Bacillus megaterium, carbon sequestration microbial agent and preparation method and application of carbon sequestration microbial agent

Abstract

The invention relates to the technical field of microbial carbon sequestration, and discloses bacillus megaterium, a carbon sequestration microbial agent as well as a preparation method and application of the carbon sequestration microbial agent. The preservation number of the bacillus megaterium provided by the invention is CGMCC (China General Microbiological Culture Collection Center) No.35586. The bacillus megaterium provided by the invention is a new strain of bacillus megaterium separated from a water sample in an oil field. The bacillus megaterium can effectively immobilize carbon dioxide in the atmosphere and generate gases such as nitrogen under a high-temperature condition through a unique metabolic pathway, so that the synergistic effect of carbon sequestration and gas production is realized, and the energy recovery rate and environmental benefits of the whole biological process are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of microbial carbon fixation, and in particular to a bacillus megaterium, a carbon fixation microbial agent, and a preparation method and application thereof. BACKGROUND

[0002] At present, researchers are actively exploring various carbon dioxide emission reduction and carbon fixation technologies, among which biological carbon fixation technology has become one of the global research focuses due to its low cost, green environmental protection and other advantages.

[0003] Biological carbon fixation technology refers to the conversion of CO2 in the atmosphere into organic matter by microorganisms, plants and other organisms, or the formation of stable carbon compounds through mineralization, and has the characteristics of environmental protection, economy, sustainability and the like, and in particular, the role of carbon fixation microorganisms is more significant in extreme environments. Among them, high-temperature carbon fixation microorganisms refer to microorganisms that can survive and fix CO2 in extremely high-temperature environments, and they usually live in geothermal activity areas, volcanic craters, hot springs and other high-temperature environments, and exhibit adaptability to high temperature, low oxygen and extreme pH conditions. Research has found that certain thermophilic microorganisms can convert CO2 into organic matter through photosynthesis or chemical synthesis, and even convert it into carbonate minerals under extreme conditions. This process not only is an important part of the Earth's carbon cycle, but also helps to alleviate the greenhouse effect. However, the carbon fixation efficiency of microorganisms is greatly affected by environmental conditions such as temperature, pressure and pH, and in natural conditions, the efficiency is usually low. For example, underground carbon dioxide mineralization sequestration usually takes hundreds or even thousands of years.

[0004] Therefore, screening high-temperature carbon fixation microorganisms and conducting in-depth research on the physiological characteristics and metabolic pathways of these microorganisms has important research value and broad application prospects in addressing climate change and achieving resource recycling. SUMMARY

[0005] The purpose of the present application is to overcome the defects of the prior art that the carbon fixation microorganisms have poor carbon fixation effect under high-temperature conditions.

[0006] To achieve the above purpose, the first aspect of the present application provides a bacillus megaterium (Bacillus megaterium) with a preservation number of CGMCC No.35586. Bacillus megaterium The bacillus megaterium has the preservation number of CGMCC No.35586.

[0007] The second aspect of the present application provides a carbon fixation microbial agent, which comprises the bacillus megaterium of the first aspect.

[0008] The third aspect of the present application provides a method for preparing a carbon fixation microbial agent, which comprises: The Bacillus megaterium described in the first aspect is inoculated into a fermentation medium for fermentation culture to obtain the carbon-fixing microbial agent.

[0009] A fourth aspect of the present invention provides a carbon-fixing microbial agent prepared by the method described in the third aspect.

[0010] The fifth aspect of this invention provides the use of Bacillus megaterium as described in the first aspect, and the microbial agents as described in the second and / or fourth aspects, in carbon fixation and / or gas production.

[0011] Through the above technical solution, compared with the prior art, the Bacillus megaterium provided by the present invention is a high-temperature resistant carbon fixation and gas-producing strain. This strain can adapt to the harsh temperature of 65°C in the strata, has carbon fixation ability, and can use carbon dioxide as a single carbon source to convert carbon dioxide in the atmosphere into its own organic matter, which is of great significance for mitigating global warming. Attached Figure Description

[0012] Figure 1 The bacterial solution was diluted to 10. -6 Colony morphology diagram of plating culture; Figure 2 The bacterial solution was diluted to 10. -7 Colony morphology diagram of plating culture; Figure 3 The bacterial solution was diluted to 10. -8 Colony morphology diagram of plating culture; Figure 4 This is an electron microscope scan of Bacillus megaterium; Figure 5 This is a phylogenetic tree diagram of Bacillus megaterium; Figure 6 The chromatogram of the initial gas; Figure 7 The chromatogram of the gas in the aerobic bottle after one week of cultivation.

[0013] Biological Preservation The present invention is based on Bacillus megaterium ( Bacillus megaterium It was deposited on August 12, 2025, at the China General Microbiological Culture Collection Center (CGMCC), with accession number CGMCC No. 35586. Detailed Implementation

[0014] The endpoints of the ranges and any values disclosed herein are not limited to the precise values recited as the exact dimensions are not considered critical for the present application. Each integer value within the range is also considered to be specifically disclosed. The endpoints of the ranges and any value between the recited values should be considered to be included in the range, even though the precise value is not specifically listed. For a range of values, the endpoints of the range are included in the range, and the range includes any intervening value between the endpoints. For a range of values, the endpoints of the range are included in the range, and the range includes any intervening value between the endpoints.

[0015] As described above, the first aspect of the present application provides a bacillus megaterium, Bacillus megaterium ), characterized in that the bacillus megaterium has a preservation number of CGMCC No. 35586.

[0016] In the present application, the bacillus megaterium, Bacillus megaterium ), also known as bacillus megaterium, Priestia megaterium ).

[0017] According to a specific embodiment, the optimal culture condition of the bacillus megaterium is that the Rubisco enzyme activity reaches 920 U / L at 65℃.

[0018] According to a specific embodiment, the optimal culture temperature of the bacillus megaterium is 65℃, the optimal pH is 7.5, and the optimal culture time is 3d.

[0019] As described above, the second aspect of the present application provides a carbon fixation microbial agent, which comprises the bacillus megaterium of the first aspect.

[0020] In the present application, the dosage form of the carbon fixation microbial agent is not particularly required, and the dosage form of the carbon fixation microbial agent can include liquid, powder, granules, and immobilized bacteria.

[0021] As described above, the third aspect of the present application provides a method for preparing a carbon fixation microbial agent, which comprises: Inoculating the bacillus megaterium of the first aspect into a fermentation medium to perform fermentation culture, so as to obtain the carbon fixation microbial agent.

[0022] Preferably, the fermentation medium contains 4.8-5.2 g / L of proteose peptone, 0.05-0.15 g / L of ferric citrate, 18-22 g / L of sodium chloride, 5.8-6.2 g / L of magnesium chloride, 2.8-3.2 g / L of sodium sulfate, 0.4-0.6 g / L of calcium chloride, 0.14-0.18 g / L of sodium carbonate, 0.4-0.6 g / L of potassium bromide, 0.032-0.036 g / L of strontium chloride, 0.018-0.022 g / L of boric acid, 0.0048-0.0052 g / L of sodium silicate, 0.0018-0.0022 g / L of sodium fluoride, 0.0018-0.0022 g / L of ammonium nitrate, 0.0098-0.012 g / L of disodium hydrogen phosphate; 0.8-1 vol% of trace element solution, 0.2-0.3 vol% of vitamin solution, and the pH value of the fermentation medium is 7.3-7.7.

[0023] Further preferably, the fermentation medium contains 5.0 g / L of proteose peptone, 0.1 g / L of ferric citrate, 20.0 g / L of sodium chloride, 6.0 g / L of magnesium chloride, 3.0 g / L of sodium sulfate, 0.5 g / L of calcium chloride, 0.16 g / L of sodium carbonate, 0.5 g / L of potassium bromide, 0.034 g / L of strontium chloride, 0.02 g / L of boric acid, 0.005 g / L of sodium silicate, 0.002 g / L of sodium fluoride, 0.002 g / L of ammonium nitrate, 0.01 g / L of disodium hydrogen phosphate, 0.8 vol% of trace element solution, 0.2 vol% of vitamin solution. The inventors found that in this preferred case, the bacterial concentration can be further increased (50% more than the original) and the Rubisco enzyme content is also further increased (35.3% more) at the same culture time.

[0024] Preferably, the trace element solution contains 45-52 mg / L of ethylenediaminetetraacetic acid (EDTA), 0.8-1.2 mg / L of zinc sulfate, 0.4-0.6 mg / L of manganese chloride, 0.1-0.3 mg / L of cobalt chloride, 0.05-0.15 mg / L of nickel chloride, 0.08-0.12 mg / L of sodium molybdate.

[0025] Preferably, the vitamin solution contains 1.8-2.2 mg / L of biotin, 1.8-2.2 mg / L of folic acid, 0.08-0.12 mg / L of vitamin B12, 4-6 mg / L of thiamine.

[0026] Preferably, the fermentation culture is carried out under aerobic conditions, and the fermentation culture conditions include a temperature of 60-80 °C, a pH value of 7.3-7.7, and a time of 60-74 h.

[0027] Preferably, the Bacillus megaterium is inoculated in the form of a seed liquid, and the preparation method of the seed liquid comprises: inoculating the Bacillus megaterium into a seed culture medium for propagation to obtain the seed liquid.

[0028] Preferably, the viable cell count in the seed liquid is 1×10 6 -1×10 8 CFU / mL, and the inoculation amount of the seed liquid is 2-10% by volume.

[0029] The present application improves the carbon fixation and / or gas production performance of the Bacillus megaterium by optimizing the culture conditions such as temperature, pH value, substrate concentration and nutrient ratio.

[0030] As described above, the fourth aspect of the present application provides a carbon fixation microbial inoculant prepared by the method of the second aspect.

[0031] As described above, the fifth aspect of the present application provides the use of the Bacillus megaterium of the first aspect, the inoculant of the second aspect and / or the fourth aspect in carbon fixation and / or gas production.

[0032] According to a specific embodiment, the Bacillus megaterium can produce nitrogen.

[0033] Preferably, the carbon source for carbon fixation is an inorganic carbon source.

[0034] Preferably, the inorganic carbon source is carbon dioxide.

[0035] Preferably, the carbon fixation comprises: converting carbon dioxide into organic matter at 60-80℃.

[0036] Preferably, the number of carbon atoms in the organic matter is ≥6.

[0037] The raw materials or instruments used in the embodiments of the present application are all commercially available if no manufacturer is indicated. In the following examples, the room temperature refers to 25±2℃.

[0038] The Rubisco activity detection kit is purchased from Solabio Company, and the item number is 50T / 48S.

[0039] The standard gas (standard mixed gas) is purchased from Anxing Tai Long Company, and the volume ratio of CO2 to air is 2:8.

[0040] The ultrasonic disrupter is purchased from Ningbo Xinzhi Biological Technology Co., Ltd., and the model number is JY92-IIDN.

[0041] The ultraviolet spectrophotometer is purchased from Yisupu Instrument Manufacturing (Shanghai) Co., Ltd., and the model number is U-T6.

[0042] The formula of the base medium is as follows: 5.0 g of peptone, 0.1 g of ferric citrate, 10.0 g of sodium chloride, 3.0 g of magnesium chloride, 1.5 g of sodium sulfate, 0.5 g of calcium chloride, 0.16 g of sodium carbonate, 0.5 g of potassium bromide, 0.034 g of strontium chloride, 0.02 g of boric acid, 0.005 g of sodium silicate, 0.002 g of sodium fluoride, 0.002 g of ammonium nitrate, 0.01 g of disodium hydrogen phosphate, 8 mL of trace element solution, 2 mL of vitamin solution, and deionized water to 1000 mL, and the pH is adjusted to 7.0.

[0043] The formula of the trace element solution is as follows: 50 mg / L of EDTA, 1 mg / L of zinc sulfate, 0.5 mg / L of manganese chloride, 0.2 mg / L of cobalt chloride, 0.1 mg / L of nickel chloride, and 0.1 mg / L of sodium molybdate.

[0044] The formula of the vitamin solution is as follows: 2 mg / L of biotin, 2 mg / L of folic acid, 0.1 mg / L of vitamin B12, and 5 mg / L of thiamine.

[0045] The formula of the agar solid plate is as follows: 30 g of agar is added to 1 L of the base medium.

[0046] Example 1: Screening and domestication of carbon-fixing bacteria 5 mL of a water sample from the Shengli oilfield is inoculated into a sterile sealed culture bottle containing 100 mL of the base medium, and standard gas is introduced into the sterile sealed culture bottle. The enrichment culture is carried out at 37°C in an anaerobic incubator (standard gas is introduced) at a rotation speed of 150 rpm. Every week, 5% of the above-mentioned enrichment culture is transferred to fresh base medium for continuous enrichment culture. After one month of enrichment culture, a bacteria solution capable of fixing CO2 is obtained.

[0047] 1 mL of the bacteria solution is diluted with sterile PBS buffer by 10 times in a gradient of 10 -1 , 10 -2 , 10 -3 , 10 -4 , 10 -5 , 10 -6 , 10 -7 , 10 -8 The diluted bacteria solution is respectively inoculated on agar solid plates containing 100 mg / L of NaHCO3, and is placed in a 37°C constant temperature incubator for culture. The morphology of the colonies on the solid plates is observed. Figure 1 The bacteria solution is diluted to 10 -6 The morphology of the colonies after inoculation and culture is shown in FIG. 1. Figure 2 The bacteria solution is diluted to 10 -7The colony morphology of the coating culture, Figure 3 Dilute the bacterial solution to 10 -8 The colony morphology of the coating culture. After 5 days of culture, a single colony with good growth was selected and obtained a CO2 fixation strain by plate streaking. Electron microscopy was performed on it, and the morphological characteristics were as follows Figure 4 .

[0048] The CO2 fixation strain was named GT-1 and sent to Wuhan Baiyihuneng Biotechnology Co., Ltd. for 16S rDNA sequencing. The 16S rDNA sequencing result is shown in SEQ ID NO. 1.

[0049] SEQ ID NO. 1:

[0050] The phylogenetic tree was constructed by MEGA12 software, and the results are shown in Figure 5 Figure 5 It can be seen that the 16S rDNA sequence homology of the strain GT-1 and the model strain Priestia megaterium (MN240409.1) is 99%, combined with the morphological characteristics and physiological and biochemical characteristics of the bacterial body, and finally identified as Bacillus megaterium Priestia megaterium .

[0051] Example 2 The base medium used in Example 1 was optimized with the bacterial liquid concentration as the optimization index. Through single factor experiment, the main inorganic salt components were changed to screen the best medium formula. The changed inorganic salt components and contents in the optimized base medium are shown in Table 1, and the rest of the components are consistent with the base medium formula.

[0052] The Bacillus megaterium was inoculated in a sterile sealed culture bottle containing 100 mL of the optimized base medium (pH 7.0), and standard gas was introduced. It was placed in a 60℃ shaking bed at a speed of 150 rpm for 48h, and three parallel groups were set for each group. The OD 600 value was measured by spectrophotometer (wavelength 600 nm), and the average value of each group was calculated. The average value of the absorbance is shown in Table 1.

[0053] Table 1

[0054] As can be seen from Table 1, with the increasing concentration of sodium chloride, magnesium chloride and sodium sulfate, the number of bacteria gradually increased, and the number of bacteria reached the maximum under the conditions of 20g / L sodium chloride, 6g / L magnesium chloride and 3g / L sodium sulfate. Increasing the concentration of sodium chloride, magnesium chloride and sodium sulfate in the medium will limit the growth of bacteria. Therefore, 20g / L sodium chloride, 6g / L magnesium chloride and 3g / L sodium sulfate are the best concentrations for culturing strain GT-1.

[0055] Therefore, the optimized medium formula is as follows: Ingredients: 5.0g of proteose peptone, 0.1g of ferric citrate, 20.0g of sodium chloride, 6.0g of magnesium chloride, 3.0g of sodium sulfate, 0.5g of calcium chloride, 0.16g of sodium carbonate, 0.5g of potassium bromide, 0.034g of strontium chloride, 0.02g of boric acid, 0.005g of sodium silicate, 0.002g of sodium fluoride, 0.002g of ammonium nitrate, 0.01g of disodium hydrogen phosphate, 8mL of trace element solution, 2mL of vitamin solution, and finally deionized water to 1000mL. The pH is adjusted to 7.0. ​

[0056] Trace element solution formula: 50 mg / L of EDTA, 1 mg / L of zinc sulfate, 0.5 mg / L of manganese chloride, 0.2 mg / L of cobalt chloride, 0.1 mg / L of nickel chloride, 0.1 mg / L of sodium molybdate.

[0057] Vitamin solution formula: 2 mg / L of biotin, 2 mg / L of folic acid, 0.1 mg / L of vitamin B12, 5 mg / L of thiamine.

[0058] Example 3 (1) Screening the best culture temperature The Bacillus megaterium was aerobically cultured using the optimized medium, different culture temperatures (60°C, 65°C, 70°C, 75°C, 80°C) were set, the culture temperature was optimized by comparing the growth of the strain, and the best culture condition was confirmed. The rest of the culture conditions were the same as in Example 2, and 3 groups were set in parallel for each culture temperature. The average results of the bacterial liquid concentration are shown in Table 2.

[0059] Table 2

[0060] As can be seen from Table 2, the best culture temperature of the Bacillus megaterium is 65°C.

[0061] (2) Screening the best pH Under the best temperature condition, the Bacillus megaterium was aerobically cultured using the optimized medium, but the pH of the medium was different (pH values were 6.0, 6.5, 7.0, 7.5, 8.0), the medium pH was optimized by comparing the growth of the strain, and the best culture condition was confirmed. The rest of the culture conditions were the same as in Example 2, and 3 groups were set in parallel for each group. The average results of the bacterial liquid concentration are shown in Table 3.

[0062] Table 3

[0063] As can be seen from Table 3, the best pH of the Bacillus megaterium is 7.5.

[0064] Therefore, the best medium formula is as follows: Ingredients: 5.0 g of proteose peptone, 0.1 g of ferric citrate, 20.0 g of sodium chloride, 6.0 g of magnesium chloride, 3.0 g of sodium sulfate, 0.5 g of calcium chloride, 0.16 g of sodium carbonate, 0.5 g of potassium bromide, 0.034 g of strontium chloride, 0.02 g of boric acid, 0.005 g of sodium silicate, 0.002 g of sodium fluoride, 0.002 g of ammonium nitrate, 0.01 g of disodium hydrogen phosphate, 8 mL of trace element solution, 2 mL of vitamin solution, finally, deionized water is added to 1000 mL, and the pH is adjusted to 7.5.

[0065] Trace element solution formula: 50 mg / L of EDTA, 1 mg / L of zinc sulfate, 0.5 mg / L of manganese chloride, 0.2 mg / L of cobalt chloride, 0.1 mg / L of nickel chloride, 0.1 mg / L of sodium molybdate.

[0066] Vitamin solution formula: 2 mg / L of biotin, 2 mg / L of folic acid, 0.1 mg / L of vitamin B12, 5 mg / L of thiamine.

[0067] (3) Screening the best culture time Under the optimal temperature and pH conditions, the Bacillus megaterium was subjected to aerobic culture using the optimal culture medium, but the culture time was different (1d, 2d, 3d, 4d, 5d, 6d, 7d), and the culture time was optimized by comparing the growth of the strain, and the optimal culture conditions were confirmed. The rest of the culture conditions were the same as in Example 2, and 3 groups of parallel were set in each group. The average results of the bacterial solution concentration are shown in Table 4.

[0068] Table 4

[0069] In summary, the optimal culture temperature of the Bacillus megaterium is 65℃, the optimal pH is 7.5, and the optimal culture time is 3d.

[0070] Example 4 This example is to illustrate the carboxylation enzyme activity of 1,5-diphosphoribulose carboxylase / oxygenase in the Bacillus megaterium under the optimal culture conditions, and the carbon fixation enzyme activity is calculated by measuring the change of absorbance of reduced coenzyme I (NADH) at 340 nm.

[0071] 1,5-diphosphoribulose carboxylase / oxygenase (Rubisco, EC 4.1.1.39) carboxylase activity determination principle: under the catalysis of Rubisco, 1 molecule of ribulose-1,5-bisphosphate (RuBP) combines with 1 molecule of CO2 to produce 2 molecules of 3-phosphoglycerate (PGA); PGA can produce glyceraldehyde-3-phosphate by the action of exogenous 3-phosphoglycerate kinase and glyceraldehyde-3-phosphate dehydrogenase, accompanied by NADH oxidation to form NAD+; NADH has a characteristic absorption peak at 340 nm, while NAD + There is no absorption peak at 340 nm, so the determination of the rate of decrease in absorbance at 340 nm can represent the carboxylase activity of Rubisco. The Rubisco carboxylase activity determination includes the following steps: 1. Bacterial liquid culture: use the optimal medium, cultivate under standard gas environment, at 65°C, at a rotation speed of 150 rpm, for 3 days.

[0072] 2. Bacterial sample treatment: collect the bacterial cells into a centrifuge tube, discard the supernatant after centrifugation; add 1 mL of extraction solution per 50 million bacteria, and ultrasonically break the bacteria (power 20%, ultrasonic 3 s, interval 10 s, repeat 30 times); centrifuge at 10,000 rpm for 10 min at 4°C, take the supernatant, and place it on ice for testing.

[0073] 3. Determination steps: (1) Preheat the ultraviolet spectrophotometer for more than 30 min, adjust the wavelength to 340 nm, and use distilled water to zero.

[0074] (2) Sample according to Table 5 system: Table 5

[0075] (3) Record the absorbance A1 at 20 s and the absorbance A2 at 5 min 20 s at 340 nm, calculate ΔA = ΔA experiment - ΔA blank; where ΔA experiment = A1 experiment - A2 experiment, ΔA blank = A1 blank - A2 blank; the reaction temperature is maintained at 25°C.

[0076] (4) Calculation method: according to the definition of the unit of sample mass: 1 g of tissue oxidizes 1 nmol of NADH per minute at 25°C as an enzyme activity unit. Rubisco activity (U / g mass) = [ΔA × V total ÷ (ε × d) × 10 9 ] ÷ (V sample ÷ V total × W) ÷ T, where V total (total volume of the reaction system) is 1.07 × 10 -3 L; ε (NADH molar extinction coefficient) is 6.22 × 10 3L / mol / cm; d (cuvette optical path) is 1 cm; Vsample (sample volume added) is 0.01 mL; Vtotal (volume of extract added) is 1 mL; T (reaction time) is 5 min; W (sample mass) is g; 500 (total number of bacteria or cells) is 5 million; 10 9 is the unit conversion factor, 1 mol = 10 9 nmol.

[0077] The results of the Rubisco enzyme activity test are shown in Table 6.

[0078] Table 6

[0079] As can be seen from Table 6, with the increase of temperature, the Rubisco enzyme activity of Bacillus megaterium presents a trend of first increasing and then decreasing. The Rubisco enzyme activity of Bacillus megaterium at 65°C is the highest, reaching 920 U / L, while the Rubisco enzyme activity at 80°C is the lowest, reaching 578 U / L. Therefore, the enzyme activity is best at 65°C.

[0080] Example 5 Bacillus megaterium strain was inoculated into a sealed culture bottle containing 1 L of sterilized optimal medium at a 5% volume inoculation amount, standard gas (standard mixed gas) was introduced, and the culture was incubated at 60°C on a shaker at a speed of 150 rpm for 1 week, after which the gas was collected. The detection of the gas product used Aglient 7890A gas chromatograph equipped with a thermal conductivity detector (TCD). The gas was collected using an aluminum foil gas sampling bag, and the experimental gas sample was analyzed simultaneously with a standard mixed gas (initial gas) of known components through a gas chromatographic column separation system. Then, using the correction normalized percentage method, the corresponding components of the two were compared, and according to the correction factor and the peak area of the spectrum, the corresponding composition of the gas sample was calculated. The formula for calculating the CO2 fixation rate is: CO2 fixation rate = (CO2 concentration in initial gas - CO2 concentration in culture gas) / CO2 concentration in initial gas.

[0081] The chromatogram of the initial gas is shown in Figure 6, and the results of the composition of the initial gas are shown in Table 7.

[0082] Table 7

[0083] After one week of culture, the chromatogram of the gas in the aerobic bottle is shown in Figure 7, and the results of the composition of the gas in the aerobic bottle after one week of culture are shown in Table 8.

[0084] Table 8

[0085] As can be seen from Table 7 and Table 8, the bacillus megaterium has a CO2 fixation rate of 99.073% in one week, and has a good carbon fixation effect.

[0086] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including that various technical features are combined in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the present application, and all fall within the protection scope of the present application.

Claims

1. A Bacillus megaterium (ATCC® 14909™) Bacillus megaterium ), characterized in that, The preservation number of the Bacillus megaterium is CGMCC No. 35586.

2. A carbon sequestration microbial inoculant, characterized by, The carbon fixation microbial agent comprises the Bacillus megaterium according to claim 1.

3. A method of preparing a carbon sequestration microbial inoculant, characterized by, The method comprises: The Bacillus megaterium according to claim 1 is inoculated into a fermentation medium for fermentation culture to obtain the carbon fixation microbial agent.

4. The method of claim 3, wherein, The fermentation medium comprises 4.8-5.2 g / L of proteose peptone, 0.05-0.15 g / L of ferric citrate, 18-22 g / L of sodium chloride, 5.8-6.2 g / L of magnesium chloride, 2.8-3.2 g / L of sodium sulfate, 0.4-0.6 g / L of calcium chloride, 0.14-0.18 g / L of sodium carbonate, 0.4-0.6 g / L of potassium bromide, 0.032-0.036 g / L of strontium chloride, 0.018-0.022 g / L of boric acid, 0.0048-0.0052 g / L of sodium silicate, 0.0018-0.0022 g / L of sodium fluoride, 0.0018-0.0022 g / L of ammonium nitrate, and 0.0098-0.012 g / L of disodium hydrogen phosphate. 0.8-1 vol% of trace element solution, 0.2-0.3 vol% of vitamin solution, and the pH value of the fermentation medium is 7.3-7.

7.

5. The method of claim 3, wherein, The fermentation culture is carried out under aerobic conditions, and the conditions of the fermentation culture comprise a temperature of 60-80℃, a pH value of 7.3-7.7, and a time of 60-74 h.

6. The method of claim 3, wherein, The Bacillus megaterium is inoculated in the form of a seed solution, and the preparation method of the seed solution comprises inoculating the Bacillus megaterium into a seed culture medium for expansion culture to obtain the seed solution.

7. The method of claim 6, wherein, The viable cell count in the seed broth is 1 x 10 6 -1 x 10 8 CFU / mL; the inoculum size of the seed broth is 2-10% by volume.

8. A carbon fixation microbial agent prepared by the method according to any one of claims 3-7.

9. The Bacillus megaterium according to claim 1, the microbial agent according to claim 2 and / or 8 for use in carbon fixation and / or gas production. Preferably, the carbon source for carbon fixation is an inorganic carbon source.

10. Use according to claim 9, characterized in that, The inorganic carbon source is carbon dioxide. The carbon fixation comprises converting carbon dioxide into organic matter at 60℃-80℃.

Images