JP7022399B2 - A kit for removing radioactive iodine containing a strain of Deinococcus radiodurance having the ability to synthesize silver nanoparticles and a method for removing radioactive iodine using the kit. - Google Patents

Description

The present invention relates to a kit for removing radioactive iodine containing a strain of Deinococcus radiodurans having the ability to synthesize silver nanoparticles, and a method for removing radioactive iodine using the kit.

The risk of nuclear power plant accidents and radioactive spills due to waste is increasing, and due to the 2011 Fukushima nuclear power plant explosion in Japan, the neighboring countries of South Korea also have radioactive iodine and cesium (Cesium). Cs) etc. have been detected. Also, with the use of radioactive iodine (I ¹³¹ ) for thyroid anticancer treatment, the volume of radioactive waste has also increased due to the recent rapid increase in thyroid cancer patients. Exposure of radioactive iodine to the natural environment can cause serious pollution to ecosystems such as soil and water systems, and continuous exposure to the human body can induce cancer or hormonal abnormalities. Therefore, there is a need for efficient technological development of radioactive iodine removal technology and radioactive waste treatment method.

Compared to techniques for removing metal radioisotopes such as uranium (U), cesium, and technetium (Technetium, Tc), relatively much research has been done on methods for removing radioactive iodine. do not have. Currently, adsorbents such as zeolite and alumina, activated carbon (Non-Patent Document 1), activated carbon fiber or anion exchange resin (anion) for the removal of radioactive iodine contained in the aqueous solution. Exchange resin) has been used, but there is a problem that new solid radioactive waste may be accumulated and its removal efficiency is low. Recently, there has been an increasing number of reports on the removal of radioisotopes using nanocompounds, and methods using microorganisms have also been reported.

In particular, Deinococcus radiodurans strains are resistant to ionizing radiation that can directly damage the DNA or protein of an organism and are produced intracellularly by enzymatic or non-enzymatic systems. It has the ability to effectively remove active oxygen species (ROS). Due to these properties, the strain can be used for purification of radioactive waste and can be utilized in various fields such as medicine, health, and biotechnology.

However, conventional microbial-based radioisotope removal techniques such as Deinococcus radiodurans strains are highly efficient in removing new secondary contaminants and are readily available in contaminated environments and sites. While it has the advantage of being applicable, it has the limitation that it is not easy to recover microorganisms that have adsorbed radioisotopes. Therefore, the present inventors have devised a method for removing radioactive iodine, which facilitates recovery of microorganisms adsorbed with radioactive iodine, using a semi-permeable membrane, and completed the present invention by making this into a kit.

E Chmielewska-Horvatova et al, J Radioanal Nucl Chem 200: 351, 1995

An object of the present invention is to provide a kit for removing radioactive iodine containing a Dinococcus radiodurance strain capable of synthesizing silver nanoparticles and a method for removing radioactive iodine using the same.

In order to achieve the above object, the present invention 1) cultivates a Deinococcus radiodurans strain in a medium containing silver ions (Ag ⁺ ), and silver nanoparticles biosynthesized on the surface of the strain are formed. Step to obtain the attached Deinococcus radiodurance strain; 2) Inject the Deinococcus radiodurance strain with the silver nanoparticles biosynthesized on the surface of the strain together with the culture medium into a container with a semi-permeable membrane. Steps; and 3) The container is brought into contact with radioactive iodine-contaminated water so that the radioactive iodine passes through the semi-permeable membrane and binds to the silver nanoparticles on the surface of the strain, and the silver nanoparticles to which the radioactive iodine is bound. Provided is a method for removing radioactive iodine, which comprises a step of obtaining a Deinococcus radiodurance strain adhering to the surface of the strain.

In addition, the present invention removes radioactive iodine containing a Deinococcus radiodurance strain, a culture medium of the strain, and a semi-permeable membrane, which are cultured in a medium containing silver ions and have silver nanoparticles biosynthesized on the surface of the strain. Kits are provided.

The kit for removing radioactive iodine containing the Deinococcus radiodurance strain that synthesizes silver nanoparticles according to the present invention removes radioactive iodine present in various types of solutions with a high efficiency of 98% or more even with a small amount of cells. It can be used and is very easy to use and manage after use. Therefore, the above-mentioned kit for removing radioactive iodine and the method for removing radioactive iodine using the same can be very usefully used for removing radioactive iodine generated in large-scale hospitals, industrial bodies, nuclear accidents, and the like.

It is a figure which showed the culture solution of the strain of Deinococcus radiodurance cultured in the TGY medium containing silver nitrate and the TGY medium containing silver nitrate, respectively. FIG. 1 is a diagram showing a precipitate from which the supernatant liquid has been removed by centrifuging the culture solution of FIG. 1a. It is a graph of the result of measuring the absorbance of the culture solution of the Deinococcus radiodurance strain that synthesizes silver nanoparticles with a UV-Vis spectrophotometer. It is a graph of the result which showed the distribution of the size of the silver nanoparticles synthesized from the strain of Deinococcus radiodurance. It is a figure which showed the cell surface of the wild-type Deinococcus radiodurance strain. It is the figure which showed the cell surface of the Deinococcus radiodurance strain which synthesizes silver nanoparticles (X50k). It is the figure which showed the cell surface of the Deinococcus radiodurance strain which synthesizes silver nanoparticles (X100k). It is a figure which showed the result of the energy dispersive X-ray analysis of the culture solution of the strain of Deinococcus radiodurans which synthesizes silver nanoparticles. It is a graph of the result of having measured the radioiodine removal rate of the Deinococcus radiodurans strain which synthesizes silver nanoparticles. It is a graph of the result of measuring the radioiodine removal rate with time of the Deinococcus radiodurans strain that synthesizes silver nanoparticles. It is a figure which showed the cellulose membrane filter paper which filtered and adsorbed the silver nanoparticles isolated and purified from the Deinococcus radiodurans strain. FIG. 5 shows a scanning electron micrograph of cellulose isolated and purified from a Deinococcus radiodurans strain and filtered and adsorbed with silver nanoparticles (X50k). FIG. 3 shows a scanning electron micrograph of cellulose isolated and purified from a Deinococcus radiodurans strain and filtered and adsorbed with silver nanoparticles (X100k). It is the figure which showed the result of the energy dispersive X-ray analysis of FIG. 6a. It is a figure which showed the weighed TGY medium powder. It is the figure which showed the photograph which dissolves the powder of FIG. 7a in sterile distilled water. It is a figure which showed the lyophilized cell of the Deinococcus radiodurance strain which synthesizes silver nanoparticles. It is a figure which shows the photograph which added FIG. 7c to FIG. 7b. FIG. 7d shows a kit for removing radioactive iodine that was activated after reacting with FIG. 7d for 12 hours. FIG. 7e is a diagram showing a method for removing radioactive iodine using FIG. 7e. It is a graph of the result of measuring the radioiodine removal rate of the kit containing the Deinococcus radiodurans strain that synthesizes silver nanoparticles.

Hereinafter, the present invention will be described in detail.

In the present invention, 1) a Deinococcus radiodurans strain is cultured in a medium containing silver ions (Ag ⁺ ), and a Deinococcus radiodurans strain having biosynthesized silver nanoparticles attached to the surface of the strain is obtained. Steps to obtain; 2) Steps to inoculate a container with a semi-permeable membrane together with a culture medium with a Deinococcus radiodurans strain with silver nanoparticles biosynthesized on the surface of the strain; and 3) Deinococcus, in which radioactive iodine adheres to the surface of the strain by contacting it with radioactive iodine-contaminated water so that the radioactive iodine passes through the semi-permeable membrane and binds to the silver nanoparticles on the surface of the strain. -Providing a method for removing radioactive iodine, which comprises a step of obtaining a radiodurance strain.

The medium containing silver ion in the above step 1) may be a medium containing a salt from which silver ions are separated, and specifically, a medium containing silver nitrate (AgNO ₃ ).

The Deinococcus radiodurance strain on which the biosynthesized silver nanoparticles were attached to the surface of the strain in step 2) above was freeze-dried of the Deinococcus radiodurance strain on which the biosynthesized silver nanoparticles were attached to the surface of the strain. It can be a cell.

The medium of the above step 1) or 2) is TGY medium, PGYM medium (10 g / L peptone, 2 g / L glucose, 4 g / L yeast extract, 10 g / L meat extract and 2 g / L sodium chloride. ), Nutrition medium (3 g / L beef extract and 5 g / L peptone) or YPD medium (5 g / L yeast extract, 10 g / L peptone and 10 g / L dextrose), but limited to these. It's not something.

The semi-permeable membrane and radioactive iodine can pass freely, but the Deinococcus radiodurance strain and the reaction precipitate of radioactive iodine and silver cannot pass through, and the pore size is 1 μm. It can be:

The form of silver (Ag) is not limited, but it may be a particle form having an average particle size of 1 nm to 1 μm, preferably a particle form having an average particle size of 10 nm to 100 nm. , Not limited to this.

The method for removing radioactive iodine can further include a step of recovering the semi-permeable membrane container. The radioisotope removal technique utilizing existing microorganisms has a problem that it is not easy to recover the radioisotope-adsorbed microorganism after removing the radioisotope. However, the method of the present invention has the above-mentioned semipermeability. A step of recovering the sex membrane container can be further included, and the treatment after removal of the radioactive iodine can be facilitated.

The iodine can be present in aqueous solution in the form of iodine anion (I ⁻ ), iodine cation (I ⁺ ), iodate ion (IO _3- ⁾ or iodine (I ₂ ). Not limited.

In the present invention, "iodine" is meant to include all possible forms of iodine as described above.

In the method for removing radioactive iodine of the present invention, the iodine-contaminated water is a solution containing iodine, and may be, but is not limited to, an aqueous solution, an organic solvent solution, or a combination thereof.

The aqueous solution can be an acidic solution, a neutral solution or a basic solution, and the organic solvent can be, but is not limited to, an organic solvent containing ethanol, dimethyl sulfoxide, DMSO, or the like, or a mixture thereof. ..

Further, the iodine-containing solution may be in a liquid or gaseous state, but is not limited thereto.

In a specific embodiment of the present invention, the present inventors induced the synthesis of silver nanoparticles by culturing the Deinococcus radiodurans strain in a TGY medium containing silver nitrate, and synthesized from the Deinococcus radiodurance strain. The characteristics of silver nanoparticles were confirmed (see Figures 1a-4c). In addition, the effect of removing radioactive iodine from Dinococcus radiodurance, which synthesizes the silver nanoparticles, was confirmed, the strain was filtered and adsorbed on a cellulose membrane filter, and the silver nanoparticles were fixed to the membrane filter paper. Confirmed that it can be done (see Figures 5a and 6c). In addition, the freeze-dried cells of the strain that synthesizes silver nanoparticles and the culture medium that can activate them are placed in a cellulose dialysis membrane to manufacture a kit for removing radioactive iodine that is easy to carry. Then, the effect of removing radioactive iodine from the kit was confirmed (see FIGS. 7a and 8). Therefore, the method for removing radioactive iodine using the Deinococcus radiodurance strain that synthesizes the nanoparticles and the semi-permeable membrane is usefully used for removing radioactive iodine generated in large-scale hospitals, industrial bodies, nuclear accidents, and the like. be able to.

The present invention is a kit for removing radioactive iodine, which comprises a Deinococcus radiodurance strain, which is cultured in a medium containing silver ions and biosynthesized silver nanoparticles are attached to the surface of the strain, a culture medium of the strain, and a transpermeable membrane. I will provide a.

The medium containing silver ion can be a medium containing silver nitrate.

The Deinococcus radiodurans strain with biosynthetic silver nanoparticles attached to the surface of the strain is a freeze-dried cell of the Deinococcus radiodurance strain with biosynthetic silver nanoparticles attached to the surface of the strain. obtain.

The culture medium can be, but is not limited to, TGY medium, PGYM medium, nutrient medium or YPD medium.

The semi-permeable membrane allows radioactive iodine to pass freely, but cannot pass through the Dinococcus radiodurance strain and the reaction precipitate of radioactive iodine and silver, and has a pore size of 1 μm. It can be:

The iodine can be present in aqueous solution in the form of iodine anion (I ⁻ ), iodine cation (I ⁺ ), iodate ion (IO _3- ⁾ or iodine (I ₂ ). Not limited.

In a specific embodiment of the present invention, the present inventors induce the synthesis of silver nanoparticles by culturing a strain of Deinococcus radiodurance in a TGY medium containing silver nitrate, and synthesize the silver nanoparticles. -Confirmed the effect of radiodurance on removing radioactive iodine (see Figures 1a to 5b), and put the freeze-dried cells of the strain that synthesizes silver nanoparticles and the culture medium that can activate them into a cellulose permeable membrane. A kit for removing radioactive iodine, which is easy to put in and carry, was manufactured, and the effect of removing radioactive iodine from the kit was confirmed (see FIGS. 6a to 8). Therefore, the above-mentioned radioactive iodine removal kit can be usefully used for removing radioactive iodine generated in large-scale hospitals, industrial bodies, nuclear accidents, and the like.

(Form for carrying out the invention)
Hereinafter, the present invention will be described in detail with reference to Examples.

However, the following examples are merely examples of the present invention, and the content of the present invention is not limited to the following examples.

Example 1. Induction of synthesis of silver nanoparticles of Deinococcus radiodurance strain Wild-type Deinococcus radiodurance strain (ATCC 13939, Agricultural Genetic Resource Information Center, Republic of Korea) was used in TGY liquid medium (0.5% (w / v) tripton, 0.1%. Precultured with (w / v) glucose and 0.3% (w / v) yeast extract) 5 ml. 50 ml of TGY medium was placed in a 250 ml flask, 500 μl of the preculture solution was added, and the cells were cultured at 30 ° C. and 200 rpm until the absorbance of the culture solution became 1. After that, the silver nitrate (AgNO ₃ ) solution was treated into a culture solution at a final concentration of 1 mM, adapted for 2 hours, transferred to a 50 ml conical tube, and centrifuged at 4,000 rpm for 20 minutes. Precipitated cells were washed twice with sterile distilled water, resuspended in 50 ml of TGY medium, then silver nitrate solution was added at a final concentration of 2.5 mM, and the cells were cultured for 24 hours. Made it possible to synthesize particles.

Comparative example 1. Culturing of Wild-type Deinococcus Radiodurance Strain The wild-type Deinococcus radiodurance strain (ATCC 13939) described in Example 1 above, except that it was cultured in TGY medium to which no silver nitrate solution was added. It was cultured in the same way as.

Experimental example 1. Confirmation of characteristics of silver nanoparticles synthesized from Deinococcus radiodurance strain In order to confirm the characteristics of silver nanoparticles synthesized from Deinococcus radiodurance strain, culture of each strain cultured in Example 1 and Comparative Example 1 above. The following experiments were performed with the liquid.

1-1. Confirmation of the presence of silver nanoparticles through the difference in the color of the culture medium As a result of comparing the colors of the culture medium of each strain cultured in Example 1 and Comparative Example 1, the culture medium of the wild-type Dinococcus radiodurance strain was yellow. On the other hand, it was confirmed that silver nanoparticles were synthesized by confirming that the culture solution of Dinococcus radiodurance cultured in the medium supplemented with the silver nitrate solution was dark brown (Fig. 1a and). Figure 1b).

1-2. Confirm the maximum absorption wavelength of silver nanoparticles
Using a UV-Vis spectrophotometer, measure the absorbance of the TGY medium to which a silver nitrate solution was added at a final concentration of 2.5 mM, the culture solution of Comparative Example 1 and the culture solution of Example 1 at wavelengths in the range of 400 nm to 800 nm. did.

As a result, only the culture solution of the Deinococcus radiodurance strain that synthesizes silver nanoparticles showed the maximum absorption wavelength in the range of 400 nm to 800 nm, and showed the maximum absorption wavelength at about 440 nm (Fig. 2). This suggests that the maximum absorption wavelength of silver nanoparticles synthesized from the Deinococcus radiodurans strain is about 440 nm.

1-3. Confirmation of size of silver nanoparticles Using a dynamic light scattering analyzer, the size of silver nanoparticles in the culture solution of Deinococcus radiodurance cultured in Example 1 was measured.

As a result, it was confirmed that the size of silver nanoparticles showed a distribution of 18 nm to 68.1 nm, and that silver nanoparticles with a size of 28.2 nm were the most distributed (Fig. 3).

1-4. Morphological Confirmation of Silver Nanoparticles The culture medium of each strain cultured in Example 1 and Comparative Example 1 was observed with a scanning electron microscope (SEM).

As a result, it was confirmed that the cell surface of the wild-type Deinococcus radiodurance strain was smooth, whereas the cell surface of the Deinococcus radiodurance strain that synthesizes silver nanoparticles contained a large number of spherical silver nanoparticles (Fig.). 4a-4c).

1-5. Confirmation of constituent elements of silver nanoparticles The culture solution of Example 1 was analyzed with an energy dispersive X-ray spectrometer (EDX).

As a result, it was confirmed that a strong silver (Ag) signal was detected near 3 keV, and the particles adsorbed on the cell surface of the Deinococcus radiodurans strain observed in Experimental Example 1-4 were silver nanoparticles. Was reconfirmed (Fig. 4d).

Experimental example 2. Confirmation of radioactive iodine removal effect of Deinococcus radiodurans strain that synthesizes silver nanoparticles Radio-thin layer chromatography (radio-) It was investigated by thin layer chromatography, radio-TLC) analysis.

Specifically, the culture broths of Example 1 and Comparative Example 1 were each transferred to a 50 ml conical tube, centrifuged at 4,000 rpm for 20 minutes, and then the precipitated cells were washed with sterile distilled water three times, and the sterile distilled water was used. Resuspended in 5 ml. Mix 1 ml of each suspension with 5 ml of distilled water containing 100 μCi [ ¹²⁵ I] Na I, react at room temperature, and remove iodine by reaction time (1 minute, 5 minutes or 15 minutes) by radio-TLC analysis. The rate (%) was measured. For comparison by cell concentration of Deinococcus radiodurance strain, the culture medium was doubled with sterile distilled water instead of the culture medium cultured until the absorbance of the culture solution described in Example 1 became 1. The culture medium of the Deinococcus radiodurance strain produced by the same method as described in Example 1 was used except that the culture medium diluted OD 0.5) or 100-fold (OD 0.01) was used.

As a result, the wild-type Deinococcus radiodurance strain can remove about 9.5% of radioactive iodine for 15 minutes, whereas the Deinococcus radiodurance strain that synthesizes silver nanoparticles has about 97.5% of radioactive iodine under the same conditions. The removal ability was shown (Fig. 5a). In addition, as a result of comparison based on the cell concentration of the Deinococcus radiodurans strain, when the culture solution was cultured until the absorbance became 1, (about 2.5 x 10 ⁵ cells), it was the most effective in removing radioactive iodine at about 97.6% for 5 minutes. It showed a high effect (Fig. 5b).

Example 2. Manufacture of membrane filters coated with silver nanoparticles
2-1. Separation and Purification of Silver Nanoparticles from Deinococcus Radiodurance Strain Silver nanoparticles were isolated from the Deinococcus radiodurance strain that synthesizes the silver nanoparticles cultured in Example 1.

Specifically, the culture solution of Example 1 was centrifuged at 4,000 rpm for 20 minutes, the supernatant was removed, the precipitate was washed 3 times with sterile distilled water, and 5 ml of 0.9% sodium chloride was added again. Suspended. The cells in the suspension were crushed with an ultrasonic crusher for 3 minutes and then centrifuged to remove the supernatant. An aqueous solution containing 25 ml of 0.5 M sodium chloride and 0.5 M sucrose was added to the precipitate in order, suspended, centrifuged at 4,000 rpm for 20 minutes, and then the supernatant was removed. Add 35 ml of complete salt solution (0.3 M sodium chloride, 10 mM potassium chloride, 50 mM magnesium sulfate aqueous solution (DDL 4.7H ₂ O) and ₁ mM Tris (pH 7.5)) to the precipitate and re-do. After suspension, 20 mg of lysozyme was treated and reacted at 37 ° C. for 22 hours. After centrifuging the completed solution to remove the supernatant, the precipitate was washed twice with a complete salt solution, then 5 ml of the complete salt solution was added and suspended, and finally from the Deinococcus radiodurance strain. Separated and purified nanoparticles were obtained.

2-2. Production of Film Filter Paper Coated with Silver Nanoparticles The silver nanoparticles purified in Example 2-1 above are filtered and adsorbed on a cellulose membrane filter paper having a pore of 0.22 μm using a vacuum device. Then, it was naturally dried at room temperature to produce a film filter paper coated with silver nanoparticles (Fig. 6a).

2-3. Confirmation of characteristics of film filter paper coated with silver nanoparticles Scanning electron microscope (SEM / EDX) equipped with an energy dispersive X-ray analyzer on the film filter paper coated with silver nanoparticles produced in Example 2-2. ), And its characteristics were analyzed.

As a result, it was confirmed that spherical particles were uniformly coated on the surface of the membrane filter paper (Figs. 6b and 6c), and it was confirmed that a strong silver (Ag) signal was detected near 3 keV. It was confirmed that the particles adsorbed on the surface of the filter paper were silver nanoparticles (Fig. 6d).

Example 3. Manufacture of kit for removing radioactive iodine
3-1. Production of freeze-dried cells The culture solution of the Deinococcus radiodurans strain that synthesizes silver nanoparticles is optimal because it is difficult to store for a long time due to the oxidation of silver and it is troublesome to culture the cells every time. The following experiments were conducted in order to facilitate weighing under these conditions and to use lyophilized cells to maintain the performance of the kit.

Specifically, 50 ml of the culture solution of the Dinococcus radiodurance strain synthesizing the silver nanoparticles cultured in Example 1 was centrifuged at 4,000 rpm for 30 minutes to remove the supernatant, and the precipitate was prepared with sterile distilled water. After washing twice, the supernatant was removed by centrifugation under the same conditions. After that, the cells were frozen at -80 ° C for 1 hour, and the cells were completely dried in a freeze-dryer for 24 hours to remove residual water. The powdery cells were crushed in a mortar and weighed with a precision scale and used in the manufacture of the kit.

3-2. Production of Disposable Radioiodine Removal Kit In order to produce a medium having the same composition as the TGY medium used in Example 1 above, 0.5 g of tryptone, 0.1 g of glucose and 0.3 g of the medium are based on a total volume of 1 L of the medium. The yeast extract was placed in a 50 ml tube and mixed to mix well (TGY medium powder). Cut a cellulose permeable membrane (flat width 25 mm, diameter 16 mm, Spectrum Laboratories, Inc., USA) that can permeate only substances with a size of 12 to 14 kDa to a length of 10 cm, and then clip both ends. I fixed it with to prevent the contents from falling down. Using a micropipette, 10 ml of sterile distilled water was added into the membrane, 9 mg of TGY medium powder was added and mixed until completely dissolved (Figs. 7a and 7b). To the dissolved TGY medium, 5, 10, 50 or 100 mg of freeze-dried cells of the Deinococcus radiodurance strain synthesizing the silver nanoparticles produced in Example 3-1 was added and activated at room temperature for 12 hours. (Figs. 7c-7e).

Comparative example 2. Production of control group kit containing lyophilized cells of wild-type Deinococcus radiodurance strain

A freeze-dried cell was produced by using the culture medium of the wild-type Deinococcus radiodurance strain cultured in Comparative Example 1 instead of the culture medium of the Deinococcus radiodurance strain synthesizing the silver nanoparticles cultured in Example 1. Then, a control group kit was produced by the same method as described in Example 3 except that 100 mg of the lyophilized cells was added to the TGY medium dissolved in the membrane.

Experimental example 3. Confirmation of Radio-Iodine Removal Effect of Kit Containing Deinococcus Radiodurance Strain for Synthesizing Silver Nanoparticles Radio TLC analysis was performed to confirm the radio-iodine removal effect of the kit produced in Example 3 above.

Specifically, 500 ml of sterile distilled water containing 100 μCi [ ¹²⁵ I] NaI was placed in a beaker, and each kit produced in Example 3 and Comparative Example 2 was placed in a beaker and reacted at room temperature for radio TLC analysis. Iodine removal rate (%) by reaction time (1 minute, 5 minutes or 15 minutes) was measured in (Fig. 7f).

As a result, the kit containing the wild-type Deinococcus radiodurans strain showed a radioactive iodine removal rate of about 3%, whereas the kit containing the Deinococcus radiodurance strain synthesizing silver nanoparticles was 15 minutes. It was confirmed that the kit containing 5 mg of lyophilized cells showed a high removal rate of up to 98% within the period, and the kit containing 100 mg showed a high removal rate of radioactive iodine without any significant difference (Fig. 8).

The kit for removing radioactive iodine containing the Deinococcus radiodurance strain that synthesizes silver nanoparticles according to the present invention has a high efficiency of 98% or more of radioactive iodine present in various types of solutions even with a small amount of cells. It can be removed and is very easy to use and manage after use. Therefore, the above-mentioned kit for removing radioactive iodine and the method for removing radioactive iodine using the same can be very usefully used for removing radioactive iodine generated in large-scale hospitals, industrial bodies, nuclear accidents, and the like.

Claims (10)

1) A process of culturing a Deinococcus radiodurans strain in a medium containing silver ions (Ag ⁺ ) to obtain a Deinococcus radiodurans strain having biosynthesized silver nanoparticles attached to the surface of the strain.
2) A step of inoculating a Deinococcus radiodurans strain in which silver nanoparticles biosynthesized on the surface of the strain together with a culture medium are inoculated into a container of a semi-permeable membrane.
3) The container is brought into contact with radioactive iodine-contaminated water so that the radioactive iodine passes through the semi-permeable membrane and binds to the silver nanoparticles on the surface of the strain, and the silver nanoparticles bound to the strain are the silver nanoparticles of the strain. A method for removing radioactive iodine, which comprises a step of obtaining a strain of Deinococcus radiodurance adhering to the surface. The Deinococcus radiodurans strain with the biosynthesized silver nanoparticles attached to the surface of the strain in step 2) is a freeze-dried bacterium of the Deinococcus radiodurance strain with the biosynthesized silver nanoparticles attached to the surface of the strain. The method for removing radioactive iodine according to claim 1, which is a body. The method for removing radioactive iodine according to claim 1, wherein the culture medium of the step 1) or 2) is a TGY medium, a PGYM medium, a nutrition medium or a YPD medium. The method for removing radioactive iodine according to claim 1, wherein the semi-permeable membrane has a pore size of 1 μm or less. The method for removing radioactive iodine according to claim 1, further comprising a step of recovering the container of the semi-permeable membrane. A kit for removing radioactive iodine, which comprises a Deinococcus radiodurance strain, which is cultured in a medium containing silver ions and biosynthesized silver nanoparticles are attached to the surface of the strain, a culture medium of the strain, and a semi-permeable membrane. The kit for removing radioactive iodine according to claim 6, wherein the medium containing silver ion is a medium containing silver nitrate. The Deinococcus radiodurans strain with the biosynthesized silver nanoparticles attached to the surface of the strain is a lyophilized cell of the Deinococcus radiodurance strain with the biosynthesized silver nanoparticles attached to the surface of the strain. The kit for removing radioactive iodine according to claim 6. The kit for removing radioactive iodine according to claim 6, wherein the culture medium is a TGY medium, a PGYM medium, a nutrient medium, or a YPD medium. The kit for removing radioactive iodine according to claim 6, wherein the semi-permeable membrane has a void size of 1 μm or less.

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