Bacillus altitudinis, microbial agent prepared from bacillus altitudinis and application of bacillus altitudinis

Abstract

The invention relates to a microbial strain and application thereof, in particular to bacillus altitudinis, a microbial agent prepared from the bacillus altitudinis and application of the microbial agent. The invention provides bacillus altitudinis CGMCC (China General Microbiological Culture Collection Center) No.33692, which has the functions of improving the fertility of soil, promoting the growth of crops and enhancing the stress resistance of the crops. And the iron carrier can be synthesized and has the capabilities of secreting auxin, fixing nitrogen and dissolving phosphorus. When applied to corn, the corn germination rate can be remarkably increased, the corn plant height, the leaf area, the dry weight and the wet weight are increased, and corn growth is promoted. When applied to tomatoes, the compound can promote tomato growth, effectively improve the activity of a tomato antioxidant system, enhance photosynthesis and significantly improve the low-temperature resistance of tomatoes. When being used as a soil conditioner, the soil conditioner can effectively improve the soil fertility, reduce the pH value, improve the conductivity and effectively improve the physicochemical properties, and provides a good soil environment condition for the growth and development of corn and tomatoes.

Description

Technical Field

[0001] The present invention relates to microbial strains and applications thereof, in particular to Bacillus albopictus, a microbial agent prepared by using the same and applications thereof. Background Art

[0002] As the main production area of ​​corn and wheat in my country, the Huanghuaihai Plain faces prominent problems such as a large proportion of medium and low-yield fields, low crop yields, and poor stress resistance, which seriously restrict the improvement of crop yield and quality. At the same time, saline-alkali land, as an important reserve resource of arable land, has a high salt and alkaline environment, which also seriously restricts the growth of crops. In addition, in the facility agriculture in northern my country, thermophilic crops such as tomatoes are easily affected by low temperature stress, resulting in a decrease in yield and quality. The solution to these problems is of great significance to ensuring national food security and promoting sustainable agricultural development.

[0003] Although traditional improvement methods such as irrigation and drainage, surface covering, and chemical amendments have certain effects, they have limitations such as long cycles, unstable effects, and environmental risks. In recent years, with the development of biotechnology, microbial remediation technology has been increasingly used in the agricultural field. Studies have shown that microbial strains such as rhizobia, nitrogen-fixing bacteria, and phosphate-solubilizing bacteria have shown significant potential in improving saline-alkali land and improving soil fertility; at the same time, the use of beneficial microorganisms to enhance crop resistance (such as cold resistance) has also become an emerging research direction. However, beneficial microbial resources with multiple functional characteristics (such as nitrogen fixation, phosphorus solubilization, growth promotion, and stress resistance) are still relatively scarce. Summary of the invention

[0004] One of the purposes of the present invention is to provide a highland bacillus with the functions of improving soil fertility, promoting crop growth and enhancing crop stress resistance. Its Latin name is Bacillus altitudinis and its preservation number is CGMCC No.33692.

[0005] The strain in the present invention is isolated from the soil of the tomato root system. The strain was deposited in the General Microbiological Center of the China Microbiological Culture Collection Administration on March 3, 2025, with the classification name Bacillusaltitudinis and the deposit number CGMCC No.33692. The address of the depository institution is located at the Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing (referred to as CGMCC).

[0006] The colony morphology and physiological and biochemical characteristics of the strain are as follows:

[0007] The colony of the strain is irregular oval, beige, rough and dry, and has 100% similarity with Bacillusaltitudinis h217. It can synthesize iron carriers, secrete auxin (IAA), fix nitrogen and dissolve phosphorus.

[0008] The second object of the present invention is to provide a microbial agent containing Bacillus altitudinis, whose Latin name is Bacillus altitudinis and whose deposit number is CGMCC No.33692.

[0009] The third object of the present invention is to provide a highland Bacillus with the Latin name Bacillus altitudinis and the preservation number CGMCC No.33692, and the use of the fermentation liquid or microbial agent containing the same in the preparation of soil conditioners.

[0010] The fourth object of the present invention is to provide a highland Bacillus containing the Latin name Bacillus altitudinis and the preservation number CGMCC No.33692, and the use of the fermentation liquid or microbial agent containing the same in promoting plant growth, wherein the plant refers to corn or tomato.

[0011] The fifth object of the present invention is to provide a highland Bacillus containing the Latin name Bacillus altitudinis and the preservation number CGMCC No.33692, and the use of the fermentation liquid or microbial agent containing the same in improving the cold resistance of plants, wherein the plant is tomato.

[0012] The sixth object of the present invention is to provide a use of Bacillus altitudinis, whose Latin name is Bacillus altitudinis and whose deposit number is CGMCC No. 33692, or a fermentation liquid or microbial agent containing the same in improving medium- and low-yield fields and / or alkaline soils.

[0013] The substantial features and significant technical advances of the present invention are:

[0014] The present invention screened and obtained a highland Bacillus with a Latin name of Bacillus altitudinis and a deposit number of CGMCC No. 33692. The applicant's experiment confirmed that the strain can synthesize iron carriers, has the ability to secrete auxin (IAA), fix nitrogen and dissolve phosphorus. When applied to corn, it can significantly increase the germination rate of corn, increase the plant height, leaf area, dry weight and wet weight of corn, and promote the growth of corn and tomatoes. When applied to tomatoes, it can promote tomato growth, effectively improve the activity of tomato antioxidant system, enhance tomato photosynthesis, and significantly improve the low temperature resistance of tomatoes. When used as a soil conditioner, it can effectively improve soil fertility, reduce soil pH, increase soil conductivity, effectively improve the physical and chemical properties of soil, and provide good soil environmental conditions for the growth and development of corn and tomatoes.

[0015] The strain in the present invention was deposited in the General Microbiology Center of the China Microorganism Culture Collection Administration on March 3, 2025, with the classification name Bacillus altitudinis and the deposit number CGMCC No.33692. The address of the depository institution is located at the Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing (referred to as CGMCC). BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings of the present invention include:

[0017] Figure 1 This is a schematic diagram of the colony of Bacillus altitudinis CGMCC No. 33692 cultured in a flat culture dish.

[0018] Figure 2 This is a plate test effect diagram for qualitative determination of siderophore synthesis by Bacillus altitudinis CGMCC No.33692.

[0019] After Bacillus altitudinis CGMCC No.33692 was activated for 24 hours and inoculated into CAS solid medium, the ability to produce siderophore was judged by whether it had an orange halo. It was verified that the strain could grow on CAS medium and produce an orange halo. The results are as follows: Figure 2 , indicating that the strain has the function of synthesizing iron carriers.

[0020] Figure 3 This is a plate test effect diagram for qualitative determination of nitrogen fixation ability of Bacillus altitudinis CGMCC No.33692.

[0021] After inoculating Bacillus altitudinis CGMCC No.33692 into Ashby solid medium, the nitrogen fixation ability of the strain was judged based on whether it grew and had a transparent circle. It was verified that the strain could produce a transparent circle on Ashby solid medium. The results are as follows Figure 3 , indicating that the strain has the ability to fix nitrogen.

[0022] Figure 4 This is a qualitative test result diagram of the phosphorus solubilizing ability of Bacillus altitudinis CGMCC No.33692.

[0023] Bacillus altitudinis CGMCC No.33692 was inoculated on PKO medium, and the phosphate solubilizing ability of the strain was judged by whether it grew and had a transparent circle. It was verified that the strain could produce a transparent circle on PKO medium. The results are as follows Figure 4 , indicating that the strain has the ability to solubilize phosphate.

[0024] Figure 5 This is a qualitative test result diagram of the ability of Bacillus altitudinis CGMCC No.33692 to secrete auxin (IAA).

[0025] Bacillus altitudinis CGMCC No.33692 was inoculated into 1 ml of LB liquid medium containing 200 mg / L of L-tryptophan, and 3 replicates were set. After culturing for 2 days at 30°C and 180 rpm, 500 μl of bacterial suspension was taken onto a 48-well plate, 500 μl of Salkowski colorimetric solution was added, and 500 μl of uninoculated LB liquid medium and 500 μl of colorimetric solution were added as controls. After being placed at room temperature and away from light for 20 minutes, the color turned pink, indicating that the auxin (IAA) could be secreted. The darker the color, the greater the secretion intensity. Figure 5 The left side of the middle is Bacillus altitudinis CGMCC No. 33692 of the present invention, and the right side is the control. It has been verified that the strain is light pink, indicating that the strain has the ability to secrete auxin (IAA).

[0026] Figure 6 This is a diagram showing the effect of Bacillus altitudinis CGMCC No.33692 on the germination rate of corn.

[0027] After soaking the seeds in ultrapure water (CK, left picture) and Bacillus altitudinis CGMCC No.33692 (treatment, right picture) for 12 hours, 30 seeds were evenly placed in a glass culture dish with two moist filter papers, and cultured in an incubator at 25°C, 6000 lux, and 60% humidity. The results are shown in Figure 2. Figure 6 , and the germination rate was counted.

[0028] Figure 7 This is a diagram showing the effect of Bacillus altitudinis CGMCC No.33692 on the low temperature resistance of tomatoes.

[0029] Figure 7From left to right in the figure are tomato seedlings treated with Bacillus altitudinis CGMCC No. 33692 at room temperature (25°C), tomato seedlings not inoculated at room temperature (25°C), tomato seedlings treated with Bacillus altitudinis CGMCC No. 33692 at low temperature (5°C), and tomato seedlings not inoculated at low temperature (5°C). The figure shows that Bacillus altitudinis CGMCC No. 33692 can maintain the normal growth of tomato seedlings under low temperature conditions, and the plant height is significantly greater than the low temperature control.

[0030] Figure 8 This is a bar graph showing the effect of Bacillus altitudinis CGMCC No.33692 on the hydrogen peroxide content in tomato leaves.

[0031] Figure 8 After the tomato leaves were treated with low temperature of 5°C, the hydrogen peroxide content of the tomato leaves increased significantly, indicating that the cell membrane was damaged and the membrane lipids were peroxidized. The control was affected by the low temperature and the hydrogen peroxide content increased significantly. The tomato leaves treated with Bacillus altitudinis CGMCC No.33692 in the present invention slowed down the rising trend under low temperature conditions and were significantly lower than the low temperature control. The hydrogen peroxide content was reduced by 32.52% compared with the control, indicating that the chilling damage of the tomato leaves treated with Bacillus altitudinis CGMCC No.33692 in the present invention was relatively light.

[0032] Fig. 9 This is a bar graph showing the effect of Bacillus altitudinis CGMCC No.33692 on catalase activity in tomato leaves.

[0033] Fig. 9 Inoculation of tomato leaves with Bacillus altitudeinis CGMCC No.33692 upregulated the activity of catalase, which can improve the ability of plant cells to scavenge reactive oxygen free radicals, maintain the balance between the production and scavenging of free radicals in cells, reduce membrane lipid peroxidation, and alleviate cell membrane damage caused by low temperature.

[0034] Fig.10 This is a bar graph showing the effect of Bacillus altitudinis CGMCC No.33692 on the ascorbic acid content in tomato leaves.

[0035] Fig.10 Under normal temperature conditions, the content of antioxidant ascorbic acid (AsA) in tomato leaves treated with Bacillus altitudeinis CGMCC No.33692 was significantly higher than that in the control. Low temperature stress caused the AsA content in tomato leaves to decrease, reaching a significant level (P < 0.05), while Bacillus altitudeinis CGMCC No.33692 treatment could significantly increase the AsA content in tomato leaves by 20.12%.

[0036] Fig.11 Bar graph of the effect of Bacillus altitudinis CGMCC No.33692 on ascorbate peroxidase (APX) activity in tomato leaves.

[0037] Fig.11 Under normal temperature conditions, the activity of antioxidant enzyme APX in tomato leaves treated with Bacillus altitudinis CGMCC No.33692 was significantly higher than that in the control group; low temperature stress significantly reduced the APX activity in tomato leaves, while Bacillus altitudinis CGMCC No.33692 treatment could significantly increase the APX activity in tomato leaves (P<0.05), which could be increased by up to 1.29 times.

[0038] Fig.12 This is a bar graph showing the effect of Bacillus altitudinis CGMCC No.33692 on the photosynthetic rate of tomato leaves under low temperature stress.

[0039] Fig.13 This is a bar graph showing the effect of Bacillus altitudinis CGMCC No.33692 on the transpiration rate of tomato leaves under low temperature stress.

[0040] Fig.12 , 13 It can be seen that the photosynthetic rate of the inoculated plants increased significantly, and it can be seen that Bacillus altitudinis CGMCC No.33692 can help plants alleviate the basal metabolism of photosynthesis under low temperature stress. Low temperature stress significantly reduced the photosynthetic rate and transpiration rate of tomato plants. Bacillusaltitudinis CGMCC No.33692 can increase the photosynthetic rate and transpiration rate of tomatoes, and alleviate the limiting effect of low temperature stress on the photosynthetic capacity of plants to a certain extent.

[0041] Fig.14 It is a bar graph showing the effect of Bacillus altitudinis CGMCC No.33692 on the stomatal conductance of tomato leaves under low temperature stress.

[0042] Fig.14 It can be seen that under normal temperature conditions, the stomatal conductance of tomato plants treated with Bacillus altitudinis CGMCC No. 33692 had no significant difference from that of the control. Low temperature significantly reduced the stomatal conductance of the control, while Bacillus altitudinis CGMCC No. 33692 alleviated the limiting effect of low temperature on stomatal conductance and increased the stomatal conductance to the normal temperature level.

[0043] Fig.15 The effect of Bacillus altitudinis CGMCC No.33692 on the intercellular CO2 in tomato leaves under low temperature stress 2 Bar graph of concentration effects.

[0044] Fig.15 It can be seen that regardless of normal temperature or low temperature conditions, the intercellular CO 2 The concentration was always lower than that of the uninoculated plants, but there was no significant difference under normal temperature. Low temperature caused the intercellular CO 2 The concentration increased rapidly, while the treatment with Bacillus altitudinis CGMCC No.33692 could reduce the intercellular CO 2 concentration to room temperature levels. DETAILED DESCRIPTION

[0045] The present invention is further described below in conjunction with embodiments, but is not intended to be limiting of the present invention. The protection scope of the present invention shall be based on the contents recorded in the claims, and any replacement of equivalent means made based on the description of the present invention shall not depart from the protection scope of the present invention.

[0046] Example 1

[0047] Isolation and Identification of Bacillus altitudinis No.33692

[0048] 1. Isolation of strains

[0049] During the tomato maturity period in medium and low-yield fields, take the rhizosphere soil of 5 healthy tomatoes, mix it thoroughly, take 10g and oscillate it evenly in 90ml sterile water to obtain a concentration of 10 -1 Then draw 10 ml of the dilution with a concentration of 10-1 The soil dilution was diluted to a concentration of 10 -3 , take 10 -1 , 10 -2 , 10 -3 The concentration dilutions were spread on oligonutrient medium R2A plates, with 3 replicates for each gradient. The culture was cultured at 30°C for 48 hours, and the colony morphology was observed and the 16S rDNA gene sequence was amplified and sequenced for verification.

[0050] Oligonutrient medium R2A (g / L): 3.0 g beef extract; 10.0 g peptone; 1.0 g yeast powder; 3.0 g glucose; 3.0 g sodium pyruvate; 1.0 g dipotassium hydrogen phosphate; 1.0 g potassium dihydrogen phosphate; 5.0 g sodium chloride; 20 g agar; 1.0 liter water.

[0051] 2. Preservation of strains

[0052] LB liquid culture medium: add distilled water to 10 g of tryptone, 5 g of yeast extract and 30 g of sodium chloride, adjust the pH to 7.2, adjust the volume to 1 liter, then sterilize at 121°C for 15 minutes, and cool before use.

[0053] LB solid medium: Add agar to LB liquid medium to a concentration of 15 g / L; then sterilize at 121°C for 15 minutes. Pour the LB liquid medium cooled to about 55°C into a culture dish and cool naturally.

[0054] Strain preservation: A single colony was inoculated into LB liquid medium and cultured at 30°C for 16 hours to obtain a culture solution. One volume of the culture solution was mixed with one volume of 50% (v / v) glycerol aqueous solution and stored at -80°C. The resulting strain was named M427.

[0055] 3. Morphological characteristics of strains

[0056] The colonies of this strain are irregularly oval, beige, with a rough and dry surface. Figure 1 .

[0057] 4. Physiological and biochemical characteristics of strains

[0058] (1) Qualitative determination of siderophore synthesis

[0059] CAS culture medium includes the following raw materials: chrome azuro blue 0.060 g; hexadecyltrimethylammonium bromide 0.073 g; ferric chloride hexahydrate 2.645 mg; sodium dihydrogen phosphate dihydrate 0.295 g; sodium dihydrogen phosphate dodecahydrate 1.213 g; ammonium chloride 0.125 g; potassium dihydrogen phosphate 0.0375 g; sodium chloride 0.0625 g; magnesium sulfate heptahydrate 0.1 g; glucose 10 g; peptone 10 g; acid hydrolyzed casein 10 g; agar 15-20 g.

[0060] Bacillus altitudinis CGMCC No.33692 activated for 24 hours was inoculated on CAS medium, and each treatment was repeated 3 times. The plate was inverted and cultured at 30°C for 3 days. The color change of each plate was observed to see if a transparent circle was produced, and the results were recorded. If the strain can grow on CAS medium and form an orange-yellow halo, it means that the strain has the function of synthesizing siderophores. The siderophores produced by microorganisms can activate the insoluble iron in the soil, increase the solubility and mobility of iron, and improve the effectiveness of iron in the soil. In the figure, strain M427 can produce an orange-yellow halo on CAS medium, indicating that strain M427 has the function of synthesizing siderophores. See for specific results. Figure 2 and its description.

[0061] (2) Analysis of nitrogen fixation ability of strains

[0062] Each liter of liquid Ashby medium is composed of the following raw materials: 0.2 g of potassium dihydrogen phosphate; 0.2 g of sodium chloride; 0.2 g of magnesium sulfate heptahydrate; 0.2 g of potassium sulfate dihydrate; 5 g of calcium carbonate; 5 g of glucose; 5 g of mannitol; the balance is water, pH = 7.0.

[0063] The selected strain M427 was inoculated on Ashby solid medium (10% agar was added to the above liquid Ashby medium), repeated 3 times, placed in an incubator at 28°C and inverted to observe whether the strain grows and produces a transparent circle. The results showed that the strain M427 can grow on Ashby medium and produce a transparent circle, indicating that it has the property of nitrogen fixation. The specific results are shown in Figure 3 And instructions.

[0064] (3) Analysis of the phosphate-dissolving ability of the strains

[0065] Each liter of PKO medium includes the following raw materials: 10 grams of glucose, 5 grams of tricalcium phosphate, 5 grams of magnesium chloride, 0.1 grams of ammonium sulfate, 0.2 grams of potassium chloride, 0.25 grams of magnesium sulfate, 17 grams of agar, and the balance is water, pH = 7.0.

[0066] Inoculate strain M427 on PKO medium. If the strain has the ability to dissolve phosphate, a transparent ring will appear around the strain after it has been cultured on PKO medium (containing insoluble calcium phosphate) for a period of time. It has been verified that the strain can produce a transparent ring on PKO medium, indicating that the strain has the ability to dissolve phosphate. For specific results, see Figure 4 And instructions.

[0067] (4) Analysis of the ability of strains to secrete auxin (IAA)

[0068] 250 ml of Salkowski colorimetric solution contains the following materials: 150 ml of concentrated sulfuric acid, 37.5 ml of 0.5 M ferric chloride solution;

[0069] The isolated and purified strain M427 was inoculated into 1 ml of LB liquid culture medium containing 200 mg / L of L-tryptophan, and 3 replicates were set up. After culturing for 2 days at a temperature of 30°C and a rotation speed of 180 rpm, 500 μl of the bacterial suspension was taken to a 48-well plate, 500 μl of Salkowski colorimetric solution was added, and 500 μl of uninoculated LB liquid culture medium and 500 μl of colorimetric solution were added as controls. After being placed at room temperature and away from light for 20 minutes, the color turns pink, indicating that it can secrete auxin (IAA). The darker the color, the greater the secretion intensity. The results showed that the strain M427 was light pink, indicating that it has the ability to secrete auxin (IAA). For specific results, see Figure 5 And instructions.

[0070] 5. Identification and preservation of strains

[0071] The isolated strain M427 has a 100% similarity with Bacillus altitudinis h217, and the specific results are shown in Table 1; through comprehensive bacterial morphology, physiological and biochemical characteristics and 16S rDNA gene sequence, it can be known that the strain in this application is Bacillus altitudeinis. The strain was deposited in the General Microbiological Center of the China Microbiological Culture Collection Administration (the depository is referred to as CGMCC, located at the Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, Postal Code 100101) on March 3, 2025, with a deposit number of CGMCC No. 33692 and a classification name of Bacillus altitudeinis.

[0072] Table 1 Comparison results between isolated strains and typical strains in the database

[0073] Strain number 16S rDNA similarity closest strain Similarity (%) Strain M427 Bacillus altitudinis h217 100％

[0074] Example 2

[0075] Effect of Bacillus altitudinis CGMCC No.33692 on the Germination Rate of Corn

[0076] Corn seeds of uniform size were selected, disinfected with 75% ethanol solution for 10 minutes, rinsed with water and placed in a beaker, soaked in Bacillus altitudinis CGMCC No.33692 bacterial solution and ultrapure water (control) for 12 hours, and then 30 seeds were evenly placed in a glass culture dish with two wet filter papers, placed in an incubator and cultured under the conditions of 25°C, 6000 lux of light intensity and 60% humidity, and the germination rate was counted. Each treatment was repeated 3 times.

[0077] Experimental results: The germination rate of Bacillus altitudinis CGMCC No.33692 was 75.86%, and the germination rate of the control was 65.51%, with significant difference. The bud length of Bacillus altitudinis CGMCC No.33692 was significantly higher than that of the control. For specific results, see Figure 6 .

[0078] Example 3

[0079] Effects of Bacillus altitudinis CGMCC No.33692 on the Growth of Potted Corn

[0080] Based on the soil of medium and low yield fields, using corn "Zhengdan 958" as the material, select corn seeds of uniform size, disinfect with 75% ethanol solution for 10 minutes, rinse with water and place in a beaker, soak corn seeds with Bacillus saltitudinis CGMCC No.33692 bacterial solution for 12 hours, use sterilized water as control, and then use potted method to cultivate corn seedlings. After 30 days, the plant height, root length, stem weight, root dry weight, and chlorophyll content of corn seedlings are measured. The data analysis and processing results are shown in Table 1.

[0081] Experimental results: Bacillus altitudinis CGMCC No.33692 significantly increased the plant height, leaf area, dry weight and wet weight of corn, increased the chlorophyll content, and promoted the growth of corn.

[0082] Table 2 Effects of Bacillus altitudinis CGMCC No.33692 on plant height, dry weight and wet weight of corn

[0083]

[0084]

[0085] Example 4

[0086] Effects of Bacillus altitudinis CGMCC No.33692 on the physical and chemical properties of maize rhizosphere soil

[0087] 1. Soil sample collection and processing

[0088] The rhizosphere soil of the corn in Example 3 was collected and passed through a 2 mm sieve. The fresh soil sample was spread on newspaper and placed indoors for air drying. The air-dried soil sample was used for the determination of soil physical and chemical properties.

[0089] Soil organic matter was determined by potassium dichromate oxidation method (external heating method); soil total nitrogen was determined by Kjeldahl method; soil total phosphorus and total potassium were determined by acid digestion-inductively coupled plasma emission spectrometry; soil available phosphorus was determined by sodium bicarbonate extraction-molybdenum antimony countercolorimetry; soil available potassium was determined by ammonium acetate extraction-atomic absorption spectrometry; soil alkaline hydrolyzable nitrogen was determined by alkaline diffusion method; soil electrical conductivity (EC) and pH were determined by extraction at a water-soil ratio of 5:1 and 2.5:1, respectively, and measured with a conductivity meter and an acidity meter.

[0090] 2. Experimental results: See Table 3. The control group shows that the original soil is a medium-low yield field soil, lacking in nitrogen, phosphorus and potassium, with low organic matter content and high soil alkalinity. Bacillus altitudinis CGMCC No.33692 treatment can significantly increase the organic matter content of corn rhizosphere soil, which is 2.206g / kg higher than the control, and increase the content of nitrogen, phosphorus and potassium elements. The total nitrogen, total phosphorus and total potassium are increased by 19.54%, 25.28% and 4.38% respectively compared with the control, and the alkaline nitrogen, available phosphorus and available potassium are increased by 38.22%, 51.50% and 3.27% respectively compared with the control, effectively improving the fertility of the soil, while reducing the soil pH value and increasing the electrical conductivity of the soil. Bacillus altitudinis CGMCC No.33692 effectively improves the physical and chemical properties of the soil, provides good soil environmental conditions for the growth and development of corn, and can be used as a soil conditioner.

[0091] Table 3 Effects of Bacillus altitudinis CGMCC No.33692 on the physical and chemical properties of maize rhizosphere soil

[0092]

[0093] Example 5

[0094] Bacillus altitudinis CGMCC No.33692 improves the low temperature tolerance of tomato plants

[0095] Experimental method: Tomato seeds of the same size were selected after disinfection and germination, and sown in plastic nutrient pots, and cultured using a special substrate for seedling cultivation. The tomato seedlings were cultivated to the 4-leaf stage in a solar greenhouse with natural light and a temperature of 20℃~25℃. When the tomato seedlings grew to 4 true leaves, they were transplanted. Two groups of treatments were set up during transplantation: inoculated with Bacillus saltitudinis CGMCC No.33692 and uninoculated plants (CK). When transplanting, the tomato roots were irrigated with 10 ml of OD 600 The bacterial solution with a value of about 1.0 (2×10 8 CFU / ml), with an equal amount of water as the control, low temperature treatment was carried out 15 days after transplanting, 10 pots were treated in each treatment, and all treatments were transferred to the artificial climate chamber for 10 days, divided into two temperature conditions: normal temperature 25℃ and low temperature 5℃, and the photoperiod was 16L:8D. After 48 hours of treatment at 5℃, the phenotype of the plants treated with low temperature was observed, and the plant height and root length of the four groups were measured. The fresh weight of the aboveground and underground parts was measured separately, and the green was fixed at 105℃ for 15 minutes. The dry weight of the aboveground and underground parts was measured after constant temperature drying at 70℃. The cold tolerance function of tomato seedlings after inoculation with Bacillus altitudinis CGMCC No.33692 was detected.

[0096] Table 4 Effects of Bacillus altitudinis CGMCC No.33692 on the growth of tomato seedlings under low temperature stress

[0097] deal with Plant height(cm) Fresh weight above ground (g) Underground fresh weight (g) Above ground dry weight (g) Underground dry weight (g) M427+C 20.75±0.94b 10.65±1.16a 4.19±0.70a 1.11±0.13a 0.30±0.05a CK+C 15.40±0.42c 6.03±0.93b 2.40±0.90b 0.57±0.13b 0.19±0.08b M427 21.83±0.41a 11.11±2.64a 4.94±0.42a 1.16±0.25a 0.35±0.06a CK 15.9±0.74c 6.17±1.02b 2.46±0.84b 0.60±0.11b 0.20±0.05b

[0098] Experimental results: See Table 4 and Figure 7 The results showed that inoculation of Bacillus lusaltitudinis CGMCC No.33692 at the seedling stage of tomatoes can significantly improve the ability of tomato seedlings to withstand low temperatures. At room temperature, the plant height, fresh weight and dry weight of tomato seedlings treated with the bacteria were significantly higher than those of the control (P < 0.05). Low temperature stress significantly reduced the plant height, fresh weight and dry weight of tomato plants, and inhibited the growth of tomato seedlings. Inoculation of Bacillus lusaltitudinis CGMCC No.33692 increased the plant height, fresh weight and dry weight of the plants, and returned the growth indicators to the normal temperature control level, thereby alleviating the inhibition of low temperature on the growth of tomato seedlings.

[0099] Example 6

[0100] Bacillus altitudinis CGMCC No.33692 improves the antioxidant enzyme activity of tomato plants

[0101] Reactive oxygen species (ROS) such as hydrogen peroxide (H 2 O 2 ) will significantly increase. 2 O 2 As a signal molecule and oxidant, its concentration changes directly affect the plant's stress resistance response. 2 O 2 Levels rise rapidly, excess H 2 O 2 CAT is a scavenger of H 2 O 2 The first line of defense is responsible for high concentrations of H 2 O 2 The APX-AsA system finely regulates H 2 O 2 The temporal and spatial distribution of CAT, APX and AsA is controlled to avoid excessive inhibition of its function as a signal molecule. At low temperatures, the stability of AsA content and APX activity is positively correlated with plant cold tolerance. Plants balance H by dynamically regulating the activity of CAT, APX and AsA. 2 O 2 scavenging and signaling functions, thereby alleviating oxidative damage and activating stress resistance responses.

[0102] Hydrogen peroxide (H 2 O 2 ) content (Article No.: H 2 O 2 The kits of Suzhou Keming Biotechnology Co., Ltd. were used for extraction and determination according to the instructions.

[0103] Experimental results:

[0104] 1. Hydrogen peroxide (H 2 O 2 ) content

[0105] The test results are shown in Figure 8After 5℃ stress treatment, the hydrogen peroxide content in tomato leaves increased significantly, indicating that the cell membrane was damaged and membrane lipid peroxidation occurred. The tomato leaves treated with Bacillus altitude inis CGMCC No.33692 slowed down the rising trend under low temperature conditions and were significantly lower than the low temperature control. The hydrogen peroxide content decreased by 32.52%, indicating that the chilling damage to tomato leaves treated with Bacillus altitudinis CGMCC No.336927 was relatively light.

[0106] 2. Effect on catalase (CAT) activity

[0107] The test results are shown in Fig. 9 Under low temperature conditions, inoculation with Bacillus altitudinis CGMCC No. 33692 upregulated the activity of CAT, resulting in an increase in the ability of plant cells to scavenge reactive oxygen free radicals, maintaining the balance between the production and scavenging of free radicals in cells, reducing membrane lipid peroxidation, and ultimately leading to the H 2 O 2 The content is lower than that of uninoculated plants, which alleviates the cell membrane damage caused by low temperature.

[0108] 3. Effect on ascorbic acid (AsA) content

[0109] The test results are shown in Fig.10 Ascorbic acid (AsA) is an important non-enzymatic active oxygen scavenger. Under normal temperature conditions, the content of antioxidant ascorbic acid (AsA) in tomato leaves treated with Bacillus altitudinis CGMCC No.33692 was significantly higher than that in the control. Low temperature stress caused the AsA content in tomato leaves to decrease, reaching a significant level (P < 0.05), while Bacillus altitudinis CGMCC No.33692 treatment could significantly increase the AsA content in tomato leaves by 20.12%.

[0110] 4. Effect on ascorbate peroxidase (APX) activity

[0111] The test results are shown in Fig.11 Ascorbate peroxidase (APX) is a regulatory enzyme in the ascorbate-glutathione cycle, which removes harmful H 2 O 2Under normal temperature conditions, the activity of antioxidant enzyme APX in tomato leaves treated with Bacillus altitudinis CGMCC No.33692 was significantly higher than that in the control group; low temperature stress significantly reduced the APX activity in tomato leaves, while Bacillus altitudinis CGMCC No.33692 treatment could significantly increase the APX activity in tomato leaves (P<0.05), which could be increased by 1.29 times.

[0112] Example 7

[0113] Bacillus altitudinis CGMCC No.33692 improves photosynthetic parameters of tomato leaves

[0114] Experimental method: The LI-6400 portable photosynthesis measurement system (LI-COR, USA) was used to measure the net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), and intercellular CO2 of the second and third leaves under good light conditions between 9:00 and 11:00 in the morning. 2 Concentration (Ci). The light intensity in the leaf chamber was 600 μmol·m -2 ·s -1 , O 2 Content 21%, CO 2 The concentration is 360μL / L.

[0115] Experimental results: The photosynthetic rate of the inoculated plants increased significantly, indicating that Bacillus altitudinis CGMCC No.33692 can help plants alleviate the basal metabolism of photosynthesis under low temperature stress. The photosynthetic rate reflects the efficiency of leaves in converting light energy into chemical energy. A decrease in the photosynthetic rate often indicates damage to the photosynthetic apparatus or stomatal restriction caused by low temperature stress. Low temperature stress significantly reduced the photosynthetic rate and transpiration rate of tomato plants. For details, see Fig.12 , 13 Bacillus altitudinis CGMCC No.33692 can increase the photosynthetic rate of tomatoes, slow down the transpiration rate, and alleviate the limiting effect of low temperature stress on the photosynthetic capacity of plants to a certain extent. Stomatal conductance represents the degree of stomatal opening. Increased stomatal conductance promotes CO 2 Absorption is beneficial to photosynthesis. Under normal temperature conditions, there is no significant difference in stomatal conductance between tomato plants treated with Bacillus saltitudinis CGMCC No. 33692 and the control. Fig.14Low temperature significantly reduced the stomatal conductance of the control, while Bacillus altitudinis CGMCC No. 33692 alleviated the limiting effect of low temperature on stomatal conductance and increased stomatal conductance to the level of normal temperature. 2 The concentration reflects CO 2 Supply and consumption balance, regardless of normal or low temperature conditions, the intercellular CO 2 The concentration was always lower than that of the uninoculated plants, but there was no significant difference under normal temperature. Low temperature caused the intercellular CO 2 The concentration increased rapidly, while the treatment with Bacillus altitudinis CGMCC No.33692 could reduce the intercellular CO 2 concentration to room temperature level, see Fig.15 .

Claims

1. Bacillus altitudinis, whose Latin name is Bacillus altitudinis, and its preservation number is CGMCC No.33692.

2. A microbial agent containing the Bacillus altitudinis described in claim 1, whose Latin name is Bacillus altitudinis and whose deposit number is CGMCC No. 33692.

3. Use of the Bacillus altitudinis with a Latin name of Bacillus altitudinis and a deposit number of CGMCC No. 33692 as claimed in claim 1 or a fermentation liquid containing the same or the microbial agent as claimed in claim 2 in preparing a soil conditioner.

4. Use of the Bacillus altitudinis with a Latin name of Bacillus altitudinis and a preservation number of CGMCC No. 33692 as claimed in claim 1 or a fermentation liquid containing the same or the microbial agent as claimed in claim 2 in promoting plant growth, wherein the plant is corn or tomato.

5. Use of the Bacillus altitudinis with a Latin name of Bacillus altitudinis and a preservation number of CGMCC No. 33692 as claimed in claim 1 or a fermentation liquid containing the same or the microbial agent as claimed in claim 2 in improving the cold resistance of plants, wherein the plant is tomato.

6. Use of the Bacillus altitudinis with a Latin name of Bacillus altitudinis and a deposit number of CGMCC No. 33692 as claimed in claim 1 or a fermentation liquid containing the same or the microbial agent as claimed in claim 2 in improving medium- and low-yield fields and / or alkaline soil.

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