CN111925956A

CN111925956A - Geobacillus altivelis with functions of producing alkali and passivating heavy metal cadmium and application thereof

Info

Publication number: CN111925956A
Application number: CN202010637833.4A
Authority: CN
Inventors: 赵方杰; 张隽; 柴成薇; 王鑫
Original assignee: Nanjing Agricultural University
Current assignee: Nanjing Agricultural University
Priority date: 2020-07-06
Filing date: 2020-07-06
Publication date: 2020-11-13
Anticipated expiration: 2040-07-06
Also published as: CN111925956B

Abstract

The invention discloses a Bacillus altitudinis with the functions of producing alkali and passivating heavy metal cadmium and application thereof, the strain is classified and named as Bacillus altitudinis XT-4, and is delivered to China Center for Type Culture Collection (CCTCC) for preservation in 2019, 5 and 20 months, and the preservation number is CCTCC NO: m2019370. The invention separates and screens the alkali-producing strain which can efficiently prevent and control the cadmium in the environment, and repairs the cadmium pollution in the environment through the application of microorganisms.

Description

Geobacillus altivelis with functions of producing alkali and passivating heavy metal cadmium and application thereof

Technical Field

The invention belongs to the technical field of biology or soil heavy metal bioremediation, and particularly relates to bacillus altitudinis with functions of producing alkali and passivating heavy metal cadmium and application thereof.

Background

Cadmium (Cd) is a heavy metal element with extremely strong biological toxicity, has strong chemical activity, large mobility and lasting toxicity in the environment, and Cd²⁺Widely exists in soil and water body, and can enter human body along with food chain, and a large amount of cadmium is accumulated in the body and has teratogenic, carcinogenic and mutagenic effects. Researches show that the pH value can influence the form of heavy metal cadmium in the paddy soil. Generally, the pH value of the soil is reduced, so that a large amount of heavy metal cadmium is activated, the cadmium is absorbed by crops, the absorption amount of the cadmium by the soil is enhanced by increasing the pH value, the precipitation effect is generated, the exchangeable state is reduced, but the dissolution of carbonate is promoted by increasing the pH value, and the cadmium is activated again. Therefore, reasonable regulation and control of the pH value of the soil has great significance for reducing the biological effectiveness of heavy metal cadmium, and according to a great deal of research and investigation, the pH value of the soil is averagely reduced by 1.2-1.5 units in nearly 30 years because of unreasonable use of a large amount of nitrogenous fertilizers and phosphate fertilizers. Acidification of the field is a significant cause of the increased bioavailability of cadmium in the soil. The method for repairing the cadmium-polluted soil comprises physical repair, chemical repair and biological repair: chemical methods such as precipitation and cementation. Physical methods such as ion exchange, solvent extraction, membrane filtration and activated carbon adsorption. The biological cadmium removing method mainly comprises two methods of adsorption and precipitation. The biological adsorption is extracellular polysaccharide secreted by cells or biological macromolecular substances such as chelated Cd of oxalic acid, malic acid and the like²⁺. The biological precipitation is that Cd in a state that organisms can make free²⁺Formation of CdS or Cd (OH)₂The precipitate is removed. Compared with physical and chemical methods, the biological removal method has the advantages of low price, environmental friendliness and the like, and is paid attention to by people. Researches show that the biological repair can effectively reduce the biological effectiveness of heavy metal cadmium, reduce the absorption of crops and ensure the safety of agricultural products.

The bacillus exists widely in nature and has the characteristics of rapid propagation, rapid metabolism, strong environmental adaptability, strong stress tolerance and the like. The bacillus can survive and grow in the environment polluted by heavy metal, on one hand, the bacillus can adsorb the heavy metal cadmium in soil particles, and on the other hand, the bacillus can influence some physicochemical properties of the soil, such as pH, organic matters and the like, so that the biological effectiveness of the heavy metal cadmium in the soil is reduced, and the toxic action of the heavy metal cadmium on plants is reduced. Therefore, the screened bacillus capable of producing alkali is applied to acid soil to finely adjust the pH value of the rhizosphere of crops in the acid soil, thereby reducing the biological effectiveness of the cadmium in the rhizosphere of the plants.

The research screens out microbes which have strong cadmium resistance and can produce alkali under different fermentation conditions from the cadmium-polluted soil, so as to finely adjust the pH value of the rhizosphere of crops in acid soil, reduce the bioavailability of heavy metal cadmium and achieve the aim of improving the yield and quality of vegetables and crops. Safe vegetables can be produced on the soil polluted by mild and moderate heavy metal cadmium, and theoretical support is provided for the development of the soil heavy metal polluted microorganism remediation technology.

The invention content is as follows:

aiming at the defects of the prior art, the invention aims to separate and screen an alkali-producing strain capable of efficiently preventing and controlling cadmium in the environment, and repair the cadmium pollution in the environment by applying the strain.

The purpose of the invention can be realized by the following technical scheme:

a strain of Bacillus altitudinis with functions of producing alkali and passivating heavy metal cadmium is classified and named as Bacillus altitudinis XT-4, and is delivered to China Center for Type Culture Collection (CCTCC) for preservation in 2019, 5 months and 20 days, wherein the preservation number is CCTCC NO: m2019370; and (4) storage address: wuhan university in Wuhan City, China. The applicant separates and screens 1 strain of microorganism strain capable of efficiently removing cadmium (Cd), and classifies and names the strain according to classical microbiological morphological characteristic classification and bioinformatics classification.

The application of the bacillus altitudinis strain in passivating soil heavy metal cadmium.

The application of the bacillus altitudinis strain in preparing microbial organic fertilizer.

A microbial organic fertilizer comprises the bacillus altitudinis strain with the functions of producing alkali and passivating heavy metal cadmium.

As a preferred technical scheme, the content of the geobacillus strain with the functions of producing alkali and passivating heavy metal cadmium in the microbial organic fertilizer is not less than 1.0 multiplied by 10²CFU/g。

The invention has the beneficial effects that:

the invention provides a strain with alkali production capacity, high growth speed, strong environmental adaptability and strong stress tolerance; the strain improves the micro-ecology of the rhizosphere of crops and decomposes and degrades soil organic matters into small molecules for crops to use, thereby remarkably improving the yield and quality of vegetables and crops; the strain has obvious effect on preparing the microbial organic fertilizer with the function of producing alkali by fermentation. The invention separates and screens the alkali-producing strain which can efficiently remove cadmium in the environment, and repairs the cadmium pollution in the environment through the application of microorganisms.

Drawings

FIG. 1: the phylogenetic dendrogram of the Bacillus altitudinis XT-4 of the invention.

FIG. 2: the invention relates to a research on the alkali-producing characteristics of Geobacillus altivelis XT-4 under different pH conditions.

FIG. 3: the invention discloses a curve chart of cadmium removal and pH change of a culture medium under different pH conditions of Geobacillus altivelis XT-4. Description of reference numerals: graph a, C in fig. 3 shows the pH change and cadmium removal curve of XT-4 at an initial Cd concentration of 10 μ M and pH 5; fig. 3, panel B, panel D, is a graph of pH change and cadmium removal for XT-4 at an initial Cd concentration of 10 μ M and pH 5.5.

FIG. 4: graph of the change in soil pH in a potting test of Bacillus altitudinis XT-4 of the present invention. Description of reference numerals: in soil (chemical fertilizer + no-inoculation, chemical fertilizer + 10)²cfu/g dw, fertilizer +10⁴cfu/g dw, organic fertilizer + no-inoculation, organic fertilizer +10²cfu/g dw, organic fertilizer +10⁴cfu/g dw) test group.

FIG. 5: bar graph of the effective cadmium change of Bacillus altitudinis XT-4 of the invention in the potting test. Description of reference numerals: in soil (chemical fertilizer + no-inoculation, chemical fertilizer + 10)²cfu/g dw, fertilizer +10⁴cfu/g dw, organic fertilizer + no-inoculation, organic fertilizer +10²cfu/g dw, organic fertilizer +10⁴cfu/g dw) test group.

FIG. 6: bar graph of the change of total cadmium in the overground part of vegetables in the potting test by the Bacillus altitudinis XT-4 of the invention. Description of reference numerals: in soil (chemical fertilizer + no-inoculation, chemical fertilizer + 10)²cfu/g dw, fertilizer +10⁴cfu/g dw, organic fertilizer + no-inoculation, organic fertilizer +10²cfu/g dw, organic fertilizer +10⁴cfu/g dw) bar graph of total cadmium change in aerial parts of vegetables in the test group.

The specific implementation mode is as follows:

example 1: separation and identification of Bacillus altitudinis XT-4

(1) Collecting samples: the soil collection and separation place is farmland surface soil polluted by cadmium in Hunan Tan City of Hunan province.

(2) Separating and screening cadmium-resistant strains: accurately weighing 5g of Hunan pool soil into a 250mL conical flask containing 100mL of sterile water, shaking the conical flask at 30 ℃ and 200rpm for 48h to completely disperse the soil, standing for 5min, and taking 1mL of soil supernatant in a 1.5mL sterile centrifuge tube from a super clean bench. Mixing 100 μ L of the soil supernatant with 900 μ L of sterile water thoroughly to obtain 10^-1Dilution in the same way gave 10^-2、10^-3、10^-4、10^-5、10^-6、10^-7、10^-8A series of dilutions was used to coat the plates. Taking the dilution of 10^-5、10^-6、10^-7、10^-8The diluted solution (100. mu.L) was applied to a plate of LB medium containing 0.15mM Cd, and the plate was placed upside down in an incubator at 30 ℃ for 5 days. Observe colony morphology, colour, wet degree, glossiness etc. pick different colonies in LB liquid test tube, the test tube is put in shaking table shake culture, again with the fungus liquid flat plate rule purify, obtain the single colony. Preparing a common LB liquid culture medium according to the following formula (1L): 10g of tryptone, 5g of yeast extract and 10g of sodium chloride, and distilled water is supplemented to 1L. Sterilizing at 121 deg.C under high pressure steam for 20 min.

(3) Screening of the alkali-producing strain: transferring the cadmium-resistant bacteria obtained in the step (2) into an M9 culture medium to regulate pH to 5.0, 5.5 and 7.0, placing the prepared culture medium in a shaking table at 28 ℃, carrying out shake culture, taking samples every 12 hours, measuring the pH change of the solution, and screening the strains capable of efficiently producing the alkali. The results of the research on the alkali-producing characteristics of the screened Geobacillus altitudinis XT-4 under different pH conditions are shown in figure 2. M9 medium: 1.5g Na₂HPO_4·12H₂O,1.5g KH₂PO₄,1.0g(NH₄)₂SO₄,0.2g MgSO_4·7H₂O,0.01g CaCl_2·2H₂O,0.001g FeSO_4·7H₂O, and pH 7.2, 1000ml of water.

(4) And (3) classifying and identifying the alkali-producing strains: genotyping was performed by amplifying a partial nucleotide sequence of 16S rRNA. PCR was performed using prokaryotic 16S rRNA universal primers 27F (5 '-AGAGTTTGATCMTGGCTCAG-3') and 1492R (5 '-GGYTACCTTGTTACGACTT-3'). The 16S rRNA of the bacillus XT-4 is amplified and sequenced (shown as SEQ ID No. 1), and then compared with an NCBIGenBank nucleotide database, the homology of the nucleotide sequence of the separated bacillus XT-4 and the geobacillus is 98.96 percent. The MEGA6.0 software is adopted to construct a phylogenetic tree, and the separated Bacillus XT-4 can be stably gathered with a strain of Bacillus (see figure 1), and the strain is identified as Bacillus altitudinis XT-4.

(5) The morphology and physiological and biochemical characteristics of the strain XT-4 are as follows: the highland bacillus is a gram-positive bacterium, and the cell is rod-shaped and can produce spores; the growth speed on an LB agar plate is high, bacterial colonies are nearly round and yellow, the edges are irregular, the degree of lackluster is not high, the bacterial colonies are not transparent, and the bacterial strains are fermented on an LB liquid culture medium to produce alkali, so that the pH value of fermentation liquor is increased to be more than pH 8.5; can grow by taking sodium malate, glucose, sodium pyruvate, yeast extract, sodium citrate and sodium succinate as the only carbon source; the pH growth range is wide, and the pH can be resisted at 4.0-10.0.

(6) Deposit of Bacillus altidinis XT-4: bacillus altidinis XT-4 can be cultured on LB liquid or solid culture medium at 37 ℃, and can be preserved for a short time at 4 ℃. If the strain is preserved for a long time, a method of preserving the strain using a glycerol freezing tube or a freeze-drying tube is suitable. The strain is delivered to China Center for Type Culture Collection (CCTCC) for preservation in 2019, 5 months and 20 days, and the preservation number is CCTCC NO: m2019370; the preservation address is Wuhan university in Wuhan City, China.

Example 2: pH change and cadmium removal curve of Bacillus altitidins XT-4

Selecting a single clone of the strain XT-4, inoculating the single clone into 100mL LB liquid medium, and performing shaking culture in a shaker at 30 ℃ until the strain OD is reached_600nmAbout 0.5, this was used as a seed solution, inoculated in a 1% (volume) inoculum size in fresh 100mL M9 liquid medium (starting OD 600. apprxeq.0.01), adjusted to pH 5.0, 5.5 and 7.0, and 10. mu.M CdCl was added to the medium₂. And (3) placing the prepared culture medium in a shaking table at 30 ℃ for shake culture, sampling every 12 hours, measuring the pH change of the solution, and simultaneously measuring the content of the residual Cd in the solution. The concentration of cadmium in the solution can be measured using a hydrogen flame Atomic Absorption Spectrometer (AAS). As shown in fig. 3: under the conditions of the initial pH of the medium at 5.0 and 5.5, the results both show that the concentration of Cd ions in the supernatant of the medium is dependent on the OD of the strain XT-4 in the medium₆₀₀The increase and decrease of the content of Cd ions in the culture medium are realized, the pH increase of the culture medium is gradually increased, the number of OH-ions in the culture medium is increased, and when the strain grows into a stationary phase, the number of bacteria is in a balanced state, and the concentration of Cd ions in the culture medium is stable. After 36 hours, the removal rate of cadmium is 95.99 percent and 96.50 percent respectively.

Example 3: chinese cabbage potting experiment

The pot culture test soil is taken from vegetable soil polluted by Hunan Tan cadmium, the vegetable soil is naturally dried in the air and then passes through a 2mm screen, and each pot (specification: caliber 9cm, height 7cm) is separately filled with 0.5kg of soil sample. The test was divided into 4 treatment groups (i.e., treatment group 1: adding organic fertilizer to the soil and adding the final concentration of 1X 10²CFU/g of combined bacterial liquid; treatment group 2: adding 2 percent (mass) of organic fertilizer into the soil, and adding the organic fertilizer with the final concentration of 1 multiplied by 10⁴CFU/g of combined bacterial liquid; treatment group 3: adding fertilizer with the content equivalent to that of the organic fertilizer N, P, K into the soil, and adding the fertilizer with the final concentration of 1 multiplied by 10²CFU/g bacterial liquid; treatment group 4: adding fertilizer into soil to a final concentration of 1 × 10⁴CFU/g bacterial liquid; each set was set to 4 replicates. The vegetable variety for the test is pakchoi"shanghai qing" (Brassica rapa ssp. chinensis, cv. Shanghaiqiing), a pakchoi with a seedling height of 7-10cm and good growth vigor after two weeks of sowing is taken for transplanting, and four treatment groups are all transplanted, and 1 plant is transplanted in each pot. After 4 weeks of planting, the plants and the rhizosphere soil (soil with root systems within 5 mm) are harvested, and the pH of the rhizosphere soil, the effective state Cd content of the rhizosphere soil, the dry weight of the plants, the fresh weight of the plants and the Cd content of the overground part are measured.

After the plants were grown for 5 weeks under potted planting conditions, the difference Δ pH between the pH in the rhizosphere soil at harvest and the pH in the soil at sowing was as shown in fig. 4, and the pH in the soil with added fertilizer and the soil with added organic fertilizer under the condition without inoculation was 5.18 and 5.31, respectively. In the test group to which the fertilizer was added, 1 x 10 was added as compared with the control group²In the test group of cfu/g dw, the pH increased from 5.18 to 5.43 by 2.9%. Adding 1 x 10⁴In the test group of cfu/g dw, the pH increased from 5.18 to 5.52 by 4.5%. In the test group inoculated with the organic fertilizer, 1 x 10 is added compared with the control group²In the test group of cfu/g dw, the pH increased from 5.31 to 5.56 by 5.3%. Adding 1 x 10⁴In the test group of cfu/g dw, the pH increased from 5.31 to 5.64 by 6.8%. The result shows that the pH value in the soil can be increased by adding the bacterial strain XT-4+ organic fertilizer.

Example 4: histogram of change in available cadmium in potting test

And extracting the effective cadmium in the soil by a calcium chloride extraction method. The method comprises the following specific steps: weigh approximately 1.5g of the slurry on an analytical balance into a 50ml centrifuge tube and add 25ml of 0.1M CaCl₂Leaching the centrifugal tube in a shaking table at 25 ℃ and 200rpm for 24h, centrifuging at 3000rpm/min for 5min, filtering the supernatant with a 0.22 mu m filter membrane, and measuring the concentration of Cd in the supernatant by ICP-MS. And finally, measuring the content of the extracted cadmium by adopting an air-acetylene flame atomic absorption spectrometry.

After the plants grow for 5 weeks under the potted planting condition, the pH value of the rhizosphere soil and the effective cadmium content of the soil during sowing are shown in figure 5, and the effective cadmium content of the soil added with the fertilizer and the soil added with the organic fertilizer is 0.57 mg/kg and 0.52mg/kg respectively under the condition of no inoculation. In the test group to which the fertilizer was added,compared with the control group, 1 × 10 is added²In the test group of cfu/g dw, the content of the effective cadmium is reduced from 0.57 to 0.55, and is reduced by 3.8 percent. Adding 1 x 10⁴In the test group of cfu/g dw, the content of the cadmium in the effective state is reduced from 0.57 to 0.51, and is reduced by 12 percent. In the test group inoculated with the organic fertilizer, 1 x 10 is added compared with the control group²In the test group of cfu/g dw, the content of the cadmium in the effective state is reduced from 0.52 to 0.51, and is reduced by 1.0 percent. Adding 1 x 10⁴In a test group of cfu/g dw, the content of the effective cadmium is reduced from 0.52 to 0.45, and is reduced by 10.8 percent. The result shows that the effective cadmium concentration in the soil can be reduced by adding the bacterial strain XT-4+ organic fertilizer, so that the cadmium passivation effect is achieved.

Example 5: histogram of total cadmium content changes in pakchoi in potting experiments

Taking a mature pakchoi sample at the 30 th day of the potting test, removing the pakchoi from the flowerpot, repeatedly washing the surface of the plant with deionized water, and washing away the attached soil. The fresh weight of the whole plant, the fresh weight of the root and the overground part of the plant were measured, respectively. The determination of the cadmium content in the pakchoi refers to a determination method recommended by national standard of people's republic of China (No. G B5009.15-2014) determination of cadmium in food.

As shown in FIG. 6, 1 x 10 of fertilizer is added to the soil to which the fertilizer is added²cfu/g dw and 1 x 10⁴compared with the non-inoculated control, the cadmium content of the edible part of the overground part of the cfu/g dw-processed Chinese cabbage is respectively reduced to 5.08mg/kg and 4.79mg/kg from 8.07mg/kg, and is reduced by 37 percent and 41 percent. Adding 1 x 10 into soil added with organic fertilizer²cfu/g dw and 1 x 10⁴compared with the non-inoculated control, the cadmium content of the edible part of the overground part of the cfu/g dw-processed pakchoi is respectively reduced to 4.43mg/kg and 3.65mg/kg from 6.15mg/kg, and is reduced by 28 percent and 41 percent.

>MK371783.1Bacillus altitudinis XT-4 16S ribosomal RNAgene

TTCATCGGGCTATAATGCAGTCGAGCGGACAGAAGGGAGCTTGCTCCCGGATGTTAGCGGCGGACGGGTGAGTAACACGTGGGTAACCTGCCTGTAAGACTGGGATAACTCCGGGAAACCGGAGCTAATACCGGATAGTTCCTTGAACCGCATGGTTCAAGGATGAAAGACGGTTTCGGCTGTCACTTACAGATGGACCCGCGGCGCATTAGCTAGTTGGTGAGGTAACGGCTCACCAAGGCGACGATGCGTAGCCGACCTGAGAGGGTGATCGGCCACACTGGGACTGAGACACGGCCCAGACTCCTACGGGAGGCAGCAGTAGGGAATCTTCCGCAATGGACGAAAGTCTGACGGAGCAACGCCGCGTGAGTGATGAAGGTTTTCGGATCGTAAAGCTCTGTTGTTAGGGAAGAACAAGTGCAAGAGTAACTGCTTGCACCTTGACGGTACCTAACCAGAAAGCCACGGCTAACTACGTGCCAGCAGCCGCGGTAATACGTAGGTGGCAAGCGTTGTCCGGAATTATTGGGCGTAAAGGGCTCGCAGGCGGTTTCTTAAGTCTGATGTGAAAGCCCCCGGCTCAACCGGGGAGGGTCATTGGAAACTGGGAAACTTGAGTGCAGAAGAGGAGAGTGGAATTCCACGTGTAGCGGTGAAATGCGTAGAGATGTGGAGGAACACCAGTGGCGAAGGCGACTCTCTGGTCTGTAACTGACGCTGAGGAGCGAAAGCGTGGGGAGCGAACAGGATTAGATACCCTGGTAGTCCACGCCGTAAACGATGAGTGCTAAGTGTTAGGGGGTTTCCGCCCCTTAGTGCTGCAGCTAACGCATTAAGCACTCCGCCTGGGGAGTACGGTCGCAAGACTGAAACTCAAAGGAATTGACGGGGGCCCGCACAAGCGGTGGAGCATGTGGTTTAATTCGAAGCAACGCGAAGAACCTTACCAGGTCTTGACATCCTCTGACAACCCTAGAGATAGGGCTTTCCCTTCGGGGACAGAGTGACAGGTGGTGCATGGTTGTCGTCAGCTCGTGTCGTGAGATGTTGGGTTAAGTCCCGCAACGAGCGCAACCCTTGATCTTAGTTGCCAGCATTCAGTTGGGCACTCTAAGGTGACTGCCGGTGACAAACCGGAGGAAGGTGGGGATGACGTCAAATCATCATGCCCCTTATGACCTGGGCTACACACGTGCTACAATGGACAGAACAAAGGGCTGCGAGACCGCAAGGTTTAGCCAATCCCACAAATCTGTTCTCAGTTCGGATCGCAGTCTGCAACTCGACTGCGTGAAGCTGGAATCGCTAGTAATCGCGGATCAGCATGCCGCGGTGAATACGTTCCCGGGCCTTGTACACACCGCCCGTCACACCACGAGAGTTTGCAACACCCGAAGTCGGTGAGGTAACCTTTATGGAGCCAGCCGCCGAAGTGCGAGTA

Sequence listing

<110> Nanjing university of agriculture

<120> Bacillus altitudinis with functions of producing alkali and passivating heavy metal cadmium and application thereof

<160> 1

<170> SIPOSequenceListing 1.0

<210> 1

<211> 1444

<212> DNA

<213> Bacillus altitudinis XT-4 (Bacillus altitudinis XT-4)

<400> 1

ttcatcgggc tataatgcag tcgagcggac agaagggagc ttgctcccgg atgttagcgg 60

cggacgggtg agtaacacgt gggtaacctg cctgtaagac tgggataact ccgggaaacc 120

ggagctaata ccggatagtt ccttgaaccg catggttcaa ggatgaaaga cggtttcggc 180

tgtcacttac agatggaccc gcggcgcatt agctagttgg tgaggtaacg gctcaccaag 240

gcgacgatgc gtagccgacc tgagagggtg atcggccaca ctgggactga gacacggccc 300

agactcctac gggaggcagc agtagggaat cttccgcaat ggacgaaagt ctgacggagc 360

aacgccgcgt gagtgatgaa ggttttcgga tcgtaaagct ctgttgttag ggaagaacaa 420

gtgcaagagt aactgcttgc accttgacgg tacctaacca gaaagccacg gctaactacg 480

tgccagcagc cgcggtaata cgtaggtggc aagcgttgtc cggaattatt gggcgtaaag 540

ggctcgcagg cggtttctta agtctgatgt gaaagccccc ggctcaaccg gggagggtca 600

ttggaaactg ggaaacttga gtgcagaaga ggagagtgga attccacgtg tagcggtgaa 660

atgcgtagag atgtggagga acaccagtgg cgaaggcgac tctctggtct gtaactgacg 720

ctgaggagcg aaagcgtggg gagcgaacag gattagatac cctggtagtc cacgccgtaa 780

acgatgagtg ctaagtgtta gggggtttcc gccccttagt gctgcagcta acgcattaag 840

cactccgcct ggggagtacg gtcgcaagac tgaaactcaa aggaattgac gggggcccgc 900

acaagcggtg gagcatgtgg tttaattcga agcaacgcga agaaccttac caggtcttga 960

catcctctga caaccctaga gatagggctt tcccttcggg gacagagtga caggtggtgc 1020

atggttgtcg tcagctcgtg tcgtgagatg ttgggttaag tcccgcaacg agcgcaaccc 1080

ttgatcttag ttgccagcat tcagttgggc actctaaggt gactgccggt gacaaaccgg 1140

aggaaggtgg ggatgacgtc aaatcatcat gccccttatg acctgggcta cacacgtgct 1200

acaatggaca gaacaaaggg ctgcgagacc gcaaggttta gccaatccca caaatctgtt 1260

ctcagttcgg atcgcagtct gcaactcgac tgcgtgaagc tggaatcgct agtaatcgcg 1320

gatcagcatg ccgcggtgaa tacgttcccg ggccttgtac acaccgcccg tcacaccacg 1380

agagtttgca acacccgaag tcggtgaggt aacctttatg gagccagccg ccgaagtgcg 1440

agta 1444

Claims

1. A strain of Bacillus altitudinis with functions of producing alkali and passivating heavy metal cadmium is classified and named as Bacillus altitudinis XT-4, and is delivered to China Center for Type Culture Collection (CCTCC) for preservation in 2019, 5 months and 20 days, wherein the preservation number is CCTCC NO: m2019370.

2. The use of the Bacillus altitudinis strain of claim 1 for inactivating the soil heavy metal cadmium.

3. Use of the Bacillus altitudinis strain of claim 1 in the preparation of a microbial organic fertilizer.

4. A microbial organic fertilizer, characterized in that the microbial organic fertilizer comprises the Bacillus altivelis strain with the functions of producing alkali and passivating heavy metal cadmium of claim 1.

5. The microbial organic fertilizer according to claim 3, wherein the content of the Bacillus altivelis strain with functions of producing alkali and passivating heavy metal cadmium in the microbial organic fertilizer of claim 1 is not less than 1.0 x 10²CFU/g。