KR20180059382A - Composition for enhancing the sensitivity of a bioreactor strain that detects oxidative damage substances - Google Patents

Abstract

The present invention relates to a composition for enhancing the sensitivity of a bio-reporter strain for detecting oxidative damage substances, which includes polyethyleneimine (PEI), and to a method for enhancing the sensitivity of a bio-reporter strain using the composition, and specifically, to a composition for enhancing reactivity and the sensitivity of the bio-reporter strain into which a gene capable of detecting the oxidative damage substances including the PEI is introduced, and to a method for enhancing the reactivity and the sensitivity of a bacterial bio-reporter using the composition.

Description

TECHNICAL FIELD [0001] The present invention relates to a composition for enhancing the sensitivity of a bioreactor strain that detects oxidative damage substances,

The present invention relates to a composition for enhancing the sensitivity of a bioreporter strain that detects oxidative damage substances, including polyethyleneimine (PEI), and a method for enhancing the sensitivity of a bioreporter strain using the composition.

Bacterial bio-reporters are known to be convenient to use because they have the ability to generate measurable signals in response to specific chemicals or stimuli and are easy to use and low in cost, so they can be used in a wide range of areas including wastewater treatment and environmental toxicity assessment Has come.

Conventionally, there has been known a technique for detecting the stress in a cell using a bio-reporter. However, when the concentration of virologen is measured using a conventional technique, the biosensor has been used as a biosensor due to toxicity due to oxidative stress of the biosensor The sensitivity of the biosensor itself deteriorates due to the death of the organism.

In order to solve the above problems, techniques for using an assistant agent have been developed to optimize the function of a bio-reporter. In fact, techniques for increasing the sensitivity of a bio-reporter using a serum complement have been developed. However, In nature, there was a problem of being sensitive to environmental factors.

Therefore, it is required to develop a technique for accurately detecting the stress in cells using a bio-reporter.

Accordingly, one object of the present invention is to provide a composition for enhancing the sensitivity of a bio-reporter strain that detects an oxidative damage substance, including polyethyleneimine (PEI).

Yet another object is to provide a method for enhancing the sensitivity of a bioreporter strain, comprising the step of treating the composition with a bioreporter strain.

Another object of the present invention is to provide a composition for detecting oxidative damage or a composition for detecting oxidative damage, which comprises a bioreporter strain that detects a polyethyleneimine and an oxidative damage substance.

It is another object of the present invention to provide a method for detecting an oxidative damage substance in a sample or a method for detecting an oxidative damage (for example, a cell) in a sample, including a step of culturing a bioreporter strain that detects an oxidative damage substance in a sample together with polyethyleneimine Provides a detection method. The sample may be any substance for which the presence of oxidative damage substances or oxidative damage is to be measured. For example, environmental samples (eg, soil, water (sewage, sewage, wastewater, , Crops, etc.).

The present invention relates to a method for detecting an oxidative stress and a method for improving sensitivity of a bio-reporter strain that detects an oxidative damage substance using polyethyleneimine (PEI).

Specifically, the present inventors have found that when pDEW201-sodA :: lux CDABE plasmid prepared by inserting the sodA promoter into the pDEW201 plasmid is transformed into a bacterium, polyethyleneimine is added to the bacterium to produce an oxidative damage substance of the bacteriophage Detection or oxidative stress sensing reaction and sensitivity are improved, thereby completing the present invention.

In the present invention, the term "bio-reporter " refers to a substance or device that detects and measures specific information from a sample and converts the value into useful signals readable by an observer. Generally, (Eg, genes, enzymes, antigens, antibodies, biochemicals, hormones, receptors, etc.) and electrochemical changes in the reaction of substances to be analyzed in the sample, changes in thermal energy, changes in fluorescence or color And a conversion device.

The term "bioreporter strain" in the present invention refers to a genetically modified strain into which the above-described bioreporter system is introduced. Preferably, the bioreporter strain of the present invention is a recombinant strain transformed with a vector comprising an inducible promoter activated under a specific stress or a specific stimulation condition and a reporter gene operably linked to the promoter, wherein a specific stress or specific stimulus May be a strain that produces a recognizable signal such as fluorescence or luminescence as expression of the reporter gene is increased by the activation of the promoter in the presence of the condition.

Examples of the specific stress or specific stimulation conditions include, but are not limited to, genotoxins, oxidative radicals, phenolic compounds, pesticides, and the like. The use of a bio-reporter strain enables rapid detection of the presence of specific stress-inducing substances or specific irritants in the sample, and the harmfulness and toxicity thereof.

As used herein, the term "oxidative stress" refers to the fact that the balance between an oxidant occurring in a living body (or cell) and its corresponding antioxidant is destroyed, , The term "oxidative damage" refers to various kinds of damage (such as genetic damage, cellular metabolic abnormalities, etc.) caused by such oxidative stress, which is caused by a decrease in the antioxidant power in the living body ). ≪ / RTI > In this specification, unless otherwise specified, an oxidative damage substance (or an oxidative damage inducing substance) and an oxidative stress substance (or an oxidative stress inducing substance) are used in an equivalent sense.

As used herein, the term "inducible promoter " refers to a promoter that induces expression of a gene operably linked to a promoter under the specific stress or under specific stimulation conditions only. In one example, the sodA gene promoter that is activated in the presence of an oxidative stress inducer can be exemplified, but the scope of the present invention is not limited thereto.

The term "reporter gene" in the present invention refers to a gene capable of visually confirming the expression thereof by expressing bioluminescence, fluorescence or color development upon gene expression, for example, Photinus sp. Or Phyrophourus sp. But are not limited to, a lux gene derived from the luc gene, Vibrio fisheri or Photorhabdus luminescens, Rluc gene derived from Renila reniformis, and a gfp gene derived from Aequorea Victoria or Renilla reniformis. Preferably, the lux CDABE gene can be used as a reporter gene.

 In the present invention, the term "luxCDABE" refers to a gene complex composed of luxC, luxD, luxA, luxB, and luxE, and has been reported as an operon present in Vibrio fisheri or Photorhabdus luminescens. In the present invention, the luxCDABE gene can be obtained by using a method such as synthesis, isolation or purchase in an organism. For example, pDEW201 (Dupont Co., USA; FIG. 8) having luxCDABE can be purchased and used , But is not limited thereto.

As used herein, the term " enhancing the sensitivity of a bio-reporter strain " may mean improving the degree to which a bioreporter reacts with a substance and improving the sensitivity for a substance and reaction.

In one example, the bio-reporter in the present invention can be produced by transforming pDEW201-sodA :: lux CDABE plasmid prepared by inserting the sodA promoter into a pDEW201 plasmid into a strain, into E. coli BW25113, but the present invention is not limited thereto. The bio-reporter strain may detect oxidative damage material or detect oxidative stress.

In this specification, the pDEW201-sodA :: luxCDABE plasmid can be used to induce a luminescent reaction in response to oxidative stress caused by an oxidative damaging substance, and the luminescent reaction is detected to determine the presence or absence of oxidative damaging substances Can be measured.

The promoter of SodA can be used to detect oxidative damage material as a promoter whose action is initiated in response to oxidative stress caused by the oxidative damaging material.

That is, the present invention can measure the oxidative stress and determine the presence or concentration of a substance to be detected or oxidative damage causing oxidative stress.

In the present specification, in order to detect oxidative damage substances, the amount of a standardized biosensor (the number of bacterial cells including a bioreactor standardized through OD, the absorbance at a wavelength of 600 nm was measured to be about 800 million (8 x 10 < 8 >) CFU), wherein the numerical value of the bioluminescence amount is an oxidative stress (for example, Lt; RTI ID = 0.0 > of sodA < / RTI > promoter by expression of the bioluminescent gene.

However, when the bacterium reacts with oxidative stress to induce a luminescent reaction, if the toxic reaction occurs, the luminescent reaction may be reduced. Therefore, when the bacterium responds to oxidative stress and a luminescent reaction is induced, a toxic reaction occurs It is necessary to make it a minimum or a minimum.

Therefore, in the case of using a bioraphotter strain to detect oxidative damage substances, the detection accuracy of the substance to be detected can be improved if the sensitivity to the substance to be detected is high so as not to cause toxicity to bacteria.

Hereinafter, the present invention will be described in more detail.

In one aspect, the present invention relates to a composition for enhancing the sensitivity of a bioreporter strain that detects oxidative damage materials, including polyethyleneimine (PEI).

The sensitivity of detecting oxidative damage substances can be enhanced by adding polyethyleneimine (PEI) to the bio-reporter strain.

For example, a bioreporter strain that detects an oxidative damage substance may be a recombinant strain transformed with a vector comprising a sodA promoter (SEQ ID NO: 1) and a reporter gene operably linked downstream of the promoter. As the reporter gene, luxCDABE can be used, but is not limited thereto.

The sodA promoter is a promoter located upstream of a gene encoding SOD (superoxide dismutase), which is the most essential enzyme in defense and recovery against oxidative stress, and its activity is induced and increased under oxidative stress conditions And can be used in a biosensor for detecting oxidative damage substances contained in a sample.

More specifically, when the sodA promoter is fused with a reporter gene (for example, a lux gene) and introduced into a strain, the promoter activity of the strain is induced in an environment exposed to an oxidative damage substance, So that the presence or the presence of the oxidative damage substance in the sample can be easily detected and quantified. Thus, strains into which the sodA promoter and reporter gene fusions are introduced can be used to determine the degree of risk for toxic chemicals causing oxidative damage.

In a specific embodiment of the present invention, a pDEWMCS plasmid is introduced by introducing various restriction enzyme sites into pDEW201 as a bio-reporter strain to detect oxidative damage substances, and the sodA promoter region Were inserted to prepare recombinant plasmids pSDK and pSDS, which were introduced into E. coli MG1655, and the obtained bioreporter strain was used.

The host strain of the bioreporter of the present invention is not particularly limited, but it is preferably a Gram negative strain, more preferably an E. coli strain.

In the present invention, measurement of luminescence or fluorescence of a bioreporter strain can be performed using all optical measuring instruments, for example, photomultipliers, charge coupled devices, luminometers, photometers, fiber optic cables, liquid scintillation counters, and the like.

In the present invention, when polyethyleneimine is added to a bio-reporter strain for detecting the oxidative damage substance, the reaction and sensitivity as bioreporters that detect oxidative stress are lower than those when polyethyleneimine is not added, for example, , About 2 times, about 2.5 times, about 3 times, about 3.5 times, about 4 times, about 4.5 times, about 5 times, (The upper limit may be about 30 times, about 25 times, or about 20 times, but not limited thereto).

The polyethyleneimine may increase the permeability of the membrane of the bio-reporter strain and penetrate molecules that induce oxidative stress into the cell membrane, thereby improving the sensitivity and detection of oxidative damage substances of the bio-reporter strain.

The polyethylene imine (PEI) may be a branched polyethyleneimine or a linear polyethyleneimine, and the branched polyethyleneimine may have a concentration of 200 to 2000 ppm, a concentration of 200 to 1800 ppm, a concentration of 200 to 1600 ppm, a concentration of 200 to 1400 ppm , A concentration of 200 to 1200 ppm, a concentration of 400 to 2000 ppm, a concentration of 600 to 2000 ppm, a concentration of 800 to 2000 ppm, or a concentration of 1000 to 2000 ppm, the oxidative damage of the bioreporter strain It is possible to increase the reaction and sensitivity as a bioreporter for detecting a substance or oxidative stress,

Wherein the linear polyethyleneimine has a concentration of 50 to 2000 ppm, a concentration of 150 to 2000 ppm, a concentration of 450 to 2000 ppm, a concentration of 750 to 2000 ppm, a concentration of 1000 to 2000 ppm, a concentration of 50 to 1800 ppm, When using concentrations of ppm, concentrations of 50 to 1400 ppm, concentrations of 50 to 1200 ppm, and concentrations of 50 to 1000 ppm, the reaction and sensitivity as bioreporters that detect oxidative damage substances or oxidative stress of the bacteria are increased .

In addition, when the branched polyethyleneimine was added to the bio-reporter strain for detecting oxidative damages, the degree of bioluminescence, which is an indicator of the toxicity of the bioreactor strain, was higher than that of the polyethylene imine , About 10 to 50%, 20 to 50%, 30 to 50%, 40 to 50%, 20 to 40%, or 20 to 30%.

The oxidative impairment substance may be caused by a variety of substances including Viologen, hydrogen peroxide or paraquat, but it is preferably meant to be caused by a viologen (viologen group) do.

The viologen may be selected from the group consisting of Benzyl Viologen (BV), Ethyl Aminopropyl Viologen (EAV), Methyl Aminopropyl Viologen (MAV), Ethyl Viologen (EV) Or Heptyl Viologen (HV).

The toxicity of the bioreactor strain may mean that it inhibits the growth of the cells in culture and causes death.

In one embodiment of the present invention, 0.8 kDa branched polyethyleneimine (BPEI) was the most cytotoxic. When 200 ppm of branched polyethyleneimine having a branched polyethylenimine of 1.3 kDa or more and 750 kDa or less was added, 30% Was found within 40 to 90 minutes, and when 200 ppm of linear polyethyleneimine of 10 kDa or more and 70 kDa or less was added, a bioluminescence reduction of 30% was found within 40 to 50 minutes (Fig. 6).

In one embodiment of the present invention, when BPEI was added at 400 ppm (mg / L) of 0.8 kDa, benzyl viologen (BV), ethyl aminopropyl viologen (EAV), methylaminopropyl biologen (Methyl Aminopropyl Viologen, MAV), Ethyl Viologen (EV), or Heptyl Viologen (HV) was improved by 2 to 16 times (FIG. 7).

In yet another aspect, the present invention relates to a method of enhancing the sensitivity of a bioreporter strain, comprising the step of treating the composition with a bioreporter strain.

By increasing the sensitivity of the bio-reporter strain, the sensitivity of the bio-reporter strain can be improved by increasing the bioluminescence intensity of the bio-reporter strain.

In one aspect, the present invention relates to a composition for detecting oxidative damage or a composition for detecting oxidative damage, which comprises a bioreporter strain that detects polyethyleneimine and oxidative damage substances.

In one embodiment, the present invention provides a method for detecting oxidative damage in a sample or a method for detecting an oxidant-impaired material in a sample, comprising culturing the bio-reporter strain detecting oxidative damage material in a sample together with polyethyleneimine, A method for detecting whether or not an oxidative damage has occurred. The sample may be any substance for which the presence of oxidative damage substances or oxidative damage is to be measured. For example, environmental samples (eg, soil, water (sewage, sewage, wastewater, , Crops, etc.).

The composition for enhancing the sensitivity of a bio-reporter strain detecting the oxidative damage substance is the same as the method for enhancing the sensitivity of the bio-reporter strain, the composition for detecting oxidative damage substances, and the method for detecting oxidative damage substances in the sample Lt; / RTI >

The present invention relates to a composition for enhancing the sensitivity of a bioreporter strain that detects oxidative damage substances, including polyethyleneimine (PEI), and a method for enhancing the sensitivity of a bioreporter strain using the composition, In the case of detecting oxidative damage substances using the reaction and sensitivity improvement method, the sensitivity can be improved by 2 to 4 times as compared with the conventional method. This makes it possible to more efficiently observe and quantify small amounts of chemicals.

1 is a diagram showing the chemical structure of a linear polyethyleneimine (LPEI).
2 is a view showing the chemical structure of a branched polyethyleneimine (BPEI).
FIG. 3 is a graph showing the relative bioluminescence compared to a control without PEI when 0.8 ppm of 400 ppm BPEI was used.
FIG. 4 is a graph showing the relative bioluminescence compared to a control without PEI when using 0.8 kDa BPEI 1600 ppm.
FIG. 5 is a graph showing the relative bioluminescence compared to a control without PEI when 100 ppm of 10 kDa LPEI was used.
6 is a graph showing cytotoxicity of various kinds of BPEI and LPEI.
FIG. 7 is a graph showing the change in relative bioluminescence according to the amount of input of 5 kinds of biologen in case of using 400 ppm of 0.8 kDa BPEI and in case of using BPEI without control.
Fig. 8 shows a cleavage map of the pDEW201.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, these examples are only for illustrating the present invention, and the scope of the present invention is not limited by these examples.

Example  1. Fabrication of biosensors

1-1. Oxidative  Stress-aware plasmid production

Biosens Bioelectron. The pDEW201-sodA :: luxCDABE plasmid was constructed by inserting the sodA promoter (SEQ ID NO: 1) into the pDEW201 plasmid (see FIG. 8) known in the art, 2013 Aug 15; 46: 175-82.

1-2. Oxidative  Stress-producing strains

The plasmid was transformed into E. coli BW25113 in order to produce a strain recognizing oxidative stress using the plasmid recognizing the oxidative stress produced in Example 1-1.

Example  2. Oxidative  Measurement and analysis of stress

2-1. Preparation of compound to be added to the strain

Compounds that improve the sensitivity of oxidative stress detection of strains were prepared as follows.

Two types of linear polyethyleneimines (linear PEI, LPEI 10 kDa, 70 kDa) were dissolved in 100% (v / v) ethanol to prepare a stock at a concentration of 10 g / L. Branched PEI (BPEI 0.8 kDa, 1.3 kDa, 2.0 kDa, 25 kDa, 750 kDa) were dissolved in 100% (v / v) ethanol to prepare a stock at a concentration of 625 g / L.

The oxidative stress-inducing biologen used the following five types of viologen: Benzyl Viologen (BV), Ethyl Aminopropyl Viologen (EAV), Methyl Aminopropyl Viologen Viologen, MAV), Ethyl Viologen (EV), and Heptyl Viologen (HV).

The five types of viols were dissolved in 100% (v / v) ethanol to prepare a stock at a concentration of 10 g / L.

All of the above compounds were purchased from Sigma Aldrich.

Experiments were conducted so that the final concentration of ethanol per sample of all experiments was 0.01% (v / v) or less.

2-2. On virologen  by Oxidative  Detection of stress

In order to detect the oxidative stress caused by the biosensor using the transformed strain of Example 2-1, the following experiment was conducted.

Specifically, the strain prepared in Example 1-2 was cultured in LB medium for 18 hours or more, diluted 1/100, viologen was diluted in LB, and LPEI or BPEI Was added to the LB to prepare a sample plate.

The amount of bioluminescence was standardized by measuring OD 0.1 ± 0.01 at a wavelength of 600 nm using a spectrophotometer.

In order to measure the bioluminescence caused by oxidative stress, the prepared sample plate was immediately analyzed with a bioluminescence analyzer, Glomax Multi-detection system (Promega, USA) and incubated at 30 DEG C for 10 minutes Shaking and bioluminescence were measured.

2-3. Data analysis method

The data of the present invention are summarized as the mean value of the results measured three times, and the error bars are set to the standard deviation. Data were analyzed by relative bioluminescence (RBL), which is the bioluminescence of the control divided by the bioluminescence of the sample. Also, the relative increase amount of the RBL value is obtained by dividing a large value of two data values of the comparison object under different conditions at the same time by a small value.

Example  3. By branched polyethylene imine On virologen  by Oxidative  Changes in Sensitivity of Detection of Damaged Substances

The following experiment was conducted to confirm the sensitivity change of the oxidative damage substance by the biologically active polyethylene imine. At the concentrations below, ppm means mg / L.

Experiments were carried out in the same manner as in Example 2 except that relative bioluminescence was confirmed using 0.8 kDa BPEI 400 ppm (FIG. 3) or 0.8 kDa BPEI 1600 ppm (FIG. 4).

As a result, as shown in FIG. 3 and FIG. 4, it was confirmed that the use of 400 ppm of 0.8 kDa BPEI increased the signal of the oxidative stress caused by viologen from 1.87 to 2.69 times as compared to the control without PEI , And 0.8 kDa BPEI 1600 ppm, the signal of the oxidative stress by the viologen increased from 1.61 to 14.3 times that of the control without PEI.

From the above results, it was confirmed that the oxidative damage substance of the strain recognizing the oxidative damage substance using the plasmid recognizing the oxidative damage substance prepared in Example 1-1 by 0.8 kDa BPEI 400 ppm or 0.8 kDa BPEI 1600 ppm The detection sensitivity of the present invention was increased by about 1.5 to 15 times.

Example  4. By linear polyethyleneimine On virologen  by Oxidative  Changes in Sensitivity of Detection of Damaged Substances

The following experiment was conducted to confirm the sensitivity change of detection of oxidative damage by biologen by linear polyethyleneimine.

Experiments were carried out in the same manner as in Example 2 except that 10 kDa LPEI 100 ppm (FIG. 5) was used.

As a result, as shown in FIG. 5, it was confirmed that the use of 100 ppm of 10 kDa LPEI increased the signal of the oxidative stress caused by the virosene 1.5 to 1.7 times as compared with the control without the PEI.

From the above results, it was confirmed that the detection sensitivity of the oxidative damage substance of the strain recognizing the oxidative damaging substance was 1.5 times or more, using the plasmid recognizing the oxidative stress produced by Example 1-1 with 10 kDa LPEI 100 ppm 1.7 times higher than that of the control group.

Example  5. Toxic effect of polyethyleneimine

The following experiments were carried out to determine whether cytotoxicity exists when polyethyleneimine is injected to increase the sensitivity of detection of oxidative damage by viologen.

The shorter the time taken for the relative bioluminescence of the bio-reporter strain to decrease by 30%, the higher the cytotoxicity of the PEI used.

Experiments were carried out in the same manner as in Example 2, and the time taken for the relative bio-luminescence of the bio-reporter strain to decrease by 30% was measured using seven types of polyethylene (PEI) shown in FIG. 6:

● 0.8 kDa BPEI; ○ - 1.3 kDa BPEI;

▼ 2.0 kDa BPEI; ? - 25 kDa BPEI;

■ - 750 kDa BPEI; □ - 10 kDa LPEI;

◆ - 70 kDa LPEI.

As a result, as shown in FIG. 6, the 0.8 kDa branched polyethyleneimine (BPEI) was the most cytotoxic, and the branched polyethyleneimine was 10% to 50% less cytotoxic than the linear polyethyleneimine Furthermore, the cytotoxicity was markedly increased when the molecular weight of the branched polyethyleneimine was less than 1.3 to 750 kDa on the basis of 200 mg / L polyethyleneimine and the cytotoxicity was observed in the case of linear polyethylene in the concentration of 10 to 70 kDa or less It can be confirmed that it has increased remarkably.

Based on the above results, the use of branched polyethylene imines (BPEI) of 1.3 to 750 kDa or less or linear polyethyleneimines (LPEI) of 10 to 70 kDa is highly cytotoxic and can not be used to increase sensitivity to detect oxidative damage substances of the bioreporter strain And it was found.

Example  6. Viologen  Depending on the type of polyethylene imine Oxidative  Changes in Sensitivity of Detection of Damaged Substances

The following experiment was conducted to confirm whether branched polyethyleneimine could improve the sensitivity of detection of various types of virologen.

The relative bioluminescence was measured and shown in FIG. 7 when BPEI was added at 400 ppm (mg / L) of 0.8 kDa by performing experiments in the same manner as in Example 2 using the following five types of viologen at various concentrations .

As a result, as shown in FIG. 7, when the BPEI was added at 400 ppm (mg / L) of 0.8 kDa, it was confirmed that the sensitivity for measuring 5 types of viologen was improved to 2 to 16 times.

The types of virologen tested are:

Benzyl Viologen (BV);

○ Ethyl Aminopropyl Viologen (EAV);

▼ Methyl Aminopropyl Viologen (MAV);

Ethyl Viologen (EV);

■ Heptyl Viologen (HV).

<110> UNIST (ULSAN NATIONAL INSTITUTE OF SCIENCE AND TECHNOLOGY) <120> Composition for enhancing the sensitivity of a bioreactor strain          that <130> DPP20173033 <150> KR 10/2016/0158630 <151> 2016-11-26 <160> 1 <170> KoPatentin 3.0 <210> 1 <211> 195 <212> DNA <213> Artificial Sequence <220> <223> sodA promoter <400> 1 ccgttgtcga tttactggca atcacggcat taagtgggtg atttgcttca catctcgggc 60 attttcctgc aaaaccatac ccttacgaaa agtacggcat tgataatcat tttcaatatc 120 atttaattaa ctataatgaa ccaactgctt acgcggcatt aacaatcggc cgcccgacaa 180 tactggagat gaata 195

Claims (13)

A composition for enhancing the sensitivity of a bioreporter strain that detects oxidative damage substances, including polyethyleneimine (PEI). 2. The composition of claim 1, wherein the bio-reporter strain detecting oxidative damage material is a strain transformed with a vector comprising a sodA promoter and a reporter gene operably linked to the promoter. 3. The composition of claim 2, wherein the reporter gene is lux CDABE. The composition of claim 1, wherein the polyethyleneimine (PEI) is a branched polyethyleneimine or a linear polyethyleneimine. 5. The composition of claim 4, wherein the branched polyethyleneimine has a concentration of from 200 to 2000 ppm. 5. The composition of claim 4, wherein the linear polyethyleneimine has a concentration of from about 50 to about 2000 ppm. The composition of claim 1, wherein the oxidative damage material is Viologen, hydrogen peroxide or paraquat. The method of claim 7, wherein the viologen is selected from the group consisting of Benzyl Viologen (BV), Ethyl Aminopropyl Viologen (EAV), Methyl Aminopropyl Viologen (MAV), Ethyl Violoen Ethyl Viologen, EV), or Heptyl Viologen (HV). 9. A method of treating a bacterium, comprising the step of treating a composition of any one of claims 1 to 8 to a bacteriophage strain,
A method for enhancing the sensitivity of a bio-reporter strain. A biot reporter strain for detecting polyethyleneimine and oxidative damage substances. 11. The composition of claim 10, wherein the bio-reporter strain detecting oxidative damage material is a strain transformed with a vector comprising a sodA promoter and a reporter gene operably linked to the promoter. A method for detecting an oxidative damaging substance in a sample, comprising the step of culturing a bioreporter strain that detects an oxidative damage substance in a sample together with polyethyleneimine. 2. The method of claim 1, wherein the bio-reporter strain detecting oxidative damage material is a strain transformed with a vector comprising a sodA promoter and a reporter gene operably linked to the promoter.

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