P.megatherium HHY-1 as well as microbial agent and application of P.megatherium HHY-1

Abstract

The invention relates to the technical field of industrial microorganisms, and particularly discloses a P.megatherium HHY-1, a microbial agent thereof and application of the P.megatherium HHY-1. The preservation number of the P.megaterium HHY-1 is CGMCC (China General Microbiological Culture Collection Center) No.34470, and the preservation number of the P.megaterium HHY-1 is CGMCC No.34470. The P.megatherium provided by the invention has multiple functions of nitrogen fixation, phosphorus solubilization, siderophore production, IAA production capacity, antioxidant enzyme activity and the like, can play a comprehensive role from multiple dimensions of nutrition supply, growth regulation, stress resistance protection and the like, effectively assists good growth of the Abajie wheat 19 in a saline-alkali environment, and has a good application prospect. The method has great significance in improving the yield of the drought alkaline wheat in the saline-alkali soil and promoting agricultural sustainable development, and shows extremely high practical value in the aspect of growth promotion of the drought alkaline wheat Gie wheat 19.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial microorganisms, in particular to Priesteria gigantea HHY-1, a microbial agent thereof and applications. Background Art

[0002] The harm of saline-alkali soil to plants is mainly manifested in three aspects: osmotic pressure stress, ion stress and high pH stress. The high osmotic pressure of the soil will inhibit the plant roots from absorbing water, resulting in water shortage in the leaves, which in turn significantly inhibits photosynthesis and growth and development; the high concentration of Na in saline-alkali soil + Easily absorbed by the roots, intracellular Na + Excessive accumulation of Fe will destroy the intracellular ion homeostasis, induce the accumulation of malondialdehyde and the oxidation of cell membrane lipids, resulting in increased membrane permeability; high pH will not only inhibit the root system from absorbing Fe 2+ and Mg 2+ The absorption of nitrogen will affect the normal progress of photosynthesis, and it will also hinder the assimilation and transportation of nitrogen, resulting in the obstruction of plant nitrogen metabolism.

[0003] Among the many means of improving saline-alkali land, salt-tolerant and growth-promoting bacteria, as a core component of microbial improvement technology, have shown significant advantages due to their ability to survive and unique effects in salt-stress environments. At present, although some salt-tolerant and alkali-tolerant microbial strains have been discovered and applied to saline-alkali land improvement, the existing strains still have limitations in terms of salt-tolerant and alkali-tolerant abilities, growth-promoting effects, and environmental adaptability. Some strains have a single growth-promoting function, making it difficult to comprehensively improve plant growth and soil quality. Therefore, screening and developing microbial strains with salt-tolerant and alkali-tolerant abilities, excellent comprehensive growth-promoting effects, and a wide range of adaptability are of great significance for improving the efficiency of saline-alkali land restoration and ensuring agricultural production. Summary of the Invention

[0004] In view of the problems that existing salt-alkali tolerant growth-promoting strains have single functions and poor comprehensive growth-promoting effects, the present invention provides Priesteria gigantea HHY-1, a microbial agent thereof and applications.

[0005] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0006] The invention relates to Priestia megaterium HHY-1, whose deposit number is CGMCC No.34470.

[0007] Priestia megaterium HHY-1 was screened out from the wheat topsoil in Huanghua County, Cangzhou City using the LB solid culture medium method containing 5% NaCl. It was classified and named Priestia megaterium. It was deposited in the General Microbiology Center of the China Culture Collection of Microorganisms, abbreviated as CGMCC, on May 9, 2025. The strain deposit number is CGMCC No. 34470, and the deposit address is: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing.

[0008] The biological characteristics of Priesteria gigantea HHY-1 provided by the present invention are: at 28°C, single colonies on LB solid culture medium are white, nearly circular, with neat edges and a relatively moist, convex surface. Under an optical microscope, the bacteria are rod-shaped, with oval spores, and are Gram-positive.

[0009] The Priesteria gigantea HHY-1 provided by the present invention can rapidly reproduce in the range of pH 5 to 9. 600 The absorbance is 2.56-2.80, indicating that the bacteria can adapt to soil environments with different acidity and alkalinity levels, and can maintain strong activity and reproduction ability regardless of whether it is acidic or alkaline saline-alkali land.

[0010] The cells were cultured in LB liquid medium containing 3% NaCl for 24 h, and the OD 600 The absorbance was 2.24; after culturing in LB liquid medium containing 5% NaCl for 24 h, its OD 600 The absorbance was 1.83, indicating that the bacteria could still grow and reproduce well even in an environment with higher salt concentration, could tolerate a certain degree of salt stress, and could be used to improve saline-alkali land with medium and high salinity.

[0011] Under 28℃ conditions, the bacteria has the ability to fix nitrogen and solubilize phosphate, can produce iron carriers and auxin (IAA), and has antioxidant capacity, which can effectively promote the germination and growth of drought-resistant alkali wheat.

[0012] In a second aspect, the present invention provides a microbial composition comprising the above-mentioned Priesteria megaterium HHY-1.

[0013] In a third aspect, the present invention further provides a microbial agent comprising Priesteria megaterium HHY-1.

[0014] The Priesteria gigantea HHY-1 provided by the present invention can be widely used in soil improvement and plant growth promotion in saline-alkali land areas. It can be prepared into a liquid microbial agent for easy use, and can be sprayed in the field or mixed with seeds.

[0015] Specifically, the microbial agent is a liquid agent.

[0016] Furthermore, the viable count of Priesteria gigantea HHY-1 in the microbial agent is 2×10 6 ~7×10 8 CFU / mL.

[0017] In a fourth aspect, the present invention further provides a method for preparing the above-mentioned microbial agent, comprising the following steps:

[0018] The Priesteria gigantea HHY-1 was inoculated into LB liquid culture medium and cultured at 25°C to 30°C and 180r / min to 200r / min for 1 to 2 days. The cultured bacterial liquid was centrifuged, the supernatant was discarded, and the cells were washed. Sterile water was then added until the number of viable bacteria in the bacterial suspension reached 2×10 6 ~7×10 8 CFU / mL, and obtain the microbial agent.

[0019] The preparation method of the above-mentioned microbial agent has the advantages of simple operation, mild culture conditions, short production cycle, low cost and stable quality of the agent. It is suitable for large-scale production and provides strong technical support for the widespread application of the Priesteria gigantea HHY-1 microbial agent.

[0020] Furthermore, the LB medium comprises: 10 g of tryptone, 5 g of yeast extract, 10 g of sodium chloride and 1000 mL of water, pH 7.4, and is sterilized at 121° C. for 20 min.

[0021] In a fifth aspect, the present invention also provides the use of the Priesteria gigantea HHY-1 in nitrogen fixation, siderophore production, elongation production, nitrogen and phosphorus absorption promotion, drought and saline-alkali stress resistance improvement, and antioxidant enzyme activity improvement.

[0022] The giant Priesteria HHY-1 provided by the present invention has nitrogen fixing ability, can convert nitrogen in the air into nitrogen that can be absorbed and utilized by plants, increase the nitrogen content in the soil, provide sufficient nitrogen nutrition for plant growth such as dry alkali wheat, alleviate the problem of nitrogen deficiency in saline-alkali land. Its phosphorus-solubilizing ability can convert the phosphorus that is difficult to be absorbed by plants in the soil into available phosphorus, improve the utilization rate of soil phosphorus, promote the absorption of phosphorus by plants, and help the growth and development of plants. At the same time, the bacteria can produce siderors, which can chelate the iron element in the soil, so that the iron that was originally difficult to be obtained by plants is converted into an absorbable form, effectively solve the iron deficiency problem caused by high pH value in plants in saline-alkali land, and ensure the normal progress of physiological processes such as plant photosynthesis. In addition, the auxin (IAA) produced by the bacteria can directly promote cell division and elongation of dry alkali wheat, is conducive to root growth and plant development, and improves the growth rate and biomass of dry alkali wheat. Moreover, the antioxidant ability of this bacterium can help the drought-resistant wheat resist the oxidative stress brought by the saline-alkali environment, reduce the accumulation of harmful substances such as malondialdehyde, protect the integrity of the cell membrane, and maintain the normal physiological functions of the cells, thereby effectively promoting the germination and growth of drought-resistant wheat and providing strong support for the cultivation and yield increase of drought-resistant wheat in saline-alkali land.

[0023] Moreover, the bacteria can maintain strong activity and reproduction ability in the pH range of 5 to 9, can tolerate a certain degree of salt stress, has high environmental adaptability, and can be widely used in different types of saline-alkali lands.

[0024] In a sixth aspect, the present invention further provides use of the Priesteria gigantea HHY-1 or the microbial composition in promoting the growth of Rhizoctonia solani.

[0025] In a seventh aspect, the present invention also provides the use of microbial agents in promoting the growth of drought-resistant alkali wheat.

[0026] Specifically, the drought-resistant alkali wheat is Jiemai 19.

[0027] The Priesteria gigantea HHY-1 provided by the present invention is particularly suitable for the cultivation of drought-alkali Maijiemai 19. The bacterium is salt-alkali tolerant and has multiple abilities such as phosphate solubilization, nitrogen fixation, siderophore production, IAA production, and antioxidant properties.

[0028] In stressful environments such as drought and salinity, plants often face the dual pressures of iron deficiency and oxidative damage. The siderophore production and antioxidant mechanisms of Priesteria gigantea HHY-1 work synergistically: siderophores enhance plant absorption and utilization of iron in the rhizosphere, alleviating iron deficiency; while antioxidant capacity mitigates the harmful effects of oxidative damage. These two synergistic effects can more effectively enhance plant resistance and promote growth in adverse conditions.

[0029] At the same time, the bacteria can also enhance the absorption of nutrients by plants. As nitrogen-fixing bacteria, it can fix nitrogen in the atmosphere and convert it into ammonium ions (NH4 + ), providing nitrogen nutrition to the host plant with which it forms a symbiotic relationship. Furthermore, this salt-tolerant bacterium can significantly improve the plant's absorption of nitrogen and phosphorus, thereby enhancing the plant's salt tolerance. This promotes the growth of alkali wheat in saline-alkali conditions, providing strong support for the cultivation and yield increase of alkali wheat in saline-alkali soils. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is the growth curve of Priesteria gigantea HHY-1 in LB liquid culture medium with different pH values; different letters in the figure indicate P<0.05 difference level;

[0031] Figure 2 The colony morphology of Priesteria gigantea HHY-1 of the present invention;

[0032] Figure 3 This is a Gram staining image of Priesteria gigantea HHY-1 of the present invention under an optical microscope;

[0033] Figure 4 is a phylogenetic tree of Priesteria gigantea HHY-1 of the present invention;

[0034] Figure 5 This is a diagram for identifying the nitrogen fixation ability of Priesteria gigantea HHY-1 in Example 2 of the present invention; wherein, (A) 7d, (B) 10d;

[0035] Figure 6 This is a diagram illustrating the siderophore production ability of Priesteria gigantea HHY-1 in Example 2 of the present invention;

[0036] Figure 7 This is a diagram illustrating the phosphate-solubilizing ability of Priesteria gigantea HHY-1 in Example 2 of the present invention;

[0037] Figure 8 This is a diagram showing the promotion of seed germination and growth of drought-resistant Maijiemai 19 in Application Example 1 of the present invention; different letters in the figure indicate a difference level of P < 0.05;

[0038] Figure 9 This is a wheat growth diagram at the seedling stage of promoting drought-alkali Maijiemai 19 in Application Example 2 of the present invention; different letters in the figure represent P < 0.05 difference level. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0040] Culture medium used in the examples:

[0041] LB liquid medium (1 L): 10 g of tryptone, 5 g of yeast extract, 10 g of sodium chloride, 1000 mL of water, pH 7.4, sterilized at 121°C for 20 min.

[0042] LB solid medium (1 L): 10 g of tryptone, 5 g of yeast extract, 10 g of sodium chloride, 15 g of agar, 1000 mL of water, adjust the pH to 7.4, and sterilize at 121°C for 20 min.

[0043] Ashubei medium for nitrogen-fixing bacteria (1 L): KH2PO4 0.2 g, MgSO4 0.2 g, NaCl 0.2 g, CaCO3 5.0 g, mannitol 10.0 g, CaSO4 0.1 g, agar 15.0 g, pH 7.0, sterilize at 121°C for 15 min.

[0044] YMA (Yeast Mannitol Agar) liquid medium (1 L): yeast extract 1.0 g, mannitol 10.0 g, potassium dihydrogen phosphate 0.5 g, magnesium sulfate 0.2 g, sodium chloride 0.1 g; calcium carbonate 5 g, pH 6.8-7.2, sterilize at 121°C for 15 min.

[0045] Inorganic phosphorus solid medium (1 L): glucose 10.0 g, (NH4)2SO4 0.5 g, NaCl 0.3 g, MgSO4 0.3 g, MnSO4 0.03 g, K2SO4 0.3 g, FeSO4 0.03 g, Ca3(PO4)2 5.0 g, agar 15.0 g, pH 7.0, sterilize at 116°C for 30 min.

[0046] Inorganic phosphorus liquid culture medium (1 L): glucose 10.0 g, (NH4)2SO4 0.5 g, NaCl 0.3 g, MgSO4 0.3 g, MnSO4 0.03 g, K2SO4 0.3 g, FeSO4 0.03 g, Ca3(PO4)2 5.0 g, pH 7.0, sterilize at 116°C for 30 min.

[0047] CAS medium (1 L): chrome azurol S 60.5 mg, cetyltrimethylammonium bromide 72.9 mg, FeCl3·6H2O 2.645 mg, Na2H2PO4·2H2O 295.25 mg, sodium hydrogen phosphate dodecahydrate 1213.5 mg, NH4Cl 125 mg, KH2PO4 37.5 mg, NaCl 62.5 mg, agar 9000 mg, pH 6.8, sterilize at 115°C for 30 min.

[0048] MSA (Modified Sucrose-Aspartate) medium (1 L): sucrose 20.0 g, L-asparagine 2.0 g, K2HPO4 1.0 g, MgSO4·7H2O 0.5 g.

[0049] Example 1

[0050] 1. Initial screening of Priesterol maxima

[0051] Soil samples were collected from the wheat topsoil layer in Houxianzhuang Village, Huanghua City. Strain isolation was performed using a dilution plating method using LB medium containing 5% NaCl. A total of 50 strains with different colony morphologies were isolated. The isolated strains were streaked and purified multiple times to obtain pure cultures and preserve them. The purified strains were inoculated into shake tubes containing 2 mL of liquid LB medium and cultured overnight. Once the culture solution became turbid, the strains were preserved in 50% (v / v) glycerol. Three replicates of each strain were used and the cultures were stored in a -80°C freezer.

[0052] 2. Rescreening of Priesterol maxima

[0053] 2.1 Determination of alkali resistance

[0054] The salt-tolerant strains obtained in the initial screening were inoculated into LB liquid medium with a pH of 3.0-11.0 at a volume of 1% and cultured at 28°C and 180 rpm. After 24 hours, the absorbance of the bacterial solution was measured, where OD 600 The strain with the highest value was recorded as HHY-1, and its growth curve was as follows Figure 1 As shown in the results, the strain grew well at pH 5-9, and its OD 600 The values ​​were 2.56 to 2.80, indicating that the strain had strong alkali resistance.

[0055] 2.2 Identification of strain HHY-1

[0056] 2.2.1 Morphological observation

[0057] At 28°C, on LB solid medium, single colonies are white, nearly round, with neat edges, a relatively moist surface, and raised areas. Figure 2 As shown. The bacteria are rod-shaped and Gram-positive under an optical microscope. Figure 3 shown.

[0058] The physiological and biochemical identification results of the strain were as follows: VP test, L-arabinose utilization test, D-mannitol utilization test, nitrate reduction test, and starch hydrolysis test were negative; citrate utilization test, propionate utilization test, D-xylose utilization test, and gelatin liquefaction test were positive.

[0059] According to the results of colony morphology, Gram staining and physiological and biochemical identification, and referring to Bergey's Manual of Bacterial Systematic Taxonomy, the strain HHY-1 was preliminarily identified as Priesteria gigantea.

[0060] 2.2.2 Molecular Biological Identification

[0061] The genome of strain HHY-1 was extracted using a bacterial genomic DNA extraction kit (Beijing Solebeau Technology Co., Ltd.) and used as a template for PCR amplification. The 16S rRNA sequence of the strain was amplified using the universal bacterial primers 27F (5′-AGT TTGATCCTGGCTCAG-3′) and 1492R (5′-GCTTA CCTTGTTACGACTT-3′). The 16S rRNA sequence was amplified using the reaction conditions (94°C for 5 min, 94°C for 30 s, 55°C for 30 s, 72°C for 90 s, 35 cycles, and 72°C for 10 min). A 1457-bp amplification product was obtained, the sequence of which is shown below:

[0062]

[0063] The determined sequences were compared with the National Center of Biotechnology (NCBI) database by BLAST analysis, and finally a phylogenetic tree was constructed using the Neighbor-Joining method of MEGA 5.1. Figure 4 As shown, the phylogenetic position of the strain was determined, and combined with the morphological characteristics of the bacteria, the bacteria were identified as Priestia megaterium HHY-1.

[0064] The strain HHY-1 was deposited in the General Microbiology Center of the China Culture Collection Administration of Microorganisms, abbreviated as CGMCC, on May 9, 2025. The strain deposit number is CGMCC No. 34470, and the deposit address is: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing.

[0065] Example 2

[0066] Growth-promoting properties of Priesteria megaterium HHY-1

[0067] 1. Identification of nitrogen-fixing ability of strains:

[0068] The Priesteria gigantea HHY-1 stored at -80℃ was inoculated into LB liquid medium at a 5% inoculum volume, cultured at 28℃ and 180r / min for 12h, and 20μL of 10 9 CFU / mL of bacterial solution was inoculated into the Ashubei medium for nitrogen-fixing bacteria, and the culture medium was placed in a 28℃ biochemical incubator for inversion culture. The size of the transparent zone was observed, and the diameter of the transparent zone (D) and the diameter of the bacterial body (d) were measured to calculate the D / d value. Figure 5 As shown in the figure, the D / d value at 7 days was 2. As the culture time of the strain increased, its transparent zone gradually expanded, and the D / d value rose to 2.5 at 10 days.

[0069] The strain was inoculated into YMA liquid culture medium and cultured at 28°C and 150 r / min for 4 days. The nitrogenase activity in the supernatant was detected using a microbial nitrogenase (NITS) ELISA kit (Jiangsu Enzyme Immunity Industrial Co., Ltd.). The nitrogenase activity of the strain was 113.2 ng / L.

[0070] Nitrogenase is a key enzyme in the microbial nitrogen fixation process, and its activity directly determines the efficiency of nitrogen fixation. This test result confirms at the molecular level that Priesteria gigantea HHY-1 has a strong nitrogen fixation ability and can convert nitrogen in the air into plant-usable nitrogen through the synthesis of nitrogenase. This lays a solid experimental foundation for its use in agricultural production to provide nitrogen nutrition to plants and improve soil nitrogen status.

[0071] 2. Identification of siderophore production capacity:

[0072] The Priesteria gigantea HHY-1 stored at -80℃ was inoculated into LB liquid culture medium at a 5% inoculum volume, cultured at 28℃ and 180r / min for 12h, and 20μL of 10 9 CFU / mL of bacterial solution was spotted on CAS solid culture medium, and the culture medium was placed in a 28℃ biochemical incubator for inversion culture. The orange-red halo was observed, and the diameter of the orange-red halo (D) and the diameter of the bacterial body (d) were measured to calculate the D / d value. Figure 6 As shown, the D / d value is 7 at 7d.

[0073] The strain was inoculated into MSA liquid medium and shaken at 28°C and 150 r / min for 2 days. The bacterial solution was centrifuged at 10000 r / min for 10 min. 1 mL of the supernatant was taken and 1 mL of CAS detection solution was added. The supernatant was allowed to stand for 60 min. The OD value was 0. 630 The absorbance (As) was measured under the condition of 0.5% OD. The blank medium without bacteria was used as the control. 630 The absorbance (Ar) was measured under 400 nm, and the siderophore activity of the strain was calculated according to the formula SU=[(Ar-As) / Ar]×100%. The SU value was 17.11%.

[0074] The SU value is an important indicator of siderophore activity. A higher SU value indicates a stronger ability of the siderophore to bind iron ions, indicating a higher siderophore activity. The strain's SU value of 17.11% further confirms its ability to produce siderophores. This ability effectively binds iron ions in the environment, creating favorable conditions for plant absorption and utilization of iron.

[0075] 3. Phosphate solubilization capacity identification:

[0076] The Priesteria gigantea HHY-1 stored at -80℃ was inoculated into LB liquid culture medium at a 5% inoculum volume, cultured at 28℃ and 180r / min for 12h, and 20μL of 10 9 CFU / mL of bacterial solution was inoculated into inorganic phosphorus solid culture medium, and the culture medium was placed in a 28℃ biochemical incubator for inversion culture. After 7 days, the size of the transparent circle was observed. Figure 7As shown in the figure, the D / d value was 2.0 at 7 days, which showed an obvious phosphorus dissolving effect.

[0077] Priesteria gigantea HHY-1 culture stored at -80°C was inoculated at a 1% inoculum into an inorganic phosphate liquid culture medium. After 7 days of culture, the supernatant was centrifuged and the phosphorus content in the culture supernatant was determined using a molybdenum antimony colorimetric method. The solubilized phosphorus content was 357.01 mg / L.

[0078] The above test results show that Priesteria gigantea HHY-1 has excellent phosphate-solubilizing properties. This property enables it to convert a large amount of insoluble phosphorus in the soil into soluble phosphorus that can be absorbed by plants, effectively improving the utilization rate of soil phosphorus and providing sufficient phosphorus nutrition for plant growth. Especially in saline-alkali environments with phosphorus deficiency, the phosphate-solubilizing ability of this strain will play an important role in improving soil fertility and promoting plant growth.

[0079] 4. IAA production capacity

[0080] Using an indoleacetic acid oxidase activity detection kit, Priesteria gigantea HHY-1 stored at -80°C was inoculated into LB liquid culture medium at a 5% inoculum size and cultured at 28°C and 180 r / min for 12 h. The bacterial liquid was collected and centrifuged according to the instructions, and the supernatant was discarded. 1 mL of extract was added for every 5 million bacteria, and the bacteria were disrupted by ultrasonication (200 W ultrasonic power for 3 s, 30 s interval, repeated 30 times). Then, the culture was centrifuged at 12000g and 4°C for 15 min. The supernatant was collected and the IAA enzyme activity was measured according to the instructions.

[0081] The standard curve equation for indoleacetic acid oxidase activity detection is y=0.1434x+0.0408(R 2 =0.9997), the IAA activity of strain HHY1 was calculated to be 0.242 U / 10 4 cell.

[0082] These results demonstrate that Priesteria gigantea HHY-1 is capable of producing IAA. In saline-alkali soils, the IAA produced by this strain can effectively alleviate the growth inhibition of plants caused by adverse conditions, promoting better plant growth and development.

[0083] 5. Antioxidant enzyme activity

[0084] The Priesteria gigantea HHY-1 stored at -80°C was inoculated into LB liquid culture medium at a 5% inoculum size and cultured at 28°C and 180 r / min for 12 h. The antioxidant capacity of the strain HHY-1 was determined using a catalase (CAT) kit and a superoxide dismutase (SOD) kit. The results showed that the catalase activity of the strain HHY-1 was 0.071 nmol / min / 104 cell, superoxide dismutase activity was 0.033U / 10 4 cell.

[0085] In adverse environments such as saline-alkali soils, plants and microorganisms produce large amounts of reactive oxygen free radicals due to environmental stress, which adversely affects their growth and metabolism. The antioxidant capacity of Priesteria gigantea HHY-1 not only protects its own normal growth and reproduction in adverse conditions, allowing it to continue to perform its functions such as nitrogen fixation, phosphate solubilization, siderophore production, and IAA production, but also helps plants reduce oxidative damage through interaction with them, enhancing their resistance to adverse conditions such as saline-alkali soils, thereby promoting their growth and development.

[0086] Example 3

[0087] This embodiment provides a Priesteria gigantea HHY-1 liquid inoculum, the preparation method of which comprises the following steps:

[0088] Priestia megaterium HHY-1 with the accession number CGMCC No. 34470 stored at -80°C was inoculated into LB liquid medium and cultured at 28°C and 180 rpm overnight. The cultured bacterial solution was centrifuged at 5000 rpm for 10 min, the supernatant was discarded, and the precipitate was washed with sterile water. This was repeated three times to remove the components of the culture medium. Bacterial suspensions of different concentrations were then prepared with sterile water to obtain liquid inoculants. The number of viable bacteria in the microbial inoculants was 10 8 CFU / mL, 10 7 CFU / mL, 10 6 CFU / mL.

[0089] Application Example 1

[0090] This application example is an experiment on promoting the germination of seeds of Araceae Maijiemai 19 by using the microbial agent prepared in Example 3.

[0091] Fifteen Jiemai 19 wheat seeds were placed in each sterile plate filled with sterile filter paper. Four treatments were set up: CK group (sterile water soaked seeds); T1 group (1.0×10 6 CFU / mL liquid inoculant soaking seeds); T2 group (1.0×10 7 CFU / mL liquid inoculant soaking seeds); T3 group (1.0×10 8 CFU / mL liquid inoculant soaked seeds), the amount of liquid inoculant added to each treatment was 4mL, and each group was repeated twice. Placed in a constant temperature incubator at 25℃ for 2.5 days, the length of wheat sprouts and wheat roots was measured, such as Figure 8 shown.

[0092] The sprout and root lengths of the wheat in the CK group were 3.36 cm and 4.49 cm, respectively. The liquid inoculant concentration was 1.0×10 7 The effect was most significant when the concentration was 1.0×10 7 After soaking seeds with CFU / mL liquid inoculant, the wheat sprout length was 3.93 cm, which was 16.96% higher than that of the CK group; the wheat root length was 5.57 cm, which was 24.05% higher than that of the CK group.

[0093] Application Example 2

[0094] This example is a potted test of drought-alkali wheat Jiemai 19. The test soil was taken from the topsoil of wheat-corn rotation in Houxianzhuang Village, Huanghua City, Hebei Province. The physical and chemical properties of the soil are shown in Table 1.

[0095] Table 1 Physical and chemical properties of soil

[0096]

[0097] The test soil was placed in a flower pot with an outer diameter of 9 cm, an inner diameter of 8 cm, and a height of 8 cm. 110 g of soil was placed in each pot. 2.5 mL of the liquid inoculum in Example 3 was added. Then, seeds of the genus Aglaonemai Jiemai 19 were sown in the flower pots, with 7 seeds per pot. Four treatments were set up in the experiment: CK group (2.5 mL of sterile water); T1 group (1.0 × 10 6 CFU / mL liquid inoculum); T2 group (1.0×10 7 CFU / mL liquid inoculum); T3 group (1.0×10 8 CFU / mL liquid inoculum), each treatment was repeated 4 times, and the wheat plant height, total nitrogen (sulfuric acid-hydrogen peroxide digestion, distillation method), total potassium (sulfuric acid-hydrogen peroxide digestion, flame photometry), and total phosphorus (sulfuric acid-hydrogen peroxide digestion, vanadium molybdenum yellow colorimetry) contents in wheat aboveground plants and wheat roots were determined after culturing in a greenhouse at 20°C, 14 h light intensity, and 65% air humidity for 30 days.

[0098] like Figure 9 As shown, application of HHY-1 liquid inoculant promoted wheat growth. Plant heights in the T1-T3 treatment groups (40.16 cm to 43.98 cm) were significantly higher than those in the control group (34.14 cm). Measurements of total nitrogen, phosphorus, and potassium levels in the aboveground wheat plants and roots revealed that application of HHY-1 liquid inoculant increased these levels. Nitrogen and phosphorus promote root growth and development, while potassium improves photosynthesis efficiency (Tables 2 and 3). Total nitrogen, potassium, and phosphorus are crucial for wheat growth and development, impacting not only yield but also quality.

[0099] Table 2 Total nitrogen, total potassium and total phosphorus contents in aboveground wheat plants

[0100]

[0101] Note: Different letters indicate differences at the P<0.05 level.

[0102] Table 3 Total nitrogen, total potassium and total phosphorus contents in wheat roots

[0103]

[0104] Note: Different letters indicate differences at the P<0.05 level.

[0105] In summary, the Priesteria gigantea provided by the present invention, with the accession number of CGMCC No. 34470, has multiple functions such as nitrogen fixation, phosphate solubilization, siderophore production, IAA production ability and antioxidant enzyme activity. This strain can effectively solve the many problems faced by the drought-alkali wheat Jiemai 19 when growing in saline-alkali land. It supplements nitrogen through nitrogen fixation, improves the effectiveness of phosphorus through phosphate solubilization, improves iron absorption through siderophore production, promotes growth and development through IAA production, and synergistically responds to oxidative stress through antioxidant enzyme activity. It plays a comprehensive role in multiple dimensions such as nutrient supply, growth regulation and stress protection, effectively helping the drought-alkali wheat Jiemai 19 to grow well in a saline-alkali environment, which is of great significance to increasing the yield of drought-alkali wheat in saline-alkali land and promoting the sustainable development of agriculture. It shows extremely high practical value in promoting the growth of drought-alkali wheat Jiemai 19.

[0106] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A Priestia megaterium HHY-1, characterized in that Its deposit number is CGMCC No.34470.

2. A microbial composition, characterized in that The invention comprises the Priesteria megaterium HHY-1 according to claim 1.

3. A microbial agent, characterized in that: The invention comprises the Priesteria megaterium HHY-1 according to claim 1.

4. The microbial agent according to claim 3, wherein The microbial agent is a liquid agent.

5. The microbial agent according to claim 4, wherein The number of viable bacteria of Priesteria gigantea HHY-1 in the microbial agent was 2×10 6 ~7×10 8 CFU / mL.

6. The method for preparing the microbial agent according to any one of claims 3 to 5, characterized in that: The steps include: The Priesteria gigantea HHY-1 was inoculated into LB liquid culture medium and cultured at 25°C to 30°C and 180r / min to 200r / min for 1 to 2 days. The cultured bacterial liquid was centrifuged, the supernatant was discarded, and the cells were washed. Sterile water was then added until the number of viable bacteria in the bacterial suspension reached 2×10 6 ~7×10 8 CFU / mL, and obtain the microbial agent.

7. The method for preparing the microbial agent according to claim 6, wherein: The LB liquid culture medium comprises: 10 g of tryptone, 5 g of yeast extract, 10 g of sodium chloride and 1000 mL of water, with a pH of 7.4, and is sterilized at 121° C. for 20 min.

8. Use of the Priesteria gigantea HHY-1 according to claim 1 in nitrogen fixation, siderophore production, elongation production, promotion of nitrogen and phosphorus absorption, improvement of resistance to drought and saline-alkali stress, and improvement of antioxidant enzyme activity.

9. Use of the Priesteria gigantea HHY-1 according to claim 1 or the microbial composition according to claim 2 in promoting the growth of alkali wheat.

10. Use of the microbial agent according to any one of claims 3 to 5 in promoting the growth of alkali wheat.

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