Bacillus cereus CMJ-As01, microbial inoculant and application thereof in microbial remediation of arsenic-contaminated soil-rice system
By screening and applying Bacillus cereus CMJ-As01, the problems of high cost and secondary pollution in the remediation of arsenic-contaminated soil-rice system were solved, and effective arsenic pollution remediation and arsenic content compliance of agricultural products were achieved in rice cultivation in farmland with low to moderate arsenic contamination.
Patent Information
- Application Number
- CN202610190351.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-10
- Publication Date
- 2026-05-15
- Estimated Expiration
- 2046-02-10
AI Technical Summary
Existing technologies for the remediation of arsenic-contaminated soil-rice systems suffer from high costs, a high risk of secondary pollution, and low economic feasibility for low- to medium-contaminated farmland. Traditional methods have failed to effectively address the transfer mechanism of arsenic between soil and plants.
A strain of Bacillus cereus CMJ-As01 is provided, which was obtained by screening and purification from heavy metal contaminated soil in mining areas. This strain has good arsenic tolerance and can be applied to the rhizosphere of rice. Through multiple synergistic mechanisms such as root surface iron film promotion, arsenic subcellular compartmentalization and regulation of soil microbial community, it can block the translocation of arsenic from soil to rice aboveground parts.
It significantly reduces the arsenic content in brown rice, achieving microbial remediation of arsenic-contaminated soil-rice systems. It is low-cost and pollution-free, suitable for paddy fields with moderate to mild arsenic contamination, and produces agricultural products with arsenic content meeting standards.
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Abstract
Description
Technical Field
[0001] This invention relates to a Bacillus cereus, specifically a Bacillus cereus strain screened from heavy metal-contaminated mine soil. Bacillus cereus CMJ-As01 also involves a species containing Bacillus cereus. Bacillus cereus CMJ-As01 microbial inoculant, and Bacillus cereus involved Bacillus cereus The application of CMJ-As01 in the microbial remediation of arsenic-contaminated soil-rice system belongs to the field of heavy metal contaminated farmland soil remediation technology. Background Technology
[0002] Arsenic is a recognized highly toxic element, and arsenic pollution in rice paddies has long been a public concern. Currently, rice, as a major food crop, shows a particularly prominent accumulation of arsenic in contaminated soil, posing a significant food safety issue.
[0003] Currently, the remediation of arsenic-contaminated soil-rice systems faces multiple challenges. Traditional physical and chemical remediation techniques (such as topsoil replacement, tillage, and chelating agent leaching), while improving the distribution of arsenic speciation in soil, are costly, prone to secondary pollution, and have low economic feasibility for low- to moderately contaminated farmland. Microbial remediation, as a green, economical, and sustainable remediation method, has gained widespread attention in recent years. Microorganisms can achieve multiple mechanisms of action against pollutants such as arsenic, including passivation, transformation and reduction, and bioaccumulation, by secreting metabolites, altering the rhizosphere microenvironment, and regulating plant physiological processes. For example, a Chinese patent application (application publication number: CN 114903049A) discloses the application of a microbial metabolite, hydroxamic acid-type siderophore, as a cadmium-reducing agent in rice. Furthermore, the composition and function of the rhizosphere microbial community directly affect the absorption and translocation of heavy metals by plants. Targeted inoculation using the strong tolerance and multiple functions of microorganisms to arsenic can effectively remediate arsenic contamination in soil-rice systems. Bacillus species, due to their strong tolerance, wide adaptability, and ability to form spores, have shown great potential in the remediation of heavy metal pollution. For example, Chinese patent application (publication number: CN120843315A) discloses a strain of Bacillus cereus resistant to combined heavy metal (As) and (Cd) pollution. Furthermore, studies have shown that Bacillus cereus and related strains can adsorb and immobilize heavy metal ions such as arsenic and lead through extracellular polymeric adsorption, while simultaneously producing metabolites such as phosphate-dissolving enzymes and siderophores, improving plant nutrition and promoting plant defense mechanisms. For instance, Bacillus subtilis and other Bacillus species have been reported to possess arsenic and sulfate-reducing abilities, capable of altering the valence state and mobility of arsenic in soil. However, these studies primarily focus on the biochemical transformation mechanism of arsenic by a single microorganism, without considering the soil-plant transfer mechanism of arsenic. Summary of the Invention
[0004] To address the shortcomings of existing technologies, the first objective of this invention is to provide a Bacillus cereus strain that can be isolated, screened, and purified from heavy metal-contaminated soil in mining areas. Bacillus cereus CMJ-As01, the Bacillus cereus Bacillus cereus CMJ-As01 not only exhibits good tolerance to arsenic, but also shows effectiveness against arsenic-contaminated soil used for rice cultivation. Bacillus cereus When CMJ-As01 is added to the rice rhizosphere, it can promote growth through multiple synergistic mechanisms, such as promoting growth through root surface iron film, arsenic subcellular compartmentalization, and regulating key soil microbial communities. It acts on multiple levels of soil, rhizosphere, and plant cells, thereby effectively blocking the translocation of arsenic from the soil to the aboveground parts of rice and significantly reducing the total arsenic and inorganic arsenic content in brown rice. This achieves the goal of ecological restoration of the arsenic-contaminated soil-rice system.
[0005] A second objective of this invention is to provide a microbial agent that primarily comprises Bacillus cereus. Bacillus cereus CMJ-As01 has the function of reducing the arsenic content in brown rice and realizing the microbial remediation of arsenic-contaminated soil-rice system. It can be widely used in rice planting in paddy fields with moderate to mild arsenic contamination.
[0006] A third objective of this invention is to provide an application of a microbial agent containing Bacillus cereus. Bacillus cereus The microbial agent CMJ-As01, when applied to rice cultivation in arsenic-contaminated farmland, can effectively reduce the arsenic content in brown rice and simultaneously complete the microbial remediation of the arsenic-contaminated soil-rice system. This enables the cultivation of rice in moderately to slightly arsenic-contaminated farmland, yielding agricultural products with arsenic content meeting standards and achieving soil arsenic remediation.
[0007] To achieve the above technical objectives, the present invention provides a Bacillus cereus. Bacillus cereus CMJ-As01, accession number CCTCC NO: M 20251941.
[0008] The Bacillus cereus of this invention was isolated, screened, and purified from soil samples collected from heavy metal-contaminated mining areas, and its classification name is: Bacillus cereus CMJ-As01 was deposited at the China Center for Type Culture Collection (CCTCC) on September 1, 2025, with accession number CCTCC NO: M 20251941, at Wuhan University, Wuhan, China.
[0009] Bacillus cereus of the present invention Bacillus cereusCMJ-As01 exhibits excellent tolerance to arsenic. In particular, it can effectively control arsenic in the soil by promoting the formation of iron films on the root surface of rice, thus alleviating arsenic stress damage. At the same time, it can regulate the subcellular arsenic distribution in the rice rhizosphere, promote arsenic fixation in the cell wall, enhance the activity of key soil enzymes, and significantly increase the functional abundance of bacterial communities. Therefore, it can reduce arsenic damage through multiple dimensions such as migration and transformation, physiological defense, and rhizosphere microecology, effectively reducing the content of total arsenic and inorganic arsenic in brown rice, and achieving the goal of bioremediation of arsenic-contaminated soil.
[0010] Bacillus cereus of the present invention Bacillus cereus The mechanism by which CMJ-As01 reduces arsenic levels in the soil-rice system: Bacillus cereus Bacillus cereus When CMJ-As01 is added to the rhizosphere of rice, it can regulate the distribution of arsenic in root subcellular cells, enhance the activity of key enzymes in the rhizosphere soil, change the abundance of microbial communities and key genes, and promote the formation of rhizosphere iron film to achieve the purpose of arsenic inhibition.
[0011] The present invention also provides a microbial inoculant comprising the aforementioned Bacillus cereus. Bacillus cereus CMJ-As01.
[0012] As a preferred embodiment, the microbial agent comprises a culture medium. As a preferred embodiment, the culture medium comprises the following components: (NH4)2SO4, KCl, K2HPO4, MgSO4·7H2O, Ca(NO3)2, glucose, and yeast.
[0013] As a preferred embodiment, the composition and concentration of each component of the culture medium are as follows: (NH4)2SO4, 3000–3100 mg / L; KCl, 100–110 mg / L; K2HPO4, 500–510 mg / L; MgSO4·7H2O, 500–510 mg / L; Ca(NO3)2, 100–110 mg / L; glucose 700–710 mg / L; yeast 300–310 mg / L. This preferred culture medium not only provides the nutrients required for the growth of Bacillus cereus but also provides nutrients for rice.
[0014] As a preferred embodiment, the Bacillus cereus Bacillus cereus The mass percentage content of CMJ-As01 in the microbial inoculant is 0.5% to 5%.
[0015] The present invention also provides an application of a microbial agent for reducing the arsenic content in brown rice and for achieving microbial remediation of rice-arsenic contaminated soil-rice systems.
[0016] The microbial agent of the present invention can be directly used for the remediation of arsenic-contaminated farmland soil, especially for rice cultivation. The microbial agent can not only effectively reduce the arsenic content in brown rice, but also achieve microbial remediation of the arsenic-contaminated soil-rice system, stabilizing the available arsenic in the arsenic-contaminated soil. This enables the cultivation of rice in farmland with low to moderate arsenic contamination, obtaining agricultural products with arsenic content that meets the standards, and achieving the bioremediation of soil arsenic pollution.
[0017] As a preferred method, when planting rice in arsenic-contaminated soil, microbial inoculants are inoculated into the rhizosphere of the rice plants during the tillering and / or grain-filling stages. Experiments have shown that inoculation with microbial inoculants during both the tillering and grain-filling stages is more effective in reducing the arsenic content in brown rice. In pot experiments, the inoculation volume per pot was approximately 200 mL (OD200). 600 =1.0).
[0018] Compared with the prior art, the technical solution of the present invention brings the following beneficial technical effects:
[0019] The technical solution of this invention involves screening and isolating Bacillus cereus from heavy metal-contaminated soil in mining areas. Bacillus cereus CMJ-As01, this type of Bacillus cereus Bacillus cereus CMJ-As01 exhibits good tolerance to arsenic and, when applied to rice cultivation in arsenic-contaminated farmland, it can effectively reduce the total and inorganic arsenic content in brown rice and complete the microbial remediation of the arsenic-contaminated soil-rice system. This enables the cultivation of rice in low-to-medium arsenic-contaminated farmland, yielding agricultural products with arsenic content meeting standards, and achieving the remediation of soil arsenic pollution.
[0020] Bacillus cereus of this invention Bacillus cereus CMJ-As01 enables rice cultivation in farmland with moderate to mild arsenic contamination, and the total arsenic and inorganic arsenic content of the obtained brown rice meets safety standards. It also remediates arsenic-contaminated soil-rice systems, offering advantages such as low cost and no pollution. Attached Figure Description
[0021] Figure 1 Bacillus cereus screened for this invention Bacillus cereus Gram staining diagram of CMJ-As01.
[0022] Figure 2 Bacillus cereus screened for this invention Bacillus cereus Phylogenetic tree diagram of CMJ-As01; by Figure 2 It can be known that the strain Bacillus cereus CMJ-As01 is closely related to Bacillus cereus.
[0023] Figure 3 The present invention contains Bacillus cereus. Bacillus cereusFigure 1 shows the arsenic content of different parts of rice at different stages after the addition of CMJ-As01 microbial agent to the rice rhizosphere; a is the arsenic content of the rice root at different stages, b is the arsenic content of the rice stem at different stages, c is the arsenic content of the rice leaf at different stages, d is the arsenic content of the rice panicle at different stages, e is the total arsenic content in the brown rice, and f is the inorganic arsenic content in the brown rice.
[0024] Figure 4 The present invention contains Bacillus cereus. Bacillus cereus The graph shows the changes in arsenic and iron content in the iron film on the root surface of rice at different time points after the addition of CMJ-As01 microbial agent to the rice rhizosphere; a represents the change in arsenic content in the iron film on the root surface, and b represents the change in iron content in the iron film on the root surface.
[0025] Figure 5 The present invention contains Bacillus cereus. Bacillus cereus Distribution of subcellular arsenic content after adding CMJ-As01 microbial agent to rice rhizosphere; a is the arsenic content in the cell wall, b is the arsenic content in the organelles, and c is the arsenic content in the soluble portion.
[0026] Figure 6 The present invention contains Bacillus cereus. Bacillus cereus The changes in the activity of key soil enzymes during the grain-filling stage after adding CMJ-As01 microbial inoculant to the rice rhizosphere; a represents soil acid phosphatase activity, b represents soil dehydrogenase activity, and c represents soil urease activity.
[0027] Figure 7 The present invention contains Bacillus cereus. Bacillus cereus The changes in soil microbial community and key gene abundance during the grain-filling period after adding CMJ-As01 microbial agent to the rice rhizosphere; a represents the abundance at the rhizosphere bacterial phylum level, b represents the abundance at the rhizosphere bacterial genus level, and c represents the abundance of key genes. Detailed Implementation
[0028] The following specific embodiments are intended to further illustrate the content of the present invention, rather than to limit the scope of protection of the claims of the present invention.
[0029] Example 1
[0030] strains Bacillus cereusIsolation and Screening of CMJ-As01: This strain was obtained from soil samples collected from a heavy metal-contaminated mining area in Loudi City, Hunan Province, after isolation, screening, and purification. The specific method is as follows: Weigh 5.0 g of the soil sample, add 100 mL of sterile water, and place in a constant temperature shaker at 180 rpm and 25°C for 24 h. After standing for 30 min, take 5 mL of the supernatant and add it to liquid LB medium with an arsenic concentration of 100 mg / L. Place in a constant temperature shaker at 180 rpm and 25°C for 24 h. Then, take 5 mL of the liquid and add it to liquid LB medium with an arsenic concentration of 200 mg / L. Place in a constant temperature shaker at 180 rpm and 25°C for 24 h. Dilute 5 mL of the liquid with 10... 4 200 μL of the diluted culture solution was spread onto LB agar plates and incubated for 24 hours. Colony morphology was then observed, and single colonies were streaked onto fresh LB agar plates for further culture to obtain a pure strain, named [strain name missing]. Bacillus cereus CMJ-As01. Finally, Bacillus cereus The CMJ-As01 strain was streaked onto slant tubes and incubated at 37°C for 24 hours, then stored at 4°C. The LB solid medium formulation in Example 1 was: 10g peptone, 10g NaCl, 5g yeast extract, 20g agar powder, 1000mL ultrapure water, pH=7. The solid LB medium was sterilized at 121°C and 1 atm for 20 minutes before use. The LB liquid medium formulation was: 10g peptone, 10g NaCl, 5g yeast extract, 1000mL ultrapure water, pH=7. The liquid LB medium was sterilized at 121°C and 1 atm for 20 minutes before use.
[0031] strains Bacillus cereus The colony morphology of CMJ-As01 is as follows: After culturing on LB solid medium for 24 hours, white colonies form with a moist, smooth, and opaque surface. After Gram staining, they appear purple under a microscope. Figure 1 ), which belongs to Gram-positive bacteria.
[0032]
[0033] The 16S rDNA partial sequence of this strain was compared with the 16S rDNA sequences of related bacteria in NCBI Genbank using BLAST, and homology analysis was performed. The results showed that this strain had the highest homology with *Bacillus cereus*, with a similarity of over 99%. Based on morphological and cultural characteristics, physiological and biochemical experiments, and 16S rDNA sequence analysis, this strain was identified as *Bacillus cereus*. The 16S rDNA partial sequence of this strain was submitted to NCBI Genbank and obtained accession number PX671495.
[0034] The 16S rDNA phylogenetic tree of this bacterium, constructed using MEGA11.0 software, is as follows: Figure 2 As shown.
[0035] Example 2
[0036] Inoculation with Bacillus cereus Bacillus cereus Changes in arsenic content in different parts of rice treated with CMJ-As01.
[0037] 200 mL (OD) 600 =1.0) Containing Bacillus cereus Bacillus cereus CMJ-As01 microbial inoculant and 200mL of Bacillus cereus-free solution Bacillus cereus The CMJ-As01 culture medium was added to the rhizosphere of potted rice plants during the tillering stage (diameter: 20cm, height: 31cm). This process was repeated during the grain-filling stage. In Example 2, the culture medium formulation was: (NH4)2SO4, 3000mg / L; KCl, 100mg / L; K2HPO4, 500mg / L; MgSO4·7H2O, 500mg / L; Ca(NO3)2, 100mg / L; glucose 700mg / L; yeast 300mg / L. Arsenic content in various tissues of rice at the tillering, heading, grain-filling, and maturity stages was determined using ICP-MS. Figure 3 As shown.
[0038] The soil used in the experiment was collected from the field, with a pH of approximately 5.1. The arsenic concentration ranged from 60.4576 to 66.1476 mg / kg, exceeding the limit of 30 mg / kg (pH≤5.5) stipulated in the "Soil Environmental Quality - Agricultural Land Soil Pollution Risk Control Standard (Trial)" (GB15618-2018). Figure 3 From (e, f), it can be seen that the bacteria were not inoculated with Bacillus cereus. Bacillus cereusThe total arsenic and inorganic arsenic content in brown rice of the CK group of CMJ-As01 were 0.51 mg / kg and 0.42 mg / kg, respectively, both exceeding the limit of 0.35 mg / kg in the National Food Safety Standard for Limits of Contaminants in Food (GB 2762-2022). (The text also mentions inoculation with Bacillus cereus.) Bacillus cereus After inoculation with CMJ-As01, the total arsenic and inorganic arsenic contents in brown rice were 0.28 mg / kg and 0.19 mg / kg, respectively, significantly reducing the total arsenic and inorganic arsenic contents by 45.1% and 55.2%, respectively. The inorganic arsenic content was far below 0.35 mg / kg. (Inoculation with Bacillus cereus...) Bacillus cereus CMJ-As01 significantly increased the arsenic content in rice roots at all stages. Figure 3 (a) significantly increased the arsenic content in rice stems ( Figure 3 (b) significantly reduced the arsenic content in rice leaves during the tillering and grain-filling stages. Figure 3 (c) The arsenic content in rice panicles also decreased slightly. Figure 3 (d).
[0039] Example 3
[0040] Inoculation with Bacillus cereus Bacillus cereus Changes in arsenic and iron in the iron film on the root surface of rice by CMJ-As01.
[0041] 200 mL (OD) 600 =1.0) Containing Bacillus cereus Bacillus cereus CMJ-As01 microbial inoculant and 200mL of Bacillus cereus-free solution Bacillus cereus The CMJ-As01 culture medium was added to the rhizosphere of potted rice plants during the tillering stage (pot size: 20cm diameter, 31cm height). This process was repeated during the grain-filling stage. Samples inoculated with Bacillus cereus were collected. Bacillus cereus Iron films were extracted from the roots of CMJ-As01 and control rice at the tillering, heading, grain-filling, and maturity stages using DCB extract. The extract contained 0.06 mol / L Na₂S₂O₄, 0.03 mol / L Na₃C₆H₅O₇·2H₂O, and 0.125 mol / L NaHCO₃. The arsenic and iron contents were determined by ICP-MS.
[0042] Inoculation with Bacillus cereus Bacillus cereus CMJ-As01 significantly increased the arsenic content in the root surface iron film. Figure 4 (a) This increased the iron content in the root surface iron film at various stages, with a significant increase in iron content in the root surface iron film during the mature stage. Figure 4 (b)
[0043] Example 4
[0044] Inoculation with Bacillus cereus Bacillus cereus Changes in arsenic content in subcellular roots of rice seedlings by CMJ-As01.
[0045] 5 mL (OD) 600 =1.0) Containing Bacillus cereus Bacillus cereus CMJ-As01 microbial inoculant and 5mL of Bacillus cereus-free solution Bacillus cereus CMJ-As01 medium was added to the rhizosphere of rice (Zhongzao 35) seedlings cultured in 1L of stress nutrient solution containing 1 mg / L trivalent arsenic. After 15 days, 1g of fresh roots were sampled, ground in liquid nitrogen, and homogenized with a pre-extraction solution containing 1 mmol / L C4H. 10 O2S4, 50 mmol / L NH2C(CH2OH)3·HCl, and 250 mmol / L sucrose. The homogenate was centrifuged at 3000 rpm for 10 min, and the resulting particles contained the cell wall. The supernatant was continuously centrifuged at 10000 rpm for 45 min, and the resulting supernatant was the soluble fraction, while the remaining fraction contained organelles. The culture medium formulation in Example 4 was as follows: (NH4)2SO4, 3000 mg / L; KCl, 100 mg / L; K2HPO4, 500 mg / L; MgSO4·7H2O, 500 mg / L; Ca(NO3)2, 100 mg / L; glucose 700 mg / L; yeast 300 mg / L. The arsenic content in each fraction was determined by ICP-MS.
[0046] Depend on Figure 5 It can be seen that inoculation with Bacillus cereus Bacillus cereus CMJ-As01 significantly increased the arsenic content in the cell wall. Figure 5 (a) significantly reduced arsenic content in organelles ( Figure 5 (b) significantly reduced the content of soluble arsenic ( Figure 5 (c)
[0047] Example 5
[0048] Inoculation with Bacillus cereus Bacillus cereus Changes in key soil enzymes in the rhizosphere soil during the grain-filling stage of rice by CMJ-As01.
[0049] 200 mL (OD) 600 =1.0) Containing Bacillus cereus Bacillus cereus CMJ-As01 microbial inoculant and 200mL of Bacillus cereus-free solution Bacillus cereus The CMJ-As01 culture medium was added to the rhizosphere of potted rice plants during the tillering stage (pot size: 20cm diameter, 31cm height). This process was repeated during the grain-filling stage. Samples inoculated with Bacillus cereus were collected separately.Bacillus cereus Fresh, naturally air-dried soil samples (passed through a 50-mesh sieve) from the CMJ-As01 and control groups during the grouting period were used to determine the activities of key soil enzymes using a kit. Changes in the activities of these key soil enzymes are shown below. Figure 6 As shown.
[0050] Depend on Figure 6 It can be seen that inoculation with Bacillus cereus Bacillus cereus CMJ-As01 significantly enhanced the activity of key soil enzymes in the rhizosphere soil of rice during the grain-filling stage, including soil acid phosphatase (SAP). Figure 6 a) Soil dehydrogenase ( Figure 6 (b) and soil urease ( Figure 6 (c)
[0051] Example 6
[0052] Inoculation with Bacillus cereus Bacillus cereus Changes in the rhizosphere soil microbial community of rice by CMJ-As01.
[0053] 200 mL (OD) 600 =1.0) Containing Bacillus cereus Bacillus cereus CMJ-As01 microbial inoculant and 200mL of Bacillus cereus-free solution Bacillus cereus The CMJ-As01 culture medium was added to the rhizosphere of potted rice plants during the tillering stage (pot size: 20cm diameter, 31cm height). This process was repeated during the grain-filling stage. Samples inoculated with Bacillus cereus were collected. Bacillus cereus Rhizosphere soil samples from rice at the grain-filling stage of CMJ-As01 and the control group were sent to Wuhan Boyuan Biotechnology Co., Ltd. for soil metagenomic sequencing. The results are as follows: Figure 7 As shown.
[0054] Depend on Figure 7 It can be seen that inoculation with Bacillus cereus Bacillus cereus Following CMJ-As01, at the phylum level, the abundance of *Lynobacteria*, which inhibits root surface iron film formation in rhizosphere soil decreased by 64.4%, and the abundance of *Lynobacteria* decreased by 43.6%. Figure 7 (a). At the genus level, the abundance of *Geotrichum*, which inhibits root surface iron film formation, decreased by 31.4% and the abundance of *Geotrichum*, which inhibits root surface iron film formation, decreased by 41.2% in rhizosphere soil. Figure 7 (a). Proteins encoded by each gene ( Figure 7c): ccoP: cbb3 type cytochrome c oxidase subunit III; afuC: ATP-binding protein of the trivalent iron transport system; COX15: cytochrome c oxidase assembly protein subunit 15; coxA: cytochrome c oxidase subunit I; coxB: cytochrome c oxidase subunit II; coxC: cytochrome c oxidase subunit III; mcrA: methyl-CoM reductase α subunit. The transcripts of related functional genes (such as mcrA, coxA, etc.) showed a significant increase in transcripts per million sequenced bases (TPM) (P < 0.05), particularly after inoculation with Bacillus cereus. Bacillus cereus After inoculation with CMJ-As01, the expression levels of coxA and ccoP genes increased to 1.12 and 1.15 times that of the control group, respectively. These genes can promote the transport and accumulation of iron in rice root tissues, thereby contributing to the formation of iron film on the rice root surface. Simultaneously, inoculation with this Bacillus cereus strain... Bacillus cereus After CMJ-As01, the expression level of the mcrA gene increased to 1.15 times that of the control group. This gene can regulate the redox state of the rhizosphere microdomain and the methylation process of arsenic, thereby indirectly affecting the absorption and translocation efficiency of arsenic in rice.
Claims
1. A type of Bacillus cereus Bacillus cereus CMJ-As01, accession number CCTCC NO: M 20251941.
2. A microbial inoculant, characterized in that: Contains the Bacillus cereus of claim 1 Bacillus cereus CMJ-As01.
3. The microbial inoculant according to claim 2, characterized in that: Includes culture medium.
4. The microbial inoculant according to claim 3, characterized in that: The culture medium contains the following components: (NH4)2SO4, KCl, K2HPO4, MgSO4·7H2O, Ca(NO3)2, glucose and yeast.
5. The microbial inoculant according to claim 4, characterized in that: The composition and concentration of each component of the culture medium are as follows: (NH4)2SO4, 3000-3100 mg / L; KCl, 100-110 mg / L; K2HPO4, 500-510 mg / L; MgSO4·7H2O, 500-510 mg / L; Ca(NO3)2, 100-110 mg / L; glucose 700-710 mg / L; yeast 300-310 mg / L.
6. A microbial inoculant according to claim 2, characterized in that: The Bacillus cereus Bacillus cereus The mass percentage content of CMJ-As01 in the microbial inoculant is 0.5% to 5%.
7. The application of a microbial agent according to any one of claims 2 to 6, characterized in that: When rice is grown in arsenic-contaminated soil, microbial agents are inoculated into the rhizosphere of rice during the tillering and / or grain-filling stages to reduce the total and inorganic arsenic content in brown rice and to achieve microbial remediation of the arsenic-contaminated soil-rice system.