Bacillus for soil microbial film sand stabilization, microbial agent containing bacillus and application of microbial agent

Abstract

The invention relates to bacillus for soil microbial film sand stabilization, a microbial agent containing the bacillus and application of the bacillus. The microbial agent is prepared by screening strains which survive in local aeolian sandy soil and are high in exopolysaccharide yield and optional auxiliary strains and matching with proper culture media and adsorbents. After the microbial agent is applied to soil needing sand stabilization treatment, the bacillus secretes exopolysaccharides, so that bacterial colonies are continuously adhered together to form a stable microbial film, a relatively stable special space structure is formed between the microbial film and soil particles, soil agglomeration is promoted, and a remarkable sand stabilization effect can be achieved. The method can effectively improve the characteristics and moisture characteristics of the aeolian sandy soil, has a good promotion effect on the growth and development of psammophyte, has great application potential and application value in the improvement of the aeolian sandy soil, is simple to operate and low in cost, and can provide a new way for the prevention and treatment of land desertification.

Description

Technical Field

[0001] The invention belongs to the technical field of new materials for sand fixation, and in particular relates to bacillus for soil microbial film sand fixation, a bacterial agent containing the bacillus and application thereof. Background Art

[0002] Desertification is a major global ecological problem that affects human survival and development. The world has been deeply harmed by desertification, and the situation of desertification prevention and control is still very serious. Desertification not only seriously threatens the global ecological environment security, but also affects the global economic development and sustainable development of human society.

[0003] The existing prevention and control measures for wind and sand hazards mainly include mechanical sand fixation, chemical sand fixation and biological sand fixation. Moreover, various sand fixation technologies often ignore the local natural ecological factors, which to some extent greatly limits the efficiency and sustainability of using these technologies to prevent and control sand.

[0004] Soil microorganisms are the most widespread and active life form in the soil. Soil microorganisms drive the earth's biochemical cycle and are a key link in the material circulation and energy flow of the ecosystem. In nature, most soil microorganisms do not exist in a separate free state, but colonize on the surface of soil particles and secrete extracellular polymers to form microbial aggregates.

[0005] The formation of microbial biofilm is an adaptive mechanism for soil microorganisms to protect themselves and grow efficiently. After forming microbial biofilm, soil microorganisms such as bacteria will secrete more extracellular polysaccharides under drought conditions to provide effective protection for themselves, prolong their survival rate and residence time in dry soil, and thus cope with the stress of drought environment.

[0006] Desert ecosystems are home to rich and special microbial resources. The bacteria in the desert have long adapted to the harsh environment and have stable special functions. Domestic and foreign scholars have mainly focused on the formation and structure of microbial membranes, but rarely on the functions and applications of microbial membranes.

[0007] After long-term experimental research, the inventors isolated new Bacillus strains with significant sand-fixing effects, and found that the soil microbial films formed by these Bacillus strains have great application potential and application value in the field of sandy soil improvement, and can provide a new approach to preventing and controlling land desertification, thereby completing the present invention. Summary of the invention

[0008] The object of the present invention is to provide soil microorganisms with sand-fixing function and a screening method thereof, a microbial agent containing the soil microorganisms and application thereof in soil microbial film sand-fixing.

[0009] To achieve the above purpose, the inventors analyzed the soil bacterial community structure characteristics and diversity of sandy soil samples (e.g., aeolian sandy soil), and analyzed the correlation between the soil bacterial community structure characteristics and diversity and the physical and chemical properties of the soil. The collected soil was screened for strains to obtain single colonies with and without the sticky stringing phenomenon, and then the screened strains were fermented and identified, and the extracellular polysaccharide content of the single colony strains with the sticky stringing phenomenon was further determined. Finally, the soil microbial strains or strain combinations with sand fixation effects were determined.

[0010] More specifically, the present invention provides a Bacillus pumilus strain DX002 in a first aspect, which is deposited in the China General Microbiological Culture Collection Center (CGMCC) with a deposit number of CGMCC No.31791.

[0011] In a second aspect, the present invention provides a Bacillus Subtilis strain GT018-JZ18111, which is deposited in the China General Microbiological Culture Collection Center (CGMCC) with a deposit number of CGMCC No.31791.

[0012] In a third aspect, the present invention provides the use of the Bacillus pumilus strain DX002 described in the first aspect of the present invention and / or the Bacillus subtilis strain GT018-JZ18111 described in the second aspect of the present invention in soil microbial film sand fixation.

[0013] In a fourth aspect, the present invention provides a method for screening soil microbial film sand-fixing bacteria, characterized in that the method comprises the following steps:

[0014] (1) Collect soil and culture bacteria to screen out single colonies with sticky stringing phenomenon (such as Figure 2 As shown) and optional single colonies without sticky stringing phenomenon;

[0015] (2) fermenting the single colony to obtain and identify the single colony culture;

[0016] (3) determining the extracellular polysaccharide content of the strain contained in the single colony culture having the sticky stringing phenomenon;

[0017] (4) The strain with high extracellular polysaccharide production (such as Figure 3 The strain with the highest extracellular polysaccharide content shown in the figure is determined as the main bacterial species for soil microbial film sand fixation, and optionally, a strain without sticky stringing phenomenon is further used as an auxiliary strain in combination with the main strain.

[0018] In a fifth aspect, the present invention provides a microbial agent, wherein the microbial species contained in the microbial agent is Bacillus, preferably Bacillus pumilus strain DX002 and / or Bacillus subtilis strain GT018-JZ18111.

[0019] The sixth aspect of the present invention provides a soil microbial film sand fixation method, the method comprising the step of forming a soil microbial film using the microbial agent described in the fifth aspect of the present invention.

[0020] Compared with the prior art, the present invention has the following technical advantages:

[0021] The inventors have screened strains or strain combinations that are particularly suitable for soil microbial film sand fixation. Among them, the Bacillus subtilis strain GT018-JZ18111 survives in local sandy soil and produces high extracellular polysaccharides. After being equipped with a suitable solid culture matrix and adsorbent and applied to the area required for sand fixation, especially after being used in conjunction with the Bacillus pumilus strain DX002, soil microorganisms use extracellular polysaccharides to make the colonies continuously stick together to form a stable microbial film, which can form a stable special spatial structure with soil particles, promote soil agglomeration, and achieve a good sand fixation effect. The soil microbial film sand fixation method provided by the present invention can effectively improve the characteristics of sandy soil, and has a significant promoting effect on the growth and development of sand-dwelling plants. It has great application potential and application value in the improvement of sandy soil, and is simple to operate and low in cost, which can provide a new way to prevent and control land desertification. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 This is the bacterial colony culture with sticky stringiness in Preparation Example 1 of the present invention.

[0024] Figure 2 The polysaccharide content changes of various strains with sticky stringing phenomenon screened in Preparation Example 1 of the present invention.

[0025] Figure 3 This is a physical picture of the microbial agent for soil microbial film sand fixation prepared in Preparation Example 2 of the present invention.

[0026] Figure 4 It is a diagram of the consolidation of the surface layer of the sandy soil in Example 1 of the present invention, wherein the left figure shows the consolidation of the surface layer of the sandy soil after application by spraying, and the right figure shows the consolidation of the surface layer of the sandy soil after application by mixing.

[0027] Figure 5 This is a scanning electron microscope image of the wind-blown sand in Example 1 of the present invention. The left image is a 200 μm magnification of the soil microbial film morphology, where the fluffy edges of the sand particles are the microbial film; the right image is a 30 μm magnification of the soil microbial film morphology, where the scale-like gray-white is the formed microbial film. DETAILED DESCRIPTION

[0028] As described above, the present invention provides a Bacillus pumilus strain DX002 in the first aspect, which is deposited in the China General Microbiological Culture Collection Center (CGMCC) with a deposit number of CGMCC No.31791.

[0029] In a second aspect, the present invention provides a Bacillus Subtilis strain GT018-JZ18111, which is deposited in the China General Microbiological Culture Collection Center (CGMCC) with a deposit number of CGMCC No.31791.

[0030] The deposit information of the Bacillus pumilus strain DX002 or the Bacillus subtilis strain GT018-JZ18111 screened and identified by the present invention is as follows:

[0031] (1) Deposit information of DX002 strain

[0032] Classification name: Bacillus pumilus;

[0033] Name of depository: China General Microbiology Center (CGMCC);

[0034] Address of the depository: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing;

[0035] Deposit date: August 30, 2024;

[0036] Deposit number: CGMCC No.31791.

[0037] (2) Deposit information of strain GT018-JZ18111

[0038] Classification name: Bacillus Subtilis;

[0039] Name of depository: China General Microbiology Center (CGMCC);

[0040] Address of the depository: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing;

[0041] Deposit date: April 30, 2019;

[0042] Deposit number: CGMCC No.17701.

[0043] The Bacillus pumilus strain DX002 and the Bacillus subtilis strain GT018-JZ18111 provided by the present invention both survive in local sandy soil, wherein the Bacillus subtilis strain GT018-JZ18111 is a high-yield extracellular polysaccharide strain, and detection has found that they have no other negative effects, for example, they are not plant pathogens, and have strong tolerance and the like.

[0044] In the present invention, the Bacillus subtilis strain GT018-JZ18111 can be used alone, but is preferably used in combination with Bacillus pumilus strain DX002. The inventors found that when Bacillus pumilus strain DX002 and Bacillus subtilis strain GT018-JZ18111 are used in combination, Bacillus pumilus strain DX002 can significantly promote the survival of Bacillus subtilis strain GT018-JZ18111, thereby improving the sand fixation effect of soil microbial film.

[0045] In a third aspect, the present invention provides the use of the Bacillus pumilus strain DX002 described in the first aspect of the present invention and / or the Bacillus subtilis strain GT018-JZ18111 described in the second aspect of the present invention in soil microbial film sand fixation.

[0046] In a fourth aspect, the present invention provides a method for screening soil microbial film sand-fixing bacteria, characterized in that the method comprises the following steps:

[0047] (1) collecting soil and culturing bacteria, screening out single colonies with a sticky stringy phenomenon and optional single colonies without a sticky stringy phenomenon;

[0048] (2) fermenting the single colony to obtain and identify the single colony culture;

[0049] (3) determining the extracellular polysaccharide content of the strain contained in the single colony culture having the sticky stringing phenomenon;

[0050] (4) The strain with high extracellular polysaccharide production is determined as the main bacterial species for soil microbial film sand fixation, and optionally, a strain without sticky stringing phenomenon is further used as an auxiliary strain in combination with the main strain.

[0051] In the application, "viscous stringing phenomenon" has no special meaning, it only means that the strain culture is sticky and forms strings when picked up, such as Figure 1 shown.

[0052] In the present application, the high yield in "high yield of exopolysaccharide" has no special meaning, it only means that the exopolysaccharide content is relatively high compared with the same strains (such as other strains screened at the same time). For example, for the Bacillus subtilis strain GT018-JZ18111 screened in the present application, after 9 days of cultivation, the exopolysaccharide is significantly higher than that of other Bacillus strains with sticky stringing phenomenon screened at the same time, for example, it can be as high as 2500 micrograms / gram (ratio of exopolysaccharide to total weight of bacteria).

[0053] In some preferred embodiments, the strain is DX002 or strain GT018-JZ18111, preferably strain GT018-JZ18111, and more preferably a combination of strain DX002 and strain GT018-JZ18111.

[0054] In a fifth aspect, the present invention provides a microbial agent, wherein the microbial strains contained in the microbial agent are the strain DX002 described in the first aspect of the present invention and / or the strain GT018-JZ18111 described in the second aspect of the present invention, preferably a combination of strain DX002 and strain GT018-JZ18111.

[0055] In some preferred embodiments, the number of viable bacteria in the microbial agent is 1×10 8 ~1×10 10 cfu / ml, for example 1×10 9 In the case where the strain is a combination of strain DX002 and strain GT018-JZ18111, the viable counts of the two strains in the combination may be, for example, 1:2 to 2:1, for example, 1:1.

[0056] In other preferred embodiments, the microbial agent comprises, in addition to the microbial strains, an adsorbent and a solid culture matrix.

[0057] In other preferred embodiments, the mass ratio of the solid culture matrix to the adsorbent is 1:1 to 1:5, for example, 1:2, 1:3 or 1:4.

[0058] In some other preferred embodiments, the solid culture matrix is ​​wood chips. In some additional or further preferred embodiments, the adsorbent is a mineral, more preferably, the mineral is diatom shale.

[0059] The present invention has no particular limitation on the particle size of the solid culture substrate such as sawdust or the adsorbent such as diatom shale. The particle size of the solid culture substrate such as sawdust and the adsorbent such as diatom shale can be independently 0.1 mm to 2 mm.

[0060] In other preferred embodiments, the strain inoculation amount of the solid culture matrix is ​​10 volume / mass % to 50 volume%, for example, 15 volume / mass %, 20 volume / mass %, 25 volume / mass %, 30 volume / mass %, 35 volume / mass %, 40 volume / mass % or 45 volume / mass %.

[0061] The sixth aspect of the present invention provides a soil microbial film sand fixation method, the method comprising the step of forming a soil microbial film using the microbial agent described in the fifth aspect of the present invention.

[0062] In some preferred embodiments, the application amount of the microbial agent is 1 to 10 grams, preferably 1 to 5 grams, of the microbial agent per kilogram of soil.

[0063] The present invention has no particular restrictions on the application mode of the microbial agent. However, in some preferred embodiments, the application mode of the microbial agent is a spraying mode or a mixed application mode. In the case of mixed application, the microbial agent can be evenly mixed with sand (e.g., sandy soil) in a certain proportion according to the target application concentration, and then applied. In the case of spraying, the microbial agent (e.g., powder) can be dissolved in distilled water according to the concentration and then directly sprayed on the sand for application. For example, the microbial agent of the present invention can use the culture solution of the above-mentioned strain, and then use sawdust as a solid culture matrix, minerals such as diatom shale as an adsorbent, and mix in proportion to prepare the microbial agent. Then the microbial agent is mixed with sand (e.g., sandy soil) or distilled water in proportion for application. The microorganisms in the microbial agent of the present invention are soil microorganisms, which continuously aggregate the colonies through extracellular polysaccharides to form a stable microbial film. The biofilm can form a relatively stable special spatial structure with soil particles, promote soil agglomeration, and thus achieve a better sand fixation and water conservation effect.

[0064] Example

[0065] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0066] Preparation Example 1

[0067] The strains were screened by using soil collected from the Horqin sandy land. The screening method is to prepare the soil into a soil suspension at a weight ratio of 1:10 (soil: water), and then use a glass spreading rod to spread it on the nutrient agar medium (the medium formula is 3.0g beef extract, 10g peptone, 5g sodium chloride, 20g agar, 1L distilled water, pH 7.0, sterilized at 121℃ for 20min), and place it in an incubator at a constant temperature of 30℃ and incubate in the dark for 72h. After the colonies are produced, use an inoculation loop to pick colonies of different morphologies, and repeatedly perform single colony purification on the nutrient agar medium. Finally, the screened single colonies are cultured separately, and several strains with sticky wire drawing phenomenon are screened out (see Figure 1 ) and a single colony without the sticky string phenomenon, and then the selected single colony strains were fermented and cultured (the culture medium formula was 3.0g beef extract, 10g peptone, 5g sodium chloride, 20g agar, 1L distilled water, pH 7.0, sterilized at 121℃ for 20min) and identified. For the strains with the sticky string phenomenon, their extracellular polysaccharide content was also determined. The results of the isolated strains with the sticky string phenomenon and their polysaccharide content can be found in Figure 2 .exist Figure 2 In the method, BA is Bacillus cereus ATCC 14579, BI is Bacillus sp.IAE248, BD is Bacillus sp.DW024, BS is Bacillus subtilis isolate S331, BT is Bacillus cereus T-o4, and BE is Bacillus cereus EC3. The single colony strain without the sticky stringing phenomenon was identified as Bacillus pumilus, and the strain was named strain DX002 and preserved with the deposit number CGMCC No.31791. Figure 2 The single colony strain BS (identified as Bacillus subtilis) with the highest exopolysaccharide content shown in the figure was also deposited with the accession number GT018-JZ18111.

[0068] Preparation Example 2

[0069] Liquid culture medium (beef extract 3.0 g, peptone 10 g, sodium chloride 5 g, distilled water 1 L, pH 7.0, sterilized at 121 ° C for 20 min) was used for constant temperature and dark culture at 30 ° C. The strains DX002 and GT018-JZ18111 obtained by screening in Preparation Example 1 were used to prepare bacterial liquid. The culture time was 72 h. The culture liquids of the two strains, i.e., the DX002 bacterial liquid and the GT018-JZ18111 bacterial liquid (diluted to a total viable count of 1×10 10 cfu / ml).

[0070] Sawdust was used as the solid culture matrix, diatom shale was used as the adsorbent (the particle size of sawdust and diatom shale was less than 0.841 mm (passed through a 20-mesh sieve), and the mass ratio was 1:3). The DX002 bacterial solution and the GT018-JZ18111 bacterial solution were used to prepare the microbial inoculum. The inoculation amount of the strain was 30 volume / mass% of the solid culture matrix (ml bacterial solution / g solid culture matrix). The total number of viable bacteria in the prepared microbial inoculum was detected (about 1×10 9 cfu / ml). The finished product of the prepared bacterial agent is as follows Figure 3 shown.

[0071] Table 1. Inoculum size of each bacterial agent.

[0072]

[0073]

[0074] Example 1

[0075] The soil microbial film sand-fixing agent prepared in Preparation Example 2 was used, and the application amount (ratio of microbial agent to sandy soil) was 5g / kg, and a control group (microbial agent dosage was 0g / kg) was set up, mixed evenly in a flower pot and placed in a greenhouse, and watered once to reach saturated field water holding capacity. The sandy soil was taken from the vegetation-free mobile sand dunes in Horqin Sandy Land, Naiman Banner, Inner Mongolia Autonomous Region, and samples were taken every 7 days after treatment, and the samples were dried to constant weight (weighed every 1 hour, and the weight change did not exceed 1%), and the microbial indicators and physical and chemical property indicators of the sandy soil were determined.

[0076] like Figure 4 As shown in Figure 2, after the bacterial agent treatment, an obvious consolidation layer was formed on the surface of the aeolian sandy soil (photographed 21 days after treatment). Figure 5 As shown in the results, bacterial agents can indeed play an important role in cementing sandy soil particles, and microbial film can significantly increase the polysaccharide content of sandy soil and increase the carbon and nitrogen content of microbial biomass in sandy soil.

[0077] The experiment was ended after 49 days of treatment, and it was found that at the end of the experiment, the polysaccharide content of the sandy soil was 2.01g / kg, which was 55.81% higher than the control group (microbial agent dosage was 0g / kg) of 1.29g / kg; the microbial carbon content of the sandy soil was 14.10mg / kg, which was 8.82% higher than the control group of 12.96mg / kg; the microbial biomass nitrogen content of the sandy soil was 5.01mg / kg, which was 8.60% higher than the control group of 4.61mg / kg.

[0078] Table 2. Extracellular polysaccharide content, microbial carbon content and microbial biomass nitrogen content of sandy soil after treatment with various bacterial agents (n=5).

[0079]

[0080] Moreover, it has been found through experiments that the microbial agent of the present invention can form a good soil microbial film.

[0081] Reduce soil bulk density, increase soil porosity, effectively retain soil moisture, increase soil organic matter content, aggregate soil particles, and increase soil pH. Specifically, after testing, the bulk density of sandy soil is 1.505g / cm 3 , compared with the control group 1.520g / cm 3 It decreased by 0.97%, the porosity was 0.385%, which was 1.035% higher than the control group's 0.372%, and the organic matter content of aeolian sandy soil was 0.480%, which was 88.46% higher than the control group's 0.255%.

[0082] Table 3. Bulk density, microbial carbon content and microbial biomass nitrogen content of aeolian sandy soil after treatment with various bacterial agents (n=5).

[0083] Microbial Agents <![CDATA[Bulk density (g / cm 3 )]]> Porosity(%) Organic matter content (%) Bacterial Agent 1 1.512 0.379 0.363 Bacterial Agent 2 1.505 0.385 0.480 Bacterial Agent 3 1.515 0.375 0.282 Bacterial Agent 4 1.520 0.372 0.255

[0084] Example 2

[0085] The method was basically the same as that of Example 1, except that: the soil property measurement time, water infiltration test was carried out after the mixture of the microbial agent and soil was placed in a 30°C incubator for 72 hours after absorbing water to saturation and then taken out and air-dried; the soil water evaporation test was measured at 9 o'clock every day; the soil water characteristic curve: after the microbial agent and soil were evenly mixed, they were placed in a ring knife and placed in water to absorb water to saturation, and then placed in a 30°C incubator for 72 hours before being taken out, and after the ring knife was taken out, water was absorbed again for 24 hours until the soil water reached saturation and centrifuged before measurement. The results are shown in Table 4 below.

[0086] Table 4. Cumulative infiltration, daily evaporation and saturated hydraulic conductivity of sandy soil after treatment with various bacterial agents (n=5).

[0087] Microbial Agents Cumulative infiltration volume (mm) Daily evaporation (mm) Saturated hydraulic conductivity (cm / h) Bacterial Agent 1 106.64 0.52 0.82 Bacterial Agent 2 122.00 0.34 0.49 Bacterial Agent 3 97.11 0.64 1.13 Bacterial Agent 4 84.86 0.74 1.39

[0088] The soil microbial film formed by the microbial agent of the present invention can promote soil infiltration, increase the cumulative soil infiltration, increase the soil infiltration rate, reduce the daily soil evaporation, and inhibit soil evaporation. The cumulative soil infiltration was 122.00 mm, which was 43.76% higher than the control group 84.86 mm, and the daily soil evaporation was 0.34 mm, which was 53.85% lower than the control group 0.74 mm; there were large differences in the soil moisture characteristic curves of different treatments, and the soil microbial film can increase the soil volume moisture content. From the above results, it can be seen that the microbial agent of the present invention can form a good soil microbial film, reduce the soil saturated hydraulic conductivity, and effectively maintain soil moisture. The soil saturated hydraulic conductivity is 0.49 cm / h.

[0089] Example 3

[0090] The concentration of the microbial agent used in this embodiment is the same as that in Example 1, except that: this embodiment uses a spraying method to treat the sandy boxwood seeds, records the germination rate and measures the seedling-related characteristics. Specifically, the microbial agents 2 and 4 (2 g) prepared in Preparation Example 2 are dissolved in 150 mL of distilled water and then sprayed. Among them, the sandy soil used in this embodiment is sterilized at 120°C in an autoclave for 25 minutes after passing through a 2 mm sieve, and each cultivation container is filled with 0.40 kg (by dry weight) of sterilized sandy soil treated with the agent as a cultivation medium. Plant germination seeds are sprinkled on the surface of the sandy soil treated with the agent, then covered with soil and sprayed with distilled water until saturated, and then cultured, observed and measured.

[0091] It was found through experiments that the microbial agent of the present invention can form a good soil microbial film, which delays the germination time of desert plant seeds by 14 days (the control group is 11 days). And when detected on the 49th day, the plant height was reduced by 23 cm (the control group was 29 cm), and the plant base diameter was increased by 1.72 mm (the control group was 1.59 mm). Therefore, the soil microbial film formed can directly affect the germination and growth of desert plants by producing soil extracellular polysaccharides and forming a consolidation layer, and can also indirectly act on plants by changing soil enzyme activity, thereby affecting their germination and growth process.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A Bacillus pumilus strain DX002 for soil microbial film sand fixation, wherein the strain is deposited in the General Microbiological Center (CGMCC) of the China Microbiological Culture Collection Administration, and the deposit number is CGMCC No.31791.

2. A Bacillus Subtilis strain GT018-JZ18111 for soil microbial film sand fixation, which is deposited in the General Microbiological Center (CGMCC) of the China Microbiological Culture Collection Administration with a deposit number of CGMCC No.31791.

3. Use of the Bacillus pumilus strain DX002 according to claim 1 and / or the Bacillus Subtilis strain GT018-JZ18111 according to claim 2 in soil microbial film sand fixation.

4. A microbial agent, characterized in that: The microbial strains contained in the microbial agent are a combination of the Bacillus pumilus strain DX002 described in claim 1 and / or the Bacillus Subtilis strain GT018-JZ18111 described in claim 2.

5. The microbial agent according to claim 4, characterized in that: The total number of viable bacteria in the microbial agent is 1×10 8 ~1×10 10 cfu / ml.

6. The microbial agent according to claim 4 or 5, characterized in that: The microbial agent includes not only the microbial strains but also an adsorbent and a solid culture matrix; Preferably, the mass ratio of the solid culture matrix to the adsorbent is 1:1 to 1:

5.

7. The microbial agent according to claim 6, characterized in that: The solid culture matrix is ​​sawdust, and / or the adsorbent is a mineral such as diatom shale; Preferably, the microbial agent is inoculated with a bacterial solution containing the microbial strain, and the inoculation amount of the bacterial solution is 10 volume / mass % to 50 volume / mass % of the solid culture matrix.

8. A soil microbial film sand fixation method, characterized in that: The method comprises the step of forming a soil microbial film using the microbial agent according to any one of claims 4 to 7.

9. The method according to claim 8, characterized in that The application amount of the microbial agent is 1 to 10 grams, preferably 1 to 5 grams, of the microbial agent per kilogram of soil.

10. The method according to claim 8 or 9, characterized in that: The microbial agent is applied by spraying or mixing.

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