Paenibacillus polymyxa capable of preventing diseases, resisting stress and promoting growth and application of paenibacillus polymyxa

Abstract

The invention relates to paenibacillus polymyxa capable of preventing diseases, resisting stress and promoting growth and application of the paenibacillus polymyxa, and belongs to the technical field of microorganisms, the paenibacillus polymyxa SS44 has the characteristics of degrading protein, degrading fat, degrading cellulose, dissolving potassium, fixing nitrogen, dissolving organic phosphorus, dissolving inorganic phosphorus and producing exopolysaccharide. The strain is capable of antagonizing pathogenic bacteria fusarium oxysporum and fusarium fusiforme which can cause potato fusarium wilt, sweet potato root rot, soybean root rot, alfalfa root rot and the like, can improve sandy soil, can generate a good growth promoting effect on wheat, soybean and corn in saline-alkali soil and sandy barren soil environments, and is very wide in application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of microorganisms, in particular to a disease-preventing, stress-resistant and growth-promoting Paenibacillus polymyxa and an application thereof. Background Art

[0002] In recent years, in order to prevent and control bacterial or fungal diseases of various crops, various chemical agents have been used in large quantities in the field for a long time, and the supplement of organic matter and microorganisms has been neglected, resulting in serious lack of organic matter and microorganisms in the soil, forming problems such as soil compaction, salinization, and desertification; the plant growth environment has been damaged, and the area of ​​soil suitable for cultivation has continued to decline. Microbial agents are products containing specific living microorganisms. Through the microorganisms contained in them, they can improve the distribution of microbial communities in the soil and the soil nutrient structure to a certain extent, so that crops can maintain normal growth in harsh environments or even better than normal growth conditions.

[0003] Plant growth-promoting rhizobacteria (PGPR) are a group of strains commonly used in microbial agents, including Bacillus ( Bacillus sp.), Pseudomonas spp. Pseudomonas sp.), Klebsiella Klebsiella sp.), Azotobacter spp. Azotobacter sp.), etc. They can directly or indirectly promote plant growth through various mechanisms such as phosphorus solubilization, potassium solubilization, and nitrogen fixation. Paenibacillus polymyxa ) is an important PGPR, which is widely found in soil, water, plant surface and rhizosphere, and can produce a variety of antimicrobial active substances such as polymyxin, colistin, cyclobactin, etc. As a model bacterium of Paenibacillus, Paenibacillus polymyxa is environmentally friendly and safe, and its metabolites are widely used in agriculture, medicine, industry and mining, wastewater treatment and other aspects.

[0004] As a microorganism widely found in soil and water, Paenibacillus polymyxa has attracted much attention in natural ecosystems. In order to promote the growth of crops in harsh environments such as saline-alkali soil and poor soil (such as sandy soil), it is of great significance to explore more characteristics of Paenibacillus polymyxa and its growth-promoting effects on crops. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a disease-preventing, stress-resistant, growth-promoting Paenibacillus polymyxa and its application. The strain has the characteristics of degrading protein, fat, cellulose, potassium, nitrogen fixation, organic phosphorus, inorganic phosphorus, and extracellular polysaccharide production, and can antagonize Fusarium oxysporum and Fusarium fujikura. The strain can improve sandy soil and has a good growth-promoting effect on wheat, soybean, and corn in saline-alkali soil and sandy soil environments, and has a very broad application prospect.

[0006] The technical solution of the present invention is as follows: A strain of Paenibacillus polymyxa ( Paenibacillus polymyxa )SS44, deposited on October 21, 2024 at the General Microbiology Center of China Culture Collection Administration, address: No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, with the deposit number CGMCC No.32283.

[0007] The 16S rDNA sequence of the Paenibacillus polymyxa SS44 is shown in SEQ ID NO.1.

[0008] The method for culturing the polymyxa bacillus SS44 comprises the following steps: (1) Inoculate the Bacillus polymyxa SS44 strain into LB solid medium and culture it upside down at 37°C until a single colony grows; (2) Pick a single colony from step (1) and place it in LB liquid culture medium, shake and culture at 120-180 rpm and 37±1°C to obtain an activated bacterial solution; (3) The activated bacterial solution of step (2) is inoculated into LB liquid culture medium at an inoculum volume percentage of 1-3%, and cultured under shaking conditions of 120-180 rpm and 37±1°C to obtain a bacterial solution of Paenibacillus multimyxogenis SS44.

[0009] The polymyxa bacillus SS44 is used in degrading proteins, degrading fats, degrading cellulose, dissolving potassium, fixing nitrogen, dissolving organic phosphorus, dissolving inorganic phosphorus, and producing extracellular polysaccharides.

[0010] The polymyxa bacillus SS44 is used for antagonizing Fusarium oxysporum and Fusarium fujikura.

[0011] The invention relates to an application of the Paenibacillus polymyxa SS44 in improving sandy soil.

[0012] The application of Paenibacillus polymyxa SS44 in promoting plant growth is described, and the plants are wheat, soybean and corn.

[0013] The polymyxa bacillus SS44 is used for promoting plant growth in saline-alkali soil with a salt content of ≤5g / Kg and a pH of ≤9.

[0014] The polymyxa bacillus SS44 is used for promoting plant growth in sandy soil with a salt content of ≤2g / Kg and a pH of ≤9.

[0015] The application of the polymyxa bacillus SS44 in promoting plant growth is as follows: the polymyxa bacillus SS44 is prepared into a granule having a live bacterial content of 2.0×10 8 ~3.0×10 8cfu / mL of live bacterial preparations should be diluted more than 100 times and applied to the soil at a dosage of 50~100mL / Kg.

[0016] A live bacteria preparation, which takes the polymyxa bacillus SS44 as an active ingredient.

[0017] Beneficial effects of the present invention: The invention provides a strain of Paenibacillus polymyxa SS44, which has the characteristics of degrading protein, degrading fat, degrading cellulose, dissolving potassium, fixing nitrogen, dissolving organic phosphorus, dissolving inorganic phosphorus and producing extracellular polysaccharide, can antagonize pathogenic bacteria Fusarium oxysporum and Fusarium fujikura that can cause potato wilt, sweet potato root rot, soybean root rot, alfalfa root rot and the like, and the strain can improve sandy soil, and can produce good growth-promoting effects on wheat, soybean and corn in saline-alkali soil and sandy soil environments, and has very broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The colony morphology of strain SS44 and its observation under a microscope after Gram staining; Figure 2 The growth of strain SS44 in casein medium; Figure 3 is the growth of strain SS44 in tributyrin medium; Figure 4 The growth of strain SS44 in sodium carboxymethyl cellulose medium; Figure 5 The growth of strain SS44 in silicate bacterial culture medium; Figure 6 The growth of strain SS44 in Axubei medium; Figure 7 The growth of strain SS44 in the Montkina organophosphate bacterial culture medium; Figure 8 The growth of strain SS44 in the Montkina inorganic phosphorus bacterial medium; Fig. 9 This is the experimental picture of the production of extracellular polysaccharide by strain SS44; Fig.10 Experimental picture of SS44 bacterial solution watering sandy soil and drying it; Fig.11 The antagonistic effect of strain SS44 on Fusarium oxysporum and Fusarium fujikuraensis; Fig.12 The morphological photos of wheat plants in different treatment groups after 10 days of cultivation in saline-alkali soil environment; Fig.13The morphological photos of wheat plants in the cultivation pots of different treatment groups after 14 days of cultivation in saline-alkali soil environment; Fig.14 The morphological photos of wheat plants in different treatment groups after harvesting after 14 days of cultivation in saline-alkali soil environment; Fig.15 The results of the test on the wheat growth promotion effect of strain SS44 in different treatment groups under saline-alkali soil environment; Fig.16 The morphological photos of wheat plants in different treatment groups after 10 days of cultivation in sandy soil environment; Fig.17 The morphological photos of wheat plants in the cultivation pots of different treatment groups after 14 days of cultivation in sandy soil environment; Fig.18 The morphological photos of wheat plants in different treatment groups after harvesting after 14 days of cultivation in sandy soil environment; Fig.19 The results of the test on the growth-promoting effect of strain SS44 on wheat in different treatment groups under sandy soil environment; Fig. 20 The morphological photos of soybean plants in different treatment groups after 14 days of cultivation in saline-alkali soil environment; Fig.21 The morphological photos of soybean plants in the cultivation pots of different treatment groups after 21 days of cultivation in saline-alkali soil environment; Fig. 22 The morphological photos of soybean plants in different treatment groups after 21 days of cultivation in saline-alkali soil environment; Fig.23 The results of the test on the growth-promoting effect of strain SS44 on soybeans in different treatment groups under saline-alkali soil environment; Fig.24 The morphological photos of soybean plants in different treatment groups after 14 days of cultivation in sandy soil environment; Fig.25 The morphological photos of soybean plants in the cultivation pots of different treatment groups after 21 days of cultivation in sandy soil environment; Fig.26 The morphological photos of soybean plants in different treatment groups after 21 days of cultivation in sandy soil environment; Fig. 27 The results of the test on the growth-promoting effect of strain SS44 on soybeans in different treatment groups under sandy soil environment; Fig.28 The morphological photos of corn plants in different treatment groups after 12 days of cultivation in saline-alkali soil environment; Fig.29 The results of the test on the growth-promoting effect of strain SS44 on corn in different treatment groups under saline-alkali soil environment; Fig.30The morphological photos of corn plants in different treatment groups after 14 days of cultivation in sandy soil environment; Fig.31 These are the results of the test on the growth-promoting effect of strain SS44 on corn in different treatment groups under sandy soil environment. DETAILED DESCRIPTION

[0019] The following is a description of a disease-preventing, stress-resistant and growth-promoting Paenibacillus polymyxa and its application Source of experimental materials: Wheat seeds: Jinchun No. 6, purchased from Fuyichun Seed Company.

[0020] Soybean seeds: Zhonghuang 57, purchased from Henan Huanghetandiyuan Seed Co., Ltd.

[0021] Corn seeds: Zhengdan 958, purchased from Gansu Agricultural Reclamation Seed Co., Ltd.

[0022] Fusarium oxysporum Fusarium oxysporum ): purchased from Shanghai Microbiological Collection Center, catalog number SHMCCD25188.

[0023] Fusarium fusarifolia Fusarium fujikuroi ): purchased from Shanghai Microbiological Collection Center, catalog number SHMCCD19154.

[0024] Example 1: Isolation, screening and identification of Paenibacillus polymyxa SS44 The soil was collected from the sandy land of Yanggu County, Liaocheng City, Shandong Province, China. The specific separation and screening methods were as follows: 10.0 g of soil was weighed and placed in a triangular flask filled with sterile water, and then placed on a constant temperature shaker at 37°C and 180 r / min for 30 min to obtain a soil suspension; the soil suspension was gradiently diluted using the gradient dilution method, and the dilution degree was 10 -4 , 10 -5 , 10 -6 The soil suspension was spread on LB solid culture medium and cultured in a constant temperature incubator at 37°C. After a single colony grew out, it was picked out with a toothpick and purified on the culture medium using the three-zone line method until a single colony was obtained. The colony was screened for its functions of degrading protein, degrading fat, degrading cellulose, solubilizing potassium, fixing nitrogen, solubilizing organic phosphorus, solubilizing inorganic phosphorus, and producing extracellular polysaccharides.

[0025] Through the above isolation and screening work, we finally screened out a strain with the characteristics of degrading protein, degrading fat, degrading cellulose, solubilizing potassium, fixing nitrogen, solubilizing organic phosphorus, solubilizing inorganic phosphorus, and producing extracellular polysaccharides, and named it "SS44".

[0026] The colony morphology of the strain SS44 obtained above on LB solid medium and the observation pictures under microscope after Gram staining are as follows: Figure 1 shown by Figure 1 As shown in Figure A, the colonies of strain SS44 are white, irregular in shape, with irregular edges, flat, smooth, sticky, and spore-forming. Figure 1 As can be seen in Figure B, the strain is a typical rod-shaped Gram-positive bacterium.

[0027] In addition, the physiological and biochemical characteristics of the screened strain SS44 were identified, and the identification results were as follows: the strain SS44 can utilize lactose, β-galactose, glucose, fructose, trehalose, sucrose, xylose, maltose, cellobiose and raffinose.

[0028] The 16S rRNA gene sequence of strain SS44 was commissioned to Sangon Biotech (Shanghai) Co., Ltd. for sequencing. The sequencing results are shown in SEQ ID NO.1. The obtained 16S rRNA sequence was subjected to BLAST analysis with the existing sequences in the NCBI database, and strains with similar homology were selected. The phylogenetic tree was constructed using MEGA 5.0 software, and the construction method was Neighborjoining. The results showed that the strain SS44 obtained by the above screening was similar to Paenibacillus polymyxa The similarity with DSM36 was 100%, and the evolutionary distance was relatively close. Combined with the physiological and biochemical characteristics of the strain, it was identified as Paenibacillus polymyxa ( Paenibacillus polymyxa ).

[0029] Paenibacillus polymyxa ( Paenibacillus polymyxa )SS44, deposited on October 21, 2024 at the General Microbiology Center of China Culture Collection Administration, address: No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, with the deposit number CGMCC No.32283.

[0030] Example 2: Cultivation of Bacillus polymyxa SS44 bacterial solution The specific cultivation methods are as follows: (1) Inoculate the Bacillus polymyxa SS44 strain into LB solid medium and culture it upside down at 37°C until a single colony grows; (2) Pick a single colony from step (1) and place it in 5 mL of LB liquid culture medium. Shake and culture at 180 rpm and 37°C for 12 h to obtain an activated bacterial solution. (3) The activated bacterial solution of step (2) was inoculated into 50 mL of LB liquid culture medium at a volume percentage of 1% (0.5 mL), and cultured under shaking conditions of 180 rpm and 37°C for 24 h. The number of viable bacteria was 2.32 × 10 8 cfu / mL of Paenibacillus polymyxa SS44 bacterial solution.

[0031] Experimental Example 1: Determination of the ability of Paenibacillus polymyxa SS44 to degrade protein, fat, cellulose, potassium, nitrogen, organic phosphorus, inorganic phosphorus, produce extracellular polysaccharides, and improve sandy soil (1) The ability of strain SS44 to degrade protein was determined using casein medium. The specific method is as follows: The strain SS44 was inoculated on casein medium with a sterilized toothpick, placed in a 37°C electric constant temperature incubator for 2 days, and the growth of the colonies was observed; The components of the casein culture medium are as follows: 10 g casein (casein), 3 g beef extract, 5 g NaCl, 2 g K2HPO4, 15 g agar, 0.05 g bromothymol blue, 1000 mL deionized water; pH 7.3.

[0032] Colony growth Figure 2 shown by Figure 2 It can be seen that strain SS44 showed a transparent degradation zone in casein medium, which indicates that strain SS44 has the ability to degrade protein.

[0033] (2) The ability of strain SS44 to degrade fat was determined using tributyrin medium. The specific method is as follows: The strain SS44 was inoculated on tributyrin medium with a sterilized toothpick and placed in a constant temperature incubator at 28°C for 3 days to observe the growth of the colonies; The components of the tributyrin culture medium are as follows: 10 g of peptone, 5 g of yeast powder, 10 g of NaCl, 2 mL of tributyrin, 15 g of agar, and 1 L of deionized water.

[0034] Colony growth Figure 3 shown by Figure 3 It can be seen that strain SS44 showed a transparent degradation zone in tributyrin medium, which indicates that strain SS44 has the ability to degrade fat.

[0035] (3) The ability of strain SS44 to degrade cellulose was determined using sodium carboxymethyl cellulose culture medium. The specific method is as follows: The strain SS44 was inoculated on sodium carboxymethyl cellulose medium with a sterilized toothpick and cultured at 37°C for 2 days. Then, a 1 mg / 100 mL Congo red solution was added to submerge the strain SS44 for staining for 30 minutes. Finally, the stain was washed off with a 1 mol / L NaCl solution, and the colony growth was observed. The components of the sodium carboxymethyl cellulose culture medium are as follows: CMC-Na 2g, MgSO4•7H2O 0.5g, (NH4)2SO42g, K2HPO41g, NaCl 0.5g, agar 15g, deionized water 1L; pH 7.0; high pressure sterilization at 121°C for 20min.

[0036] Colony growth Figure 4 shown by Figure 4 It can be seen that in the sodium carboxymethylcellulose culture medium, a transparent degradation zone appeared in the strain SS44, which indicates that the strain SS44 has the ability to degrade cellulose.

[0037] (4) The potassium solubilizing ability of strain SS44 was determined using silicate bacterial culture medium. The specific method is as follows: The strain SS44 was inoculated onto silicate bacterial culture medium with a sterilized toothpick and cultured at 30°C for 3 days to observe the growth of the colonies. The components of the silicate bacterial culture medium are as follows: 5 g sucrose, 0.5 g MgSO4, 0.1 g CaCO3, 2 g Na2HPO4, 0.005 g FeCl3, 1 g glass powder, 15 g agar, and 1000 mL deionized water; pH 7.0.

[0038] Colony growth Figure 5 shown by Figure 5 It can be seen that strain SS44 appears as smooth and transparent oil droplet-shaped colonies on silicate bacterial culture medium, which indicates that strain SS44 has the ability to solubilize potassium.

[0039] (5) The nitrogen fixation ability of strain SS44 was determined using Axubei medium. The specific method is as follows: The strain SS44 was inoculated onto the Axubei medium with a sterilized toothpick and cultured at 28°C for 5 days to observe the growth of the colonies; The components of the Axubei culture medium are as follows: 10 g mannitol, 5 g CaCO3, 0.2 g KH2PO4, 0.2 g MgSO4•7H2O, 0.2 g NaCl, 0.1 g CaSO4•2H2O, 18 g agar, and 1000 mL deionized water.

[0040] Colony growth Figure 6 shown by Figure 6 It was found that SS44 was slightly raised on the Ashubei bacterial culture medium, had a slimy appearance, and had a smooth surface with a transparent circle, which indicated that strain SS44 had the ability to fix nitrogen.

[0041] (6) The ability of strain SS44 to degrade organic phosphorus was determined using the Montana organic phosphorus bacteria culture medium. The specific method is as follows: The strain SS44 was inoculated on the Montgena organophosphate bacterial culture medium with a sterilized toothpick and placed in a 28°C electric constant temperature incubator for 5 days to observe the growth of the colonies; The components of the Montgina organophosphorus bacterial culture medium are as follows: 10 g glucose, 0.5 g (NH4)2SO4, 0.3 g MgSO4·7H2O, 0.03 g MnSO4·4H2O, 0.3 g KCl, 0.03 g FeSO4·7H2O, 0.3 g NaCl, 5 g CaCO3, 0.2 g lecithin, 15 g agar, and 1000 mL distilled water; pH 7.0.

[0042] Colony growth Figure 7 shown by Figure 7 It can be seen that in the Montgina organophosphorus bacteria culture medium, a transparent degradation zone appeared for strain SS44, which indicates that strain SS44 has the ability to degrade organophosphorus.

[0043] (7) The ability of strain SS44 to solubilize inorganic phosphorus was determined using the Montana inorganic phosphorus bacterial culture medium. The specific method is as follows: The strain SS44 was inoculated on the Montkina inorganic phosphate bacterial culture medium with a sterilized toothpick and placed in a 28°C electric constant temperature incubator for 5 days to observe the growth of the colonies; The components of the Montgina inorganic phosphorus bacterial culture medium are as follows: 10 g glucose, 0.5 g (NH4)2SO4, 0.3 g MgSO4·7H2O, 0.03 g MnSO4·4H2O, 0.3 g KCl, 0.03 g FeSO4·7H2O, 0.3 g NaCl, 10 g Ca3(PO4)2, and 1000 mL distilled water; pH 7.0.

[0044] Colony growth Figure 8 shown by Figure 8 It was found that in the Montgina inorganic phosphorus bacteria culture medium, a transparent degradation zone appeared for strain SS44, which indicated that strain SS44 had the ability to dissolve inorganic phosphorus.

[0045] (8) The ability of strain SS44 to produce extracellular polysaccharides was determined using PDA medium and acetone solvent. The specific method is as follows: The strain SS44 was inoculated into LB liquid culture medium and cultured at 180 rpm. When the culture reached the logarithmic phase, the culture medium was transferred to PDA liquid culture medium and cultured for 36 hours at 30°C and 180 rpm to obtain bacterial liquid. The bacterial liquid was centrifuged at 12000 rpm for 20 minutes, and then the supernatant after centrifugation was mixed with frozen acetone in a volume ratio of 1:2 in a conical flask. After 24 hours, a precipitate (i.e., extracellular polysaccharide) was produced in the conical flask, as shown in FIG. Fig. 9As shown in Figure A; place the precipitate on filter paper, as shown in Figure A. Fig. 9 As shown in Figure B; Fig. 9 It was found that strain SS44 had the ability to produce extracellular polysaccharides.

[0046] The components of the PDA liquid culture medium are as follows: 200 g potato, 20 g sucrose, 1000 mL deionized water; and natural pH.

[0047] (9) The ability of strain SS44 to improve sandy soil was determined as follows: Sandy soil was collected from the field (taken from the sandy soil test field in Liaocheng City, Shandong Province) and divided into three groups, namely Group A (CK1), Group B (CK2) and Group C (SS44); wherein the sandy soil in Group A was not treated in any way, the sandy soil in Group B was irrigated with sterile water, and the sandy soil in Group C was irrigated with the same volume of SS44 bacterial solution (prepared in Example 2) as that in Group B; after the irrigating, the three groups of sandy soils were dried at 105° C. for 3 h, 6 h, and 12 h, respectively, and photographs were taken to record and observe the changes in the sandy soil in the different treatment groups.

[0048] The results are as follows Fig.10 shown by Fig.10 It can be obtained that after drying for 3 hours, the sandy soil in group C treated with strain SS44 remained moist and had a higher water content than that in group B; after drying for 6 hours, the sandy soil in group B had become hard and cracked like a stone, while the sandy soil in group C only had signs of water loss at the edge. When the surface of the sandy soil in group C was removed with a sterilized gun tip, it could be clearly seen that there was still a lot of water inside; after drying for 12 hours, the sandy soils in groups B and C were both hardened, and the sandy soil in group B was more hardened. It can be obtained that the sandy soil treated with strain SS44 had a higher water content and a slower water loss, which indicates that strain SS44 can change the texture of sandy soil, increase the water retention capacity of sandy soil, and thus play a role in improving sandy soil.

[0049] Experimental Example 2: Determination of the antagonistic ability of Paenibacillus polymyxa SS44 against Fusarium oxysporum and Fusarium fujikura Among them, Fusarium oxysporum is the pathogen of alfalfa root rot, potato wilt, and sweet potato root rot; Fusarium fusiformis is the pathogen of soybean root rot, rice seedling rot, and tobacco root rot.

[0050] The specific determination method is as follows: (1) Inoculate the Fusarium oxysporum or Fusarium fujikura stored on the slant onto the PDA solid culture medium and activate and culture in a constant temperature incubator at 28°C until the plate is fully grown; (2) Use a sterile punch to make a round bacterial block of Fusarium oxysporum or Fusarium fujikura, and use tweezers to transfer the round bacterial block to the middle part of the new PDA solid culture medium; (3) Select Paenibacillus polymyxa SS44 and inoculate it with a sterilized toothpick 2 cm away from the edge of Fusarium oxysporum or Fusarium fujikura. Then continue to culture in a constant temperature incubator at 28°C for 3 days to observe the antagonistic effect of strain SS44 on Fusarium oxysporum or Fusarium fujikura.

[0051] The components of the PDA solid culture medium are as follows: 200 g potato, 20 g sucrose, 1000 mL deionized water, 15 g agar, and natural pH.

[0052] The results are as follows Fig.11 As shown, Figure A shows the antagonistic effect of strain SS44 on Fusarium oxysporum, and Figure B shows the antagonistic effect of strain SS44 on Fusarium fujikura. Fig.11 It can be seen that Bacillus polymyxa SS44 can effectively inhibit the growth of Fusarium oxysporum and Fusarium fujikura.

[0053] Experimental Example 3: Determination of the wheat growth-promoting effect of Paenibacillus polymyxa SS44 in saline-alkali soil and sandy soil environments The specific steps are as follows: (1) Soak Jinchun No. 6 wheat seeds in 1% (10 mL / L) sodium hypochlorite solution for 10 min, wash the soaked wheat seeds with sterile water, then soak the washed wheat seeds in 75% ethanol for 5 min, wash them again with sterile water, wrap the washed wheat seeds with wet gauze for 12 h and set aside.

[0054] (2) Prepare 18 cultivation pots for wheat cultivation and divide them into 6 groups, namely, saline-alkali soil CK-LB group, saline-alkali soil SS44 group, saline-alkali soil CK-sterile water group, sandy soil CK-LB group, sandy soil SS44 group, and sandy soil CK-sterile water group, with 3 replicates in each group.

[0055] Among them, the SS44 group applied SS44 bacterial solution (prepared in Example 2) to the cultivation pot, and the application method was: the bacterial solution was diluted 200 times with water and applied to the cultivation pot, and the application amount was 70mL / Kg; the CK-LB group applied a sterile LB liquid culture medium with an equal volume of bacterial solution to the cultivation pot; the CK-sterile water group applied a sterile water with an equal volume of bacterial solution to the cultivation pot.

[0056] Among them, the saline-alkali soil added to the cultivation pot was taken from the saline-alkali soil experimental field in Liaocheng City, Shandong Province, with a salt content of 3.45g / Kg and a soil pH of 8.5; the sandy soil added to the cultivation pot was taken from the sandy soil experimental field in Liaocheng City, Shandong Province, with a salt content of 1.1g / Kg and a soil pH of 8.27.

[0057] (3) Select wheat seeds of uniform size in step (1) and plant them in cultivation pots. After the seedlings emerge, thin out the seedlings so that there are 3 wheat seedlings in each cultivation pot. After thinning, add bacteria treatment; on the 10th and 14th days of cultivation, take photos of the growth morphology of the wheat and measure the physiological plant height of the wheat (the maximum distance after straightening); on the 14th day of cultivation, measure the aboveground fresh weight, underground fresh weight, aboveground dry weight, underground dry weight and other agronomic traits of the wheat.

[0058] The results are as follows: ① Photos of wheat morphology in different treatment groups after 10 days of cultivation in saline-alkali soil environment Fig.12 The wheat morphology photos in different treatment groups after 14 days of cultivation are shown in Figures 13 and 14 As shown, Fig.13 This is a photo of the wheat morphology in the cultivation pot after 14 days of cultivation. Fig.14 This is a photo of wheat morphology after the wheat seedlings were harvested on the 14th day of cultivation. Figures 12-14 It can be seen that at 10 and 14 days of culture, the wheat plants in the SS44 group grew more vigorously than those in the CK-LB group and the CK-sterile water group.

[0059] The results of the determination of the wheat growth-promoting effect of strain SS44 on different treatment groups under saline-alkali soil environment are as follows Fig.15 As shown, Figure A shows the physiological plant height of each treatment group at 10 and 14 days of wheat cultivation, Figure B shows the aboveground fresh weight and underground fresh weight of each treatment group at 14 days of wheat cultivation, and Figure C shows the aboveground dry weight and underground dry weight of each treatment group at 14 days of wheat cultivation. Fig.15 As shown in Figure A, the wheat plant height in the SS44 group was significantly increased compared with the CK-LB group and the CK-sterile water group. Specifically, the wheat plant height in the SS44 group increased by 26.34% compared with the CK-LB group after 10 days of cultivation ( p <0.01, and the wheat plant height in the SS44 group increased by 18.74% compared with the CK-LB group on day 14 of cultivation ( p <0.01). Fig.15 From the B-C graphs in Figure 1, it can be seen that compared with the CK-LB group and the CK-sterile water group, the fresh weight and dry weight of wheat in the SS44 group increased significantly after 14 days of cultivation. Specifically, in terms of aboveground fresh weight, the SS44 group increased by 66.67% compared with the CK-LB group ( p<0.01); in terms of aboveground dry weight, the SS44 group increased by 67.74% compared with the CK-LB group (reaching a very significant difference, p <0.01); in terms of underground fresh weight, the SS44 group increased by 64.61% compared with the CK-LB group (reaching a significant difference, p <0.05); in terms of underground dry weight, the SS44 group increased by 41.67% compared with the CK-LB group.

[0060] ② Photos of wheat morphology in different treatment groups after 10 days of cultivation in sandy soil environment Fig.16 The wheat morphology photos in different treatment groups after 14 days of cultivation are shown in Figures 17 and 18 As shown, Fig.17 This is a photo of the wheat morphology in the cultivation pot after 14 days of cultivation. Fig.18 This is a photo of wheat morphology after the wheat seedlings were harvested on the 14th day of cultivation. Figures 16-18 It can be seen that at 10 and 14 days of culture, the wheat plants in the SS44 group grew more vigorously than those in the CK-LB group and the CK-sterile water group.

[0061] The results of the determination of the wheat growth-promoting effect of strain SS44 on different treatment groups in sandy soil environment are as follows Fig.19 As shown, Figure A shows the physiological plant height of each treatment group at 10 and 14 days of wheat cultivation, Figure B shows the aboveground fresh weight and underground fresh weight of each treatment group at 14 days of wheat cultivation, and Figure C shows the aboveground dry weight and underground dry weight of each treatment group at 14 days of wheat cultivation. Fig.19 As shown in Figure A, the wheat plant height in the SS44 group was significantly increased compared with the CK-LB group and the CK-sterile water group. Specifically, the wheat plant height in the SS44 group increased by 58.39% compared with the CK-LB group after 10 days of cultivation ( p <0.01, and the wheat plant height in the SS44 group increased by 37.28% compared with the CK-LB group on day 14 of cultivation ( p <0.01). Fig.19 From the B-C graphs in Figure 1, it can be seen that compared with the CK-LB group and the CK-sterile water group, the fresh weight and dry weight of wheat in the SS44 group increased significantly after 14 days of cultivation. Specifically, in terms of aboveground fresh weight, the SS44 group increased by 86.08% compared with the CK-LB group ( p <0.01); in terms of aboveground dry weight, the SS44 group increased by 96.23% compared with the CK-LB group (reaching a very significant difference, p <0.01); in terms of underground fresh weight, the SS44 group increased by 34.69% compared with the CK-LB group; in terms of underground dry weight, the SS44 group increased by 32.18% compared with the CK-LB group.

[0062] Experimental Example 4: Determination of the growth-promoting effect of Paenibacillus polymyxa SS44 on soybean in saline-alkali soil and sandy soil environments The specific steps are as follows: (1) Select soybean seeds with full grains and uniform size, soak them in 75% ethanol for 5 min, then soak them in 1% (10 mL / L) sodium hypochlorite solution for 3 min, and then wash them with sterile water. Spread the washed soybean seeds evenly on moist gauze and place them upright for germination at 28°C for 3 days.

[0063] (2) Prepare 18 cultivation pots for soybean cultivation and divide them into 6 groups, namely, saline-alkali soil CK-LB group, saline-alkali soil SS44 group, saline-alkali soil CK-sterile water group, sandy soil CK-LB group, sandy soil SS44 group, and sandy soil CK-sterile water group, with 3 replicates in each group.

[0064] Among them, the SS44 group applied SS44 bacterial solution (prepared in Example 2) to the cultivation pot, and the application method was: the bacterial solution was diluted 150 times with water and applied to the cultivation pot, and the application amount was 80 mL / Kg; the CK-LB group applied a sterile LB liquid culture medium with an equal volume of bacterial solution to the cultivation pot; the CK-sterile water group applied a sterile water with an equal volume of bacterial solution to the cultivation pot.

[0065] Among them, the saline-alkali soil added to the cultivation pot was taken from the saline-alkali soil experimental field in Liaocheng City, Shandong Province, with a salt content of 3.45g / Kg and a soil pH of 8.5; the sandy soil added to the cultivation pot was taken from the sandy soil experimental field in Liaocheng City, Shandong Province, with a salt content of 1.1g / Kg and a soil pH of 8.27.

[0066] (3) Selecting soybean seeds of uniform size in step (1) and planting them in cultivation pots, thinning out the seedlings after they emerge so that there are 3 soybean seedlings in each cultivation pot, and adding bacteria after thinning out; taking photos of the growth morphology of the soybeans and measuring the physiological plant height and stem diameter of the soybeans on days 14 and 21 of cultivation; and measuring the aboveground fresh weight, underground fresh weight, aboveground dry weight, underground dry weight and other agronomic traits of the soybeans on days 21 of cultivation.

[0067] The results are as follows: ① The morphological photos of soybeans in different treatment groups after 14 days of cultivation in saline-alkali soil environment are as follows Fig. 20 The soybean morphology photos of different treatment groups at 21 days of cultivation are shown in Figures 21 and 22 As shown, Fig.21 This is a photo of the soybean morphology in the cultivation pot on the 21st day of cultivation. Fig. 22 This is a photo of soybean morphology after the soybean seedlings were harvested on the 21st day of cultivation. Figures 20 to 22It can be seen that at 14 and 21 days of culture, the soybean plants in the SS44 group grew more vigorously than those in the CK-LB group and the CK-sterile water group.

[0068] The results of the test on the growth-promoting effect of strain SS44 on soybeans in different treatment groups under saline-alkali soil environment are as follows: Fig.23 As shown, Figure A shows the physiological plant height of each treatment group at 14 and 21 days of soybean cultivation, Figure B shows the stem diameter of each treatment group at 14 and 21 days of soybean cultivation, Figure C shows the aboveground fresh weight and underground fresh weight of each treatment group at 21 days of soybean cultivation, and Figure D shows the aboveground dry weight and underground dry weight of each treatment group at 21 days of soybean cultivation. Fig.23 As shown in Figure A, compared with the CK-LB group and the CK-sterile water group, the soybean plant height in the SS44 group was significantly increased. Specifically, the soybean plant height in the SS44 group increased by 30.09% compared with the CK-LB group after 14 days of cultivation ( p <0.01, and the soybean plant height in the SS44 group increased by 17.86% compared with the CK-LB group on day 21 of cultivation ( p <0.05). Fig.23 As shown in Figure B, compared with the CK-LB group and the CK-sterile water group, the soybean stem thickness in the SS44 group was significantly increased. Specifically, the soybean stem thickness in the SS44 group increased by 16% compared with the CK-LB group after 14 days of cultivation ( p <0.01), the soybean stem thickness in the SS44 group increased by 10.97% compared with the CK-LB group on day 21 of cultivation ( p <0.05). Fig.23 From the C-D graphs in Figure 1, we can see that compared with the CK-LB group and the CK-sterile water group, the fresh weight and dry weight of soybeans in the SS44 group increased significantly after 21 days of cultivation. Specifically, in terms of aboveground fresh weight, the SS44 group increased by 45.01% compared with the CK-LB group ( p <0.01); in terms of aboveground dry weight, the SS44 group increased by 42.52% compared with the CK-LB group ( p <0.01); in terms of underground fresh weight, the SS44 group increased by 91.67% compared with the CK-LB group ( p <0.01); in terms of underground dry weight, the SS44 group increased by 31.55% compared with the CK-LB group.

[0069] ② The morphological photos of soybeans in different treatment groups after 14 days of cultivation in sandy soil environment are as follows Fig.24 The soybean morphology photos of different treatment groups at 21 days of cultivation are shown in Figures 25 and 26 As shown, Fig.25 This is a photo of the soybean morphology in the cultivation pot on the 21st day of cultivation. Fig.26 This is a photo of soybean morphology after the soybean seedlings were harvested on the 14th day of cultivation. Figures 24 to 26It can be seen that at 14 and 21 days of culture, the soybean plants in the SS44 group grew more vigorously than those in the CK-LB group and the CK-sterile water group.

[0070] The results of the determination of the growth-promoting effect of strain SS44 on soybeans in different treatment groups under sandy soil environment are as follows: Fig. 27 As shown, Figure A shows the physiological plant height of each treatment group at 14 and 21 days of soybean cultivation, Figure B shows the stem diameter of each treatment group at 14 and 21 days of soybean cultivation, Figure C shows the aboveground fresh weight and underground fresh weight of each treatment group at 21 days of soybean cultivation, and Figure D shows the aboveground dry weight and underground dry weight of each treatment group at 21 days of soybean cultivation. Fig. 27 As shown in Figure A, compared with the CK-LB group and the CK-sterile water group, the soybean plant height in the SS44 group was significantly increased. Specifically, the soybean plant height in the SS44 group increased by 35.55% compared with the CK-LB group after 14 days of cultivation ( p <0.05, the soybean plant height in the SS44 group increased by 33.91% compared with the CK-LB group on day 21 of cultivation ( p <0.01). Fig. 27 As shown in Figure B, compared with the CK-LB group and the CK-sterile water group, the soybean stem thickness in the SS44 group was significantly increased. Specifically, the soybean stem thickness in the SS44 group increased by 16% compared with the CK-LB group after 14 days of cultivation ( p <0.05), the soybean stem thickness of the SS44 group increased by 9.63% compared with the CK-LB group on the 21st day of cultivation. Fig. 27 From the C~D figures in the figure, it can be seen that compared with the CK-LB group and the CK-sterile water group, the fresh weight and dry weight of soybeans in the SS44 group were significantly increased at 21 days of cultivation. Specifically, in terms of aboveground fresh weight, the SS44 group increased by 19.77% compared with the CK-LB group; in terms of aboveground dry weight, the SS44 group increased by 21.91% compared with the CK-LB group; in terms of underground fresh weight, the SS44 group increased by 23.91% compared with the CK-LB group; in terms of underground dry weight, the SS44 group increased by 29.65% compared with the CK-LB group.

[0071] Experimental Example 5: Determination of the growth-promoting effect of Paenibacillus polymyxa SS44 on corn in saline-alkali soil and sandy soil environments The specific steps are as follows: (1) Select corn seeds with full grains and uniform size, soak them in 75% ethanol for 5 min, then soak them in 1% (10 mL / L) sodium hypochlorite solution for 3 min, and then wash them with sterile water. Spread the cleaned corn seeds evenly on moist gauze and germinate them at 30°C for 24 h in the dark until the seeds germinate.

[0072] (2) Prepare 18 cultivation pots for corn cultivation and divide them into 6 groups, namely, saline-alkali soil CK-LB group, saline-alkali soil SS44 group, saline-alkali soil CK-sterile water group, sandy soil CK-LB group, sandy soil SS44 group, and sandy soil CK-sterile water group, with 3 replicates in each group.

[0073] Among them, the SS44 group applied SS44 bacterial solution (prepared in Example 2) to the cultivation pot, and the application method was: the bacterial solution was diluted 100 times with water and applied to the cultivation pot, and the application amount was 90mL / Kg; the CK-LB group applied a sterile LB liquid culture medium with an equal volume of bacterial solution to the cultivation pot; the CK-sterile water group applied a sterile water with an equal volume of bacterial solution to the cultivation pot.

[0074] Among them, the saline-alkali soil added to the cultivation pot was taken from the saline-alkali soil experimental field in Liaocheng City, Shandong Province, with a salt content of 3.45g / Kg and a soil pH of 8.5; the sandy soil added to the cultivation pot was taken from the sandy soil experimental field in Liaocheng City, Shandong Province, with a salt content of 1.1g / Kg and a soil pH of 8.27.

[0075] (3) Select corn seeds of uniform size in step (1) and plant them in cultivation pots. After the seedlings emerge, thin out the seedlings so that there are 3 corn seedlings in each cultivation pot. After the thinning is completed, add bacteria treatment; on the 9th day of cultivation, measure the physiological plant height of corn in the saline-alkali soil group; on the 12th day and 14th day of cultivation, take photos of the growth morphology of corn in the saline-alkali soil group (12th day of cultivation) and the sandy soil group (14th day of cultivation), and measure the agronomic traits data of corn such as physiological plant height, aboveground fresh weight, underground fresh weight, aboveground dry weight, and underground dry weight.

[0076] The results are as follows: ① Photos of corn morphology in different treatment groups after 12 days of cultivation in saline-alkali soil environment Fig.28 shown by Fig.28 It can be seen that after 12 days of cultivation, the corn plants in the SS44 group grew more vigorously than those in the CK-LB group and the CK-sterile water group.

[0077] The results of the test on the growth-promoting effect of strain SS44 on corn in different treatment groups under saline-alkali soil environment are as follows Fig.29 As shown, Figure A shows the physiological plant height of each treatment group at 9 and 12 days of corn cultivation, Figure B shows the aboveground fresh weight and underground fresh weight of each treatment group at 12 days of corn cultivation, and Figure C shows the aboveground dry weight and underground dry weight of each treatment group at 12 days of corn cultivation. Fig.29Figure A shows that compared with the CK-LB group and the CK-sterile water group, the height of corn in the SS44 group was significantly increased. Specifically, after 9 days of cultivation, the height of corn in the SS44 group increased by 9.67% and 11.7% compared with the CK-sterile water group. After 12 days of cultivation, the height of corn in the SS44 group increased by 3.21% and 7.73% compared with the CK-LB group and the CK-sterile water group. Fig.29 From Figures B to C in the figure, it can be seen that compared with the CK-LB group and the CK-sterile water group, the fresh weight and dry weight of corn in the SS44 group were significantly increased after 12 days of cultivation. Specifically, in terms of aboveground fresh weight, the SS44 group increased by 13.24% compared with the CK-LB group and 14.84% compared with the CK-sterile water group; in terms of aboveground dry weight, the SS44 group increased by 19.21% compared with the CK-LB group and 18.76% compared with the CK-sterile water group; in terms of underground fresh weight, the SS44 group increased by 10.61% compared with the CK-LB group and 14.11% compared with the CK-sterile water group; in terms of underground dry weight, the SS44 group increased by 4.97% compared with the CK-LB group and 8.66% compared with the CK-sterile water group.

[0078] ② Photos of corn morphology in different treatment groups after 14 days of cultivation in sandy soil environment Fig.30 shown by Fig.30 It can be seen that after 14 days of cultivation, the corn plants in the SS44 group grew more vigorously than those in the CK-LB group and the CK-sterile water group.

[0079] The results of the test on the growth-promoting effect of strain SS44 on corn in different treatment groups under sandy soil environment are as follows: Fig.31 As shown, Figure A shows the physiological plant height of each treatment group after 14 days of corn cultivation, Figure B shows the aboveground fresh weight and underground fresh weight of each treatment group after 14 days of corn cultivation, and Figure C shows the aboveground dry weight and underground dry weight of each treatment group after 14 days of corn cultivation. Fig.31 Figure A shows that compared with the CK-LB group and the CK-sterile water group, the corn plant height in the SS44 group did not increase significantly. Fig.31 From Figures B to C in the figure, we can see that the aboveground fresh weight of the SS44 group was 39.20% higher than that of the CK-LB group; the aboveground dry weight of the SS44 group was 40.53% higher than that of the CK-LB group; the underground fresh weight of the SS44 group was 33.22% higher than that of the CK-LB group; and the underground dry weight of the SS44 group was 4.83% higher than that of the CK-LB group.

Claims

1. A strain of Paenibacillus polymyxa ( Paenibacillus polymyxa )SS44, characterized in that, It was deposited on October 21, 2024 at the General Microbiology Center of China Culture Collection Administration, address: No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, with the deposit number CGMCC No.32283.

2. The method for culturing Paenibacillus polymyxa SS44 according to claim 1, characterized in that: The steps include: (1) Inoculate the Bacillus polymyxa SS44 strain into LB solid medium and culture it upside down at 37°C until a single colony grows; (2) Pick a single colony from step (1) and place it in LB liquid culture medium, shake and culture at 120-180 rpm and 37±1°C to obtain an activated bacterial solution; (3) The activated bacterial solution of step (2) is inoculated into LB liquid culture medium at an inoculum volume percentage of 1-3%, and cultured under shaking conditions of 120-180 rpm and 37±1°C to obtain a bacterial solution of Paenibacillus multimyxogenis SS44.

3. The use of Paenibacillus polymyxa SS44 according to claim 1, characterized in that: It is used to degrade protein, fat, cellulose, release potassium, fix nitrogen, release organic phosphorus, dissolve inorganic phosphorus, and produce extracellular polysaccharides.

4. The use of Paenibacillus polymyxa SS44 according to claim 1, characterized in that: Used to antagonize Fusarium oxysporum and Fusarium fujikura.

5. The use of Paenibacillus polymyxa SS44 according to claim 1, characterized in that: Used to improve sandy soil.

6. The use of Paenibacillus polymyxa SS44 according to claim 1, characterized in that: The invention is used for promoting the growth of plants, wherein the plants are wheat, soybean and corn.

7. The use according to claim 6, characterized in that The polymyxa bacillus SS44 promotes plant growth in saline-alkali soil with a salt content of ≤5g / Kg and a pH of ≤9.

8. The use according to claim 6, characterized in that The polymyxa bacillus SS44 promotes plant growth in sandy soil with a salt content of ≤2g / Kg and a pH of ≤9.

9. The use according to any one of claims 6 to 8, characterized in that: The application method is to prepare the polymyxa bacillus SS44 into a living bacteria content of 2.0×10 8 ~3.0×10 8 cfu / mL of live bacterial preparations should be diluted more than 100 times and applied to the soil at a dosage of 50~100mL / Kg.

10. A live bacteria preparation, characterized in that: The polymyxa bacillus SS44 described in claim 1 is used as an active ingredient.

Images