cellulase; d: lipase; e: β-1,3-glucanase.

[0023] Figure 4 This is the inhibitory effect of the Burkholderia paludis strain S3-22L provided in the embodiment of the present invention on Ralstonia solanacearum. DETAILED DESCRIPTION

[0024] Many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar modifications without violating the connotation of the present invention, so the present invention is not limited to the specific implementation disclosed below.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0026] The materials of the embodiments of the present invention are as follows: 1. Soil The test soil was collected from the hickory forest in Changhua Town, Lin'an District, Hangzhou (30°16′N, 118°52′E). Five standard hickory trees with a spacing of more than 10 m, uniform growth, and good health were randomly selected in the sample plot as sampling objects. After removing the dead branches and leaves and other surface coverings within a radius of 2 m from the base of the trees with a shovel, carefully dig to the end of the root to collect fine root samples, collect soil samples at a depth of 0−30 cm, and collect rhizosphere soil by shaking the roots. Mix evenly, put one portion in a sterile sealed bag, store at 4°C, and air-dry the other for later use. The specific soil physical and chemical properties are as follows: pH 5.21, ω (organic matter) 55.87 g·kg −1 ,ω (alkaline hydrolyzed nitrogen) 132.8mg·kg −1 ,ω(available phosphorus)8.65 mg·kg −1 ,ω (fast-acting potassium) 147.0 mg·kg −1 .

[0027] 2. Culture medium LB medium (g / L): 10.0% tryptone, 5.0% yeast extract, 10.0% sodium chloride, distilled water to 1 L, pH 7.2–7.4.

[0028] NA medium (g / L): beef extract 3.0, peptone 10.0, NaCl 5.0, agar 20.0, distilled water to 1 L, pH 7.0–7.5.

[0029] NBRIP medium (g / L): glucose 10.0, Ca3(PO 4)2 5.0, MgCl2 5.0, KCL 0.2, MgSO4·7H2O 0.25, (NH4)2SO4 0.1, agar powder 20.0, pH 7.0.

[0030] King medium (g / L): peptone 20.0, K2HPO4 1.5, MgSO4·7H2O 1.5, tryptophan 0.1, glycerol 15.0 mL, distilled water to 1 L, pH 7.2.

[0031] Lipase detection medium (g / L): Rhodamine B 0.05, yeast powder 0.2, NaCl 0.5, KH2PO4 0.5, Na2HPO4·7H2O 3.5, (NH4)2SO4 5.0, peanut oil 1.0, agar powder 20.0, distilled water to 1 L, pH 6.0.

[0032] Phosphatase assay medium (g / L): glucose 10.0, CaCO3 5.0, (NH4)2SO4 0.5, NaCl 0.3, KCL0.3, MgSO4·7H2O 0.3, FeSO4·7H2O 0.03, distilled water to 1 L, pH 7.0–7.5. When pouring the plate, add 3–4 mL of egg yolk liquid (prepared with 1:1 egg yolk and 0.8% NaCl) for every 100 mL and shake well.

[0033] Cellulase detection medium (g / L): sodium carboxymethyl cellulose 2.0, Congo red 2.0, (NH4) SO4 2.0, NaCl 0.5, MgSO4·7H2O 0.5, K2HPO4 1.0, agar powder 20.0, distilled water to 1 L, pH 7.2.

[0034] β-1,3-Glucanase detection medium (g / L): glucose 1.0, Poria powder 4.0, K2HPO4 1.0, Na2HPO4 3.0, MgSO4·7H2O 0.5, FeSO4.7H2O 0.05, agar powder 20.0, distilled water to 1 L, add 60 mg of water-soluble aniline blue before pouring the plate and shake well.

[0035] CAS detection medium (g / L): sucrose 2.0, acid hydrolyzed casein 3.0, CaCl2 1.11, MgSO4 0.24, agar powder 20.0, distilled water to 1 L.

[0036] CAS dye solution (g / L): chrome azuro 0.61, FeCl3 0.016, hexadecyltrimethylammonium bromide (HDTMA) 1.458.

[0037] 0.1 mol / L phosphate buffer (g / L): Na2HPO4·12H2O 24.27, NaH2PO4·2H2O 5.905, KH2PO4 0.75, NH4Cl 2.5, NaCl 1.25, pH 6.8, diluted 10 times when used. When pouring the plate, slowly add 5 mL each of 0.1 mol / L phosphate buffer and CAS dye solution and mix well.

[0038] Example 1 Isolation and purification of strain S3-22L Three phosphate-solubilizing bacteria isolation media with tricalcium phosphate, lecithin and calcium phytate as the sole phosphorus source were prepared for use. Eight glass beads were placed in a 200 mL conical flask and 49.5 mL of deionized water was added. Then, the autoclave was sterilized at 121°C for 0.5 h. After cooling, 0.5 g of rhizosphere soil was weighed and placed in the autoclave. The conical flask was then placed in a shaker and shaken at 180 r / min for 1 h. After standing for 15 min, the supernatant was taken and diluted with sterile water by ten-fold dilution to a 10−3 −10−8 gradient bacterial suspension. 0.1 mL of the bacterial suspension was applied to the phosphate-solubilizing bacteria screening medium. Three replicates were set for each gradient and cultured in the dark in an incubator at (28±0.5)°C for 3−7 d. Colonies with different morphologies and obvious transparent circles (D / d≥1, D: halo diameter; d: colony diameter) were picked for further streaking purification, and the process was repeated several times until a pure strain with a stable transparent circle was obtained. The purified strain suspension was then mixed with 40% glycerol in a ratio of 1:1 and stored in an ultra-low temperature refrigerator at −80 ℃.

[0039] The strains stored in the −80 ℃ refrigerator were taken out, inoculated into LB solid medium by streaking method, and cultured in the dark at (28±0.5) ℃ in a bacterial incubator for 3−7 d. Prepare NA liquid medium, take 20 mL and dispense into 50 mL Erlenmeyer flasks, steam sterilize in a 121 ℃ autoclave for 0.5 h, and cool for use. Take out the LB solid medium, pick a single colony strain and inoculate it into NA liquid medium, culture it in a constant temperature oscillator at (28±0.5) ℃ and 180 r / min for 3 d, then transfer the bacterial suspension to a sterile centrifuge tube in an ultra-clean workbench, centrifuge at 10 000 r / min for 15 min, retain the bottom cells, wash with sterile saline, centrifuge again, and repeat 3 times; finally, adjust the concentration of the bacterial suspension to 1.0×10 3 , 1.0×10 6 CFU / mL, for future use.

[0040] Example 2 Identification of strain S3-22L Morphological observation and physiological and biochemical experiments were performed according to the Manual of Identification of Common Bacterial Systems and the Bergey Manual of Bacterial Identification: The obtained strain S3-22L was streaked on NA plates and cultured at 28°C for 24 h before observing the color, size, and morphological characteristics of the colonies. Figure 1 As shown, after streaking on NA medium and culturing at 28°C for 24 h, the colonies of the strain on NA medium were light yellow with tiny protrusions on the edges and were opaque.

[0041] The strain was subjected to physiological and biochemical analysis, and the results are shown in Table 1, with reference to the Bergey Manual of Bacterial Identification. Combined with morphological observation, strain S3-22L was preliminarily identified as Burkholderia paludis.

[0042] Table 1 Physiological and biochemical characteristics of strain S3-22L Index Result Index Result Index Result Denitrification − Adipate + D-Alanine + Oxidase V Azelaic acid salt + L-Valine V Arginine dihydrolase − D-Tartrate − Leucine + Gelatin hydrolysis V Glycolate V DL-a-aminobutyric acid − Starch hydrolysis − Cis-aconitate + Kynurenate − Utilizes: Rhamnose V Fructose + Anthranilic acid + maltose − Citrate + Ethanolamine + Citrate + Mesaconic acid salt − Benzylamine V Muclate + Erythritol − Acetamide V Malonate + 2,3-Butanediol + Nicotinate V Glutarate + Benzoate + G+C mol% 66.6 Note: +: positive; -: negative; V: unstable reaction among strains A small amount of bacterial cells were scraped and DNA was extracted using the DNeasyⓇ PowerSoilⓇ DNA Isolation Kit (Qiagen Enterprise Management (Shanghai) Co., Ltd.) according to the instructions. The 16S rRNA gene sequence was amplified using the bacterial primer pair 27F: 5′-AGAGTTTGATCCTGGCTCAG-3′ (SEQ ID NO.2) and 1492R: 5′-CTACGGCTACCTTGTTACGA-3′ (SEQ ID NO.3). PCR amplification conditions: 95 ℃ pre-denaturation for 5 min; 95 ℃ denaturation for 30 s, 58 ℃ annealing for 30 s, 72 ℃ extension for 1 min 30 s, a total of 35 cycles; 72 ℃ final extension for 7 min. After the reaction was completed, 3 μL of PCR product was taken for 1% agarose gel electrophoresis to confirm the PCR amplification fragment. Sequencing services were entrusted to Shenzhen Micro-Science Group Co., Ltd. The sequenced base sequences were compared with BLAST in the National Center for Biotechnology Information (NCBI) to analyze closely related species.

[0043] The 16S rRNA gene sequencing results were uploaded to NCBI, and the strain phylogenetic analysis was performed using the sequencing data and database information using MEGA7.0 software. Figure 2As shown. Homology comparison on NCBI showed that the strain had the closest evolutionary relationship with Burkholderia paludis, with a sequence homology of 99.34%. Based on the colony morphology observation and molecular biological identification results of the strain, strain S3-22L was identified as Burkholderia paludis. The NCBI accession number is: PP542128. The strain was deposited in the General Microbiology Center of the China Microbiological Culture Collection Administration on July 16, 2024, with the deposit number GGMCCNO:31325. The base sequence of strain S3-22L is as follows: CAAAATCCTTTTCG TGCATGAGCGTCAGTATTGGCCCAGGGGGCTGCCTTCGCCATCGGTATTCCTCCACATCTCTACGCATTTCACTGCTACACGTGGAATTCTACCCCCCTCTGCCATACTCTAGCCTGCCAGTCACCAATGCAGTTCCCAGGTTGAGCCCGGGGATTTCACATCGGTCTTAGCAAACCGCCTGCGCACGCTTTACGCCCAGTAATTCCGATTAACGCTCGCACCCTACGTATTACCGCGGCTGCTGGCACGTAGTTAGCCGGTGCTTATTCTTCCGGTACCGTCATCCCCCGACTGTATTAGAGCCAAGGATTTCTTTCCGGACAAAAGTGCTTTACAACCCGAAGGCCTTCTTCACACACGCGGCATTGCTGGATCAGGCTTTCGCCCATTGTCCAAAATTCCCCACTGCTGCCTCCCGTAGGAGTCTGGGCCGTGTCTCAGTCCCAGTGTGGCTGGTCGTCCTCTCAGACCAGCTACTGATCGTCGCCTTGGTAGGCCTTTACCCCACCAACTAGCTAATCAGCCATCGGCCAACCCTATAGCGCGAGGTCCGAAGGTCCCCCGCTTTCATCCGTAGATCGTATGCGGTATTAATCCGGCTTTCGCCGGGCTATCCCCCACTACAGGACATGTTCCGATGTATTACTCACCCGTTCGCCACTCGCCACCAGGTGCAAGCACCCGTGCTGCCGTTCGACTTGCATGTGTAAGGCATGCCGCCAGCGTTCAATCTGAGCCAGGTTTCAAAACTCTG (SEQ ID NO.1).

[0044] Example 3 Analysis of phosphate-solubilizing ability of strain S3-22L NBRIP liquid culture medium (phosphorus mass concentration was set to 1 g P / L) containing different insoluble inorganic phosphorus (Ca3(PO4)2, AlPO4 and FePO4) and organic phosphorus (lecithin, sodium phytate) was prepared respectively, and 20 mL was dispensed into 50 mL conical flasks. After sterilization at 121℃ for 30 min, the test strain suspension was inoculated at 1% inoculum size and cultured in a constant temperature shaking box at (28±0.5)℃ and 180 r / min for 3 d. The culture was centrifuged at 10 000 r / min for 15 min, and the supernatant was retained. The soluble phosphorus content in the supernatant was determined by molybdenum blue colorimetry. The culture without bacteria was used as the control, and each treatment was repeated 3 times.

[0045] The strain has the ability to dissolve insoluble inorganic phosphorus and mineralize organic phosphorus, and the ability varies depending on the phosphorus source. Among inorganic phosphorus sources, the strain has a higher solubility of tricalcium phosphate, and the net soluble phosphorus content in the culture solution (C 接种处理 With C 未接种处理 The difference between the two values ​​(the same below) was 234.50 mg / L. When iron phosphate and aluminum phosphate were used as phosphorus sources, the net soluble phosphorus content in the culture solution was 4.97 and 41.37 mg / L, respectively. After inoculation and cultivation, the net soluble phosphorus content in the culture solution with lecithin and calcium phytate as phosphorus sources was 12.20 and 169.24 mg / L, respectively.

[0046] Example 4 Analysis of the ability of strain S3-22L to produce siderophores and secrete hydrolases Siderophore is a low molecular weight compound that chelates iron. 3+ It has a high affinity. It is reported that microorganisms can chelate Fe in soil by secreting siderophores. 3+ , converting iron oxides into an effective state that can be absorbed and utilized by plants, effectively improving the iron deficiency stress of crops and improving the utilization rate of iron.

[0047] The solid plate method was used to qualitatively evaluate the ability of the strain to produce iron carriers and secrete hydrolases by observing the hydrolysis zone. CAS detection plates and solid culture medium detection plates for phosphatase, cellulase, lipase, and β-1,3-glucanase were prepared respectively. Single colonies were picked and dotted in the center of the solid plate. Each treatment was repeated 3 times and cultured in the dark in a (28±0.5)℃ incubator for 3-7 days. Observe whether an orange halo can be produced around the colony. If so, it indicates that the strain can secrete iron carriers, otherwise it cannot; identification method for phosphatase, cellulase, and β-1,3-glucanase: If a transparent circle is produced around the strain, it means that it has the ability to produce the hydrolase, otherwise it does not. Lipase identification method: If a grease-like precipitate is produced around the strain, it means that the strain has the ability to produce lipase, otherwise it does not.

[0048] like Figure 3As shown, the strain was inoculated into a solid culture medium, and the strains around the strains produced the corresponding strains with the ability to produce siderophores, and at the same time, they could secrete phosphatase, cellulase, lipase and β-1,3-glucanase. Therefore, strain S3-22L can compete with pathogens for iron ions by secreting siderophores, effectively inhibiting the growth of soil-borne pathogens.

[0049] Example 5 Ability of strain S3-22L to secrete indole-3-acetic acid (IAA) Prepare King liquid culture medium, take 20 mL and dispense it into 50 mL Erlenmeyer flasks, sterilize the liquid in a 121 ℃ autoclave for 0.5 h, inoculate the test strain, and culture it in a constant temperature oscillator at (28±0.5) ℃ and 180 r / min for 3 d. Then transfer the bacterial suspension to a sterile centrifuge tube and centrifuge it at 10000 r / min for 15 min. The IAA concentration in the supernatant was determined by the Salkowski colorimetric method. In short, take equal volumes of supernatant and S2 colorimetric solution (1 mL 0.5 mol / L FeCl3 added to 50 mL 35% HClO4) and mix them evenly. After standing at room temperature for 30 min, observe the color change of the solution, and compare the color at a wavelength of 530 nm. The IAA concentration in the culture medium was determined and calculated using the standard IAA calibration curve.

[0050] The test strain S3-22L showed a dark pink color after reacting with the Salkowski colorimetric solution. The IAA production was measured by spectrophotometry, and the results showed that its IAA production was high, at 343.95 mg / L. Among the known IAA-producing strains, the IAA secretion levels of different strains vary greatly. For example, Liu Lin et al. (Liu Lin, Sun Lei, Zhang Ruiying, et al. Diversity of endophytic bacteria that can secrete indoleacetic acid in the roots of spring orchids [J]. Biodiversity, 2010, 18 (2): 182-187) obtained 57 strains of IAA-secreting endophytic bacteria from spring orchids, and their IAA secretion was 0.5-129.68 μg / mL. Hu Zerui et al. (Hu Zerui, Liu Yuan, Peng Changlian, et al. Diversity of endophytic bacterial populations and heavy metal tolerance and indoleacetic acid production potential in Bidens pilosa [J]. Microbiology Bulletin, 2019, 46 (1): 29-41.) isolated 7 IAA-producing bacteria from Bidens pilosa, and their secretion amount was 57.48-312.22 μg / mL. The IAA production of strain S3-22L far exceeded that of the strains reported by previous researchers, and it has good application potential.

[0051] Example 6 Analysis of the ability of strain S3-22L to inhibit the growth of Ralstonia solanacearum The tested Ralstonia solanacearum strain RS was from tomato plants infected with bacterial wilt. Ralstonia solanacearum was inoculated into LB liquid medium and cultured in a shaking incubator at 30℃ and 160 r / min for 48 h. The OD600 of the culture medium was adjusted to 2.0. The LB agar medium was heated and dissolved. When it cooled to about 50℃, 1 mL of Ralstonia solanacearum culture solution was added to each 150 mL of culture medium. After being shaken thoroughly, the plate was poured. After being cultured in a bacterial incubator at 28℃ for 1 day, the strain S3-22L was inoculated on the LB plate mixed with Ralstonia solanacearum. After being cultured at 28℃ for 2-3 days, the D / d value of the inhibition zone of the strain against Ralstonia solanacearum was observed (D: inhibition zone diameter; d: colony diameter), and 5 replicates were set.

[0052] like Figure 4 As shown, strain S3-22L stably produces a large inhibition zone in LB solid medium mixed with Ralstonia solanacearum, with a D / d value of 3.82-4.55 cm (D: inhibition zone diameter; d: L colony diameter). Compared with previous studies, strain S3-22L has a significant inhibitory effect on the growth of Ralstonia solanacearum; at the same time, to ensure its accuracy, strain S3-22L and Ralstonia solanacearum RS were inoculated on NA solid medium based on the cross method, and the inhibitory effect was tested twice. The results showed that Ralstonia solanacearum grew less near strain S3-22L, and the closer the distance, the less it grew, or even no growth. It can be seen that strain S3-22L has a significant inhibitory effect on the growth of Ralstonia solanacearum. It can be seen that it has the potential to develop into a fertilizer for the prevention and control of plant bacterial wilt, laying a foundation for the research and development of microbial fertilizers that solubilize phosphorus and promote growth.

[0053] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0054] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A Burkholderia paludis S3-22L, characterized in that It is deposited in the General Microbiology Center of China Microbiological Culture Collection Administration, and the strain collection number is GGMCC NO:31325.

2. The Burkholderia parudis S3-22L according to claim 1, characterized in that The 16S rDNA sequence of the Burkholderia parudis S3-22L is shown in SEQ ID NO.

1.

3. A bacterial agent, characterized in that: The method comprises the Burkholderia parudis S3-22L according to claim 1.

4. Use of the Burkholderia parudis S3-22L described in claim 1 or 2 or the bacterial agent described in claim 3 in controlling Ralstonia solanacearum.

5. Use of the Burkholderia parudis S3-22L according to claim 1 or 2 or the bacterial agent according to claim 3 for decomposing poorly soluble inorganic phosphorus and organic phosphorus in soil into soluble phosphorus.

6. Use of the Burkholderia parudis S3-22L described in claim 1 or 2 or the bacterial agent described in claim 3 in the preparation of a bacterial fertilizer for promoting plant growth.

7. Use of the Burkholderia parudis S3-22L according to claim 1 or 2 or the bacterial agent according to claim 3 in treating soil containing sparingly soluble phosphorus.

8. Use of the Burkholderia parudis S3-22L described in claim 1 or 2 or the bacterial agent described in claim 3 in the production of a hydrolase, preferably, the hydrolase comprises at least one of a phosphatase, a cellulase, a lipase and a β-1,3-glucanase.

9. Use of the Burkholderia parudis S3-22L according to claim 1 or 2 or the bacterial agent according to claim 3 in secreting siderophores.

10. Use of the Burkholderia parudis S3-22L according to claim 1 or 2 or the bacterial agent according to claim 3 in the production of indoleacetic acid.

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