An extremely acidophilic iron-oxidizing bacterium and its application in bioleaching

Abstract

The application provides an extremely acidophilic iron-sulfur oxidizing bacterium and application thereof in bioleaching of ores. The iron-sulfur oxidizing bacterium (Sulfobacillus thermotolerants) hq2 strain has a preservation number of CGMCC No. 26454. The iron-sulfur oxidizing bacterium provided by the application can oxidize Fe 2+ into Fe 3+ , and can be used for leaching of various low-grade ores and other heavy metals.

Description

Technical Field

[0001] The present invention belongs to the technical field of comprehensive development and utilization of medium- and low-grade iron ores and associated ores in the energy-saving and environmental protection industry, and specifically relates to an extremely acidophilic iron-sulfur oxidizing bacterium and its application in biological leaching. Background Art

[0002] Iron-sulfur-oxidizing bacteria are widely found in acidic mines or acidic environments containing iron or sulfur. Their key characteristics are the ability to oxidize ferrous iron to ferric iron, as well as elemental sulfur and various reduced forms of inorganic sulfur to sulfate, while utilizing the energy released in this process for growth. Iron-sulfur-oxidizing bacteria not only play a vital role in Earth's chemical cycles but are also widely used in bioleaching, biometallurgy, and remediation of contaminated environments.

[0003] Most of the currently known iron-sulfur oxidizing bacteria are chemoautotrophic microorganisms. Typical iron-sulfur oxidizing strains Acidithiobacillus ferrooxidans As obligate autotrophic microorganisms, the presence of certain organic matter will inhibit their growth. In addition, in terms of acid resistance, most acidophiles can tolerate a pH of around 2-4 and cannot tolerate more extreme acidic conditions. Summary of the Invention

[0004] The purpose of the present invention is to provide an extremely acidophilic iron-sulfur oxidizing bacterium and its application in biological leaching. The iron-sulfur oxidizing bacterium is separated and purified from pyrite leaching bacteria and can be used for biological leaching.

[0005] The present invention first provides an iron-sulfur oxidizing bacterium ( Sulfobacillus thermotolerans ) hq2 strain, whose deposit number is CGMCC No. 26454, was deposited in the China General Microbiological Culture Collection Center (CGMCC for short) on January 12, 2023. The depository address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing.

[0006] The iron-sulfur oxidizing bacteria hq2 strain provided by the present invention has a 16S gene sequence as SEQ ID NO: 1.

[0007] The pH range for the growth of the iron-sulfur oxidizing bacteria provided by the present invention is 1.0-5.0.

[0008] The growth temperature range of the iron-sulfur oxidizing bacteria provided by the present invention is 30-50°C.

[0009] The iron-sulfur oxidizing bacteria provided by the present invention can be used for the oxidation of ferrous ions or the oxidation of sulfur elements.

[0010] The ferrous ions are ferrous ions in sewage.

[0011] The iron-sulfur oxidizing bacteria hq2 strain provided by the present invention can also be used for biological leaching of minerals.

[0012] The present invention also provides a method for bioleaching, which uses the screened iron-sulfur oxidizing bacteria hq2 strain as the bioleaching bacteria to carry out bioleaching.

[0013] The iron-sulfur oxidizing bacteria provided by the present invention can 2+ Oxidized to Fe 3+ , can be used for leaching of various low-grade minerals and other heavy metals. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 :Morphological photos of iron-sulfur oxidizing bacteria on solid plates,

[0015] Figure 2 :Phylogenetic tree of iron-sulfur oxidizing bacteria based on 16S rRNA sequences,

[0016] Figure 3 :Electron microscope photos of iron-sulfur oxidizing bacteria,

[0017] Figure 4 :The results of the temperature growth range determination of iron-sulfur oxidizing bacteria,

[0018] Figure 5 :The pH growth range of iron-sulfur oxidizing bacteria was measured.

[0019] Figure 6 :Graph showing the utilization of different carbon sources by Bacillus iron-sulfur oxidizing bacteria on Biolog GEN III MicroPlate.

[0020] Figure 7 Figure 3: Iron-sulfur oxidizing bacteria's ability to oxidize ferrous ions under extreme conditions. (A) ORP trend; higher ORP indicates better ferrous ion oxidation. (B) pH trend. (C) CFU / mL bacterial count. DETAILED DESCRIPTION

[0021] The present invention screened out a new iron-sulfur oxidizing Bacillus strain from the original bacterial group 5Biol. The strain can efficiently oxidize ferrous iron in the presence of 0.02% yeast, thereby overcoming the defect of other iron-sulfur oxidizing Bacillus that their growth is inhibited in the presence of organic matter. In addition, the strain can oxidize high-concentration ferrous ions at a pH of 1, making it an excellent mineral leaching microorganism and environmental microorganism with wide application value.

[0022] The present invention is described in detail below with reference to the embodiments and accompanying drawings.

[0023] Example 1: Screening of target strains

[0024] The 5Biol bacterial strains used for screening were obtained from the Applied Microbial Ecological Engineering Laboratory (AMEE) of Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences.

[0025] The culture medium and reagent information used in this example are as follows:

[0026] (1) 44.2 g / L FeSO4.7H2O mother solution: Prepare 10 times the mother solution with dilute sulfuric acid solution, adjust the final pH to 1.2, filter with a 0.22 μm filter membrane and add to sterilized 9K culture medium at a dosage of 10 mL / 100 mL.

[0027] (2) 0.02% Yeast stock solution: Prepare 100 times the stock solution with pure water, sterilize at 121℃ and add 1mL / 100mL.

[0028] (3) Sulfur powder 10 / L: Wrap the weighed sulfur powder in tin foil and sterilize it by dry heat at 105℃ for 24 hours before use.

[0029] (4) The specific formula of 9K culture medium is as follows: (NH4)2SO4 3g, KCI 0.1g, MgSO4.7H2O 0.5g, K2HPO40.5g, Ca(NO3)2 0.01g, adjust pH to 2.0, make up to 1L, and sterilize at 121℃ for 20min.

[0030] (5) 9K-Fe-Yeast liquid culture medium: Sterilized 9K culture medium, add sterilized FeSO4.7H2O mother solution under aseptic conditions, and add sterilized Yeast mother solution.

[0031] (6) 9K-S-yeast liquid culture medium: Sterilized 9K culture medium, add dry heat sterilized sulfur powder under aseptic conditions, and add sterilized yeast mother liquor.

[0032] (7) 9K-Fe-S-Yeast solid culture medium:

[0033] Solution A: 250 mL of 9K basic salt culture medium + 15.0 g of agar, adjust the pH to 7.0;

[0034] Solution B: 750 mL of 9K basic salt culture medium, adjusted to pH 2.0;

[0035] Sulfur powder 10 / L: Wrap the weighed sulfur powder in tin foil and dry-heat sterilize at 105°C for 24 hours.

[0036] Sterilize Solution A and Solution B at 121°C for 20 minutes. Once cooled to 80°C, mix them, add sterilized sulfur powder, and pour into a Petri dish to cool. Sterilize the FeSO₄.7H₂O solution by filtering it through a 0.22µm filter membrane and apply it evenly to the plate.

[0037] (8) PBS buffer: 8.0 g NaCl, 0.2 g KCl, 1.44 g Na2HPO4, 0.24 g KH2PO4, dilute to 1 L, adjust pH to 7.4, and sterilize.

[0038] The soil samples from Tengchong hot springs and Hebei mines were mixed and enriched with pyrite to obtain the original 5Biol bacterial community with leaching function. After the bacterial community was continuously subcultured and domesticated in pyrite for ten generations, the domesticated 5Biol bacterial community was obtained. The sequencing results showed that the bacterial community became Acidithiobacullus thiooxidans 97% Sulfobacillus thermotolerans Subsequently, the acclimated 5Biol bacterial colony was subjected to differentiation culture with either iron or sulfur alone or with both iron and sulfur. The proportion of Sulfobacillus strains in the medium containing both iron and sulfur increased to 27%.

[0039] After differentiation and culture in a medium containing both iron and sulfur, 5 biol of bacterial liquid was inoculated onto a 9K-Fe-S-Yeast solid medium by streaking. After incubation at 37°C for about 20 days, a single colony appeared on the plate. The single colony was picked and cultured in a liquid medium for identification, resulting in a strain hq2. The morphology of the strain on the solid plate is as follows: Figure 1 The colony morphology is round, with smooth edges and dark yellow color.

[0040] The selected hq2 strain was inoculated into 9K-S-Yeast liquid medium and cultured at 37°C in a shaker at 180 rpm for 4-5 days. 10 mL of exponentially active bacterial culture was collected and centrifuged at 10,000 rpm for 15 minutes. After washing with PBS, DNA was extracted using the PowerSoil DANIsolation kit (MOBIO). The extracted DNA was analyzed for concentration and integrity using a NanoDrop 2000 and 1% (w / v) agarose gel electrophoresis. The 16S rRNA gene was then amplified using universal bacterial primers 27F and 1492R. The 16S rRNA sequence of the hq2 strain is as follows:

[0041]

[0042] 16S rRNA gene identification results showed that the strain Sulfobacillus thermotolerans The sequence similarity of Kr1 strain is up to 99% ( Figure 2 The strain was named iron-sulfur oxidizing bacteria ( Sulfobacillus thermotolerans ) hq2 strain, was deposited in the China General Microbiology Culture Collection Center (CGMCC) on January 12, 2023. The deposit address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, and the deposit number is CGMCC No. 26454.

[0043] Example 2: Physicochemical properties of strain hq2

[0044] 1. Morphological characteristics of strains

[0045] Morphological observation of the selected Acidithiobacillus strains was performed using a scanning electron microscope (Hitachi SU8010, Japan). The strain was grown aerobically at 37°C in 9K-S-Yeast liquid medium with an initial pH of 2.0. Cultures were cultured until mid-exponential growth. A certain amount of the bacterial culture medium was collected during the stationary phase and centrifuged at 10,000 rpm for 15 minutes. The culture was washed twice with 0.25N dilute sulfuric acid and then three or more times with PBS buffer or saline to remove impurities from the culture medium. Before observation, the samples were fixed (soaked in 2.5% glutaraldehyde and suspended in the fixative, fixed overnight at 4°C. Washed with buffer three times, each time for 10 min, to remove the effects of glutaraldehyde on subsequent steps. After centrifugation and enrichment, 1% osmium hydroxide was added to cover the cells, and the cells were suspended and fixed for 1 h. After washing with buffer three times, each time for 10 min.), dehydrated (gradient dehydration with 30%, 50%, 75%, 95%, 100%, and 100% ethanol, each time for 15 min.), critical point drying (using a critical point dryer, Leica EM CPD030, Germany, to replace the ethanol in the cells with liquid CO2, and then through the gasification process of the liquid CO2, the CO2 gas was discharged to obtain a dry sample), coated (using an ion sputtering instrument, Hitachi E-1045, Japan, to evenly cover the sample surface with platinum (Pt) to increase the conductivity of the biological sample) and observed (scanning electron microscope, Hitachi SU8010, Japan, morphological observation of the screened Acidithiobacillus). Scanning electron microscopy results showed that the strain was approximately 0.6×3.8-3.0μm in size and had a short rod shape ( Figure 3 ).

[0046] 2. Determination of optimal growth temperature and pH

[0047] The isolated strain was inoculated by centrifugation at a ratio of 10%, inoculated into 9K-S-Yeast liquid medium, and then cultured at 20°C, 30°C, 37°C, 42°C, 50°C, 55°C, and 60°C, respectively. The initial pH was 2.0, and the shaking culture was performed at 180 r / min. The OD was measured every two days. 600 The values ​​were used to evaluate cell growth and obtain the growth temperature range.

[0048] Different initial pH values ​​of 0.5, 1.0, 2.0, 3.0, 4.0, 5.0, and 6.0 were used, and the cultures were cultured at 37°C and 180 rpm. Samples were taken every day to measure the OD 600 To evaluate cell growth and obtain the pH range suitable for the growth of the strain.

[0049] The test results showed that the strain could grow in the temperature range of 30℃-50℃, with the optimal growth temperature being 37℃ and 42℃ ( Figure 4 ), and the stable period was longer when grown at 37℃.

[0050] Regarding the optimal growth pH of the strain, the strain can grow in the range of pH 1.0-5.0. The optimal pH is 2.0. When the pH changes from 2.0 to 1.0 and then to 0.5, the growth of the strain is gradually inhibited, and the growth ability is lost at pH 0.5. When the pH reaches 6.0, the growth of the strain is completely inhibited ( Figure 5 ).

[0051] 3. Screening of strains’ utilization of different carbon sources

[0052] The ability of the strain to grow on different carbon sources was tested using the Biolog GEN III MicroPlate. The carbon sources contained in the test plate are shown in Table 1. Before the test, different carbon sources or other chemicals were pre-filled in the GEN III MicroPlate. The cells of the cultivated pure culture were harvested by centrifugation at 10,000 rpm for 15 minutes, washed three times with inorganic salt culture medium without carbon source, and then inoculated into IF-C inoculum. The turbidity was adjusted to 90–98% to prepare the inoculum. Then 100 μL of the inoculum was inoculated into each well of the GEN III MicroPlate. The well plate was incubated at 37°C for 240 hours, and then Biolog's GEN III OmniLog II combo plus kinetic software (Biolog, United States) was used for data reading (Table 1) and map generation ( Figure 6The photographic measurement of the color intensity produced by dye reduction in the presence of substrate is expressed in OmniLog units (OU). The definitions of positive, negative, and borderline values ​​in Table 1 are based on the instrument's results.

[0053] The results of the Biolog GEN III Microplate carbon source test showed that the strain was positive for 5 of the 72 carbon sources, including D-fructose, D-fructose-6-phosphate, glucuronamide, α-ketoglutaric acid, and acetoacetic acid. It showed borderline values ​​(i.e., it may have the ability to grow using these substances) for 24 carbon sources, including D-maltose, D-trehalose, D-cellobiose, gentiobiose, sucrose, D-turanose, stachyose, α-D-lactose, α-D-glucose, D-mannose, D-galactose, 3-formylglucose, D-fucose, L-fucose, L-rhamnose, D-mannitol, D-glucose-6-phosphate, L-histamine, D-galacturonic acid, L-galacturonolactone, D-glucuronic acid, citric acid, α-ketobutyric acid, and acetic acid.

[0054] Table 1: Carbon source names, corresponding Biolog values, and default classifications for each well position in the Biolog GEN III Microplate.

[0055] Chinese Name English Name Biolog Value Classification A1 Negative Control Negative Control 76 - A2 Dextrin Dextrin 88 Cannot Utilize A3 D-Maltose D-Maltose 94 Cut-off Value A4 D-Trehalose D-Trehalose 96 Cut-off Value A5 D-Cellobiose D-Cellobiose 97 Cut-off Value A6 Gentiobiose Gentiobiose 120 Cut-off Value A7 Sucrose Sucrose 98 Cut-off Value A8 D-Turanose D-Turanose 104 Cut-off Value A9 Stachyose Stachyose 92 Cut-off Value B1 D-Raffinose D-Raffinose 72 Cannot Utilize B2 α-D-Lactose α-D-Lactose 89 Cut-off Value B3 D-Melibiose D-Melibiose 79 Cannot Utilize B4 β-Methyl-D-Glucoside β-Methyl-D-Glucoside 86 Cannot Utilize B5 D-Salicin D-Salicin 51 Cannot Utilize B6 N-Acetyl-D-Glucosamine N-Acetyl-D-Glucosamine 87 Cannot Utilize B7 N-Acetyl-β-D-Mannosamine N-Acetyl-β-D-Mannosamine 81 Cannot Utilize B8 N-Acetyl-D-Galactosamine N-Acetyl-D-Galactosamine 86 Cannot Utilize B9 N-Acetyl Neuraminic Acid N-Acetyl Neuraminic Acid 57 Cannot Utilize C1 α-D-Glucose α-D-Glucose 113 Cut-off Value C2 D-Mannose D-Mannose 112 Cut-off Value C3 D-Fructose D-Fructose 142 Can Utilize C4 D-Galactose D-Galactose 121 Cut-off Value C5 3-Methyl Glucose 3-Methyl Glucose 104 Cut-off Value C6 D-Fucose D-Fucose 131 Cut-off Value C7 L-Fucose L-Fucose 133 Cut-off Value C8 L-Rhamnose L-Rhamnose 128 Cut-off Value C9 Inosine Inosine 75 Cannot Utilize D1 D-Sorbitol D-Sorbitol 54 Cannot Utilize D2 D-Mannitol D-Mannitol 94 Cut-off Value D3 D-Arabitol D-Arabitol 82 Cannot Utilize D4 myo-Inositol myo-Inositol 82 Cannot Utilize D5 Glycerol Glycerol 78 Cannot Utilize D6 D-Glucose-6-PO4 D-Glucose-6-PO4 104 Cut-off Value D7 D-Fructose-6-PO4 D-Fructose-6-PO4 167 Can Utilize D8 D-Aspartic Acid D-Aspartic Acid 68 Cannot Utilize D9 D-Serine D-Serine 62 Cannot Utilize E1 Gelatin Gelatin 32 Cannot Utilize E2 e Amino Acetyl-L-Proline Glycyl-L-Proline 72 Cannot be used E3 L-Alanine L-Alanine 84 Cannot be used E4 L-Arginine L-Arginine 69 Cannot be used E5 L-Aspartic Acid L-Aspartic Acid 68 Cannot be used E6 L-Glutamic Acid L-Glutamic Acid 63 Cannot be used E7 L-histamine L-Histidine 112 Boundary value E8 L-Pyroglutamate L-Pyroglutamic Acid 63 Cannot be used E9 L-Serine L-Serine 59 Cannot be used F1 pectin Pectin 81 Cannot be used F2 D-galacturonic acid D-Galacturonic Acid 108 Boundary value F3 L-Galactosuronolactone L-Galactonic Acid Lactone 103 Boundary value F4 D-gluconic acid D-Gluconic Acid 53 Cannot be used F5 D-glucuronic acid D-Glucuronic Acid 123 Boundary value F6 Glucuronamide Glucuronamide 184 Can be used F7 mucic acid; mucous acid Mucic Acid 52 Cannot be used F8 Quinic acid Quinic Acid 47 Cannot be used F9 Glycolic acid D-Saccharic Acid 55 Cannot be used G1 p-Hydroxyphenylacetic acid p-Hydroxy Phenylacetic Acid 30 Cannot be used G2 Methyl pyruvate Methyl Pyruvate 54 Cannot be used G3 D-Methyl lactate D-Lactic Acid Methyl Ester 64 Cannot be used G4 L-lactic acid L-Lactic Acid 48 Cannot be used G5 citric acid Citric Acid 105 Boundary value G6 α-Ketoglutaric acid α-Keto-Glutaric Acid 147 Can be used G7 D-Malic acid D-Malic Acid 59 Cannot be used G8 L-Malic acid L-Malic Acid 82 Cannot be used G9 Bromo-succinic acid Bromo-Succinic Acid 61 Cannot be used H1 Twain 40 Tween 40 60 Cannot be used H2 γ-aminobutyric acid γ-Amino-Butryric Acid 75 Cannot be used H3 α-Hydroxybutyric acid α-Hydroxy_x0002_Butyric Acid 55 Cannot be used H4 β-Hydroxy-D,L-butyric acid β-Hydroxy-D,L Butyric Acid 69 Cannot be used H5 α-Ketobutyrate α-Keto-Butyric Acid 104 Boundary value H6 Acetoacetic acid Acetoacetic Acid 164 Can be used H7 Propionic acid Propionic Acid 87 Cannot be used H8 Acetic acid Acetic Acid 114 Boundary value H9 Formic acid Formic Acid 69 Cannot be used

[0056] 4. Test the ability of screening strains to utilize other substances

[0057] The energy substances shown in Table 2 were added to the 9K basic salt culture medium, and the iron-sulfur oxidizing bacteria hq2 strain was centrifuged and inoculated at a ratio of 10%. Samples were taken every 3 days to test the OD 600 The strain's utilization of various energy sources was assessed by monitoring its growth at the absorbance value (Table 2). The results showed that the screened iron-sulfur oxidizing bacteria strain hq2 had little ability to utilize glucose, sucrose, mannose, trehalose, and malic acid. In the absence of yeast, it was unable to utilize ferrous ions or sulfur for autotrophic growth. However, it could oxidize iron and sulfur in the presence of trace amounts of yeast.

[0058] Table 2: Utilization of other substances by strain hq2

[0059]

[0060] Example 3: Screening of strain hq2 for its utilization of different iron concentrations at extreme pH

[0061] During the experiments, the selected strains demonstrated robust activity at pH 1. Furthermore, in the presence of trace organic matter, they were able to efficiently oxidize ferrous ions at extremely low pH and high ferrous ion concentrations. This physiological property is crucial for their growth in extreme pH environments rich in iron and sulfur, poor in organic matter, or in inorganic mineral environments. It also provides advantages in the leaching of various low-grade minerals, such as pyrite. Ferrous iron and sulfur are the primary energy sources available in many natural and artificial extremely acidic environments. Sulfur, when utilized by various microorganisms, ultimately forms sulfate, which inevitably leads to a continuous decrease in pH. Furthermore, high concentrations of ferrous and ferric ions can also pose a certain stress to cell growth. Therefore, the strain's ability to tolerate low pH and high ferrous / ferric concentrations significantly enhances its application in extreme environments.

[0062] The culture medium and reagent information used in this example are as follows:

[0063] 1) 11.05 g / L, 22.1 g / L, and 44.2 g / L FeSO4.7H2O stock solutions: Prepare 10 times the stock solution with dilute sulfuric acid solution, adjust the final pH to 1.2, filter through a 0.22 μm filter membrane, and add to sterilized 9K culture medium at a rate of 10 mL / 100 mL.

[0064] 2) 0.02% Yeast stock solution: Prepare 100 times the stock solution with pure water, sterilize at 121°C, and add 1 mL / 100 mL.

[0065] 3) The specific formula of 9K medium is as follows: (NH4)2SO4 3g, KCI 0.1g, MgSO4.7H2O 0.5g, K2HPO4 0.5g, Ca(NO3)2 0.01g. Adjust the pH to 1.0 with sulfuric acid, make up to 900mL, and sterilize at 121°C for 20min.

[0066] The specific experimental steps are as follows:

[0067] To 9K medium at pH 1.0, sterilized 0.02% yeast stock solution was added at a ratio of 1 mL / 100 mL. Filter-sterilized FeSO4.7H2O stock solutions of varying concentrations were added at a ratio of 10 mL / 100 mL.

[0068] At a 30% inoculation ratio, centrifuge and collect the exponential phase cells of the selected strain hq2, wash them three times with 9K medium at pH 1.0, and inoculate them into the prepared medium. The culture temperature was 37°C and the shaker was 180 rpm. Every two days during the culture process, samples were taken to test the changes in pH, ORP, and cell number. ORP is used to indicate Fe 2+The degree of oxidation, when Fe 2+ Oxidized to Fe 3+ And it continues to accumulate in the culture system, which will lead to increased oxidative strength in the system and an increase in the redox potential (ORP). When ORP increases from about 300 to about 600, it means that Fe 2+ The cells have been oxidized to a great extent. Then the number of cells was detected by direct counting under a microscope. Figure 7 As shown. It can be seen that the screened strains were sensitive to different concentrations of Fe at pH 1.0. 2+ They all have strong oxidizing ability. And in 2 days, the Fe contained in 11.05g / L to 44.2g / L FeSO4.7H2O 2+ The oxidation rate of ions is over 90%. Figure 7 C can be seen that the number of cells has also increased from 10 7 Increased to 10 8 This shows that the screened strain still has good growth at the extreme pH of 1.0 and exhibits excellent oxidation efficiency for high concentrations of ferrous ions.

[0069] In addition, the strains of Sulfobacillus that have been reported so far include Sulfobacillus thermotolerans Kr1, S. thermosulfidooxidans VKM B-1269, S.acidophilus NAL, and S. sibiricus N1 strains cannot grow at pH 1.0. The strains that are most closely related to the screened strain hq2 Sulfobacillus thermotolerans Kr1, and also no effect on high concentration Fe at pH 1.0 2+ The FeSO4.7H2O concentration used in the culture of Kr1 strain in related reports was only 9.82 g / L (Table 3).

[0070] Table 3: Screening strains hq2 and Sulfobacillus thermotolerans Comparison of growth characteristics of Kr1 strains

[0071] Characteristic Sulfobacillussp.hq2 Sulfobacillus.thermotolerans Kr1 Nutritional types mixotrophic mixotrophic Cell size(um) 0.6×3.8-3.0 0.8-1.2×1.5-4.5 Growth pH range(optimum) 1.0-5.0(2.0) 1.2-2.4(2.0) Growth temperature range(optimum)(℃) 30-50（37 or 42） 20-60(40) Mineral substrate Fe 2+ , S 0 ]] Fe 2+ ,S 0 ,S4O6 2- ]]>

[0072] The strain screened by the present invention not only has a wider growth pH, ​​higher concentration of Fe 2+ and Fe 3+ It has high tolerance and can oxidize high concentration Fe efficiently under extremely low pH conditions. 2+ , is a good resource leaching microbial strain.

Claims

1. An iron-sulfur oxidizing bacterium, characterized in that The deposit number of the iron-sulfur oxidizing bacteria is CGMCC No. 26454, and the Latin name of the iron-sulfur oxidizing bacteria is Sulfobacillus thermotolerans .

2. Use of the iron-sulfur oxidizing bacteria according to claim 1 in oxidizing ferrous ions or elemental sulfur.

3. The use according to claim 2, characterized in that The ferrous ions are ferrous ions in sewage.

4. Use of the iron-sulfur oxidizing bacteria according to claim 1 in biological leaching.

5. A method for bioleaching, characterized in that: The method is to use the iron-sulfur oxidizing bacteria according to claim 1 as biological leaching bacteria to carry out biological leaching.

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