Biological catalysis method for enhancing clostridium arsenic methylation and volatilization and application thereof

Abstract

The invention belongs to the technical field of microorganisms, discloses a biological catalysis method for strengthening arsenic methylation and volatilization of clostridium and application of the biological catalysis method, and particularly discloses application of resazurin in improving the methylation capacity of bacteria on arsenic. The invention provides the functions of improving the generation and volatilization of methyl arsenic, cell adsorption and the like of bacteria (such as clostridium sporogenes) by resazurin for the first time. Experiments prove that the methylation and volatilization effects of clostridium sporogenes on inorganic trivalent arsenic can be remarkably improved by exogenously adding resazurin, and an effective means can be provided for remediation of arsenic-polluted soil and water.

Description

Technical Field

[0001] The invention belongs to the technical field of microorganisms, and in particular relates to a biocatalytic method for enhancing methylation and volatilization of arsenic by clostridium and an application thereof. Background Art

[0002] Arsenic is a toxic metalloid element that is ubiquitous in the environment, mainly existing in the form of inorganic trivalent and pentavalent arsenic. In addition to the natural high arsenic background in some areas, human activities including fossil fuel development, ore smelting, and pesticide use can also increase arsenic in the environment, thereby increasing the health risks of human arsenic exposure. Arsenic methylating functional microorganisms can convert inorganic trivalent arsenic into low-toxic methylarsenic and volatile arsenic gas, reduce the concentration of effective arsenic, and help remove arsenic from water bodies. Therefore, the use of microbial arsenic methylation can provide an environmentally friendly and sustainable remediation technology for arsenic-contaminated water bodies. Arsenic methylation and volatilization, as a detoxification mechanism of microorganisms, are catalyzed by intracellular S-adenosylmethionine (SAM) methyltransferase ArsM, in which the synthesis of the methyl donor SAM requires the consumption of ATP to drive. The efficiency of arsenic methylation will be affected by the internal arsenic transformation process of the cell (such as cellular arsenic efflux, etc.) and external environmental factors (such as redox potential and organic matter concentration), which limits the application effect of arsenic volatilization in arsenic microbial remediation technology. Therefore, it is urgent to propose effective means to improve arsenic volatilization in arsenic-contaminated groundwater and soil environments.

[0003] Chinese invention patent CN114480230A provides a strain of Clostridium sporogenes with the function of fermentation, hydrogen production and simultaneous anaerobic arsenic methylation. However, the strain has certain deficiencies in arsenic methylation and volatilization. Therefore, the present application is proposed. Summary of the invention

[0004] The first aspect of the present invention aims to provide the use of resazurin in improving the methylation ability of bacteria to arsenic.

[0005] The second aspect of the present invention aims to provide a method.

[0006] The third aspect of the present invention aims to provide a method.

[0007] The fourth aspect of the present invention aims to provide a reagent that can improve the methylation and volatilization functions of bacterial arsenic.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is:

[0009] The first aspect of the present invention provides the use of resazurin in any one of (1) to (12):

[0010] (1) Improve the ability of bacteria to methylate arsenic;

[0011] (2) preparing products that improve the ability of bacteria to methylate arsenic;

[0012] (3) Improve the volatilization performance of bacteria to arsenic;

[0013] (4) preparing products that improve the volatility of bacteria to arsenic;

[0014] (5) Improve the adsorption of arsenic by bacteria;

[0015] (6) preparing products that enhance the adsorption of arsenic by bacteria;

[0016] (7) Promote bacterial growth;

[0017] (8) preparing products that promote bacterial growth;

[0018] (9) Inhibit the hydrogen production activity of bacteria;

[0019] (10) preparing products that inhibit the hydrogen production activity of bacteria;

[0020] (11) Inhibit the production of fermentation metabolites of bacteria;

[0021] (12) preparing products that inhibit the production of bacterial fermentation metabolites;

[0022] The fermentation metabolites include acetic acid and / or lactic acid.

[0023] In some embodiments of the present invention, the bacteria include at least one of Clostridium sporogenes, Bacillus, Shewanella, Cellulotrophic bacteria, Chitinophaga, and Achromobacter xylosoxidans.

[0024] In some preferred embodiments of the present invention, the bacteria are Clostridium sporogenes and / or Bacillus.

[0025] In some more preferred embodiments of the present invention, the bacteria is Clostridium sporogenes (deposit number is GDMCC No: 62212) and / or Bacillus (deposit number is GDMCC No: 62092).

[0026] In some embodiments of the present invention, the arsenic is trivalent arsenic.

[0027] In some embodiments of the present invention, the arsenic includes arsenous acid and / or arsenite.

[0028] In some embodiments of the present invention, the methylation in (1) to (2) includes monomethylation, dimethylation and / or trimethylation.

[0029] The second aspect of the present invention provides a reagent or a kit comprising resazurin, glucose and trypticase.

[0030] In some embodiments of the present invention, when the reagent or kit is used, the reaction system contains 1 to 600 μM resazurin.

[0031] In some preferred embodiments of the present invention, when the reagent or kit is used, the reaction system contains 50-500 μM resazurin.

[0032] In some embodiments of the present invention, when the reagent or kit is used, the reaction system contains 5-20 mM glucose and 0.5-3 g / L trypticase.

[0033] In some embodiments of the present invention, when the reagent or kit is used, the reaction system contains 7-15 mM glucose and 0.5-2 g / L trypticase.

[0034] In some embodiments of the present invention, when the reagent or kit is used, the reaction system contains 10-15 mM glucose and 1-2 g / L trypticase.

[0035] The third aspect of the present invention provides a method, comprising the steps of placing resazurin, the reagent or the kit of the second aspect of the present invention in an environment containing arsenic and bacteria;

[0036] The method comprises any one of (a1) to (a3):

[0037] (a1) A method for improving the methylation ability of bacteria to arsenic;

[0038] (a2) A method for improving the volatility of arsenic by bacteria;

[0039] (a3) A method for improving the adsorption of arsenic by bacteria.

[0040] In some embodiments of the present invention, the methylation includes monomethylation, dimethylation and / or trimethylation.

[0041] In some embodiments of the present invention, the arsenic is inorganic trivalent arsenic.

[0042] In some embodiments of the present invention, the arsenic includes arsenous acid and / or arsenite.

[0043] In some embodiments of the present invention, the environment is culture medium, soil or water.

[0044] In some embodiments of the present invention, the concentration of the inorganic trivalent arsenic in the environment and water is in the range of 0 to 200 μmol / L.

[0045] In some embodiments of the present invention, the culture medium comprises NBAF medium.

[0046] In some embodiments of the present invention, the carbon and nitrogen sources in the culture medium include at least one of glucose, trypsin, and methionine.

[0047] In some embodiments of the present invention, the carbon and nitrogen sources in the culture medium are glucose and trypticase.

[0048] In some embodiments of the present invention, the bacteria include at least one of Clostridium sporogenes, Bacillus, Shewanella, Cellulotrophic bacteria, Chitinophaga, and Achromobacter xylosoxidans.

[0049] In some preferred embodiments of the present invention, the bacteria are Clostridium sporogenes and / or Bacillus.

[0050] In some more preferred embodiments of the present invention, the bacteria is Clostridium sporogenes (deposit number is GDMCC No: 62212) and / or Bacillus (deposit number is GDMCC No: 62092).

[0051] A fourth aspect of the present invention provides a method comprising the steps of treating bacteria using resazurin, the reagent or the kit of the second aspect of the present invention;

[0052] The method comprises any one of (b1) to (b3):

[0053] (b1) a method for promoting bacterial growth;

[0054] (b2) A method for inhibiting the hydrogen production activity of bacteria;

[0055] (b3) A method for inhibiting the production of fermentation metabolites of bacteria.

[0056] In some embodiments of the invention, the fermentation metabolites include acetic acid and / or lactic acid.

[0057] In some embodiments of the present invention, the bacteria include at least one of Clostridium sporogenes, Bacillus, Shewanella, Cellulotrophic bacteria, Chitinophaga, and Achromobacter xylosoxidans.

[0058] In some preferred embodiments of the present invention, the bacteria are Clostridium sporogenes and / or Bacillus.

[0059] In some more preferred embodiments of the present invention, the bacteria is Clostridium sporogenes (deposit number is GDMCC No: 62212) and / or Bacillus (deposit number is GDMCC No: 62092).

[0060] The beneficial effects of the present invention are:

[0061] The present invention proposes for the first time that resazurin can improve the arsenic methylation, volatilization and adsorption of bacteria (such as Clostridium sporogenes). Experiments have shown that exogenous addition of resazurin can significantly improve the methylation and volatilization of inorganic trivalent arsenic by Clostridium sporogenes.

[0062] Specifically, 50-500 μM resazurin can significantly promote the production of water-soluble methylarsenic in Clostridium sporogenes compared with the blank, and the concentration increases with the increase of concentration. The concentrations of water-soluble dimethylarsenic and trimethylarsenic in the 500 μM treatment are increased by 2.3 times and 2.7 times respectively compared with the blank. The proportion of dimethyl arsenic in the total methyl arsenic is 95.6% to 96.6%. The production of volatile arsenic (mainly dimethyl arsenic hydride, accounting for 90.8% to 94.9% of the total volatile arsenic) also shows a trend of significant increase with the addition of resazurin. There is no significant difference in volatile arsenic between the 100 μM resazurin and 300 μM treatments, and the volatile arsenic in the 500 μM treatment is increased by 3.2 times compared with the blank. The presence of resazurin significantly increased the concentration of cell-adsorbed arsenic by 1.4 to 2.1 times compared with the blank treatment (0.47 μg / L). There was no significant difference in cell-adsorbed methyl arsenic between the 100 μM resazurin treatment and the 300 μM resazurin treatment. In all treatments, the proportion of dimethyl arsenic in the total adsorbed methyl arsenic was 67.7% to 83.4%.

[0063] 50-500 μM resazurin significantly promoted the growth of Clostridium sporogenes, increasing by 11.7%-18.3%. For fermentation metabolites, resazurin reduced lactic acid production, and it decreased with the increase of resazurin concentration. The lactic acid production was the lowest when the resazurin concentration was 500 μM, which was 52.5% lower than the blank treatment; for the fermentation product acetic acid, the acetic acid production in the resazurin treatment group decreased with the increase of resazurin concentration, which was 21.1%-38.8% lower than the non-resazurin treatment group, and the acetic acid production under 500 μM resazurin treatment was the lowest. The cumulative production of hydrogen in the resazurin treatment decreased with the increase of resazurin concentration, which was 5.3%-25% lower than the non-resazurin treatment (12.3 mM), and the hydrogen accumulation was the lowest under 500 μM resazurin (9.2 mM).

[0064] It can be seen that Clostridium sporogenes can accelerate growth and arsenic volatilization under the condition of exogenous addition of resazurin, and has application potential in carbon neutral arsenic pollution remediation.

[0065] The method provided by the present invention can effectively improve the methylation and volatilization rate of arsenic by Clostridium, can provide an effective means for the restoration of arsenic-contaminated soil and water bodies, and has the characteristics of simple operation, economy and practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 This figure shows the effects of carbon and nitrogen organic substrate components in the culture medium on the production of water-soluble methyl arsenic by C.sporogenes LHA6.

[0067] Figure 2 The figures show the effects of different concentrations of resazurin (RZ) on arsenic methylation and volatilization of C. sporogenes LHA6; (a) shows the change of water-soluble dimethyl arsenic concentration with culture time, (b) shows the change of water-soluble trimethyl arsenic concentration with culture time, (c) shows the composition and concentration of volatile methyl arsenic after 72 hours of culture, and (d) shows the composition and concentration of cell-bound methyl arsenic after 72 hours of culture.

[0068] Figure 3 The graph shows the effect of different concentrations of resazurin (RZ) on the growth and fermentation product production of C. sporogenes LHA6; (a) shows the protein quality and the concentrations of short-chain fatty acids acetic acid and lactic acid after 72 hours of culture, and (b) shows the change in headspace hydrogen concentration with culture time. DETAILED DESCRIPTION

[0069] The present invention is further described in detail below through specific examples.

[0070] It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0071] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0072] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0073] Example 1 Differences in arsenic conversion by arsenic methylating Clostridium LHA6 under different carbon and nitrogen sources

[0074] Clostridium sporogenes LHA6 (deposit number GDMCC No: 62212, deposited on January 14, 2022 at Guangdong Microbiological Culture Collection Center, Building 59, No. 100, Xianlie Middle Road, Yuexiu District, Guangzhou City, Guangdong Province, and disclosed in patent document CN114480230A).

[0075] First, in order to obtain the seed solution of the strain in the logarithmic growth phase, LHA6 was inoculated at 5% (v / v) in 1 / 4 TSB medium containing 30 mM piperazine-1,4-diethanesulfonic acid (PIPES) buffer (pH = 7.0). The culture system volume was 50 mL in a 120 mL vial. After passing high-purity nitrogen for 30 minutes, it was sealed to form an anaerobic state. Then, it was cultured at 30°C in a dark environment for 30 hours to obtain the seed solution of the strain in the logarithmic growth phase. The cell density reached 0.8×10 8 ~1.6×10 8 cells / mL. The obtained seed solution was centrifuged at 5000×g for 10 min, the bacteria were washed three times with physiological saline, and then resuspended with a modified NBAF medium. The resuspended seed solution was inoculated into an arsenic-containing modified NBAF medium at 5% (v / v), wherein the concentration of sodium arsenite was 30 μM. The components of the arsenic-containing modified NBAF medium include CaCl2·2H2O 0.04g / L, MgSO4·7H2O 0.1g / L, NaHCO3 1.8g / L, Na2CO3 0.4273g / L, Na2SeO4 0.001mM, 100X NB Salts 10mL / L and NB MineralElixir 10mL / L. Among them, the composition of 100X NB Salts is as follows: KH2PO4 42g / L, K2HPO4 22g / L, NH4Cl 20g / L, KCl 38g / L and NaCl 36g / L. The composition of NB Mineral Elixir is as follows: nitrilotriacetic acid 2.14 g / L, MnCl2·4H2O 0.1 g / L, FeSO4·7H2O 0.3 g / L, CoCl2·6H2O 0.17 g / L, ZnSO4·7H2O 0.2 g / L, CuCl2·2H2O 0.03 g / L, AlK(SO4)2·12H2O 0.005 g / L, H3BO3 0.005 g / L, Na2MnO4·2H2O0.09 g / L, NiSO4·6H2O0.11 g / L and Na2WO4·2H2O 0.02 g / L.

[0076] In order to determine the optimal carbon and nitrogen components of the culture medium for arsenic methylation of the strain, different organic substrate treatments were set up, including methionine (10mM), methionine (10mM) + trypticase (1g / L), glucose (10mM) and glucose (10mM) + trypticase (1g / L). The volume of the culture system was 50mL in a 120mL cillin bottle, the pH of the culture system was adjusted to 7.0, and a CO2:N2 (20:80) mixed gas was introduced for 30min and then sealed, and then cultured at 30℃ in the dark for 72h. After the culture was completed, the liquid sample was filtered through a 0.22μm filter head, and the concentrations of soluble trimethylarsenic, dimethylarsenic and monomethylarsenic in the solution were determined by high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS, PerkinElm).

[0077] Results of methylarsenic production by LHA6 in different carbon and nitrogen organic substrate treatments Figure 1 As shown in the results, the amount of dimethyl arsenic produced in glucose treatment was 8.4 μg / L, and the amount of dimethyl arsenic produced in glucose + trypticase complex substrate treatment was 31.4 times higher than that in glucose treatment. The production of trimethyl arsenic showed similar changes. The production of trimethyl arsenic in glucose treatment was 0.3 μg / L, which increased to 5.1 μg / L after complex substrate treatment. There was no significant difference in the production of dimethyl arsenic and trimethyl arsenic when methionine was the only substrate compared with methionine + trypticase and single glucose treatment. These results indicate that carbohydrate substrates (glucose) and trypticase complex substrates are more conducive to the arsenic methylation process of LH16 strains than amino acid (methionine) complex substrates. Therefore, glucose and trypticase complex substrates are recommended to be the preferred substrates for LHA6 arsenic methylation reactions.

[0078] Example 2: Effect of Resazurin on the Methylation and Volatilization of Arsenic by Clostridium LHA6

[0079] After obtaining the strain seed solution in the logarithmic growth phase with the method of Example 1, it was inoculated into the arsenic-containing modified NBAF medium at 5% (v / v), wherein the sodium arsenite concentration was 30 μM, and glucose (10 mM) + trypsin (1 g / L) was used as the organic substrate. In order to determine the resazurin (resazurin, ZR) concentration in the culture system with the best arsenic methylation and volatilization, the resazurin concentration gradient treatment was set, including 0 μM, 50 μM, 100 μM, 300 μM and 500 μM. The volume of the culture system was 50 mL in a 120 mL cillin bottle, the pH of the culture system was adjusted to 7.0, and the CO2: N2 (20: 80) mixed gas was introduced for 30 min and then sealed, and then cultured at 30 ° C for 72 h in dark.

[0080] Liquid sampling was performed at various time points during the culture process, and the bacterial cells and headspace arsenic gas were collected at the end of the culture after 72 hours for testing cell-adsorbed arsenic and volatile arsenic. All bacterial liquids were centrifuged at 5000×g for 10 minutes, the supernatant was discarded, the bacteria were washed three times with PIPES buffer, and the liquid after being digested with 0.5% nitric acid for 1 hour was used to determine cell-adsorbed methyl arsenic. The chemical capture of volatile arsenic compounds was achieved by reacting them with the solid oxidant Ag(NO3). High-purity nitrogen (100kPa) filtered through a 0.22μm syringe filter was used to blow the headspace of the anaerobic tube for 10 minutes, and the nitrogen outlet was connected to a 1mL syringe filled with high-purity silica gel particles (sigma, Davisil Grade 636, pore size 636) soaked in 10% AgNO3. 35–60 mesh particlesize). The silica gel particles after arsenic capture were boiled at 90°C for 1 h in 2 mL 0.5% (V / V) HNO3 under reflux to recover volatile arsenic. 5 μL H2O2 (3%) was added to 0.5 mL of the recovered solution to oxidize CH3AsH2, (CH3)2AsH and (CH3)3As to monomethyl arsenic, dimethyl arsenic and trimethyl arsenic, respectively. All liquid samples were filtered through a 0.22 μm filter head, and the concentrations of soluble trimethyl arsenic, dimethyl arsenic and monomethyl arsenic were determined using the above-mentioned high performance liquid chromatography-inductively coupled plasma mass spectrometry.

[0081] The quantitative analysis results of soluble and volatile methyl arsenic products of LHA6 strain under different concentrations of resazurin showed that methyl arsenic accumulated continuously during the 72h culture period, and 33μg / L water-soluble dimethyl arsenic and 1.3μg / L water-soluble trimethyl arsenic were generated at 72h. Figure 2 In the resazurin treatment group, 50-500 μM significantly promoted the generation of water-soluble methylarsenic in LHA6 compared with the blank, and the concentration increased with the increase of concentration. In the 500 μM treatment, the concentrations of water-soluble dimethylarsenic and trimethylarsenic increased by 2.3 times and 2.7 times respectively compared with the blank ( Figure 2 b). The proportion of dimethyl arsenic to total methyl arsenic in all treatments was 95.6% to 96.6%. The volatile arsenic production of LHA6 strain in the blank treatment was 0.025 μg. The volatile arsenic production also showed a trend of significant increase with the addition of resazurin. There was no significant difference in volatile arsenic between the 100 μM resazurin and 300 μM treatments, and the volatile arsenic in the 500 μM treatment increased by 3.2 times compared with the blank ( Figure 2c). The form of volatile methyl arsenic in all treatments was mainly dimethyl arsenic hydride, accounting for 90.8% to 94.9% of the total volatile arsenic. The presence of resazurin significantly increased the concentration of cell-adsorbed arsenic by 1.4 to 2.1 times compared with the blank treatment (0.47 μg / L), and there was no significant difference in cell-adsorbed methyl arsenic between the 100 μM resazurin and 300 μM treatments. The proportion of dimethyl arsenic to the total adsorbed methyl arsenic in all treatments was 67.7% to 83.4% ( Figure 2 These results suggest that exogenous resazurin can increase the arsenic methylation and volatilization efficiency of LHA6.

[0082] Example 3 Growth and fermentation product changes of arsenic-methylating Clostridium LHA6 under the influence of resazurin

[0083] This example is used to verify the growth and fermentation products of arsenic-methylating Clostridium LHA6 under different resazurin concentration treatment conditions in Example 2, as follows:

[0084] After the culture was completed, all the cells were collected and washed three times with PIPES buffer and resuspended to 5 mL. 0.3 mL of the resuspended bacterial solution was aspirated and 1 mL of 0.2 M NaOH solution was added. The cell lysate was obtained after shaking at 120 r / min for 30 min at 100 ° C. The protein concentration in the lysate was determined using a modified Bradford protein concentration determination kit (Sangon, China) to characterize the cell biomass. Organic acids were detected by high performance liquid chromatography (Agilent 1260, USA) with a UV detector, using a C18 column (4.6 mm × 250 mm), a column temperature of 30 ° C, a mobile phase of 0.1 M NaH2PO4·2H2O, pH adjusted to 3.1, and a flow rate of 1 mL / min.

[0085] 50-100 μM and 500 μM resazurin significantly promoted the growth of strain LHA6, increasing by 11.7% to 18.3% compared with the blank treatment ( Figure 3 (a). Resazurin promoted cell growth at lower concentrations (50-100 μM), which may be related to the fact that AQDS and resazurin enhanced the extracellular electron transfer flux of cells. For fermentation metabolites, the presence of resazurin reduced lactic acid production, and it decreased with the increase of resazurin concentration. The lactic acid production was the lowest when the resazurin concentration was 500 μM, which was 52.5% lower than that of the blank treatment ( Figure 3 For the fermentation product acetic acid, the acetic acid production in the resazurin treatment group decreased with the increase of resazurin concentration, which was 21.1% to 38.8% lower than that in the non-resazurin treatment group. The acetic acid production under 500 μM resazurin treatment was the lowest ( Figure 3The cumulative production of hydrogen in the resazurin treatment decreased with the increase of resazurin concentration, and was 5.3% to 25% lower than that in the no-resazurin treatment (12.3 mM). The hydrogen accumulation was the lowest under the 500 μM resazurin condition (9.2 mM) ( Figure 3 b). The hydrogen production was further normalized by protein concentration to reflect the hydrogen production capacity of the strain per unit mass. The results showed that the hydrogen production of strain LHA6 in the presence of resazurin (0.81-1.05 mmol / mg) was 17.6%-36.6% lower than that in the absence of resazurin, indicating that resazurin inhibited the hydrogen production activity of the strain.

[0086] The above results show that the presence of resazurin has an inhibitory effect on the hydrogen production of the strain and the production of fermentation metabolites acetic acid and lactic acid. Since the redox potential of resazurin (-51mV) is higher than the redox potential of hydrogen (-410mV), this potential difference makes the presence of resazurin helpful to increase the extracellular electron transfer flux of Clostridium. In addition, resazurin is a small molecule, lipid-soluble electron shuttle that can directly enter the periplasm and interact with periplasmic proteins and inner membrane proteins to affect electron distribution, which may affect the intracellular carbon metabolic pathway. Therefore, resazurin promotes the occurrence of arsenic methylation reaction and the generation of volatile methyl arsenic by adjusting the intracellular carbon metabolic pathway while inhibiting the fermentation metabolic activity.

[0087] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. Use of resazurin in any one of (1) to (12): (1) Improve the ability of bacteria to methylate arsenic; (2) preparing products that improve the ability of bacteria to methylate arsenic; (3) Improve the volatilization performance of bacteria to arsenic; (4) preparing products that improve the volatility of bacteria to arsenic; (5) Improve the adsorption of arsenic by bacteria; (6) preparing products that improve the adsorption of arsenic by bacteria; (7) Promote bacterial growth; (8) preparing products that promote bacterial growth; (9) Inhibit the hydrogen production activity of bacteria; (10) preparing products that inhibit the hydrogen production activity of bacteria; (11) Inhibit the production of fermentation metabolites of bacteria; (12) preparing products that inhibit the production of bacterial fermentation metabolites; The fermentation metabolites include acetic acid and / or lactic acid.

2. The use according to claim 1, characterized in that: The bacteria include at least one of Clostridium sporogenes, Bacillus, Shewanella, Cellulotrophic bacteria, Chitinophagous bacteria, and Achromobacter xylosoxidans.

3. The use according to claim 1, characterized in that: The arsenic is inorganic trivalent arsenic; Preferably, the arsenic includes arsenous acid and / or arsenite.

4. The use according to any one of claims 1 to 3, characterized in that: The methylation in (1) to (2) includes monomethylation, dimethylation and / or trimethylation.

5. A reagent or kit comprising resazurin, glucose and trypticase.

6. A method comprising placing resazurin, the reagent or the kit of claim 5 in an environment containing arsenic and bacteria; The method comprises any one of (a1) to (a3): (a1) A method for improving the methylation ability of bacteria to arsenic; (a2) A method for improving the volatility of arsenic by bacteria; (a3) A method for improving the adsorption of arsenic by bacteria.

7. The method according to claim 6, characterized in that The methylation includes monomethylation, dimethylation and / or trimethylation; Preferably, the arsenic is inorganic trivalent arsenic; Preferably, the arsenic comprises arsenous acid and / or arsenite; Preferably, the environment is culture medium, soil or water; Preferably, the concentration range of the inorganic trivalent arsenic in the environment and water is 0 to 200 μmol / L.

8. The method according to claim 7, characterized in that The culture medium comprises NBAF culture medium; Preferably, the carbon and nitrogen sources in the culture medium include at least one of glucose, trypticase, and methionine; Preferably, the carbon and nitrogen sources in the culture medium are glucose and trypticase.

9. A method comprising the step of treating bacteria using resazurin, the reagent or the kit according to claim 5; The method comprises any one of (b1) to (b3): (b1) a method for promoting bacterial growth; (b2) A method for inhibiting the hydrogen production activity of bacteria; (b3) A method for inhibiting the production of fermentation metabolites of bacteria.

10. The method according to any one of claims 6 to 9, characterized in that: The bacteria include at least one of Clostridium sporogenes, Bacillus, Shewanella, Cellulotrophic bacteria, Chitinophagous bacteria, and Achromobacter xylosoxidans.

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