Application of electrochemical active bacteria sensitive to heavy metal pollutants in detection of biotoxicity of water quality

Abstract

The invention discloses application of electrochemical active bacteria sensitive to heavy metal pollutants in detection of water quality biotoxicity, and belongs to the technical field of water quality biotoxicity detection.After the electrochemical active bacteria are exposed to toxic pollutants, the water quality biotoxicity is determined according to an electric signal inhibition rate; the toxic pollutants are heavy metal pollutants; the electrochemical active bacteria are enterobacter aerogenes or enterobacter cloacae and are selected from enterobacter. The electrochemical active bacteria sensitive to the heavy metal pollutants are used, so that the sensitivity of determining the biotoxicity of the heavy metal pollutants is expected to be improved, the application bottleneck of low sensitivity is overcome, and a technical support is provided for biotoxicity monitoring work in China.

Description

Application of an electrochemically active bacterium sensitive to heavy metal pollutants in the detection of water biotoxicity Technical Field

[0001] This invention belongs to the field of water quality biotoxicity detection technology, and in particular relates to the application of an electrochemically active bacterium sensitive to heavy metal pollutants in the detection of water quality biotoxicity. Background Technology

[0002] Biotoxicity indicators reflect the impact of toxic pollutants in the aquatic environment on the metabolism of organisms. When toxic pollutants are present in water, the metabolism of organisms is inhibited by toxicological effects. Therefore, measuring the metabolic characteristics of organisms can help determine the quality of the water environment. Using biotoxicity indicators to detect toxic pollutants in water has advantages such as simple operation, rapid response, wide detection range, and reflection of the overall toxicity of water quality. The core of biotoxicity indicator detection is the test organism, commonly including fish, algae, fleas, mussels, and bacteria. Fish were the earliest test organisms used, but their sensitivity is low and individual differences are significant. Currently, the most commonly used test organism is luminescent bacteria. The luminescence intensity of luminescent bacteria reflects intracellular metabolic activity; therefore, measuring the effect of water on the luminescence intensity of luminescent bacteria can evaluate the biotoxicity of water quality. However, the luminescence intensity of luminescent bacteria is easily affected by the concentration of chloride ions in the water, and the light signal is also interfered with by the color and turbidity of the water, resulting in low accuracy and a high likelihood of false positives in the detection of biotoxicity by luminescent bacteria.

[0003] Novel biotoxicity detection technologies based on electrochemically active bacteria exhibit strong anti-interference capabilities. These bacteria possess a unique energy metabolism mechanism, enabling them to transfer electrons from their respiratory chain to the extracellular space, generating an electric current while maintaining physiological metabolism. When toxic pollutants are present in the water, the metabolic activity of the electrochemically active bacteria decreases, leading to a drop in current. Therefore, measuring the electrical signal of the electrochemically active bacteria can detect the biotoxicity of the water. Compared to other biotoxicity detection technologies, electrochemically active bacteria serve as both the test organism and the transducer, ensuring that the detection results are unaffected by water color, turbidity, or chloride ions. Furthermore, the formed electrochemically active biofilm possesses advantages such as adaptability to water flow, self-sustaining properties, and self-repairing capabilities. Consequently, electrochemically active bacteria-based water biotoxicity detection technology has become a research hotspot both domestically and internationally, and is considered one of the most promising water biotoxicity detection technologies currently available.

[0004] Since the first report of electrochemically active bacteria for detecting water biotoxicity, existing technologies have utilized these bacteria in laboratory settings to detect heavy metals, antibiotics, benzene compounds, organophosphorus pesticides, and herbicides, with some successful cases of early warning of water pollution incidents. Furthermore, these studies have optimized the process parameters for electrochemically active bacteria-based water biotoxicity detection, including configuration, substrate concentration, control mode, influent method, and signal acquisition method, achieving detection levels for common toxic pollutants that have reached or exceeded those of other tested organisms. However, despite these advancements, the sensitivity of electrochemically active bacteria for detecting toxic pollutants remains relatively low, making it difficult to detect trace amounts of toxic pollutants in water bodies.

[0005] Employing electrochemically active bacteria sensitive to toxic pollutants holds promise for improving the sensitivity of water quality biotoxicity detection. This is because electrochemically active bacteria detect water quality biotoxicity based on the stress effect of toxic pollutants on bacteria, and different types of bacteria exhibit varying resistance to toxic pollutants. Therefore, changing the type of electrochemically active bacteria used as the test organism and utilizing those sensitive to toxic pollutants (referred to as sensitive electrochemically active bacteria) is expected to improve the sensitivity of water quality biotoxicity detection. Currently, existing studies have primarily used strains of the genus *Shewanella* as the test organisms for biotoxicity testing, but have not used sensitive electrochemically active bacteria specifically targeting toxic pollutants. Heavy metal pollutants are the most common toxic pollutants. A review of existing research reveals that sensitive electrochemically active bacteria for heavy metal pollutants are unclear, and no studies using sensitive electrochemically active bacteria to determine the biotoxicity of heavy metal pollutants have been reported.

[0006] Therefore, how to provide a method for effectively determining the biotoxicity of heavy metal pollutants using electrochemically active bacteria is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention proposes the application of electrochemically active bacteria sensitive to heavy metal pollutants in the detection of biotoxicity in water.

[0008] To achieve the above objectives, the present invention provides the following technical solution: the application of electrochemically active bacteria sensitive to heavy metal pollutants in the detection of water biotoxicity, wherein the water biotoxicity of toxic pollutants is determined based on the electrical signal inhibition rate of the bacterial solution of the electrochemically active bacteria; wherein the toxic pollutant is a heavy metal pollutant; and wherein the electrochemically active bacteria is Enterobacter, selected from Enterobacter aerogenes or Enterobacter cloacae.

[0009] Beneficial effects: This invention utilizes the high sensitivity of Enterobacteriaceae to heavy metal pollutants to provide a novel and effective method for detecting the biotoxicity of heavy metal pollutants in water.

[0010] Preferably, the method for preparing the bacterial solution of the electrochemically active bacteria includes the following steps: after culturing the electrochemically active bacteria in a shake flask to the stable period, centrifuging, and then resuspending the bacterial precipitate using the test solution or pure water to obtain the bacterial solution of the electrochemically active bacteria.

[0011] More preferably, the resuspension time is 1 minute.

[0012] More preferably, the bacterial solution of the electrochemically active bacteria has an absorbance of about 1.0 at 600 nm.

[0013] Preferably, the heavy metal pollutant includes one of Pb, Hg, Tl, Cd, and Cr.

[0014] Preferably, the method for calculating the electrical signal inhibition rate is as follows: electrical signal inhibition rate CR = (C0 - C) / C0 × 100%; where C is the electrical signal of the electrochemically active bacteria solution obtained by resuspending the bacterial precipitate in the test solution; and C0 is the electrical signal of the electrochemically active bacteria solution obtained by resuspending the bacterial precipitate in pure water.

[0015] Preferably, the method for detecting the electrical signal includes the following steps: adding NaCl solution to the bacterial culture of electrochemically active bacteria, exposing it with high-temperature shaking, adding potassium ferricyanide solution, reacting with high-temperature shaking, centrifuging after the reaction is completed, taking the supernatant and adding it to a screen-printed electrode, and testing the current using the chronoamperometry method.

[0016] More preferably, the NaCl solution has a mass concentration of 13.6%, and the volume ratio of the NaCl solution to the electrochemically active bacteria solution is 1:15.

[0017] Preferably, the high-temperature oscillation exposure is at a temperature of 50°C for 2 hours, and the vortex oscillation speed is 200 rpm.

[0018] More preferably, the concentration of the potassium ferricyanide solution is 1 mol / L, and the volume ratio of the potassium ferricyanide solution to the electrochemically active bacteria solution is 1:22.5.

[0019] Preferably, the high-temperature oscillation reaction is carried out at a temperature of 50°C for 1 hour, and the vortex oscillation speed is 200 rpm.

[0020] Compared with the prior art, the present invention has the following advantages and technical effects: The present invention uses electrochemically active bacteria of the genus Enterobacter, instead of the traditional electrochemically active bacteria of the genus Shewanella. This genus has higher sensitivity to heavy metal pollutants, which can improve the sensitivity of the determination of the biotoxicity of heavy metal pollutants, overcome the application bottleneck of low sensitivity, and provide technical support for my country's biotoxicity monitoring work. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application. In the accompanying figures: Figure 1 shows the bacterial genera with significant changes in abundance after exposure to high and low concentrations of Cd(II) in Example 1; where CdH represents the high-concentration Cd exposure group; CdL represents the low-concentration Cd exposure group; and Con represents the blank control. Figure 2 shows the bacterial genera with significant changes in abundance after exposure to high and low concentrations of Cr(VI) in Example 1; where CrH represents the high-concentration Cr exposure group; CrL represents the low-concentration Cr exposure group; and Con represents the blank control. Figure 3 shows the bacterial genera with significant changes in abundance after exposure to high and low concentrations of Pb(II) in Example 1; where PbH represents the high-concentration Pb exposure group; PbL represents the low-concentration Pb exposure group; and Con represents the blank control. Figure 4 shows the time-current curves of electricity generation by Enterobacter aerogenes (a) and Enterobacter cloacae (b) in Example 2. Figure 5 shows the effects of 10 mg / L Cr(VI) exposure on Shewanella loihicaPV-4 (a), Enterobacter aerogenes (b), and Enterobacter cloacae (c) in Example 3. The effect of cloacae (c) on electrical performance, and the electrical signal inhibition rate of common heavy metal pollutants determined by three strains (d). Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] This invention provides an application of electrochemically active bacteria sensitive to heavy metal pollutants in the detection of biotoxicity in water quality. The biotoxicity of toxic pollutants is determined based on the electrical signal of the bacterial solution of the electrochemically active bacteria. The toxic pollutant is a heavy metal pollutant. The electrochemically active bacteria is Enterobacter, selected from Enterobacter aerogenes or Enterobacter cloacae.

[0025] In a preferred embodiment, the method for preparing the bacterial solution of the electrochemically active bacteria includes the following steps: culturing the electrochemically active bacteria to the stable period, centrifuging, and then resuspending the bacterial precipitate using the test solution or pure water to obtain the bacterial solution of the electrochemically active bacteria.

[0026] In a more preferred embodiment, the resuspension time is 1 minute.

[0027] In a preferred embodiment, the heavy metal pollutant includes one of Pb, Hg, Tl, Cd, and Cr.

[0028] Preferably, the method for calculating the electrical signal inhibition rate is as follows: electrical signal inhibition rate CR = (C0 - C) / C0 × 100%; where C is the electrical signal of the electrochemically active bacteria solution obtained by resuspending the bacterial precipitate in the test solution; and C0 is the electrical signal of the electrochemically active bacteria solution obtained by resuspending the bacterial precipitate in pure water.

[0029] Preferably, the method for detecting the electrical signal includes the following steps: adding NaCl solution to the bacterial culture of electrochemically active bacteria, exposing it with high-temperature shaking, adding potassium ferricyanide solution, reacting with high-temperature shaking, centrifuging after the reaction is completed, taking the supernatant and adding it to a screen-printed electrode, and testing the current using the chronoamperometry method.

[0030] In a more preferred embodiment, the NaCl solution has a mass concentration of 13.6%, and the volume ratio of the NaCl solution to the electrochemically active bacteria solution is 1:15.

[0031] In a preferred embodiment, the high-temperature oscillation exposure is at a temperature of 50°C for 2 hours and the vortex oscillation speed is 200 rpm.

[0032] In a more preferred embodiment, the concentration of the potassium ferricyanide solution is 1 mol / L, and the volume ratio of the potassium ferricyanide solution to the electrochemically active bacteria solution is 1:22.5.

[0033] In a preferred embodiment, the temperature of the high-temperature oscillation reaction is 50°C, the time is 1 hour, and the vortex oscillation speed is 200 rpm.

[0034] Unless otherwise specified, all raw materials used in the embodiments of this invention were purchased through commercial channels; among them, the ATCC number of Enterobacter cloacae strain is 13047; the ATCC number of Enterobacter aerogenes strain is 13048; and the ATCC number of Shewanella loihicaPV-4 strain is BAA-1088.

[0035] The effluent from the microbial electrochemical cell was prepared in the laboratory. The specific method was as follows: anaerobic activated sludge was used as the seed source and inoculated into a three-electrode electrochemical cell at a ratio of 10 g / L. The three-electrode electrochemical cell was positioned at a depth of 2 cm. A 2cm carbon cloth is used as the working electrode. 2cm A 1 mm platinum sheet was used as the counter electrode, and an Ag / AgCl electrode as the reference electrode. The electrolyte was a DM solution, containing 2.5 g NaHCO3, 0.08 g CaCl2·H2O, 1.0 g NH4Cl, 0.94 g MgCl2·6H2O, 10 g NaCl, and 7.2 g HEPES per liter of DM solution. The microbial electrochemical cell was started and operated using a chronoamperometry method, with the electrode potential set to 0 V.

[0036] The microbial electrochemical system used in this embodiment of the invention has been operating stably in the laboratory for more than 3 years, and the sludge in it was taken from the anaerobic tank of a municipal sewage treatment plant.

[0037] The specific components of the vitamins in the embodiments of the present invention are shown in Table 1: Table 1 The specific composition of the minerals is shown in Table 2: Table 2 Unless otherwise specified, room temperature or normal temperature in the embodiments of the present invention refers to 25±3℃.

[0038] Example 1 Screening of sensitive electrochemically active bacteria includes the following steps: (1) Prepare an electrochemically active bacteria enrichment culture medium for a simplified electron transfer model of a microbial fuel cell by adding raw materials including 2.5 g NaHCO3, 0.068 g CaCl2, 1 g NH4Cl, 0.094 g MgCl2, 10 g NaCl, 7.2 g HEPES, 5 mL vitamins, 12.5 mL minerals, 5 mmol ferric citrate, and 10 mmol sodium acetate per liter. Sodium acetate is the only electron donor and ferric citrate is the only electron acceptor.

[0039] (2) Take the same electrochemically active bacteria enrichment culture medium obtained in step (1) and divide it into high concentration Cd exposure group, low concentration Cd exposure group, high concentration Cr exposure group, low concentration Cr exposure group, high concentration Pb exposure group, and low concentration Pb exposure group, and set up three parallel test groups for each group.

[0040] The high-concentration Cd exposure group (CdH) used a culture medium containing electrochemically active bacteria enriched with 5 mg / L Cd(II); the low-concentration Cd exposure group (CdL) used a culture medium containing electrochemically active bacteria enriched with 2.5 mg / L Cd(II); the high-concentration Cr (CrH) exposure group used a culture medium containing electrochemically active bacteria enriched with 5 mg / L Cr(VI); the low-concentration Cr exposure group (CrL) used a culture medium containing electrochemically active bacteria enriched with 2.5 mg / L Cr(VI); the high-concentration Pb exposure group (PdH) used a culture medium containing electrochemically active bacteria enriched with 5 mg / L Pb(II); the low-concentration Pb exposure group (PdL) used a culture medium containing electrochemically active bacteria enriched with 2.5 mg / L Pb(II).

[0041] (3) In the anaerobic workstation, the same microbial electrochemical cell effluent containing electrochemically active mixed bacteria capable of stable electricity generation was inoculated into each group of electrochemically active bacteria enrichment culture medium in step (2), and anaerobic culture was carried out. The inoculation amount was 50% (v / v, i.e., 50% volume of microbial electrochemical cell effluent and 50% volume of electrochemically active bacteria enrichment culture medium), the culture temperature was 30℃, the shaking speed was 150rpm, and the culture time was 5d.

[0042] (4) The culture medium obtained in step (3) was sequenced using 16S rRNA to compare the differences in microbial composition in each group, and the microbial species that significantly decreased under toxic exposure conditions were screened for potentially heavy metal pollutant sensitive electrochemically active bacteria. The results are shown in Figure 1-3.

[0043] As shown in Figures 1-3, the abundance of *Enterobacter* (Enterobacteria) significantly decreased from 41.94% (Con, blank group) to 26.74% after exposure to low concentrations of Cd(II). Upon exposure to high concentrations of Cd(II), the abundance further decreased to 7.21%. Analysis of variance showed a significant difference among the three groups (p < 0.05), suggesting that *Enterobacter* has high sensitivity to Cd(II). *Arcobacter* (Toxoplasma) exhibits resistance to heavy metal pollutants, and its abundance shows a positive trend. Therefore, strains of *Arcobacter* are not suitable for the detection of heavy metal pollutants.

[0044] Similar results were found for exposure to the other two heavy metal pollutants. After exposure to low concentrations of Cr(VI), the abundance of *Enterobacter* decreased to 27.93%, and after exposure to high concentrations of Cr(VI), it decreased to 25.12%. Similarly, after exposure to low concentrations of Pb(II), the abundance of *Enterobacter* decreased to 41.40%, and after exposure to high concentrations of Pb(II), it decreased to 27.66%. All of these differences were statistically significant between the groups.

[0045] Example 2: Electrochemically active bacteria power generation test, including the following steps: (1) Enterobacter aerogenes and Enterobacter cloacae were aerobically activated and cultured in LB medium, with a culture temperature of 30°C, a shaking speed of 150 rpm, and a culture time of 36 h. Each liter of LB medium contained 10 g peptone, 10 g NaCl, and 5 g yeast extract. Activated bacterial solution was obtained.

[0046] (2) Construct a three-electrode electrochemical cell, using a 2 cm electrode. A 2 cm carbon cloth is used as the working electrode, and a 2 cm piece of carbon cloth is used as the working electrode. A 2cm platinum sheet was used as the counter electrode, and an Ag / AgCl electrode as the reference electrode. The three-electrode electrochemical cell was filled with an inoculum of 50% (v / v, i.e., 50% volume of LB medium and 50% volume of activated bacterial solution). The three-electrode electrochemical cell was then connected to a multichannel potentiostat, and the operation was performed using the chronoamperometry method. The electrode potential was set to 0.5 V vs. the reference electrode. The electrogenic performance results are shown in Figure 4.

[0047] As shown in Figure 4, after inoculation with *Enterobacter aerogenes*, the three-electrode electrochemical cell exhibited a current of approximately 10 μA. Subsequently, the current in each three-electrode electrochemical cell rapidly increased, reaching a peak after approximately 30 h of operation, with a maximum peak current of 39.2 μA and an average peak current of 32.0 μA. After reaching the peak current, the current in each group of three-electrode electrochemical cells slowly decreased. These results demonstrate that *Enterobacter aerogenes* possesses electrochemical activity and electrogenic capacity. Similarly, *Enterobacter cloacae* also exhibited electrochemical activity and electrogenic capacity, with a maximum peak current of 40.1 μA and an average peak current of 36.8 μA.

[0048] Example 3 Biotoxicity test of electrochemically active bacteria against heavy metal pollutants: Potentially sensitive electrochemically active bacteria (Enterobacter cloacae and Enterobacter aerogenes, experimental group) and model electrochemically active bacteria (Shewanella loihica PV-4) were used as test organisms (control group). The following water quality biotoxicity test method was used for determination, including the following steps: (1) The above bacteria were cultured in LB medium in a shake flask until the stationary phase to obtain a bacterial suspension; (2) 50 mL of bacterial suspension was centrifuged, and the bacterial precipitate was resuspended in a solution containing toxic pollutants (concentration of heavy metal pollutants of 5 mg / L or 10 mg / L) or pure water for 1 min to obtain the bacterial solution of electrochemically active bacteria. The amount of solution containing toxic pollutants added was such that the absorbance of the bacterial solution of electrochemically active bacteria at 600 nm was about 1.0; (3) 900 μL of the above electrochemically active bacteria bacterial solution was added to 60 (3) Add 13.6% (0.85%×16 physiological saline) NaCl solution of μL and vortex at 50 ℃ for 2 h at a vortex speed of 200 rpm to complete the high temperature vortex exposure; (4) Add 40 μL of 1 M potassium ferricyanide solution and vortex at 50 ℃ for 1 h at a vortex speed of 200 rpm to complete the high temperature vortex reaction; (5) Centrifuge the solution obtained after the high temperature vortex reaction, take 100 μL of supernatant and add it to the screen-printed electrode, and use the chronoamperometry to test the current. The electrical signal represents the rate at which electrochemically active bacteria reduce potassium ferricyanide to produce potassium ferrocyanide. The higher the electrical signal, the stronger the metabolic activity of the electrochemically active bacteria. At the same time, the electrical signal inhibition rate is calculated using the electrical signal.

[0049] Wherein, the electrical signal suppression rate CR = (C0-C) / C0×100%; where C is the electrical signal of the electrochemically active bacteria solution obtained by resuspending the bacterial precipitate in a solution containing toxic pollutants; and C0 is the electrical signal of the electrochemically active bacteria solution obtained by resuspending the bacterial precipitate in pure water.

[0050] The results are shown in Figure 5. Part b shows that when the solution contained 10 mg / L Cr(VI), the electrical signal of *Enterobacter aerogenes* decreased from 20.84 μA to 14.95 μA, with an inhibition rate of 28.26%. Part c shows that strain *Enterobacter cloacae* also showed a significant response, with the electrical signal decreasing from 13.50 μA to 8.23 ​​μA, with an inhibition rate of 39.04%. Part a shows that the electrical signal of *Shewanellaloihica PV-4* not only did not decrease but actually increased significantly, with an inhibition rate of -18.32%. Clearly, this intuitively demonstrates that the two *Enterobacter* strains responded better to the presence of the heavy metal Cr(VI).

[0051] In addition to Cr (VI), four other common heavy metal pollutants were tested: 5 mg / L Pb (II), 5 mg / L Hg (II), 10 mg / L Tl (III), and 5 mg / L Cd (II) to further verify this conclusion. The results are shown in part d of Figure 5. As shown in section d, the electro-signal inhibition rates of the three strains after Pb(II) exposure were 15.26% (Enterobacter cloacae), 28.07% (Enterobacter aerogenes), and 8.41% (Shewanella loihicaPV-4), respectively; after Hg(II) exposure, the electro-signal inhibition rates of the three strains were 16.95% (Enterobacter cloacae), 26.16% (Enterobacter aerogenes), and 9.06% (Shewanella loihicaPV-4), respectively; after Tl(III) exposure, the electro-signal inhibition rates of the three strains were 7.04% (Enterobacter cloacae), 7.41% (Enterobacter aerogenes), and 1.66% (Shewanella loihicaPV-4), respectively; and after Cd(II) exposure, the electro-signal inhibition rates of the three strains were 25.22% (Enterobacter cloacae), 28.07% (Enterobacter aerogenes), and 8.41% (Shewanella loihicaPV-4), respectively. cloacae), 16.67% (Enterobacteraerogenes), -8.97% (Shewanella loihicaPV-4).

[0052] All these results demonstrate that the two Enterobacter strains have a higher sensitivity to heavy metal pollutants than the electrochemically active model bacteria Shewanella loihica PV-4, indicating that these two strains are sensitive electrochemically active bacteria to heavy metal pollutants, and also demonstrating that the Enterobacter genus has a better sensitivity to heavy metal pollutants than the electrochemically active model bacteria Shewanella genus.

[0053] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. The application of an electrochemically active bacterium sensitive to heavy metal pollutants in the detection of biotoxicity in water quality, characterized in that, The biotoxicity of toxic pollutants in water was determined based on the inhibition rate of the electrochemically active bacteria's bacterial solution; the toxic pollutants were heavy metal pollutants; the electrochemically active bacteria were Enterobacteriaceae, specifically Enterobacter aerogenes or Enterobacter cloacae.

2. The application of electrochemically active bacteria sensitive to heavy metal pollutants according to claim 1 in the detection of biotoxicity in water quality, characterized in that, The method for preparing the bacterial solution of the electrochemically active bacteria includes the following steps: after culturing the electrochemically active bacteria to the stable period, centrifuging, and then resuspending the bacterial precipitate with the test solution or pure water to obtain the bacterial solution of the electrochemically active bacteria.

3. The application of electrochemically active bacteria sensitive to heavy metal pollutants according to claim 1 in the detection of biotoxicity in water quality, characterized in that, The heavy metal pollutants include one of Pb, Hg, Tl, Cd, and Cr.

4. The application of electrochemically active bacteria sensitive to heavy metal pollutants according to claim 1 in the detection of biotoxicity in water quality, characterized in that, The method for calculating the electrical signal inhibition rate is as follows: Electrical signal inhibition rate CR = (C0 - C) / C0 × 100%; where C is the electrical signal of the electrochemically active bacteria solution obtained by resuspending the bacterial precipitate in the test solution; and C0 is the electrical signal of the electrochemically active bacteria solution obtained by resuspending the bacterial precipitate in pure water.

5. The application of an electrochemically active bacterium sensitive to heavy metal pollutants according to claim 1 in the detection of biotoxicity in water quality, characterized in that, The method for detecting the electrical signal includes the following steps: adding NaCl solution to the bacterial culture of electrochemically active bacteria, exposing it with high temperature and shaking, adding potassium ferricyanide solution, reacting with high temperature and shaking, centrifuging after the reaction is completed, taking the supernatant and adding it to a screen-printed electrode, and testing the current using the chronoamperometry method.

6. The application of an electrochemically active bacterium sensitive to heavy metal pollutants according to claim 5 in the detection of biotoxicity in water quality, characterized in that, The high-temperature oscillation exposure was conducted at a temperature of 50°C for 2 hours, with a vortex oscillation speed of 200 rpm.

7. The application of electrochemically active bacteria sensitive to heavy metal pollutants according to claim 5 in the detection of biotoxicity in water quality, characterized in that, The high-temperature oscillation reaction was carried out at a temperature of 50°C for 1 hour, with a vortex oscillation speed of 200 rpm.

Images