JP4572135B2 - Method for detoxifying cyanide compounds - Google Patents

Description

  The present invention relates to a cyanide detoxifying method and a cyanide detoxifying agent.

  Cyanide compounds are toxic compounds that are taken up by animals by inhalation and skin respiration and cause cyanide poisoning of symptoms such as paralysis of the respiratory center. Cyanide compounds are used in insecticides, electroplating, pharmaceutical raw materials, etc., and are contained in industrial wastewater.

  For the purification of soil, groundwater and industrial wastewater contaminated with cyanide compounds, oxidative decomposition methods, insoluble complex methods, boiled methods, hydrothermal reaction methods, microbial treatment methods and the like are used. For example, there is a soil slurry method in which cyanide is chemically or biologically decomposed by adding chemicals and water to the soil in order to purify cyan-contaminated soil. Dehydration etc.) is necessary, and a large amount of cost is required for the slurry stirring facility (see Patent Documents 1 to 6). There are no cheap chemicals that can directly detoxify cyanide in the soil mixing method, which mixes chemicals with soil and chemically decomposes cyanide, and high alkaline and oxidizers used as chemicals are an environmental burden. Is large (see Patent Document 7). In addition, there is a known cleaning method that separates cyanide by mixing chemicals in the soil, but this method requires treatment of the cyan-containing soil after classification, and the cleaning facility requires significant costs. (See Patent Documents 8 to 10). A heat treatment method in which a chemical is mixed in soil and heated at 200 to 500 ° C. also requires a large cost for the heating facility (see Patent Documents 11 to 13).

  In addition, for example, for the purification of cyan-contaminated groundwater, there is known a pumping treatment method in which cyan-contaminated groundwater is pumped and coagulated by chemicals, etc., or dissolved chemically, but it is necessary to treat cyanide-containing sludge and the like. In addition, the ground treatment facility requires a large cost (see Patent Document 14). A sparging method in which an oxidizing / decomposing agent is injected into cyanogen-contaminated groundwater and chemically decomposed has been proposed, but there is a concern that the oxidizing / decomposing agent used may destroy the ecosystem in the soil environment. (See Patent Document 15). In addition, the in-situ microbial purification method that uses microorganisms that decompose cyanide by injecting nutrients into cyan contaminated groundwater is used, but in this method there are no microorganisms that can efficiently decompose cyanide. Is not effective, and it is necessary to treat the ammonia produced after the cyanide decomposition (see Patent Document 16).

Furthermore, in the microbial treatment method, cyanide-decomposing microorganisms are introduced into contaminated soil and water to decompose cyanide, but the decomposition reaction is often not rapid, and ammonia produced after cyanide decomposition is treated. There is a need (patent documents 17 and 18, etc.).
Therefore, an improved method for purifying soil and water contaminated with cyanide compounds is desired.

Japanese Patent Laid-Open No. 2004-97962 JP 2004-66195 A JP 2004-66193 A JP 2003-320366 A Japanese Patent Laid-Open No. 2003-126838 Japanese Patent Laid-Open No. 10-34124 JP 2004-58011 A JP 2004-57992 A JP 2003-88847 A JP 2000-157964 A JP 2003-181438 A JP 2000-157961 A JP 2000-157964 A JP 2004-81979 A JP 2002-254061 A JP 2002-273408 A JP 2001-245655 A JP 2000-312582 A

  Accordingly, an object of the present invention is to provide an efficient and simple method for detoxifying a cyanide compound at low cost in view of the above-described actual situation.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor has found that the cyanide detoxification bacterium (rhodanase-producing bacterium) is used in the detoxification method of the cyanide compound by using thiosulfate to proliferate the bacteria. The present inventors have obtained the knowledge that the dehydration of the cyanide compound is promoted and the detoxification of the cyanide compound is promoted, and the present invention has been completed.

That is, the present invention includes the following.
(A) A cyanide detoxification method comprising detoxifying a cyanide using a cell of rhodanase-producing bacteria or a culture thereof, or a rhodanase enzyme and thiosulfate.
In the cyanide detoxification method, it is preferable to further detoxify by supplying a nutrient selected from nitrogen and phosphorus. Further, in the method for detoxifying the cyanide compound, it is preferable that the detoxification is performed under supply of air. Furthermore, detoxification is preferably performed at a temperature of 15 to 35 ° C. at a pH of 6 to 10.

(B) A cyanide detoxifying agent characterized by containing a cell of rhodanase-producing bacteria or a culture thereof or a rhodanase enzyme and thiosulfate.
The cyanide detoxifying agent preferably further contains a nutrient salt selected from nitrogen and phosphorus.

  With the cyanide detoxification method and cyanide detoxifying agent according to the present invention, the cyanide compound can be detoxified efficiently, simply and at low cost. Further, the cyanide detoxification method and the cyanide detoxification agent according to the present invention can purify soil and water contaminated with the cyanide.

Hereinafter, the present invention will be described in detail.
1. Method of detoxifying cyanide compound The method of detoxifying cyanide compound according to the present invention (hereinafter also referred to as “the present method”) is a method for detoxifying cyanide using a rhodanase-producing bacterium or a culture thereof or a rhodanase enzyme. It is characterized by using. That is, thiosulfate is an electron acceptor that is essential for promoting the growth of rhodanase-producing bacteria and for producing the rhodanase enzyme. Furthermore, the rhodanase enzyme produced by the rhodanase-producing bacteria can detoxify cyanide compounds by producing thiocyanate and sulfite from cyanide and thiosulfate, as shown in the following formula. Further, thiocyan produced by this reaction is a stable compound that is not detected as a cyanide compound, and is thus fixed as a stable substance in the environment.

  Therefore, it becomes possible to detoxify the cyanide efficiently and in a short time by using rhodanase-producing bacteria or rhodanase enzyme in combination with thiosulfate.

  In the present method, a rhodanase-producing bacterium or a culture thereof or a rhodanase enzyme is used. In the present specification, the term “rhodanase-producing bacterium” means a bacterium that respires using thiosulfate and produces a rhodanase enzyme that renders cyanide harmless. Such bacteria are known in the art, and numerous bacteria have been described and reported in the literature. For example, there are bacteria belonging to the genus Thiobacillus, Azotobacter, Ferrobacillus, Acinetobacter, Escherichia, Shigella, Citrobacter, Klebsiella, Enterobacter, Hafnia, Pseudomonas, Acidithiobacillus, Warinella It has been reported. More specific bacterial strains include, but are not limited to, Thiobacillus ferrooxidans, Thiobacillus thiooxidans, Thiobacillus caldus, Thiobacillus novels (Thiobacillus). novellus), Azotobacter vinelandii, Ferrobacillus ferrooxidans, Acinetobacter calcoaceticus, Escherichia coli, Shigera flexneri ella flexor Citrobacter freundi, Hafnia alvei, Pseudomonas spp, Acidithiobacillus ferrooxida (Acidithiobacillus ferrooxida) ns), Wolinella succinogenes (Gardner, MN and Rawlings, DE, Journal of Applied Microbilogy 2000, 89: 185-190; Fukumori, Y. et al., FEMS Microbiology Letter 1989, 53: 159 -163; Cicero, DO et al., Int. J. Biol. Macromol. 2003, 33: 193-201; Tabita, R., M. Silver, et al. (1969). Can J Biochem 47 (12): 1141-5; Yoch, DC and ES Lindstrom (1971). J Bacteriol 106 (2): 700-1; Westley, J. (1973). Adv Enzymol Relat Areas Mol Biol 39: 327-68; Silver, M. and DP Kelly (1976). J Gen Microbiol 97 (2): 277-84; Vandenbergh, PA and RS Berk (1980). Can J Microbiol 26 (3): 281-6; Lanyi, B. (1982). J Med Microbiol 15 (2): 263-6; Vennesland, B., PA Castric, et al. (1982). Fed Proc 41 (10): 2639-48; Aird, BA, RL Heinrikson, et al. (1987). J Biol Chem 262 (36): 17327-35; Alexander, K. and M. Volini (1987). J Biol Chem 262 (14): 6595-604; Fukumori, Y., K. Hoshiko, et al. (1989) FEMS Microbiol Lett 53 (1-2): 159-63; A ird, BA and PM Horowitz (1990). Biochim Biophys Acta 1038 (1): 10-7; Pagani, S., G. Sessa, et al. (1993). Biochem Mol Biol Int 29 (4): 595-604 Colnaghi, R., S. Pagani, et al. (1996). Eur J Biochem 236 (1): 240-8; Bordo, D., R. Colnaghi, et al. (1999). Acta Crystallogr D Biol Crystallogr 55 (Pt 8): 1471-3; Bordo, D., TJ Larson, et al. (2000). Acta Crystallogr D Biol Crystallogr 56 Pt 12: 1691-3; Bordo, D., D. Deriu, et al. (2000). Mol Biol 298 (4): 691-704; Pagani, S., F. Forlani, et al. (2000). FEBS Lett 472 (2-3): 307-11; Ray, WK, G. Zeng, et al. (2000). J Bacteriol 182 (8): 2277-84; Bordo, D., F. Forlani, et al. (2001). Biol Chem 382 (8): 1245-52; Bouchal, P ., Z. Glatz, et al. (2001). Folia Microbiol (Praha) 46 (5): 385-9; Colnaghi, R., G. Cassinelli, et al. (2001). FEBS Lett 500 (3): 153-6; Adams, H., W. Teertstra, et al. (2002). FEBS Lett 518 (1-3): 173-6; Lin, YJ, F. Dancea, et al. (2004). Biochemistry 43 (6): see 1418-24).

Further, in the method for detoxifying a cyanide compound according to the present invention, it is also possible to use a novel Rhizobiales TC-2 strain isolated in Example 2 described later. These strains may be grown by utilizing sulfur and thiosulfate and also is resistant to cyanide (CN up to 20 mg / l ^- viable in the presence of a) for use in the method Is preferable. The TC-2 strain was registered in the National Institute of Advanced Industrial Science and Technology Patent Biological Depositary Center (1st, 1st, 1st East, 1st Street, Tsukuba, Ibaraki Prefecture, January 6, 2005) as the accession number FERM P-20354. Deposited on the 12th.

  In this method, as long as at least one of the above rhodanase-producing bacteria is used, it is also possible to use a combination of plural types. For example, a combination of two or more rhodanase-producing bacteria can be used.

  In the present method, a culture of the above-mentioned rhodanase-producing bacteria can also be used. Here, when a culture of rhodanase-producing bacteria is used, the culture can be prepared by culturing the rhodanase-producing bacteria, and the culture conditions described below may be used.

  In this method, cyanogen compounds may be detoxified using a culture of rhodanase-producing bacteria cultured in the presence of thiosulfate, or a culture of rhodanase-producing bacteria and thiosulfate may be used together. May be used to render the cyanide harmless.

  The culture may be used as it is, or the culture may be used after purification treatment such as filtration, centrifugation or extraction, or the culture is diluted with water or the like. May be.

  Furthermore, in the present method, a rhodanase enzyme can also be used. Rhodanese is a well-known enzyme that catalyzes the reaction of thiosulfate and hydrogen cyanide to thiocyanate and sulfite. In addition to the above-mentioned rhodanase-producing bacteria, animals (for example, cattle, mice, sheep, goats, pigs, (Aminlari, M. et al., Comp. Biochem. Physiol. B. Biochem. Mol. Biol. 2002, 132: 309-313; Miller, DM, R. Delgado, et al. (1991). J Biol Chem 266 (8): 4686-91; Pallini, R., GC Guazzi, et al. (1991). Biochem Biophys Res Commun 180 (2): 887-93 Miller, DM, GP Kurzban, et al. (1992). Biochim Biophys Acta 1121 (3): 286-92; Dooley, TP, SK Nair, et al. (1995). Biochem Biophys Res Commun 216 (3): 1101-9; Aita, N., K. Ishii, et al. (1997). Biochem Biophys Res Commun 231 (1): 56-60; Aminlari, M., S. Gholami, et al. (2000). Comp Biochem Physiol B Biochem Mol Biol 127 (3): 369-74; Nandi, DL, PM Horowitz, et al. (2000 Int J Biochem Cell Biol 32 (4): 465-73; Nazifi, S., M. Aminlari, et al. (2003). Comp Biochem Physiol B Biochem Mol Biol 134 (3): 515-8). Thus, rhodanase can be isolated from an organism (eg, rhodanase producing bacteria). Rhodanase is commercially available, for example, from SIGMA.

  Moreover, in this method, a cyanide compound can be detoxified using a rhodanase enzyme obtained from a culture of a rhodanase-producing bacterium cultured in the presence of thiosulfate. Since thiosulfate promotes the growth of rhodanase-producing bacteria and is an electron acceptor essential for the production of rhodanase enzymes, it is considered that the production of rhodanase enzymes increases when added during the cultivation of rhodanase-producing bacteria. Alternatively, the cyanide compound may be rendered harmless using rhodanase enzyme and thiosulfate together.

In this method, thiosulfate is used. The thiosulfate is a compound represented by the general formula M ₂ ^I S ₂ O ₃ or M ^II S ₂ O ₃ , and includes alkali metal salts, magnesium salts, calcium salts, barium salts and the like.

  In this method, any substance containing a cyanide compound can be detoxified. For example, soil contaminated with cyanide, ground water, waste water, river water and the like can be mentioned.

  In this method, the cyanide can be detoxified by applying the above-mentioned rhodanase-producing bacteria or the culture thereof or the rhodanase enzyme and thiosulfate to the cyanide. Here, this method involves culturing a cell of a rhodanase-producing bacterium together with a cyanide in the presence of a thiosulfate, a mixture of a cyanide and a rhodanase-producing bacterium or a culture thereof, or a mixture of a rhodanase enzyme and a thiosulfate. Spraying rhodanase-producing bacterial cells or their culture and thiosulfate on cyanide, inoculating non-woven fabric etc. with rhodanase-producing bacterial cells or their culture or rhodanase enzyme and thiosulfate Can be carried out by standing in a cyanide compound. Alternatively, when it is considered that rhodanase-producing bacteria are already present in the soil or water to be detoxified, this method can be carried out simply by adding thiosulfate to the detoxified target.

  When culturing rhodanase-producing bacteria together with cyanide in the presence of thiosulfate, and preparing a culture of rhodanase-producing bacteria, normal culture conditions may be used except for the addition of thiosulfate. For example, the medium contains carbon sources such as glucose, starch and sucrose, nitrogen sources such as potassium nitrate, ammonium nitrate, yeast extract, and peptone, preferably inorganic salts such as potassium phosphate, magnesium nitrate, calcium chloride, and trace metals A medium containing trace components such as amino acids, amino acids and vitamins can be used. In this method, for example, nutrient salts (generally nitrogen and phosphorus) that are necessary for the growth of rhodanase-producing bacteria and that are deficient in soil, groundwater, etc. that are to be detoxified with cyanide are added. It is preferable. The addition amount of the nutrient salt can be within the range of about 0 to 500 mg / kg nitrogen and about 0 to 100 mg / kg phosphorus with respect to the detoxification target. Moreover, it is preferable to use both a solid culture medium and a liquid culture medium.

  The type and amount of thiosulfate added depends on the type and amount of rhodanase-producing bacteria to be used, the amount of cyanide, the detoxification target (soil, water), etc., but the target soil And it is preferable to add so that it may become the range of about 0.01 to about 1 mg / kg with respect to water.

  In the culture of rhodanase-producing bacteria in this method, the culture can be performed using various culture conditions such as stationary culture, shaking culture, aeration culture, and aeration and agitation culture. Here, since the optimum culture conditions vary depending on the type of bacteria used, the above medium and culture method are appropriately selected and adjusted to those suitable for the bacteria used, and other culture conditions such as temperature, pH, culture period, etc. It is preferable that the culture is carried out with appropriate selection.

  For example, the culture temperature is preferably maintained at about 15 to 35 ° C. in order to maintain the activity of bacteria. In addition, since the pH during culture is lowered due to the production of sulfate from thiosulfate by rhodanase producing bacteria, a pH adjuster is used during the detoxification reaction, and the pH is in the range of about 6-10. It is preferable to adjust so that it may be maintained.

  Furthermore, the rhodanase-producing bacterium grows using carbon dioxide in the air as a carbon source. Accordingly, when the present method is performed without excavating soil or water to be detoxified, it is preferable to supply air (carbon dioxide) by a soil suction method or an air sparging method. Moreover, also when applying this method with respect to excavated soil or water, it is preferable to supply air (carbon dioxide gas) to soil or water by use of an air pipe or a stirring process. Furthermore, when a detoxification reaction is performed in a biological treatment tank, it is preferable to perform an aeration process. The supply amount of air (carbon dioxide gas) is set to a range of about 0.01 to 1 L / min with respect to 1 kg of the target soil and water.

  Using the culture conditions as described above, a culture of rhodanase-producing bacteria can be prepared. Regarding the rhodanase enzyme, when an enzyme derived from a rhodanase-producing bacterium is used, a protein purification method known in the art (for example, ammonium sulfate precipitation, gel chromatography, Pure or partially pure enzyme can be isolated using ion exchange chromatography, affinity chromatography, etc.).

The amount of the rhodanase-producing bacterium used or its culture or the amount of the rhodanase enzyme can be determined so as to obtain a desired result in consideration of the type of bacterium used, the amount of cyanide present, and the like. For example, in the detoxification of cyanide in the treatment of cyanide-contaminated water, it is preferable that rhodanase-producing bacteria are present at 10 ⁶ cells / ml or more in the biological treatment tank.

  In addition, this method can be applied to the purification of cyanide contamination, and harmless cyanide compounds contained in soil or water containing cyanogen-contaminated soil or water using rhodanase-producing bacteria or cultures thereof or rhodanase enzyme and thiosulfate. Can be purified.

  After detoxification of the cyanogen compound by the rhodanase-producing bacteria or the culture thereof or the rhodanase enzyme, the treated soil or water is removed with an appropriate separation device such as a vibrating sieve, membrane, belt press or centrifugal separator. It can be used to isolate rhodanase-producing bacteria or their cultures or enzymes. It is preferable to use bacteria and enzymes whose safety has been confirmed in advance by animal tests or the like, or to sterilize after use in order to ensure safety.

2. Cyanide detoxifying agent The cyanide detoxifying agent according to the present invention (hereinafter also referred to as “the detoxifying agent”) comprises a cell of a rhodanase-producing bacterium or a culture thereof or a rhodanase enzyme and thiosulfate. The detoxifying agent can contain one kind of rhodanase-producing bacteria alone or in combination of two or more kinds, and is a culture prepared from one or more kinds of rhodanase-producing bacteria, or one kind A rhodanase enzyme derived from the above organisms may be contained. The rhodanase-producing bacterium, the culture thereof, and the rhodanase enzyme can be prepared as described in the previous section “1. Method for detoxifying cyanide compound”.

  The form of the detoxifying agent is not particularly limited, and the form of rhodanase-producing bacteria or the culture thereof as it is, the body of rhodanase-producing bacteria or the culture thereof, or the rhodanase enzyme is dissolved or suspended in an appropriate solvent. Any form such as a frozen form or a frozen or dried form so that the rhodanase enzyme can be stored can be taken. Such a form can be appropriately prepared according to a method known in the art.

  Further, the present detoxifying agent may contain other components. Other components are not particularly limited as long as they do not impair the cyanide detoxification activity of the bacterial body or rhodanase enzyme. For example, nutrient salts (nitrogen and phosphorus) necessary for the growth of rhodanase-producing bacteria are included. Can be mentioned.

  The detoxifying agent can be used by applying it to a cyanide compound. For example, it can be used by mixing with a cyanide compound or spraying on a cyanide compound. The amount used can be determined so as to obtain a desired result in consideration of the type of bacteria used, the amount of cyanide present, and the like. The present detoxifying agent can also be used as a cleaning agent for cyanide contamination.

  By using the present method and the present detoxifying agent, the cyanide compound desired to be purified can be made harmless efficiently and at low cost. That is, this harmless agent (or a cell of rhodanase-producing bacteria or its culture or rhodanase enzyme and thiosulfate) and, in some cases, air are supplied to soil or water contaminated with cyanide. The cyanide can be detoxified only by this. In addition, because this method or this detoxifying agent detoxifies harmful cyanide compounds in the enzyme reaction, the purification period is shorter than when using microorganisms, enzymes, or chemical substances alone, and it is safe for the environment. It is.

  Hereinafter, although this method is demonstrated in detail using an Example, the technical scope of this invention is not limited to these Examples.

  In this example, cyan contaminated groundwater was purified by an air sparging method, and it was confirmed whether or not there were microorganisms that detoxify cyan compounds.

  As a result of air sparging on groundwater contaminated with about 7 mg / l cyanide (benzene and cyanate groundwater in the factory site), the cyan concentration gradually decreased and about 97% of cyanide was removed after 150 days (FIG. 1). ). Since cyan was not detected in the aerated recovered gas, it was considered that these cyanides were detoxified by microorganisms in the ground.

  In this example, cyanide detoxifying bacteria (rhodanase producing bacteria) were isolated.

  From the groundwater at the contaminated site used in Example 1, a medium containing cyan as the sole carbon source (medium components shown in Table 1 (250 ml of trace element solution, 10 ml of Wolf trace element solution and 1 ml of vitamin mixture solution), After measuring with 1 L of distilled water, the pH was adjusted to 7 with 6N hydrochloric acid, which was dispensed into a culture bottle and sterilized at 121 ° C. for 15 minutes. As a result, an elliptical gonococcus (TC-2 strain) that proliferated while reducing cyanide in this medium was isolated. The form of the TC-2 strain is shown in FIG. Moreover, as a result of characterization (see below) of this strain, TC-2 strain was found to have 99.0% homology with Starkeya sp. (Former name Thiobacillus novellus) belonging to the genus Rhizobiales by 16S rRNA analysis. It was found that there was no obvious related species, and this strain was found to be a novel bacterial species. In addition, TC-2 shares are registered in the National Institute of Advanced Industrial Science and Technology patent biological depository center (1st, 1st, 1st, 1st, 1st, Tsukuba City, Ibaraki Prefecture, 6th) as accession number FERM P-20354 in 2005. Deposited on January 12th.

TC-2 strain (FERM P-20354)
(1) Morphological properties a. 1 to 3 μm bacilli b. No flagella (2) Physiological properties a. Optimal growth temperature 30 ℃
b. Optimal growth pH 7.0
c. Cyan assimilation (3) Chemical physics a. 16S rRNA sequence SEQ ID NO: 1

In this example, the cyanide detoxification effect of thiosulfate was confirmed.
Since thiosulfate is known to have cyanide detoxification, the detoxification effect of thiosulfate was investigated using cyan simulated contaminated groundwater. Thiosulfuric acid was added to the simulated cyanide groundwater, and the total cyan concentration was measured after standing for 1 hour. As a result, cyan was slightly reduced by adding thiosulfate, but even if the concentration of added thiosulfate was increased, It was confirmed that the detoxification effect remains within a certain range (Fig. 3).

In this example, the effect of promoting the growth of cyanide-detoxifying bacteria by adding thiosulfate was confirmed.
In order to confirm the growth promotion effect of cyanide detoxified bacteria by addition of thiosulfate, mineral medium containing cyanide (no addition of thiosulfate; medium components shown in Table 2 (250 ml trace element solution, 10 ml Wolfe trace element solution) And 1 ml of vitamin mixture solution) with 1 L of distilled water, adjust the pH to 7 using 6N hydrochloric acid, dispense it into a culture bottle and sterilize at 121 ° C. for 15 minutes. The cyanide detoxified bacterium TC-2 strain isolated in Example 2 was cultured using a medium in which thiosulfate was added to the same medium to a final concentration of 1 g / l. As a result, it was confirmed that the addition of thiosulfuric acid increased the TC-2 strain more than 10 times. After 9 days of culture, the removal rate of the total cyan concentration in the medium without thiosulfate was about 30%, whereas most of the cyanide was removed in the medium with thiosulfate added (Fig. 4).

  Therefore, it was found that thiosulfate promotes the growth of cyanide detoxifying bacteria (rhodanase producing bacteria) and promotes the detoxification of cyanide compounds.

In this example, the proper supply range of thiosulfate was examined.
In order to grasp the appropriate supply range of thiosulfate, the TC-2 strain was cultured at 30 ° C. for 12 days while changing the addition concentration of thiosulfate stepwise. As a result, the growth promoting effect of TC-2 strain by thiosulfate was confirmed within the range of 0.01 to 1 mg / L (FIG. 5).

  With the cyanide detoxification method and cyanide detoxifying agent according to the present invention, the cyanide compound can be detoxified efficiently, simply and at low cost. Further, the cyanide detoxification method and the cyanide detoxification agent according to the present invention can purify soil and water contaminated with the cyanide.

It is a figure which shows transition of the cyan density | concentration in the ground under execution of sparging. It is an electron micrograph of TC-2 strain. It is a figure which shows the cyan density | concentration change by thiosulfate addition. It is a figure which shows the cyanogen detoxification promotion effect of cyanide detoxification bacteria (rhodanase producing bacteria) by thiosulfate addition. The growth promotion effect of the TC-2 strain | stump | stock at the time of changing and adding thiosulfate density | concentration is shown.

Claims (11)

The soil or water containing cyanide, and supplying the bacteria with thiosulphate Rodanaze producing bacteria, the method of detoxifying a cyanide compound, characterized in that detoxifies cyanide of the soil or water. A method for detoxifying a cyanide, comprising supplying a rhodanase enzyme and a thiosulfate to soil or water containing the cyanide to detoxify the cyanide in the soil or water. Supplying a culture of rhodanase-producing bacteria cultured in the presence of thiosulfate to soil or water containing cyanide and detoxifying cyanide in the soil or water Method. A method for detoxifying a cyanide, comprising supplying a thiosulfate to soil or water containing a cyanide and having rhodanase-producing bacteria, thereby detoxifying the cyanide in the soil or water. Furthermore, the detoxification method of Claim 1 or 4 which supplies the nutrient salt selected from nitrogen and phosphorus, and detoxifies. The detoxification method according to any one of claims 1 , 4, and 5 , wherein the detoxification is performed by supplying air. The detoxification method according to any one of claims 1 to 6 , wherein the detoxification is performed at a pH of 6 to 10. The detoxification method according to any one of claims 1 to 7 , wherein the detoxification is performed at a temperature of 15 to 35 ° C. The bacteria or Rodanaze enzyme Rodanaze producing bacteria, characterized in that it comprises a thiosulfate, detoxifying agents of cyanide contained in the soil or water. The cyanide according to claim 9 , wherein the cyanide detoxifying agent further includes a nutrient selected from nitrogen and phosphorus when the rhodanase-producing bacteria are contained in the cells or when the rhodanase-producing bacteria are present in the soil or water. Compound detoxifying agent. A detoxifying agent for cyanide contained in soil or water, comprising a culture of rhodanase-producing bacteria cultured in the presence of thiosulfate.

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