Saline-alkali tolerant zoobacteria FY231025 and application thereof

Abstract

The invention belongs to the technical field of microorganism application, and particularly relates to saline-alkaline tolerant zoobacteria FY231025 and application thereof. The Streptococcus sp. FY231025 provided by the invention is preserved in the China General Microbiological Culture Collection Center (CGMCC), the preservation time is May 13, 2025, and the preservation number is CGMCC NO: 34534. The strain has the functions of resisting salt and alkali, dissolving phosphorus, producing IAA (Indoleacetic Acid) and promoting plant growth, can be used for improving the saline-alkaline tolerance of plants, slowing down the soil salinization degree, protecting the plants from being damaged by active oxygen and promoting plant growth, and can be prepared into a fertilizer with the effects of promoting plant growth and improving saline-alkali soil for use.

Description

Technical Field

[0001] The present invention belongs to the technical field of microbial application, and more specifically, relates to a salt- and alkali-resistant Mosinococcus FY231025 and an application thereof. Background Art

[0002] With global climate change and irrational agricultural irrigation, soil salinization has become a major issue affecting global agricultural production. As soil salinization intensifies, related environmental problems such as soil desertification and land desertification have gradually emerged, causing the agricultural production environment to deteriorate rapidly. These environmental problems not only hinder the long-term application of crop production, but also pose a serious threat to the coordination and stability of the entire ecosystem. Therefore, effectively carrying out the improvement and management of saline-alkali land and seeking new ways to utilize it have become major scientific and technological issues that must be addressed in agricultural production in the new era. Focusing on the application of microbial improvement technology, especially the role of salt-tolerant bacteria in the improvement of saline-alkali soil, has positive significance for the long-term utilization of saline-alkali land resources.

[0003] Microorganisms play a vital role in saline soil improvement. Through various mechanisms, they can improve soil structure, reduce salinity, and enhance soil fertility, thereby promoting plant growth. With the advancement and development of science and technology, microbial improvement of saline-alkali soils has gained increasing attention as a new and continuously effective improvement method. This technology primarily leverages the power of microorganisms to improve saline-alkali soils by enhancing soil microbial activity and diversity, demonstrating its low pollution, high ecological and environmental benefits, and sustainability. This process, primarily involving microbial tissues such as animals, plants, and microorganisms, converts salt and other harmful substances in saline-alkali soils into harmless or low-toxic substances. It also increases the organic matter content, creating an environment conducive to plant growth and establishing a complete and sustainable soil ecosystem. Therefore, the development of functional microorganisms and their products that can enhance crop tolerance to salt stress and improve soil conditions in saline-alkali soils is crucial. Summary of the Invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a salt- and alkali-resistant Mosinococcus FY231025 and its application.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows: The present invention provides a motile coccus FY231025, and the motile coccus FY231025 is classified and named Planococcus rhizosphaerae, deposited in the General Microbiology Center of China Culture Collection Administration, the deposit address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, the deposit date is May 13, 2025, and the deposit number is CGMCCNO.34534.

[0006] The Motile Coccus FY231025 provided by the present invention has the functions of salt-alkali tolerance, phosphate solubility, IAA production and plant growth promotion. It can be used to improve the salt-alkali tolerance of plants, slow down the degree of soil salinization, protect plants from active oxygen damage and promote plant growth. The strain provided by the present invention can be prepared into a fertilizer with plant growth promotion and saline-alkali land improvement functions.

[0007] The present invention also provides a bacterial fertilizer, which uses the Motile Coccus FY231025 as an effective component.

[0008] The present invention also provides the use of the Motile Coccus FY231025 in producing IAA.

[0009] The present invention also provides the use of the Motile Coccus FY231025 or the bacterial fertilizer in improving salinized soil.

[0010] Furthermore, the improvement is achieved through the phosphate-solubilizing function of Mosinococcus FY231025.

[0011] The present invention also provides the use of the Motile Coccus FY231025 or the bacterial fertilizer in improving the salt-alkali tolerance of corn.

[0012] Furthermore, the improvement of the salt-alkali tolerance of corn is achieved by soaking corn seeds in a bacterial solution of Planococcus sp. FY231025.

[0013] The present invention also provides the use of the Motile Coccus FY231025 or the bacterial fertilizer in promoting corn growth.

[0014] Furthermore, the corn growth promotion includes increasing the root length, fresh weight, plant height, stem diameter and leaf thickness of corn. The present invention has the following beneficial effects: The Motile Coccus FY231025 provided by the present invention is salt- and alkali-tolerant, phosphate-solubilizing, and IAA-producing. It can effectively improve the soil microenvironment of plant roots, reduce salt- and alkali-induced stress on plants, and provide nutrients for plant growth, ultimately promoting plant growth. Therefore, FY231025 of the present invention has important application value in improving saline-alkali soil, enhancing plant tolerance to saline- and alkali-induced stress, and promoting plant growth. It can be used to prepare fertilizers that promote plant growth and improve saline-alkali soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the colony morphology of FY231025.

[0016] Figure 2 This is the transmission electron microscope image of FY231025.

[0017] Figure 3 This is the growth statistics chart of FY231025.

[0018] Figure 4 The above is a bar chart of the growth of FY231025 under different NaCl concentration conditions, where A is a bar chart of the growth conditions under the NaCl concentration range of 0 g / mL~12 g / mL, and B is a bar chart of the growth conditions under the NaCl concentration range of 13 g / mL~22 g / mL.

[0019] Figure 5 This is a bar chart showing the growth of FY231025 under different pH conditions.

[0020] Figure 6 This is the result of the phosphorus dissolution test of FY231025.

[0021] Figure 7 This is a diagram showing the growth-promoting effect of FY231025 on corn.

[0022] Figure 8 This is a bar graph of the growth-promoting effect of FY231025 on corn, where A is the statistical graph of corn root length, B is the statistical graph of corn stem diameter, C is the statistical graph of corn fresh weight, and D is the statistical graph of corn plant height.

[0023] Figure 9 This is a statistical chart of corn leaf thickness, where * indicates P < 0.05 and ** indicates P < 0.01. DETAILED DESCRIPTION

[0024] The present invention will be described in detail below with reference to the accompanying drawings and specific examples, but they should not be construed as limiting the present invention. Unless otherwise specified, the technical means used in the following examples are conventional means well known to those skilled in the art, and the materials, reagents, etc. used in the following examples, unless otherwise specified, can be obtained from commercial sources.

[0025] Example 1: Isolation, identification and application of FY231025.

[0026] 1. Separation of FY231025.

[0027] The rhizosphere soil samples of Suaeda salsa in Wuhai, Inner Mongolia Autonomous Region were selected and placed in sterile sterilization bags. They were brought back to the laboratory for treatment at low temperature. The rhizosphere soil was gently shaken off. 0.1 g of saline-alkali soil from the rhizosphere of Suaeda salsa was added to 900 μL of sterile water to form a mixed solution. The solution was vortexed for 2 minutes to fully disperse the rhizosphere soil in sterile deionized water. The solution was allowed to stand for 5 minutes to obtain a suspension. 1 mL of the suspension was drawn and added to 9 mL of sterile deionized water to obtain a concentration of 10 -1 g / mL soil suspension, and dilute it in sequence to obtain 10 -2 g / mL, 10 -3 g / mL, 10 -4 g / mL, 10 -5 g / mL gradient suspension, vortex to mix thoroughly, take each dilution gradient soil suspension, spread on LB solid medium, repeat each gradient three times, and incubate inverted in a 30°C constant temperature incubator. Pick a single colony and inoculate it into LB liquid medium to obtain a pure culture of FY231025 single colony.

[0028] 2. Identification of FY231025.

[0029] 1. Morphological identification: Figure 1 As shown in Figure 2, after FY231025 was cultured on LB agar medium at 32°C for two days, the strain formed round, low-convex circular colonies, which is consistent with the colony morphology characteristics of the genus Haloperidol. Figure 2 As shown, the transmission electron micrograph shows that the bacteria of strain FY231025 are spherical and have flagella.

[0030] 2. Whole genome analysis: Genomic DNA was extracted using the cetyltrimethylammonium bromide method, and all genome sequencing tasks were performed by Shanghai Paisono Biotechnology Service Co., Ltd. using the Illumina Novaseq platform. The whole genome sequence results showed that the genome of FY231025 was 3798726 bp in length and had a G+C content of 50.2%. The ANI value was calculated using the JSpeciesWS online ANI tool (http: / / jspecies.ribohost.com / jspeciesws / ). Planococcus antioxidans Y74T, Planococcus chinensis DX3-12T, Planococcus glaciei 0423T and Planococcus halotolerans SCU63T was used as the reference strain. The ANI values ​​used were calculated using the BLAST method and are referred to as ANIb values. dDDH values ​​were calculated using the Genome-to-Genome Distance Calculator (https: / / ggdc.dsmz.de / ggdc.php).

[0031] The results are shown in Table 1. FY231025 and four reference strains of Mosinococcus Planococcus antioxidans Y74T, Planococcus chinensis DX3-12T, Planococcus glaciei 0423T and Planococcus halotolerans The ANIb values ​​for SCU63T were 77.5%, 77.1%, 84.4%, and 78.2%, all significantly below the 95% threshold for species classification. The dDDH values ​​were 22.6%, 21.3%, 39.2%, and 22.4%, also well below the 70% threshold for species classification. Therefore, these values ​​confirm the unique taxonomic status of FY231025 within the genus Planococcus.

[0032] Table 1: ANIb and dDDH values ​​between FY231025T and reference strains

[0033] Note: 1 is Planococcus antioxidans Y74T, 2 Planococcus chinensis DX3-12T, 3 for Planococcus glaciei 0423T, 4 Planococcus halotolerans SCU63T.

[0034] Based on the results of morphological and molecular biological identification, FY231025 showed morphological characteristics similar to the model strain of Salinacoccosis and had low levels of ANI and dDDH values, proving that FY231025 is a new species of the genus Moinecoccus.

[0035] 3. Study on the function of strains.

[0036] 1. Growth curve determination: Take a single colony of FY231025 and place it in LB liquid medium. Place it in a constant temperature shaking incubator at 30°C and 170r / min. Measure the absorbance OD value with a UV spectrophotometer every 12 hours. 600 , repeat three times at each time point, take the average value, and draw the growth curve. Figure 3 As shown, FY231025 reached the logarithmic growth phase at 24h~36h.

[0037] 2. Salt tolerance test: Take a single colony of FY231025 in the logarithmic growth phase and inoculate it into LB liquid medium with a NaCl concentration of 0g / mL~20g / mL. Then place it in a constant temperature shaking incubator at 30℃ and 170r / min for 36h. Measure the absorbance OD using a UV spectrophotometer. 600 The results are as follows Figure 4 As shown in the results, the salt concentration range that FY231025 can tolerate is 1 g / mL~18 g / mL, indicating that the strain has good salt tolerance.

[0038] 3. Alkali resistance test: Take a single colony of FY231025 in the logarithmic growth phase and inoculate it into LB liquid medium with a pH of 3-12. Then place it in a constant temperature shaking incubator at 30°C and 170 r / min for 36 hours. Measure the absorbance OD using a UV spectrophotometer. 600 The results are as follows Figure 5 As shown, FY231025 grew normally in the pH range of 7-10, indicating that the strain has good alkali resistance.

[0039] 4. Determination of IAA Production Capacity: IAA was determined using the Salkowski colorimetric method. FY231025 in the logarithmic growth phase was inoculated into 50 mL of LB liquid medium containing 100 mg / L tryptophan and cultured at 30°C, 170 rpm, and shaking for 48 hours. Aspirate 2 mL of the bacterial suspension and centrifuge at 8000 rpm for 10 minutes. Take 0.5 mL of the supernatant and add an equal volume of Salkowski colorimetric solution. Incubate in the dark for 30 minutes. Measure the absorbance at 530 nm and calculate the IAA content based on the absorbance. The calculation formula is: y = 104.2x - 3.8341, where x represents the absorbance at 530 nm and y represents the IAA content.

[0040] The results are shown in Table 2. The FY231025 fermentation broth contained 3.12±0.032 mg / L of IAA. This result indicates that FY231025 plays an important role in promoting the growth of plants in saline-alkali soils. This is because IAA is the main form of natural auxin in plants. It can increase the plant root system and promote root elongation, thereby increasing the plant's absorption of nutrients in the soil and promoting plant growth.

[0041] Table 2: IAA results of FY231025T

[0042] 5. Phosphate solubilization function test of FY231025: Inoculate FY231025 in the logarithmic growth phase on an inorganic phosphate culture medium, e.g. Figure 6 As shown in the figure, a transparent circle appeared around the colony after 72 hours, which shows that FY231025 has the ability to decompose inorganic phosphorus, convert insoluble phosphate into soluble phosphate, and improve the soluble phosphate content in the soil.

[0043] 4. Impact of FY231025 on corn growth.

[0044] 1. Seed treatment: Select corn seeds with full kernels, which were provided by Inner Mongolia Xingfeng Seed Industry Co., Ltd. The test variety was Xingke 5. The seeds of the experimental group were treated with OD 600The seeds were soaked in FY231025 solution with a dilution of 1.0 for 24 h, and the seeds of the control group were soaked in deionized water for 24 h.

[0045] 2. Experimental soil: Saline-alkali soil was collected from the Yellow River Equestrian Park in Jiuyuan District, Baotou City, Inner Mongolia Autonomous Region, with coordinates E109.811645, N40.515128. Soil 3 cm from the surface was collected and placed in a sealed bag.

[0046] 3. Experimental Treatments: CK served as the control group, using saline-alkali soil as the potting medium and three seeds soaked in deionized water. T served as the experimental group, using saline-alkali soil as the potting medium and three seeds soaked in bacterial solution. Plants were harvested after 27 days of incubation. Root length, stem diameter, plant height, leaf thickness, and fresh weight of corn seedlings were measured using a ruler and a scale.

[0047] 4. Experimental indicator detection: Root length is measured as the straight-line length from the base of the root to the tip of the longest root of the complete root system. Dig out the target plant together with the soil around the root system, keeping the root system intact. Place the roots with soil in a large basin filled with clean water. Shake gently and use water to rinse off the soil attached to the roots. Change the water and rinse repeatedly until the roots are clean and free of soil. Drain the water, spread the washed roots flat on absorbent paper or hang them in the air to drain for a while to remove excess water. Arrange the roots, use tweezers to carefully stretch and straighten the roots as much as possible, and spread them flat on a measuring table or a clean surface. Use a tape measure to measure the straight-line distance from the base of the stem to the end of the longest root. The recording unit is centimeters.

[0048] Stem diameter is measured as the diameter of the first internode at the base of the corn stalk, i.e., the first noticeable internode above ground. Use a vernier caliper. Gently place the measuring jaws on either side of the middle of the selected internode, ensuring the caliper is perpendicular to the stalk axis. Gently close the caliper, touching the stalk surface without squeezing or deforming it. Read and record the reading. Record in centimeters.

[0049] Plant height is measured vertically from the rhizome to the highest point of the plant, which is the tip of the last fully expanded leaf. Place the plant upright on a flat surface and use a tape measure to measure vertically from the root collar to the highest point. Record the height in centimeters.

[0050] Leaf thickness is measured in the middle of a fully expanded leaf, avoiding the main vein. Select a flat area in the middle of the leaf, avoiding the main vein and large lateral veins, midway between the midrib and the leaf margin. Place the measuring point of the leaf between the caliper jaws. Very gently close the caliper until it just touches both sides of the leaf, making sure not to compress the leaf and deform it. Read the reading. Record in centimeters.

[0051] Fresh weight measures the weight of the entire plant in its fresh, hydrated state. Dig up the target plant along with the soil surrounding the roots, keeping the roots intact. Rinse with running water to remove any soil adhering to the roots. Repeat with changing water until the roots are clean and free of dirt. Gently blot the washed roots with absorbent paper to remove any loose water droplets. Quickly and steadily place the plant on the weighing container. Once the balance reading stabilizes, record the weight immediately. Record in grams.

[0052] 5. Experimental results: Figure 7 It can be seen intuitively that the inoculation of the strain has a significant promoting effect on the growth of corn. The roots of corn are responsible for absorbing nutrients, providing energy for corn, fixing the plant, and preventing the plant from falling over. The growth of corn roots can be used as an important indicator to judge the growth of corn. The stem diameter of corn seedlings affects the later growth of the plant, so the stem diameter of corn seedlings can be used as an important indicator of corn growth. The fresh weight of corn can reflect the degree of thriving of corn. The growth of root length, stem diameter, plant height, leaf thickness and fresh weight of corn with and without bacteria is shown in the figure. Figure 8 and Figure 9 As shown in the figure, the root length, stem diameter, and fresh weight of corn treated with FY231025 were all greater than those of the untreated control group. Increased root length improved the plant's ability to absorb water and nutrients, reducing salt accumulation. Significance analysis showed that the difference between the experimental corn group treated with FY231025 and the untreated corn control group was significantly higher. Increased plant height can reduce soil surface evaporation and salt accumulation. Increased stem diameter can enhance plant resistance and reduce soil erosion. Increased leaf thickness can reduce water evaporation and thus salt accumulation. Increased fresh weight indicates healthy plant growth and reduced salt accumulation. Increased fresh weight indicates healthy plant growth and better adaptation to saline-alkali environments. Therefore, FY231025 promotes corn growth.

[0053] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

Claims

1. A Motile Coccus FY231025, characterized in that The classification of the motile coccus FY231025 is named Planococcus rhizosphaerae , deposited in the General Microbiology Center of China Culture Collection Administration, the deposit date is May 13, 2025, and the deposit number is CGMCC NO.34534.

2. A bacterial fertilizer, characterized in that: The active ingredient is the Motile Coccus FY231025 described in claim 1.

3. Use of the mobile coccus FY231025 according to claim 1 in producing IAA.

4. Use of the Motile Coccus FY231025 according to claim 1 or the bacterial fertilizer according to claim 2 in improving salinized soil.

5. The use according to claim 4, characterized in that The improvement is achieved through the phosphate-solubilizing function of Mosinococcus sp. FY231025.

6. Use of the Motile Coccus FY231025 according to claim 1 or the bacterial fertilizer according to claim 2 in improving the salt-alkali tolerance of corn.

7. The use according to claim 6, characterized in that The improvement of the salt-alkali resistance of corn is achieved by soaking corn seeds in a bacterial solution of Planococcus sp. FY231025.

8. Use of the Motile Coccus FY231025 according to claim 1 or the bacterial fertilizer according to claim 2 in promoting corn growth.

9. The use according to claim 8, characterized in that The promoting of corn growth includes increasing the root length, fresh weight, plant height, stem diameter and leaf thickness of corn.

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