Strain Solidesulfovibrio magneticus Sm-4 and application thereof

Abstract

The invention relates to the technical field of microbial remediation, and provides a strain Solidesulfovibrio magneticus Sm-4 and an application of the strain Solidesulfovibrio magneticus Sm-4. The strain Sm-4 has a reduction effect on SO4 < 2-> and a solidification effect on heavy metals, and provides a strain resource for removing SO4 < 2-> and heavy metals in AMD water and heavy metal contaminated soil. The magnetic soil desulfurization vibrio sp. Sm-4 provided by the invention can tolerate high-concentration SO4 < 2-> and remove heavy metals, has a high SO4 < 2-> reduction rate, and has a relatively good treatment effect on SO4 < 2-> and heavy metals in soil and water; the method has a wide application prospect in the in-situ remediation technology of acidic mine wastewater, polluted soil around a waste mining area, heavy metal polluted farmland soil and the like.

Description

Technical Field

[0001] The present invention relates to the field of microbial remediation technology, and in particular to strains Solidesulfovibrio magneticus Sm-4 and its applications. Background Art

[0002] The random discharge of industrial wastewater, agricultural irrigation water, domestic sewage, etc. is the main cause of water pollution and surrounding soil. Among the many pollution problems, the accumulation and discharge of acid mine drainage (AMD) is one of the main problems of mining pollution at present, and the amount of wastewater accounts for about 10% of the total industrial wastewater discharge in my country. Since most metal or non-metallic deposits in nature are composed of sulfide minerals, these sulfide minerals constantly react with oxygen and water in the environment during mining or stacking, resulting in the production of sulfates and the dissolution of heavy metals, forming acid mine drainage. The heavy metal pollution caused by it leads to extremely serious water quality deterioration and surrounding soil pollution. It has the characteristics of high toxicity, difficulty in removal, and easy to be enriched by organisms. Once the wastewater overflows, the impact on the surrounding ecological environment is immeasurable.

[0003] In response to water and soil pollution caused by acid mine drainage, people have been exploring and proposing some remediation technologies to reduce its damage to the ecological environment, including physical remediation technology: such as adsorption, ion exchange, membrane treatment, etc.; chemical remediation technology: such as neutralization precipitation, artificial wetland + lime precipitation co-treatment, continuous alkali production system, etc.; microbial treatment and remediation technology is an emerging AMD pollution remediation technology. Physical remediation technology has high investment costs and poor sustainability. Chemical remediation technology requires a large amount of neutralizers and precipitants, but the solidified heavy metals are easy to dissolve, which will cause secondary pollution. The microbial in-situ remediation method is simple to operate, low in investment costs, and has a long-lasting heavy metal solidification effect. It has application prospects in the sustainability of remediation. The current problem is the lack of acid resistance and resistance to high concentrations of SO 4 2- Microbial strains to ensure SO 4 2- High removal rate and long-lasting solidification of heavy metals. Summary of the invention

[0004] The present invention aims to provide a strain Solidesulfovibrio magneticus Sm-4 and its applications.

[0005] In order to achieve the purpose of the present invention, in the first aspect, the present invention provides a strain Sm-4 enriched and isolated from an acid mine drainage sludge water sample in a copper mine area in Yunnan, which is classified and named Solidesulfovibrio magneticusThe strain has been deposited in the General Microbiology Center of China Microbiological Culture Collection Administration, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, Postal Code 100101, with the deposit number CGMCC No. 41191 and the deposit date April 17, 2024.

[0006] In a second aspect, the present invention provides a microbial preparation comprising one or more selected from the bacterial cells, bacterial powder, bacterial suspension or bacterial liquid extract of the strain Sm-4.

[0007] In a third aspect, the present invention provides a method for preparing the microbial preparation, which comprises the step of culturing the strain Sm-4.

[0008] Furthermore, the strain Sm-4 is cultured at 25-45°C and pH 4.5-7.0, preferably at 30-35°C and pH 6.0-7.0, and more preferably at 30°C and pH 6.0.

[0009] Furthermore, the strain Sm-4 was cultured using a modified Baars medium.

[0010] Preferably, the modified Baars medium contains MgSO 4 7H 2 O 2g / L, sodium citrate dihydrate 5g / L, CaSO 4 ·2H 2 O 1g / L, NH 4 Cl 1g / L, K 2 HPO 4 0.5 g / L and sodium lactate 3.5 g / L, prepared with deionized water, pH 6; before inoculation, add 0.1 mL of filter-sterilized 5% Fe(NH 4 ) 2 •(SO 4 ) 2 .

[0011] Preferably, the culture conditions are: 30°C for 7 days.

[0012] In a fourth aspect, the present invention provides the strain Sm-4 or the microbial preparation for any of the following uses: (1) Used for sulfate reduction; (2) Used for the remediation of acid mine drainage; (3) Used for the remediation of heavy metal contaminated soil; (4) Used to prepare heavy metal curing agents.

[0013] Preferably, the application objectives of (2) and (3) are to increase the pH of acid mine drainage and heavy metal contaminated soil in mining areas, and to solidify heavy metals in mine water and soil.

[0014] More preferably, the acid mine drainage and heavy metal contaminated soil in mining areas are wastewater and contaminated soil produced by sulfur-containing minerals such as copper mines, iron mines, lead-zinc mines, antimony mines and coal mines, and the heavy metal is one or more of copper, cadmium, chromium and arsenic.

[0015] In a fifth aspect, the present invention provides a sulfate reduction method, using the strain Sm-4 or the microbial preparation to reduce sulfate in the environment.

[0016] Preferably, the pH value of the environment in which the strain Sm-4 or the microbial preparation is used is 5.1-7.2; preferably 6.0-7.0; further preferably 6.0-6.5, and more preferably 6.0.

[0017] Preferably, the C / S ratio of the environment in which the strain Sm-4 or the microbial preparation is used is 1:1-5:1; preferably 2:1-5:1; further preferably 3:1-5:1, and more preferably 3:1.

[0018] Furthermore, the strain Sm-4 or the microbial preparation can tolerate a sulfate concentration of 50 g / L or less, preferably 25 g / L or less, and more preferably 10 g / L or less.

[0019] Furthermore, the strain Sm-4 or the microbial preparation utilizes different carbon sources in the environment, including alcohols, small molecule organic acids and sugars, etc., preferably alcohols and small molecule organic acids, and more preferably ethanol (YC) and sodium lactate (RSN).

[0020] Furthermore, the strain Sm-4 or the microbial preparation utilizes different sulfur sources in the environment, including magnesium sulfate, sodium sulfate, sodium thiosulfate and calcium sulfate, etc., preferably magnesium sulfate and sodium thiosulfate, and more preferably sodium thiosulfate.

[0021] In a sixth aspect, the present invention provides a method for remediating acid mine drainage (AMD), using the strain Sm-4 or the microbial preparation to remediate acid mine drainage.

[0022] Preferably, the amount of wastewater added is 0-100%, more preferably 25-50%, most preferably 50%.

[0023] By means of the above technical solution, the present invention has at least the following advantages and beneficial effects: The new sulfate-reducing bacteria Sm-4 that tolerates high concentrations of sulfate provided by the present invention can efficiently reduce SO under weakly acidic conditions. 4 2-It can further solidify heavy metal ions and can be used in the in-situ ecological restoration of acid mine drainage and its contaminated soil. It has the advantages of more economical and sustainable treatment of AMD and contaminated soil, and is an effective way to remove SO in AMD water and heavy metal contaminated soil. 4 2- and heavy metals provide bacterial resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The electron microscope photographs of the colony and bacterial morphology of the magnetic soil Desulfovibrio sulphuridis Sm-4 of the present invention are shown.

[0025] Figure 2 This is a phylogenetic evolutionary tree of the magnetic soil desulfurizing vibrio Sm-4 of the present invention and similar model strains.

[0026] Figure 3 The growth and desulfurization curve of the magnetic soil desulfurizing vibrio Sm-4 provided in Example 1 of the present invention.

[0027] Figure 4 The desulfurization capacity of the magnetic soil desulfurizing vibrio Sm-4 provided in Example 2 of the present invention at different initial pH values.

[0028] Figure 5 The adaptability of the magnetic soil desulfurizing vibrio Sm-4 to the initial C / S ratio provided in Example 3 of the present invention.

[0029] Figure 6 The magnetic soil desulfurization vibrio Sm-4 provided in Example 4 of the present invention has different SO 4 2- The reducing power of the initial concentration.

[0030] Figure 7 SO of the magnetic soil desulfurization vibrio Sm-4 provided in Example 5 of the present invention under different initial carbon sources 4 2- Restore capability.

[0031] Figure 8 SO of magnetic soil desulfurizing vibrio Sm-4 under different initial sulfur sources provided in Example 6 of the present invention 4 2- Restore capability.

[0032] Fig. 9 The wastewater remediation ability of the magnetic soil desulfurizing Vibrio Sm-4 provided in Example 7 of the present invention. DETAILED DESCRIPTION

[0033] The present invention provides a magnetic soil desulfurization vibrio Sm-4 and its application. The strain Sm-4 belongs to the genus magnetic soil desulfurization vibrio ( Solidesulfovibriosp.), and through the comparison of 16S rRNA sequences in the Ezbiocloud database, the bacteria (sequencing length 1434bp, sequence integrity 97.5%, the 16S rRNA gene sequence of strain Sm-4 is shown in SEQ ID NO:1) are similar to magnetic soil Desulfovibrio ( Solidesulfovibrio magneticus RS-1 T ) with a maximum similarity of 99.6% in 16S rRNA sequence. Combined with physiological and biochemical characteristics and phylogenetic analysis, the bacterium was identified as Solidesulfovibrio magneticus Sm-4.

[0034] The present invention adopts the following technical solution: The present invention provides a strain of bacteria ( Solidesulfovibrio magneticus ) and its application in wastewater remediation.

[0035] The present invention provides a sulfate-reducing bacterium tolerant to high concentration of sulfate radicals Solidesulfovibrio magneticus Sm-4, strain Sm-4 was enriched and isolated from a sample of acid mine drainage mud in a copper mining area in Yunnan. This strain is sensitive to SO 4 2- It has a reducing effect and can solidify heavy metals, and is used to remove SO in AMD water and heavy metal-contaminated soil. 4 2- and heavy metals provide bacterial resources.

[0036] The strain Sm-4 was cultured in modified Baars solid medium at 30℃ for 7 days. The phenotypic characteristics were as follows: the colonies were black and round with neat edges, the cells were oval in shape, arranged in pairs or singly, with terminal flagella, and the size was (0.8-1) μm×(1.8-5) μm. The growth temperature was 25-45℃, the pH was 5.0-7.0, and the cells were oval in shape, arranged in pairs or singly under electron microscope ( Figure 1 ).

[0037] The model strain with the greatest similarity to the 16S rRNA gene sequence of strain Sm-4 is: Solidesulfovibrio magneticus RS-1, with a 16S rRNA sequence similarity of 99.6%. Solidesulfovibrio ) The phylogenetic tree was constructed based on the 16S rRNA gene sequence of the model strain. Figure 2 As shown, sequence similarity and evolutionary relationships demonstrate that it is a member of the genus Desulfovibrio.

[0038] 1L of modified Baars medium contains: MgSO 42g / L, sodium citrate dihydrate 5g / L, CaSO 4 ·2H 2 O 1g / L, NH 4 Cl 1g / L, K 2 HPO 4 0.5 g / L and sodium lactate 3.5 g / L were prepared with deionized water and the pH was adjusted to 6. Before inoculation, 0.1 mL of filter-sterilized 5% Fe(NH 4 ) 2 •(SO 4 ) 2 .

[0039] 1L of modified Baars solid medium contains: MgSO 4 2g / L, sodium citrate dihydrate 5g / L, CaSO 4 ·2H 2 O1g / L, NH 4 Cl 1g / L, K 2 HPO 4 0.5 g / L and sodium lactate 3.5 g / L, prepared with deionized water, agar powder 20 g / L, adjusted pH to 6, and added 0.1 mL of filter-sterilized 5% Fe(NH 4 ) 2 •(SO 4 ) 2 .

[0040] The sulfate-reducing bacteria Sm-4 of the present invention is 4 2- The plant can still grow in the modified Baars medium with a concentration of 50 g / L, and the reduction rate reaches more than 70% in 7 days, which can greatly reduce SO 4 2- It can reduce the concentration of heavy metals in soil or water, increase the pH value of soil or water, and has a fast growth rate and low use cost. It can be put into use quickly on a large scale, which is beneficial to protecting environmental safety.

[0041] The strain Sm-4 is deposited in the General Microbiological Center of China Microbiological Culture Collection Administration Committee, and the deposit number is CGMCC No. 41191. The present invention explores the reduction effect and conditions of the bacteria on sulfate ions, and provides bacterial resources for sulfate reduction and heavy metal fixation in soil and water.

[0042] The present invention also provides a microbial preparation, comprising one or more of the bacterial bodies, bacterial powder, bacterial suspension or bacterial liquid extracts of the magnetic soil desulfurization vibrio Sm-4.

[0043] The present invention also provides a method for preparing the microbial preparation, which comprises the step of culturing the magnetic soil desulfurization vibrio Sm-4.

[0044] The preparation method of the microbial preparation comprises culturing the Desulfovibrio sp. Sm-4 at 25-45°C and pH 4.5-7.0, preferably at 30-35°C and pH 6.0-7.0, and more preferably at 30°C and pH 6.0.

[0045] Preferably, the magnetic soil desulfurization vibrio Sm-4 is cultured in a modified Baars medium. 1 L of the modified Baars medium contains MgSO 4 7H 2 O 2g / L, sodium citrate dihydrate 5g / L, CaSO 4 ·2H 2 O 1g / L, NH 4 Cl 1g / L, K 2 HPO 4 0.5 g / L and sodium lactate 3.5 g / L, prepared with deionized water, pH 6, and 0.1 mL of filter-sterilized 5% Fe(NH 4 ) 2 •(SO 4 ) 2 . Incubate at 30°C for 7 days.

[0046] The present invention also provides the use of the magnetic soil desulfurization vibrio Sm-4 or the microbial preparation in any one or more of the following items: (1) Remediation of acid mine drainage or heavy metal contaminated soil; (2) Heavy metal curing agent.

[0047] The preferred goal is to increase the pH of acid mine drainage and heavy metal contaminated soil in mining areas, and to solidify heavy metals in mine water and soil.

[0048] More preferably, the acid mine drainage and heavy metal contaminated soil in mining areas are wastewater and contaminated soil produced by sulfur-containing minerals such as copper mines, iron mines, lead-zinc mines, antimony mines and coal mines, and the heavy metals are one or more of copper, cadmium, chromium and arsenic.

[0049] The present invention also provides a sulfate reduction method: The pH value of the environment in which the magnetic soil desulfurization vibrio Sm-4 or the microbial preparation is used is 5.1-7.2; preferably 6.0-7.0; further preferably 6.0-6.5, and more preferably 6.0.

[0050] The C / S ratio of the magnetic soil desulfurization vibrio Sm-4 or the microbial preparation in the use environment is 1:1-5:1; preferably 2:1-5:1; further preferably 3:1-5:1, and more preferably 3:1.

[0051] The magnetic soil desulfurizing vibrio Sm-4 or the microbial preparation tolerates a sulfate concentration of 50 g / L or less, preferably 25 g / L or less, and more preferably 10 g / L or less.

[0052] The magnetic soil desulfurization vibrio Sm-4 or the microbial preparation can utilize different carbon sources, including alcohols, small molecule organic acids and sugars, etc., preferably alcohols and small molecule organic acids, and more preferably ethanol (YC) and sodium lactate (RSN).

[0053] The magnetic soil desulfurizing vibrio Sm-4 or the microbial preparation can utilize different sulfur sources, including magnesium sulfate, sodium sulfate, sodium thiosulfate and calcium sulfate, etc., preferably magnesium sulfate and sodium thiosulfate, and more preferably sodium thiosulfate.

[0054] The present invention also provides a method for repairing acid mine drainage (AMD), using the magnetic soil desulfurization vibrio Sm-4 or the microbial preparation: preferably the wastewater amount is 0-100%, preferably 25-50% wastewater addition, and most preferably 50% wastewater addition.

[0055] The magnetic soil desulfurization vibrio Sm-4 provided by the present invention can tolerate high concentrations of SO 4 2- , and remove heavy metals, SO 4 2- High reduction rate for SO in soil and water 4 2- And heavy metals have a good treatment effect.

[0056] The results showed that the strain Sm-4 could reduce sulfate in 50 g / L SO 4 2- Growth and reduction of SO 4 2- , especially when the OD of the strain 600 When it is greater than 1, the removal rate of sulfate ion can reach more than 80%, and the desulfurization rate is fast and effective. When a single S source is used as the initial sulfur source, the available single S source is also gradually enhancing its ability to reduce sulfate. Therefore, it has broad application prospects in in-situ remediation technologies for acidic mine wastewater, contaminated soil around waste mines, and heavy metal-contaminated farmland soil.

[0057] The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art, and the raw materials used are all commercially available products.

[0058] Example 1 Sulfate reduction ability of strain Sm-4 like Figure 3 As shown, the strain of the present invention Solidesulfovibrio magneticus Sm-4 was grown in modified Baars medium at pH 6 for 7 days. Figure 3 The results in Figure a show that strain Sm-4 has the ability to grow rapidly, and the strain growth reaches the maximum OD on the 6th day. 600 is 1.4; Figure 3 b The results showed that strain Sm-4 had the ability to increase pH. On the second day of growth, the pH increased to 7.7, and the pH gradually increased with time. Figure 3 The results showed that strain Sm-4 had strong reducing ability, with the redox potential reaching around -400 mV on the second day and stabilizing in this range over time; Figure 3 The results showed that the sulfate reduction capacity of strain Sm-4 reached 53% on the second day of growth, and stabilized at more than 80% after the fourth day. 4 2- Restore capability.

[0059] Example 2 Sulfate reduction ability of strain Sm-4 at different initial pH like Figure 4 As shown, the strain of the present invention Solidesulfovibrio magneticus Sm-4 was grown in modified Baars culture at different pH values ​​for 14 days. Figure 4 a The results showed that strain Sm-4 could grow above pH 5.5, and after 14 days of culture, strain Sm-4 grew most vigorously in the medium with pH 5.5; Figure 4 b The results showed that when pH ≥ 5.5, the pH value of strain Sm-4 reached the maximum at 48-72h. When pH = 6.5, strain Sm-4 had the strongest ability to increase pH, reaching pH 8.0-8.3; Figure 4 c The results showed that 0-48h was the rapid growth period of strain Sm-4, and its sulfate reduction ability increased rapidly. When pH ≥ 5.5, the sulfate reduction rate reached 70-90% on the 5th day, indicating that the strain of the present invention can efficiently reduce sulfate above pH 5.5.

[0060] Example 3 Sulfate reduction ability of strain Sm-4 at different initial C / S ratios like Figure 5 As shown, the strain of the present invention Solidesulfovibrio magneticus Sm-4 can grow normally at C / S ratios from 1:1 to 5:1. Figure 5 a The results show that when the C / S ratio is 1:1, the OD of strain Sm-4 on the 4th day 600The value was higher than that of other groups, but significantly lower than that of other groups after the 4th day. On the 8th day, the OD of the C / S ratio was 3:1. 600 The values ​​were higher than those of other treatment groups; Figure 5 b The results showed that when the C / S ratio was 1:1, the sulfate reduction ability of strain Sm-4 was significantly lower than that of other groups. When the C / S ratio was 1:1 and 2:1, the sulfate reduction ability of strain Sm-4 reached the maximum on the 6th day and then began to decline. When the C / S ratio was 3:1-5:1, the sulfate reduction rate of strain Sm-4 was stable at more than 95% after the 6th day. Figure 5 c The results showed that the chemical oxygen demand (COD) of strain Sm-4 was the lowest when the C / S ratio was 1:1 and 3:1. Combined with the sulfate reduction ability and the growth status of the strain, the C / S ratio of 3:1 was selected as the optimal C / S ratio of strain Sm-4.

[0061] Example 4 Strain Sm-4 in different initial SO 4 2- Sulfate reduction capacity The results are as follows Figure 6 As shown, the present invention Solidesulfovibrio magneticus Sm-4 in initial SO 4 2- When the concentration is ≤50g / L, it can reduce sulfate. Figure 6 a The results showed that strain Sm-4 had different initial SO 4 2- The concentration of medium can quickly enter the logarithmic growth phase, SO 4 2- When the concentration is ≤10g / L, the OD on the 7th day 600 Reach 0.9-1.2, then enter the decline stage, OD 600 Decreased to 0.5-0.7; Figure 6 b The results show that the initial SO 4 2- At each concentration of ≤25 g / L, the pH-raising ability of strain Sm-4 showed a steady upward trend, with the pH increasing to between 7.25 and 8.5 on the 7th day, and the pH stabilized above 7.5 on the 14th day; Figure 6 c The results show that the initial SO 4 2- The lower the concentration, the stronger the sulfate reduction ability of strain Sm-4. 4 2- When the concentration is ≤10g / L, the sulfate reduction rate is >40%, and when 10g / L<initial SO 4 2 When the sulfate reduction rate is ≤50g / L, it is between 5% and 28%. This indicates that the strain of the present invention can 4 2-Growth is restored when the concentration is ≤50g / L.

[0062] Example 5 Sulfate reduction ability of strain Sm-4 under different carbon sources The results are as follows Figure 7 As shown, the strain of the present invention Solidesulfovibrio magneticus Sm-4 can reduce sulfate efficiently under different carbon sources. Figure 7 a The results showed that strain Sm-4 grew best with sodium formate (JSN) and sodium lactate (RSN) as carbon sources among 12 different carbon sources, and could not grow with maltose (MYT) and n-butanol (ZDC) as carbon sources; Figure 7 The results in Figure b show that the strain The pH of Sm-4 increased most significantly when sodium lactate was used as the carbon source, followed by ethanol (YC); Figure 7 c The results showed that on the 5th day, the sulfate reduction rate of strain Sm-4 using 12 carbon sources was >40%, and on the 7th day, the sulfate reduction ability using ethanol as the carbon source was the best; therefore, the strain of the present invention Solidesulfovibrio magneticus The preferred carbon source for Sm-4 is ethanol, followed by small molecule organic acids.

[0063] Example 6 Sulfate reduction ability of strain Sm-4 under different sulfur sources The results are as follows Figure 8 As shown, the strain of the present invention Solidesulfovibrio magneticus Sm-4 can effectively reduce sulfate under different sulfur sources. Figure 8 The results showed that the strain Solidesulfovibrio magneticus Sm-4 was able to grow when magnesium sulfate, sodium sulfate, sodium thiosulfate and calcium sulfate were used as the S source. When sodium sulfate was used as the substrate, the OD 600 The value can reach 0.9, but Sm-4 cannot grow with sodium sulfite and sodium dithionite as substrates; Figure 7 b The results showed that the strain Solidesulfovibrio magneticus Sm-4 can raise the pH of the solution from 6 to 7.5 when using magnesium sulfate, sodium sulfate, sodium thiosulfate and calcium sulfate as the S source, but there is no significant change in pH when using sodium sulfite and sodium dithionite as the S source; Figure 7 c The results showed that the strain Solidesulfovibrio magneticus Sm-4 can reduce SO in the solution when magnesium sulfate, sodium sulfate, sodium thiosulfate and calcium sulfate are used as S sources. 4 2- The reducing capacity is S4: sodium thiosulfate > S1: magnesium sulfate > S2: sodium sulfate > S6: calcium sulfate. However, when sodium sulfite and sodium dithionite are used as S sources, SO 4 2- .

[0064] Example 7 Effect of strain Sm-4 on SO in acid mine drainage4 2- Efficient removal of The results are as follows Fig. 9 As shown: When the pH of acid mine wastewater is 6, the strain of the present invention Solidesulfovibrio magneticus When Sm-4 was added with 25% mineral water, OD 600 The pH value can be stabilized at 0.8, the pH value can be increased from 6 to about 7.5, and the sulfate reduction rate can reach 60%-70%. When 50% of the mineral water is added, the OD value after 14 days of cultivation is 600 The value can reach 0.6, the pH can be increased from 6 to 7.8, and the sulfate reduction rate can reach 40%; when the mineral water addition amount is 75%, the OD 600 The value can reach 0.55, the pH can rise from 6 to 7.2, and the sulfate reduction rate is only 30%; when 100% mineral water is added, the OD 600 When the pH value reaches 0.4, the pH can be increased from 6 to 7.1, and the sulfate reduction rate is only 32%. When the pH of acid mine wastewater is 4, the strain does not grow after 14 days of culture at 75% and 100% mineral water addition, the pH is still acidic, and the sulfate reduction rate is only 10%-20%, and the reduction effect is not obvious.

[0065] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. Strains Solidesulfovibrio magneticus Sm-4, the deposit number is CGMCC No. 41191.

2. A microbial preparation, characterized in that: It comprises one or more selected from the bacterial bodies, bacterial powders, bacterial suspensions or bacterial liquid extracts of the strain Sm-4 described in claim 1.

3. The method for preparing the microbial preparation according to claim 2, characterized in that: The preparation method comprises the step of culturing the strain Sm-4.

4. The preparation method according to claim 3, characterized in that: The strain Sm-4 is cultured at 25-45°C and pH 4.5-7.0, preferably at 30-35°C and pH 6.0-7.0, and more preferably at 30°C and pH 6.

0.

5. The preparation method according to claim 3 or 4, characterized in that: The strain Sm-4 was cultured using a modified Baars medium; Preferably, the modified Baars medium contains MgSO4·7H2O 2g / L, sodium citrate dihydrate 5g / L, CaSO4·2H2O 1g / L, NH4Cl 1g / L, K2HPO4 0.5g / L and sodium lactate 3.5g / L, prepared with deionized water, pH 6; 0.1mL of filter-sterilized 5% Fe(NH4)2•(SO4)2 is added before inoculation; Preferably, the culture conditions are: 30°C for 7 days.

6. The strain Sm-4 according to claim 1 or the microbial preparation according to claim 2 is used in any of the following applications: (1) Used for sulfate reduction; (2) Used for the remediation of acid mine drainage; (3) Used for the remediation of heavy metal contaminated soil; (4) Used to prepare heavy metal curing agents; Preferably, the application objectives of (2) and (3) are to increase the pH of acid mine drainage and heavy metal contaminated soil in mining areas, and to solidify heavy metals in mine water and soil; More preferably, the acid mine drainage and heavy metal contaminated soil in mining areas are wastewater and contaminated soil generated by sulfur-containing minerals in copper mines, iron mines, lead-zinc mines, antimony mines and coal mines, and the heavy metal is one or more of copper, cadmium, chromium and arsenic.

7. A sulfate reduction method, characterized in that: Using the strain Sm-4 described in claim 1 or the microbial preparation described in claim 2 to reduce sulfate in the environment; Preferably, the pH value of the environment in which the strain Sm-4 or the microbial preparation is used is 5.1-7.2; preferably 6.0-7.0; further preferably 6.0-6.5, more preferably 6.0; and / or, Preferably, the C / S ratio of the environment in which the strain Sm-4 or the microbial preparation is used is 1:1-5:1; preferably 2:1-5:1; further preferably 3:1-5:1, and more preferably 3:

1.

8. The method according to claim 7, characterized in that The strain Sm-4 or the microbial preparation can tolerate a sulfate concentration of 50 g / L or less, preferably 25 g / L or less, and more preferably 10 g / L or less.

9. The method according to claim 7 or 8, characterized in that: The strain Sm-4 or the microbial preparation utilizes different carbon sources in the environment, including alcohols, small molecule organic acids and sugars, preferably alcohols and small molecule organic acids, more preferably ethanol and sodium lactate; The strain Sm-4 or the microbial preparation utilizes different sulfur sources in the environment, including magnesium sulfate, sodium sulfate, sodium thiosulfate and calcium sulfate, preferably magnesium sulfate and sodium thiosulfate, and more preferably sodium thiosulfate.

10. A method for remediating acid mine drainage, using the strain Sm-4 described in claim 1 or the microbial preparation described in claim 2 to remediate acid mine drainage; Preferably, the amount of wastewater added is 0-100%, more preferably 25-50%, most preferably 50%.

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