JP3865575B2 - Dioxins-degrading bacteria and methods for degrading dioxins by microorganisms - Google Patents

Description

以上の形態的な特徴と、長期間貧栄養寒天培地上に培養しても完全世代が現れなかったことから、本菌株は不完全世代のカビであり、その詳細な特徴からアクレモニウム（Acremonium）属に属するカビと結論するに達した。
【００１４】
請求項２に係る本発明の微生物によるダイオキシン類の分解方法は、アクレモニウム（Acremonium）属であってダイオキシン類の分解能を有する菌株を培養し、この培養株を培地においてダイオキシン類と接触させるものである。
【００１５】
請求項３に係る本発明の微生物によるダイオキシン類の分解方法は、アクレモニウム（Acremonium）属であってダイオキシン類の分解能を有する菌株を培養し、この培養株を水溶液中においてダイオキシン類と接触させるものである。
【００１６】
請求項４に係る本発明の微生物によるダイオキシン類の分解方法は、アクレモニウム（Acremonium）属であってダイオキシン類の分解能を有する菌株を培養し、この培養株を含む培養物をダイオキシン類と接触させるものである。
【００１７】
請求項５に係る本発明の微生物によるダイオキシン類の分解方法は、アクレモニウム（Acremonium）属であってダイオキシン類の分解能を有する菌株を培養し、この培養株を含む培養物から菌体を含む固形分を除いた後の培養液をダイオキシン類と接触させるものである。
【００１８】
請求項６に係る本発明の微生物によるダイオキシン類の分解方法は、ダイオキシン類の分解能を有する菌株として、ＦＥＲＭ Ｐ−１７９８８として寄託されているアクレモニウム（Acremonium）属の菌株を使用するものである。
【００１９】
本発明における分解対象物は、ジベンゾ−Ｐ−ジオキシンとジベンゾフランを基本骨格に持ち、そのベンゼン環上に塩素が置換されたダイオキシン類の異性体の全てであり、その存在形態が水中、土壌中の何れであっても、培地に懸濁して菌体を接種する事によって分解可能である。なお、本発明においては上記菌株あるいはその変異株に限ることなく、アクレモニウム（Acremonium）属に属し、ダイオキシン類分解能を有する株であればすべて使用できる。
【００２０】
上記微生物を培養する培地組成としては、通常これらの微生物が生育しうるものであれば天然培地および合成培地のいずれでも使用でき、培地は固体あるいは液体培地のいずれでもよい。例えば、炭素源として、グルコース、デンプン等の糖類、窒素源として硫酸アンモニウム、硝酸塩などの無機塩が使用できる。その他、リン酸塩、カリウム塩、マグネシウム塩、鉄塩、カルシウム塩、マンガン塩等の無機塩類が必要である。上記微生物の培養は慣用の方法で行うことが出来る。通常、培養温度は２０℃から４０℃で、ｐＨは７前後から培養時４まで低下し、振とうあるいは通気攪拌等の手段により好気的条件下で行われる。
【００２１】
本発明によるダイオキシン類の分解は、上記培地中にダイオキシン類を添加するか、あるいは予め上記微生物を前記のごとき培養条件下で培養し、これらの微生物を集菌した後、この微生物を水溶液中でダイオキシン類と接触させればよい。また本発明においては微生物自体のほか、その培養液も使用することが出来る。本発明における該培養液とは、菌体を培養して得た培養物から菌体などの固形分を除いた後の培養液のことを指す。本発明でもちいる微生物とダイオキシン類を接触させる時のダイオキシン類の濃度は、４塩素以上のダイオキシン類が０．１ｐｐｍで含まれていると分解が可能であり、それ以下の濃度でも良好な分解を示す。接触時間は通常１日であり、異性体の塩素数に関係なく分解は進む。このようにして、ダイオキシン類は上記微生物による分解によってその毒性が減少する。
【００２２】
【発明の実施の形態】
以下に本発明の実施の形態を説明するが、本発明はこれらに限定されるものではない。また、本実施の形態におけるダイオキシン類は環境分析済みの廃液で、その組成を表２に示す。
【００２３】
【表２】

実施例１
１．５ｍｌ容のスクリューキャップ付き試験管に、ダイオキシン類（分析済み廃液、４価から８価のミクスチャー）を全量で２ｎｇ加え、窒素気流下で乾燥し、これにキャップをし、１２０℃で１０ｍｉｎ蒸気滅菌した。一方、別途滅菌した培地に菌体（ＦＥＲＭ Ｐ−１７９８８）を一白金耳接種した後に、この培地１ｍｌを５ｍｌ容のスクリューキャップ付き試験管に加え、キャップを施し培養を行った。
【００２４】
２．培養後の培地は凍結乾燥によって乾燥し、その後に３００ｍｌのトルエンを用いて固−液抽出（ソックスレー抽出）を２０ｈ行った。なお前処理におけるロスを後に換算するために、環境分析に準じて、１３Ｃラベルした2,3,7,8-TCDD、ISOTOPE LABELED CHLORODIOXIN STANDARDS ED-900（2,3,7,8-TCDD（13C12,99％）（Cambridge lsotope Laboratories社製）を内部標準物質として固−液抽出後に１０ｎｇ添加した。
【００２５】
前処理は、ソックスレ−抽出したトルエン相を１０ｍｌの容量まで減圧下濃縮し、次に有機化合物の分配処理を行うために硫酸を用いてトルエン相を洗浄した。この洗浄は硫酸相の黄色の着色が肉眼で確認出来なくなるまで行った。硫酸処理後のトルエン相は、蒸留水で２度洗浄して残留する硫酸を除き、さらに無水硫酸ナトリウムでトルエン相を乾燥させて約１ｍｌに濃縮した。
【００２６】
これを色素成分の除去を行うためにカラムクロマトグラフィーにアプライした。このカラムクロマトグラフィーは、シリカゲル３ｇを内径１０ｍｍ、長さ３００ｍｍのカラムクロマト管にヘキサンで湿式充填し、その上に無水硫酸ナトリウムを約１０ｍｍ積層したものである。
【００２７】
試料液１ｍｌを静かに移し入れ、ヘキサン１５０ｍｌで滴下速度約２．５ｍｌ／ｍｉｎ（毎秒１滴程度）の速度でゆっくり流して溶出した。溶出液は最終的に１００μｌとし、そのうち１μｌを分析に用いた。
【００２８】
３．ＧＣ−ＭＳにはＴＲＡＣＥ ＧＣ２０００、ＧＣＱ ｐｌｕｓ（ＴｈｅｒｍｏＱｕｅｓｔ社製）を用いた。カラムにはＪ＆Ｗ社製ＤＢ−５（０．２５ｍｍ×３０ｍ）を用いた。ＧＣの条件は１００℃で１ｍｉｎの保持の後、２５０℃まで３０℃／ｍｉｎで昇温し、続いて３１０℃まで５℃／ｍｉｎの昇温した後に３１０℃で５分間保持した。
【００２９】
またインジェクションの条件は、温度：２７０℃（Splitless）で、キャリアーガスとしてヘリウムを用い、その流速は１．０ｍｌ／ｍｉｎ（constant flow）とした。ＭＳ条件はイオン源温度を２００℃とし、トランスファーライン温度を３１０℃とした。
【００３０】
本実施例においてスパイクしたダイオキシンはほぼ１００％回収された。定量にはＧＣ−ＭＳ用ダイオキシン類スタンダード、PCDD/PCDF STANDARD MIXTURES EDF-4931（Cambridge lsotope Laboratories社製）を用いた。
【００３１】
表３に示すように、一日の培養によって、添加したダイオキシン類は異性体に対する分解特性もなくほぼ等しく分解され、平均で９０％の４塩素以上のダイオキシン類が分解された。なおこの分解率は、菌体を接種せずに１日同様の操作を行ったものから回収されたダイオキシン類量を１００とした場合に、菌体接種したものから回収されたダイオキシン類量の割合を示すものである。
【００３２】
【表３】

図１は本発明の他の実施の形態を示すダイオキシン類分解微生物を用いた水処理システムを示すものである。ダイオキシン類分解微生物は上述したようにアクレモニウム（Acremonium）属であってダイオキシン類の分解能を有する菌株（ＦＥＲＭ Ｐ−１７９８８）である。
【００３３】
図１において、リアクターは既設生物反応槽１であり、既設の生物反応槽を改造することによってダイオキシン類分解微生物の菌体育成条件を満たす環境を槽内に具現している。この菌体の生育条件の重要項目としては、菌体増殖速度、培養条件と分解反応条件（温度、ｐＨ、ＤＯ、ＯＲＰ）、生育阻害物質、反応阻害物質、菌体の物理的性状等がある。ダイオキシン類を含む処理対象水は、最終処分場の埋立地から生じる埋立浸出水２であり、添加物３はダイオキシン類分解微生物の生存環境を整えるための栄養源である。
【００３４】
この構成により、槽内でダイオキシン類分解微生物を生育する既設生物反応槽１に添加物３を加えた埋立浸出水２を導いて埋立浸出水２に含まれたダイオキシン類を微生物分解する。
【００３５】
図２は本発明の他の実施の形態を示すダイオキシン類分解微生物を用いた水処理システムを示すものである。図２において、リアクターは既設生物反応槽１とは別途に設けたＤＸＮ分解槽４であり、ダイオキシン類分解微生物の菌体育成条件を満たす環境を槽内に具現している。
【００３６】
この構成により、埋立浸出水２を既設生物反応槽１に導いて通常の生物処理を行ない、既設生物反応槽１を通過した処理水をＤＸＮ分解槽４に循環させて処理水に残留するダイオキシン類を微生物分解する。
【００３７】
図３は本発明の他の実施の形態を示すダイオキシン類分解微生物を用いた水処理システムを示すものである。図３において、リアクターは既設生物反応槽１であり、既設生物反応槽１とは別途に設けた菌体培養槽５でダイオキシン類分解微生物を培養する。
【００３８】
この構成により、埋立浸出水２もしくはスラリーを既設生物反応槽１に導いて通常の生物処理を行なうとともに、菌体培養槽５からダイオキシン類分解微生物の菌体を既設生物反応槽１に補充し、埋立浸出水２に含まれたダイオキシン類を微生物分解する。
【００３９】
図４は本発明の他の実施の形態を示すダイオキシン類分解微生物を用いた水処理システムを示すものである。図４において、リアクターはＤＸＮ分解槽４であり、ダイオキシン類分解微生物の菌体育成条件を満たす環境を槽内に具現している。ダイオキシン類を含む処理対象水は、汚染土壌からダイオキシン類を抽出した抽出水６である。
【００４０】
この構成により、抽出水６をＤＸＮ分解槽４に導いてダイオキシン類を微生物分解する。
【００４１】
【発明の効果】
以上にように、本発明によれば、アクレモニウム（Acremonium）属のカビを用いることで、難分解性の毒性ダイオキシン類を１日と言う短期間に９０％以上分解することができる。これによりダイオキシン類に汚染された水、あるいは土壌にこの菌体あるいは培養液を加えて放置するといった簡単な方法によりダイオキシン類を分解でき、自然界にダイオキシン類が蓄積され、人体を害すると言った問題を解決することができる。
【図面の簡単な説明】
【図１】本発明の実施の形態におけるダイオキシン類分解微生物を用いた水処理システムのフローシート図である。
【図２】本発明の他の実施の形態におけるダイオキシン類分解微生物を用いた水処理システムのフローシート図である。
【図３】本発明の他の実施の形態におけるダイオキシン類分解微生物を用いた水処理システムのフローシート図である。
【図４】本発明の他の実施の形態におけるダイオキシン類分解微生物を用いた水処理システムのフローシート図である。
【符号の説明】
１ 既設生物反応槽
２ 埋立浸出水
３ 添加物
４ ＤＸＮ分解槽
５ 菌体培養槽
６ 抽出水[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dioxin-degrading bacterium and a method for decomposing dioxins by microorganisms, and particularly relates to a technique for degrading dioxins using a cultured strain of a genus Acremonium belonging to a kind of mold.
[0002]
[Prior art]
Dioxins pollute the soil and water in the natural environment by being discharged from incineration facilities by inappropriate treatment or by being sprayed as impurities mixed in pesticides. Since dioxins are chemically and physically stable compounds, they persist in the natural environment for a long period of time, and during that time they are taken into the human body by the food chain, etc., causing carcinogenesis and teratogenicity.
[0003]
Since such pollution is widespread at low concentrations except for a part, it is costly disadvantageous to transport contaminated soil and water to special facilities and use a lot of energy for physicochemical treatment. is there.
[0004]
On the other hand, the method using microorganisms that grow at room temperature can save energy and can be purified on the spot without the movement of contaminants to be purified. However, among the microorganisms that decompose dioxins that have been found so far, bacteria such as Pseudomonas genus and Sphingomonas genus only decompose low-chlorine dioxins with extremely low toxicity. Fast but high chlorine dioxins cannot be decomposed.
[0005]
In addition, methanogens dechlorinate high chlorine dioxins in a dechlorinated manner, but the reaction rate is extremely slow, and the reaction takes more than one month. Furthermore, mold belonging to white rot fungi can be decomposed from high chlorine dioxins to low chlorine dioxins, but the reaction requires one week or more and the decomposition rate is also inferior.
[0006]
In addition, in the technique disclosed in Japanese Patent Laid-Open No. 10-257895 “Microbial Oxygen Oxidase Gene and Dioxin Removal Method Using It”, it only catalyzes the decomposition of trichlorine to dioxins, and has further toxicity. High dioxins are not decomposed.
[0007]
[Problems to be solved by the invention]
Thus, isolation of a new microorganism is desired for the decomposition of dioxins by a practical microorganism.
[0008]
The first object of the present invention is to provide a microorganism that contributes to the degradation of dioxins. The second object is to provide a method for microbial degradation of dioxins, particularly highly chlorinated dioxins. The third object is to provide a method in which dioxins are easily decomposed even if left by allowing simple treatment of dioxins. The fourth object is to provide a method for purifying the environment so that dioxins released into the natural environment do not accumulate in the human body.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, the present inventors have extensively searched for the decoloring activity of natural polymer lignin having a structure similar to that of dioxins from the natural world. It was isolated and identified from biological treatment tank sludge (biological membrane backwash sludge) in the leachate treatment facility at the general waste disposal site. The inventors have found that this identified Acremonium mold decomposes about 90% of dioxins in one day, and has come to the present invention.
[0010]
That is, the dioxin-degrading bacterium of the present invention according to claim 1 is a cultured strain of the Acremonium genus strain deposited as FERM P-17988, which degrades dioxins.
[0011]
The mold belonging to the genus Acremonium according to the present invention is a mold that exists widely in soil, etc., but the present inventors have made a biological treatment tank sludge (biological film of the biofilm) of the leachate treatment facility at the general waste final disposal site. It is a strain isolated from backwash sludge and identified as a mold that decolorizes the brown coloration caused by lignin in the medium.
[0012]
This strain was deposited with the Patent Microorganism Deposit Center of Biotechnology Institute of Industrial Technology, August 7, 2000, and the deposit number is FERM P-17988. The bacteriological properties of this strain are as shown in Table 1.
These mycological identifications were based on Ainsworth &bisby's “Dictionary of the fungi” 8th edn.
[0013]
[Table 1]

Because of the above morphological characteristics and the absence of a complete generation even after culturing on an oligotrophic agar medium for a long time, this strain is an incomplete generation of mold. From its detailed characteristics, Acremonium It came to the conclusion that the mold belongs to the genus.
[0014]
The method for decomposing dioxins by a microorganism of the present invention according to claim 2 comprises culturing a strain belonging to the genus Acremonium and having the resolution of dioxins, and bringing the cultured strain into contact with dioxins in a medium. is there.
[0015]
The method for decomposing dioxins by a microorganism according to the present invention according to claim 3 comprises culturing a strain belonging to the genus Acremonium and having a resolution of dioxins, and bringing the cultured strain into contact with dioxins in an aqueous solution. It is.
[0016]
In the method for decomposing dioxins by a microorganism of the present invention according to claim 4, a strain that belongs to the genus Acremonium and has a resolution of dioxins is cultured, and a culture containing this culture strain is brought into contact with the dioxins. Is.
[0017]
The method for decomposing dioxins by a microorganism of the present invention according to claim 5 is a method of culturing a strain belonging to the genus Acremonium and having a resolution of dioxins, and a solid containing cells from a culture containing this culture strain. The culture solution after removing the minutes is brought into contact with dioxins.
[0018]
The method for decomposing dioxins by the microorganism of the present invention according to claim 6 uses a strain belonging to the genus Acremonium deposited as FERM P-17988 as a strain having a resolution of dioxins.
[0019]
The decomposition targets in the present invention are all isomers of dioxins having dibenzo-P-dioxin and dibenzofuran in the basic skeleton and substituted with chlorine on the benzene ring, and their existence forms are in water and in soil. Any of these can be decomposed by suspending in a medium and inoculating cells. In the present invention, any strain belonging to the genus Acremonium and capable of dioxin resolution can be used without being limited to the above strains or mutants thereof.
[0020]
As a medium composition for culturing the above microorganisms, any natural or synthetic medium can be used as long as these microorganisms can grow. The medium may be a solid or liquid medium. For example, sugars such as glucose and starch can be used as the carbon source, and inorganic salts such as ammonium sulfate and nitrate can be used as the nitrogen source. In addition, inorganic salts such as phosphate, potassium salt, magnesium salt, iron salt, calcium salt and manganese salt are necessary. The microorganism can be cultured by a conventional method. Usually, the culture temperature is 20 ° C. to 40 ° C., the pH is lowered from around 7 to 4 at the time of culture, and it is carried out under aerobic conditions by means such as shaking or aeration stirring.
[0021]
The decomposition of dioxins according to the present invention may be carried out by adding dioxins to the medium or by previously culturing the microorganisms under the culture conditions as described above and collecting these microorganisms in an aqueous solution. What is necessary is just to make it contact with dioxins. In addition to the microorganism itself, the culture solution thereof can also be used in the present invention. The culture solution in the present invention refers to a culture solution after removing solids such as cells from a culture obtained by culturing cells. The concentration of dioxins when the microorganisms used in the present invention are brought into contact with dioxins can be decomposed when dioxins containing 4 chlorines or more are contained at 0.1 ppm, and good decomposition is possible even at concentrations below that. Indicates. The contact time is usually 1 day, and the decomposition proceeds regardless of the number of isomers. In this way, the toxicity of dioxins is reduced by degradation by the microorganisms.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below, but the present invention is not limited to these. The dioxins in the present embodiment are waste liquids that have been subjected to environmental analysis, and their compositions are shown in Table 2.
[0023]
[Table 2]

Example 1
Add 2 ng of dioxins (analyzed waste liquid, tetravalent to octavalent mixture) in a total volume of 1.5 ml to a test tube with a screw cap, dry under nitrogen flow, cap this, and cap at 120 ° C for 10 min. Steam sterilized. On the other hand, after inoculating one platinum loop of microbial cells (FERM P-17988) in a separately sterilized medium, 1 ml of this medium was added to a 5 ml test tube with a screw cap, and the cap was applied to perform culture.
[0024]
2. The cultured medium was dried by freeze-drying, and then solid-liquid extraction (Soxhlet extraction) was performed for 20 h using 300 ml of toluene. In order to convert the loss in pretreatment later, according to environmental analysis, 2,3,7,8-TCDD, ISOTOPE LABELED CHLORODIOXIN STANDARDS ED-900 (2,3,7,8-TCDD (13C12 , 99%) (manufactured by Cambridge lsotope Laboratories) as an internal standard substance, 10 ng was added after solid-liquid extraction.
[0025]
In the pretreatment, the Soxhlet-extracted toluene phase was concentrated under reduced pressure to a volume of 10 ml, and then the toluene phase was washed with sulfuric acid in order to distribute the organic compound. This washing was performed until the yellow coloration of the sulfuric acid phase could not be confirmed with the naked eye. The toluene phase after the sulfuric acid treatment was washed twice with distilled water to remove the remaining sulfuric acid, and the toluene phase was further dried over anhydrous sodium sulfate and concentrated to about 1 ml.
[0026]
This was applied to column chromatography in order to remove the dye component. In this column chromatography, 3 g of silica gel is wet-filled with hexane into a column chromatograph tube having an inner diameter of 10 mm and a length of 300 mm, and anhydrous sodium sulfate is laminated thereon to a thickness of about 10 mm.
[0027]
1 ml of the sample solution was gently transferred and eluted with 150 ml of hexane at a slow dropping rate of about 2.5 ml / min (about 1 drop per second). The eluate was finally made 100 μl, 1 μl of which was used for analysis.
[0028]
3. For GC-MS, TRACE GC2000 and GCQ plus (manufactured by ThermoQuest) were used. DB-5 (0.25 mm × 30 m) manufactured by J & W was used for the column. The GC was maintained at 100 ° C. for 1 min, then heated to 250 ° C. at 30 ° C./min, subsequently heated to 310 ° C. at 5 ° C./min and then held at 310 ° C. for 5 minutes.
[0029]
The injection conditions were temperature: 270 ° C. (Splitless), helium was used as a carrier gas, and the flow rate was 1.0 ml / min (constant flow). The MS conditions were an ion source temperature of 200 ° C. and a transfer line temperature of 310 ° C.
[0030]
In this example, almost 100% of the spiked dioxin was recovered. For quantification, a dioxin standard for GC-MS, PCDD / PCDF STANDARD MIXTURES EDF-4931 (manufactured by Cambridge lsotope Laboratories) was used.
[0031]
As shown in Table 3, the added dioxins were decomposed almost equally without any decomposition property to the isomers, and 90% of the dioxins of 4 or more chlorines were decomposed on average by the daily culture. This degradation rate is the ratio of the amount of dioxins recovered from the cells inoculated when the amount of dioxins recovered from the same operation for 1 day without inoculating the cells was taken as 100. Is shown.
[0032]
[Table 3]

FIG. 1 shows a water treatment system using a dioxin-degrading microorganism according to another embodiment of the present invention. As described above, the dioxin-degrading microorganism is a strain (FERM P-17988) belonging to the genus Acremonium and having the resolution of dioxins.
[0033]
In FIG. 1, the reactor is an existing biological reaction tank 1, and an environment that satisfies cell growth conditions for dioxin-degrading microorganisms is embodied in the tank by remodeling the existing biological reaction tank. Important items of the growth conditions of the cells include cell growth rate, culture conditions and decomposition reaction conditions (temperature, pH, DO, ORP), growth inhibitors, reaction inhibitors, and physical properties of the cells. . The water to be treated containing dioxins is landfill leachate 2 generated from the landfill site of the final disposal site, and the additive 3 is a nutrient source for preparing a living environment for dioxin-degrading microorganisms.
[0034]
With this configuration, the landfill leachate 2 to which the additive 3 has been added is introduced into the existing biological reaction tank 1 in which the dioxin-decomposing microorganisms grow in the tank, and the dioxins contained in the landfill leachate 2 are microbially degraded.
[0035]
FIG. 2 shows a water treatment system using a dioxin-degrading microorganism according to another embodiment of the present invention. In FIG. 2, the reactor is a DXN decomposition tank 4 provided separately from the existing biological reaction tank 1, and an environment that satisfies the cell growth conditions of dioxin-degrading microorganisms is embodied in the tank.
[0036]
With this configuration, the landfill leachate 2 is guided to the existing biological reaction tank 1 for normal biological treatment, and the treated water that has passed through the existing biological reaction tank 1 is circulated to the DXN decomposition tank 4 to remain in the treated water. Microbial decomposition.
[0037]
FIG. 3 shows a water treatment system using dioxin-degrading microorganisms according to another embodiment of the present invention. In FIG. 3, the reactor is an existing biological reaction tank 1, and dioxins-decomposing microorganisms are cultured in a cell culture tank 5 provided separately from the existing biological reaction tank 1.
[0038]
With this configuration, the landfill leachate 2 or slurry is guided to the existing biological reaction tank 1 to perform normal biological treatment, and the cells of the dioxin-degrading microorganisms are replenished to the existing biological reaction tank 1 from the cell culture tank 5. Dioxins contained in landfill leachate 2 are microbially decomposed.
[0039]
FIG. 4 shows a water treatment system using a dioxin-degrading microorganism according to another embodiment of the present invention. In FIG. 4, the reactor is a DXN decomposition tank 4, which embodies an environment that satisfies the cell growth conditions for dioxin-decomposing microorganisms. The water to be treated containing dioxins is extracted water 6 obtained by extracting dioxins from contaminated soil.
[0040]
With this configuration, the extracted water 6 is guided to the DXN decomposition tank 4 to microbially decompose dioxins.
[0041]
【The invention's effect】
As described above, according to the present invention, by using a mold belonging to the genus Acremonium, it is possible to decompose 90% or more of hardly decomposable toxic dioxins within a short period of one day. As a result, dioxins can be decomposed by simple methods such as adding water or soil to the soil contaminated with dioxins or leaving it to stand, causing dioxins to accumulate in nature and harming the human body. Can be solved.
[Brief description of the drawings]
FIG. 1 is a flow sheet diagram of a water treatment system using dioxin-degrading microorganisms in an embodiment of the present invention.
FIG. 2 is a flow sheet diagram of a water treatment system using dioxin-degrading microorganisms according to another embodiment of the present invention.
FIG. 3 is a flow sheet diagram of a water treatment system using dioxin-degrading microorganisms according to another embodiment of the present invention.
FIG. 4 is a flow sheet diagram of a water treatment system using dioxin-degrading microorganisms according to another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Existing biological reaction tank 2 Landfill leachate 3 Additive 4 DXN decomposition tank 5 Cell culture tank 6 Extracted water

Claims (6)

A culture of a strain of the genus Acremonium deposited as FERM P-17988 that degrades dioxins. A method for decomposing dioxins by a microorganism, comprising culturing a strain belonging to the genus Acremonium and having a resolution of dioxins, and contacting the cultured strain with dioxins in a medium. A method for decomposing dioxins by a microorganism, comprising culturing a strain belonging to the genus Acremonium and having a resolution of dioxins, and contacting the cultured strain with dioxins in an aqueous solution. A method for decomposing dioxins by a microorganism, comprising culturing a strain belonging to the genus Acremonium and having a resolution of dioxins, and bringing the culture containing the culture strain into contact with dioxins. It is characterized by culturing a strain belonging to the genus Acremonium and having the resolution of dioxins, and contacting the culture solution after removing solids containing cells from the culture containing this culture with dioxins A method for decomposing dioxins by microorganisms. The culture strain of the strain of the genus Acremonium (Acremonium) deposited as FERM P-17988 is used as the strain having a resolution of dioxins, according to any one of claims 2 to 5, Decomposition method of dioxins by microorganisms.

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