JP2001352970A - Control method for bacterium level in methane fermentation tank - Google Patents

Control method for bacterium level in methane fermentation tank

Info

Publication number
JP2001352970A
JP2001352970A JP2000178767A JP2000178767A JP2001352970A JP 2001352970 A JP2001352970 A JP 2001352970A JP 2000178767 A JP2000178767 A JP 2000178767A JP 2000178767 A JP2000178767 A JP 2000178767A JP 2001352970 A JP2001352970 A JP 2001352970A
Authority
JP
Japan
Prior art keywords
bacteria
methane
electrode
methane fermentation
electric field
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
JP2000178767A
Other languages
Japanese (ja)
Inventor
Masayuki Tabata
雅之 田畑
Takeshi Nakamura
中村　　剛
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Heavy Industries Ltd
Original Assignee
Mitsubishi Heavy Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Heavy Industries Ltd filed Critical Mitsubishi Heavy Industries Ltd
Priority to JP2000178767A priority Critical patent/JP2001352970A/en
Publication of JP2001352970A publication Critical patent/JP2001352970A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E50/00—Technologies for the production of fuel of non-fossil origin
    • Y02E50/30—Fuel from waste, e.g. synthetic alcohol or diesel

Abstract

PROBLEM TO BE SOLVED: To provide a method for the control of a bacterium level in a methane fermentation tank by making use of difference in electrical properties between methane-fermentative bacteria and acid-productive bacteria. SOLUTION: This method comprises the following practice: a base mounted with electrodes capable of generating nonuniform electric field is disposed in a methane fermentation liquid containing methane-fermentative bacteria, an alternate voltage is applied to the electrodes to generate a nonuniform electric field in the above fermentation liquid and bacteria other than the methane- fermentative bacteria are allowed to preferentially adhere to the electrodes based on difference in dielectrophoretic potency between respective bacterial cells to raise the existence rate of the methane-fermentative bacteria in the above fermentation liquid.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、メタン発酵槽内の
メタン発酵菌の存在比を制御する方法に関する。[0001] The present invention relates to a method for controlling the abundance ratio of methane fermentation bacteria in a methane fermentation tank.

【０００２】[0002]

【従来の技術】有機性廃棄物の嫌気処理に用いられてい
るメタン発酵法は、有機酸、水素、二酸化炭素等からメ
タンを生成する作用をもつメタン発酵菌を利用したエネ
ルギー回収型の廃棄物処理方法である。2. Description of the Related Art The methane fermentation method used for anaerobic treatment of organic waste is an energy-recovery waste using methane fermentation bacteria having an action of producing methane from organic acids, hydrogen, carbon dioxide and the like. Processing method.

【０００３】メタン発酵は、有機性廃棄物から有機酸を
生成する第一の過程と有機酸からメタンガスを生成する
第二の過程から成り、これら二つの過程をそれぞれ担う
二種類の微生物群が連携、協調して働く非常に複雑な反
応系である。各過程を説明すると、第一の過程は、有機
性廃棄物中の蛋白質、炭水化物、脂質等を可溶化して、
アミノ酸や糖類などを生成し、さらにアミノ酸、糖等か
ら有機酸や水素を生成する過程であり、この過程を担う
微生物群は酸生成菌群と総称される。第二の過程は、第
一の過程で生成された有機酸や水素と二酸化炭素からメ
タンガスを生成する過程であり、この過程を担う微生物
群はメタン発酵菌と称される。このような二つの反応系
を安定に維持するためには、負荷に応じて二つの菌群の
菌濃度および活性度のバランスが保たれていることが重
要である。[0003] Methane fermentation consists of a first process for producing organic acids from organic waste and a second process for producing methane gas from organic acids. Two types of microorganisms, which respectively carry out these two processes, cooperate. It is a very complex reaction system that works in concert. To explain each process, the first process is to solubilize proteins, carbohydrates, lipids, etc. in organic waste,
This is the process of producing amino acids and sugars, and further producing organic acids and hydrogen from amino acids, sugars, and the like. Microorganisms responsible for this process are collectively referred to as acid-producing bacteria. The second process is a process of generating methane gas from the organic acid, hydrogen, and carbon dioxide generated in the first process, and a group of microorganisms responsible for this process is called a methane fermenter. In order to stably maintain such two reaction systems, it is important that the balance between the bacterial concentration and the activity of the two bacterial groups is maintained according to the load.

【０００４】メタン発酵菌は、酸生成菌群に属する微生
物と比べて増殖速度が遅いため、負荷変動等で他の微生
物の菌濃度が変化した場合、これに追随することが難し
く、菌群のバランスを保つことができなくなり処理系が
破綻する場合がある。[0004] Since the growth rate of methane fermenting bacteria is lower than that of microorganisms belonging to the group of acid-producing bacteria, it is difficult to follow the change in bacterial concentration of other microorganisms due to load fluctuation or the like. The balance cannot be maintained, and the processing system may fail.

【０００５】特に、急激な負荷の上昇時等に、酸生成菌
群の増殖にメタン発酵菌の増殖が追いつかず、酸生成菌
の生成した有機酸類が蓄積して系が破綻した状態は「酸
敗」と呼ばれ、一度この状態になると安定した状態に戻
すことは非常に困難であることが知られている。[0005] In particular, when the load suddenly rises, etc., the growth of the methane-fermenting bacteria cannot keep up with the growth of the acid-producing bacteria, and the organic acids generated by the acid-producing bacteria accumulate and the system is broken. It is known that once in this state, it is very difficult to return to a stable state.

【０００６】[0006]

【発明が解決しようとする課題】上記事情に鑑み、本発
明の目的は、メタン発酵菌と酸生成菌群の電気的性質の
差異を利用して、メタン発酵槽内の菌濃度の制御を行う
方法を提供することである。SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to control the concentration of bacteria in a methane fermentation tank by utilizing the difference in electrical properties between a methane fermentation bacterium and an acid-producing bacterium group. Is to provide a way.

【０００７】[0007]

【課題を解決するための手段】上記目的を達成するた
め、以下に示す手段を採用する。In order to achieve the above object, the following means are employed.

【０００８】本発明のメタン発酵槽内の菌濃度制御方法
は、不均一電場を発生させることが可能な電極を設けた
基板を、メタン発酵菌を含むメタン発酵液中に配置させ
るとともに、前記電極に交流電圧を印加して前記発酵液
中に不均一電場を発生させ、各菌細胞の誘電泳動力の差
によって、メタン発酵菌以外の菌を優先的に電極に付着
させ、前記発酵液中のメタン発酵菌の存在比を高めるこ
とを特徴とする。According to the method for controlling the concentration of bacteria in a methane fermentation tank of the present invention, a substrate provided with electrodes capable of generating a non-uniform electric field is placed in a methane fermentation solution containing methane fermentation bacteria, and A non-uniform electric field is generated in the fermentation broth by applying an AC voltage to the fermentation broth, and a difference in the dielectrophoretic force of each microbial cell causes bacteria other than methane fermentation bacteria to preferentially adhere to the electrode, and the fermentation broth in the fermentation broth. It is characterized by increasing the abundance ratio of methane fermentation bacteria.

【０００９】また、本発明のメタン発酵槽内の菌濃度制
御方法は、不均一電場を発生させることが可能な電極を
設けた基板を、メタン発酵菌を含むメタン発酵液中に配
置させるとともに、前記電極に交流電圧を印加して前記
発酵液中に不均一電場を発生させ、各菌細胞の誘電泳動
力の差によって、メタン発酵菌を優先的に電極に付着さ
せ、前記発酵液中のメタン発酵菌の存在比を低くするこ
とを特徴とする。Further, the method for controlling the concentration of bacteria in a methane fermenter according to the present invention comprises disposing a substrate provided with electrodes capable of generating a non-uniform electric field in a methane fermentation solution containing methane fermenters. An AC voltage is applied to the electrode to generate a non-uniform electric field in the fermentation liquor, and methane fermentation bacteria are preferentially adhered to the electrode by a difference in dielectrophoretic force of each bacterial cell. It is characterized in that the ratio of fermentation bacteria is reduced.

【００１０】[0010]

【発明の実施の形態】以下、本発明を詳細に説明する。BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

【００１１】一般に、誘電体を不均一電場中に置くと、
電気的泳動力が働き、誘電体は電場の強い方へ引き寄せ
られるか、あるいは逆に電場の弱い方へ押しやられると
いう挙動を示す。この現象は誘電泳動と称されるもの
で、電場の強い方へ引き寄せられる現象は「正の誘電泳
動」と呼ばれ、電場の弱い方へ押しやられる現象は「負
の誘電泳動」と呼ばれる。また、誘電泳動は交流電場に
おいても生じるが、均一電場、即ち、電界強度が位置に
よって変化しない電場では生じない。本発明は、この誘
電泳動を利用したものである。Generally, when a dielectric is placed in a non-uniform electric field,
The electrophoretic force acts, and the dielectric shows a behavior of being drawn toward the strong electric field or conversely pushed toward the weak electric field. This phenomenon is called dielectrophoresis, and the phenomenon of being attracted to a stronger electric field is called “positive dielectrophoresis”, and the phenomenon of being pushed to a weaker electric field is called “negative dielectrophoresis”. Dielectrophoresis also occurs in an alternating electric field, but does not occur in a uniform electric field, that is, an electric field in which the electric field intensity does not change with position. The present invention utilizes this dielectrophoresis.

【００１２】一般に微生物の細胞は誘電体であり、各微
生物はそれぞれ固有の誘電率を有する。誘電体とは電場
を加えた際に誘電分極を生じる物質をいい、誘電体の誘
電率は物質によって定まっている。微生物がどのような
値の誘電率を示すかは、微生物の誘電率と媒質の誘電率
との差によって決定されるため、電気的物性が同じでな
い限り微生物種が異なれば同一条件での挙動は異なる。
また、交流電場中では、微生物と媒質の誘電率の大きさ
は周波数によって変化するため、同一の微生物であって
も周波数によって正負の挙動が変化する。Generally, cells of microorganisms are dielectrics, and each microorganism has its own dielectric constant. A dielectric refers to a substance that causes dielectric polarization when an electric field is applied, and the dielectric constant of the dielectric is determined by the substance. Since the value of the dielectric constant of a microorganism is determined by the difference between the dielectric constant of the microorganism and the dielectric constant of the medium, the behavior under the same conditions for different types of microorganisms is not affected unless the electrical properties are the same. different.
Further, in an alternating electric field, the magnitude of the dielectric constant of the microorganism and the medium changes depending on the frequency. Therefore, even for the same microorganism, the positive or negative behavior changes depending on the frequency.

【００１３】上述の誘電泳動の原理を微生物に対して適
用し、且つ電極へ付着させたい微生物の誘電率が媒質の
誘電率より大きくなるように条件を整えることにより
（すなわち正の誘電泳動が起こるようにすることによ
り）、前記微生物を選択的に電極へ付着固定化させるこ
とができる。By applying the above-described principle of dielectrophoresis to microorganisms and adjusting conditions so that the dielectric constant of the microorganism to be attached to the electrode is higher than the dielectric constant of the medium (that is, positive dielectrophoresis occurs). By doing so, the microorganisms can be selectively adhered and immobilized on the electrode.

【００１４】また、二種類の微生物がたとえ同一条件で
同じ方向の誘電泳動を示したとしても、電場中での移動
速度や電極へ付着する強さの差を利用して、両者を分け
ることが可能である。[0014] Even if two kinds of microorganisms show dielectrophoresis in the same direction under the same conditions, it is possible to separate the two by utilizing the difference in the moving speed in an electric field and the strength of attachment to the electrode. It is possible.

【００１５】即ち、複数種類の微生物が存在する懸濁液
中で不均一電場を発生させることにより、より強い正の
誘電泳動を示す微生物は、優先的に電極に付着、保持さ
れる。この後、微生物の付着した電極を懸濁液中から除
去するか、あるいは電極と接触している懸濁液を回収す
ることによって、メタン発酵菌のように弱い正の誘電泳
動を示す微生物や負の誘電泳動を示す微生物の存在比の
高まった微生物懸濁液を得ることができる。That is, by generating a heterogeneous electric field in a suspension in which a plurality of types of microorganisms are present, microorganisms exhibiting stronger positive dielectrophoresis are preferentially attached to and retained on the electrode. Thereafter, the electrode with the microorganism attached thereto is removed from the suspension, or the suspension in contact with the electrode is recovered, so that the microorganism having a weak positive dielectrophoresis such as a methane fermentation bacterium or a negative electrode can be obtained. Thus, a microorganism suspension having a high abundance ratio of microorganisms exhibiting dielectrophoresis can be obtained.

【００１６】本発明において「不均一な電場を発生させ
ることが可能な電極」とは、不均一な電場を形成するも
のであればどのような形状、材質のものでも特に限定さ
れない。形状の一例としては、棒状の電極に（好ましく
は複数の）突出部または突起部を有することにより、電
極間に形成される電場を不均一にできるものが挙げられ
る。前記電極は、微生物の付着できる表面積を広くする
ため、複数の突出部を有することが好ましい。例えば、
電極の突出部が更に突起部を有する、図１に示すような
形状の電極を用いることができる。また、電極の材質は
好ましくはアルミニウム、白金を用いることができる
が、これに限定されない。In the present invention, the "electrode capable of generating a non-uniform electric field" is not particularly limited, as long as it forms a non-uniform electric field, of any shape and material. As an example of the shape, a rod-shaped electrode having (preferably a plurality of) projections or projections can make the electric field formed between the electrodes non-uniform. The electrode preferably has a plurality of protrusions in order to increase the surface area to which microorganisms can adhere. For example,
An electrode having a shape as shown in FIG. 1 in which the protruding portion of the electrode further has a protruding portion can be used. The material of the electrode is preferably aluminum or platinum, but is not limited thereto.

【００１７】上記電極を設ける基板は、平坦な基板を使
用してもよいし、あるいは不均一電場を発生させること
ができる電極を設けることが可能であれば立体的な基板
を使用することもでき、その形状は限定されない。また
基板の材質は、好ましくはガラスを用いることができる
が、絶縁体であればこれに限定されない。As the substrate on which the electrodes are provided, a flat substrate may be used, or a three-dimensional substrate may be used if an electrode capable of generating a non-uniform electric field can be provided. The shape is not limited. In addition, as a material of the substrate, glass can be preferably used, but it is not limited to this as long as it is an insulator.

【００１８】上記電極は、例えばフォトリソグラフ法に
より基板上に設けることができる。The electrodes can be provided on the substrate by, for example, a photolithographic method.

【００１９】また、電極に印加する交流電圧は、およそ
１〜20 Ｖ、周波数は100Hz−10MHzの範囲において、優
先的に付着させたい微生物と付着させたくない微生物と
が誘電泳動力の差を生ずるように、そしてこれら微生物
を取り巻く媒質との関係により、適宜設定することがで
きる。「不均一電場を発生させることが可能な電極」に
交流電圧を印加することにより、不均一な電場を発生さ
せることができる。Further, when the AC voltage applied to the electrodes is in the range of about 1 to 20 V and the frequency is in the range of 100 Hz to 10 MHz, the difference in dielectrophoretic force between the microorganisms to be preferentially attached and the microorganisms not to be attached is generated. As appropriate, and depending on the relationship with the medium surrounding these microorganisms. By applying an AC voltage to the “electrode capable of generating a non-uniform electric field”, a non-uniform electric field can be generated.

【００２０】本発明において使用される「メタン発酵菌
を含むメタン発酵液」とは、有機性廃棄物をメタン発酵
する能力を有する微生物、即ち酸生成菌群とメタン発酵
菌の両方を含むものであれば特に限定されない。本発明
において酸生成菌群とは、メタン発酵の酸生成過程を担
う微生物であればよく、メタン発酵菌とは、生成された
酸からメタンを生成するものであれば特に限定されな
い。また本発明において「メタン発酵菌以外の菌」と
は、酸生成菌を意味していますが、酸生成能力をもたな
い菌を含んでいてもよい。各微生物の一例として、酸生
成菌群はParacoccusdenitrificans、メタン発酵菌はMet
hanobacterium bryantiiが挙げられる。The term "methane fermentation liquor containing methane fermentation bacteria" used in the present invention is a microorganism having the ability to methane ferment organic wastes, that is, a microorganism containing both acid-producing bacteria and methane fermentation bacteria. There is no particular limitation as long as it exists. In the present invention, the acid-producing bacterium group may be any microorganism that is responsible for the acid production process of methane fermentation, and the methane-fermentation bacterium is not particularly limited as long as it produces methane from the produced acid. In the present invention, “a bacterium other than a methane fermenting bacterium” means an acid-producing bacterium, but may include a bacterium having no acid-producing ability. As an example of each microorganism, acid-producing bacteria group is Paracoccus denitrificans , and methane fermentation bacteria is Met
hanobacterium bryantii .

【００２１】また、微生物を含む液およびその濃度は、
各微生物の生育に適した溶液であれば限定されないが、
溶液を選択する際に媒質の有する誘電率が重要なファク
ターとなる。例えば、10μＳ/ｃｍの280ｍＭマンニトー
ル溶液に微生物を懸濁したものを本発明に使用すること
ができる。The liquid containing microorganisms and the concentration thereof are as follows:
It is not limited as long as it is a solution suitable for the growth of each microorganism,
When selecting a solution, the dielectric constant of the medium is an important factor. For example, a suspension of microorganisms in a 10 μS / cm 280 mM mannitol solution can be used in the present invention.

【００２２】優先的に付着させたい微生物と付着させた
くない微生物とを含む懸濁液を電極上へ添加する方法
は、電極を設置した基板上に微生物懸濁液を滴下しても
よいし、微生物懸濁液中に基板を浸漬してもよい。The method of adding a suspension containing microorganisms to be preferentially adhered and microorganisms not to be adhered onto the electrode may be a method in which the microorganism suspension is dropped on a substrate provided with the electrode, The substrate may be immersed in the microorganism suspension.

【００２３】このようにして、上記電極を覆うように満
たされた微生物懸濁液中の特定の微生物細胞を、以下に
説明するように優先的に電極に付着させたり、あるいは
優先的に付着させないようにしたりすることができる。In this manner, specific microbial cells in the microbial suspension filled to cover the electrode are preferentially adhered to the electrode or not preferentially adhered as described below. And so on.

【００２４】特定の微生物を優先的に基板上に付着させ
るためには、優先的に付着させたい微生物の誘電率を、
付着させたくない微生物の誘電率より大きくすることに
より行うことができる。微生物の泳動の挙動は、微生物
種および周波数によって変化し、更に各々の微生物同士
の相対関係にも依存するため、優先的に付着させたい微
生物の種に応じて、強い正の誘電泳動が起こるような条
件を設定することにより、当該微生物を優先的に電極に
付着させることができる。In order to attach a specific microorganism preferentially to a substrate, the dielectric constant of the microorganism to be attached preferentially is determined by
This can be achieved by making the dielectric constant higher than the permittivity of microorganisms not to be attached. Since the behavior of microbial migration changes depending on the microorganism type and frequency, and also depends on the relative relationship between each microorganism, strong positive dielectrophoresis may occur depending on the type of microorganism to be preferentially attached. By setting appropriate conditions, the microorganism can be preferentially attached to the electrode.

【００２５】例えば、メタン発酵菌Methanobacterium b
ryantii DSM863、およびメタン発酵菌以外の菌Paracocc
us denitrificans IFO13301を含有する280ｍＭマンニト
ールの懸濁液は、電界強度が１×105 Ｖ/Ｍ以上となる
ような周波数100 kHzの交流電圧を印加することによ
り、Paracoccus denitrificans IFO13301を優先的に電
極に付着させることができる。For example, the methane fermentation bacterium Methanobacterium b
Paracocc other than ryantii DSM863 and methane fermentation bacteria
suspension of 280mM mannitol containing us denitrificans IFO13301, by the electric field strength is applied to the frequency 100 kHz of the AC voltage such that 1 × 10 5 V / M or more, the Paracoccus denitrificans IFO13301 preferentially to the electrode Can be attached.

【００２６】ここで、本発明の方法において使用される
不均一電場を発生させるのに好ましい電極を、図面を参
照して説明する。Now, preferred electrodes for generating a non-uniform electric field used in the method of the present invention will be described with reference to the drawings.

【００２７】図１において、１は基板であり、該基板の
表面には第一の電極２および第二の電極３が形成されて
いる。第一の電極２は、第一の電極から突出する複数の
突出部４を有し、第二の電極も同様に第二の電極から突
出する複数の突出部５を有する。前記第一の突出部４と
前記第二の突出部５は互いに向かい合って、交互に入り
組んだ配置をとる。両突出部４および５は、更にその両
側に複数の凸部を有し、第一の突出部４の凸部の対向す
る面に第二の突出部５の凹部が配置される。In FIG. 1, reference numeral 1 denotes a substrate on which a first electrode 2 and a second electrode 3 are formed. The first electrode 2 has a plurality of protrusions 4 protruding from the first electrode, and the second electrode also has a plurality of protrusions 5 protruding from the second electrode. The first projections 4 and the second projections 5 face each other and have an alternately intricate arrangement. Each of the protrusions 4 and 5 further has a plurality of protrusions on both sides thereof, and a recess of the second protrusion 5 is arranged on a surface of the first protrusion 4 opposite to the protrusion.

【００２８】第一の電極２および第二の電極３に交流電
圧を印加すると、上述の両電極の構造ゆえに不均一な電
場が形成される。この不均一な電場により、誘電分極を
示す微生物は誘電泳動力を発生させ、電場の強い方もし
くは電場の弱い方へ、誘電分極の程度に応じて移動させ
ることができる。When an AC voltage is applied to the first electrode 2 and the second electrode 3, a non-uniform electric field is formed due to the structure of the two electrodes. Due to this non-uniform electric field, the microorganisms exhibiting dielectric polarization generate dielectrophoretic force and can be moved to a stronger or weaker electric field depending on the degree of the dielectric polarization.

【００２９】上述したような本発明の方法を用いれば、
電極に優先的に付着させたい微生物種（例えばメタン発
酵菌以外の菌）と付着させないで懸濁液中の存在比を高
めたい微生物種（例えばメタン発酵菌）が、同一条件下
で同じ方向の誘電泳動を示したとしても、両微生物が誘
電泳動力の差を生ずるように媒質を選択し、交流電圧の
周波数を適宜設定することにより、付着させる微生物種
を制御することが可能となる。更に本発明の方法におい
て、微生物を付着させる電極の構造を変えることによ
り、微生物を任意の形状、任意の面積に付着させ、任意
の形状、任意の面積の微生物膜を作成することが可能と
なる。Using the method of the present invention as described above,
A microbial species (eg, a bacterium other than methane fermentation bacterium) that is to be preferentially attached to the electrode and a microbial species (eg, methane fermentation bacterium) that is desired to increase the abundance in the suspension without adhering to the same electrode under the same conditions Even if dielectrophoresis is exhibited, it is possible to control the type of microorganism to be attached by selecting a medium so that both microorganisms generate a difference in dielectrophoretic force and appropriately setting the frequency of the AC voltage. Furthermore, in the method of the present invention, by changing the structure of the electrode to which the microorganisms are attached, the microorganisms can be attached to an arbitrary shape and an arbitrary area, and a microorganism film having an arbitrary shape and an arbitrary area can be prepared. .

【００３０】[0030]

【実施例】〈実施例１〉図１に示す電極を使用し、メタ
ン発酵菌以外の菌を優先的に電極に付着させ、懸濁液中
のメタン発酵菌の存在比を高める実験を行った。実験方
法は、基盤上にフォトリソグラフ法で二つの電極を設
け、二つの電極を覆うように滴下した微生物懸濁液中の
微生物細胞を何れかの電極に付着させることにより行っ
た。EXAMPLE 1 Using the electrode shown in FIG. 1, an experiment was conducted to increase the abundance ratio of methane fermentation bacteria in the suspension by preferentially attaching bacteria other than methane fermentation bacteria to the electrode. . The experimental method was performed by providing two electrodes on a substrate by a photolithographic method, and attaching microbial cells in a microbial suspension dropped so as to cover the two electrodes to one of the electrodes.

【００３１】メタン発酵菌として、Methanobacterium b
ryantii DSM863、およびメタン発酵菌以外の菌として、
Paracoccus denitrificans IFO13301を混合したもの
を、10μＳ/cmの280ｍＭマンニトール溶液に懸濁し、電
界強度が１×105 Ｖ/Ｍ以上となるような100 kHzの交流
電圧を印加した。次いで、二種類の微生物を含んだ懸濁
液を電極と接触させ、電場を印加する前および電場を印
加している途中の懸濁液を採取した。採取した各懸濁液
の全菌数とメタン発酵菌数を、FISH法を用いて計測し、
電場印加前と電場印加中それぞれのメタン発酵菌の存在
比（メタン発酵菌数/全菌数（％））を求めた。[0031] Methanobacterium b
As a fungus other than ryantii DSM863 and methane fermentation bacteria,
The mixture of Paracoccus denitrificans IFO13301 was suspended in a 280 mM mannitol solution of 10 μS / cm, and an AC voltage of 100 kHz was applied so that the electric field intensity became 1 × 10 5 V / M or more. Next, the suspension containing the two kinds of microorganisms was brought into contact with the electrode, and the suspension before and after applying the electric field was collected. The total number of bacteria and the number of methane-fermenting bacteria in each collected suspension were measured using the FISH method,
The abundance ratio of the methane fermentation bacteria before and during the application of the electric field (the number of methane fermentation bacteria / the total number of bacteria (%)) was determined.

【００３２】その結果を図２に示す。図中、電場印加前
のメタン発酵菌の存在比を「原液」として表示し、電場
印加中のメタン発酵菌の存在比を「電極接触液」として
表示する。また、測定１回目、測定２回目は、試験の再
現性を示すために同じ試験を繰り返した測定結果を示
す。図２に示されるように、電場の印加前後で懸濁液中
のメタン発酵菌の存在比は変化しており、電場の印加に
よって懸濁液中のメタン発酵菌の比率を高めることが可
能である。FIG. 2 shows the results. In the figure, the abundance ratio of methane fermentation bacteria before application of the electric field is displayed as “stock solution”, and the abundance ratio of methane fermentation bacteria during application of the electric field is displayed as “electrode contact solution”. The first measurement and the second measurement show the measurement results obtained by repeating the same test in order to show the reproducibility of the test. As shown in FIG. 2, the abundance ratio of methane fermentation bacteria in the suspension changes before and after the application of the electric field, and it is possible to increase the ratio of methane fermentation bacteria in the suspension by applying the electric field. is there.

【００３３】〈実施例２〉実施例１と同じ電極を使用
し、同様の方法を用いて、周波数を変化させたことによ
る、メタン発酵菌およびメタン発酵菌以外の菌の誘電泳
動力を観察した。Example 2 The dielectrophoretic force of methane-fermenting bacteria and bacteria other than methane-fermenting bacteria was observed by changing the frequency using the same electrodes as in Example 1 and using the same method. .

【００３４】メタン発酵菌として、Methanobacterium b
ryantii DSM863、およびメタン発酵菌以外の菌として、
Paracoccus denitrificans IFO13301をそれぞれ、10μ
Ｓ/cmの280ｍＭマンニトール溶液に懸濁し、電界強度が
１×105 Ｖ/Ｍ以上となるような50 kHz−10 MHzの交流
電圧を印加し、誘電泳動の強弱（移動の速さ、電極への
付着量）を観察した。その結果を下記表１に示す。As a methane fermenting bacterium, Methanobacterium b
As a fungus other than ryantii DSM863 and methane fermentation bacteria,
Paracoccus denitrificans IFO13301 each 10μ
S / cm is suspended in a 280 mM mannitol solution, and an AC voltage of 50 kHz to 10 MHz is applied so that the electric field strength becomes 1 × 10 5 V / M or more. Was observed. The results are shown in Table 1 below.

【００３５】[0035]

【表１】 [Table 1]

【００３６】表１に示されるように、メタン発酵菌およ
びメタン発酵菌以外の菌は、どちらも100 kHz−10 MHz
の交流電圧を印加した時に正の誘電泳動を示すが、その
強さには大きな違いがあることがわかった。As shown in Table 1, the methane-fermenting bacteria and the bacteria other than the methane-fermenting bacteria were both 100 kHz-10 MHz.
When the AC voltage was applied, positive dielectrophoresis was exhibited, but it was found that there was a great difference in the intensity.

【００３７】その様子を図３および図４に示す。図３は
メタン発酵菌８が第一の電極６および第二の電極７のエ
ッジ部分に付着した様子を示した顕微鏡写真である。ま
た図４は、メタン発酵菌以外の菌１１が第一の電極９お
よび第二の電極１０のエッジ部分に付着した様子を示し
た顕微鏡写真である。FIG. 3 and FIG. 4 show this state. FIG. 3 is a photomicrograph showing the appearance of the methane fermentation bacteria 8 attached to the edge portions of the first electrode 6 and the second electrode 7. FIG. 4 is a micrograph showing a state in which bacteria 11 other than methane fermentation bacteria adhere to the edge portions of the first electrode 9 and the second electrode 10.

【００３８】図３および図４から、同じ正の誘電泳動が
みられた場合でも菌の種類によって電極への付着量には
大きな違いがあることが明らかである。It is apparent from FIGS. 3 and 4 that even when the same positive dielectrophoresis is observed, the amount of adhesion to the electrode varies greatly depending on the type of bacteria.

【００３９】この結果、メタン発酵菌を含む混合菌液に
不均一電場を印加することによって、メタン発酵菌以外
の微生物を電極に優先的に付着、保持させることが可能
であることが示された。As a result, it was shown that by applying a heterogeneous electric field to the mixed bacterial solution containing methane fermentation bacteria, microorganisms other than methane fermentation bacteria can be preferentially attached to and retained on the electrode. .

【００４０】[0040]

【発明の効果】以上説明したように、本発明の方法によ
り、メタン発酵槽内において発酵液中のメタン発酵菌の
存在比を高めることが可能である。As described above, according to the method of the present invention, it is possible to increase the ratio of methane-fermenting bacteria in the fermentation broth in the methane fermentation tank.

【図面の簡単な説明】[Brief description of the drawings]

【図１】 本発明の不均一電場発生用電極の一実施形態
を示す図。FIG. 1 is a diagram showing one embodiment of an electrode for generating a non-uniform electric field according to the present invention.

【図２】 電極との接触、電場印加によって、液中のメ
タン発酵菌の存在比が変化する様子を説明する図。FIG. 2 is a diagram illustrating a state in which the abundance ratio of methane fermentation bacteria in a liquid changes by contact with an electrode and application of an electric field.

【図３】 電極へメタン発酵菌が付着した状態を示す顕
微鏡写真。FIG. 3 is a micrograph showing a state in which methane fermentation bacteria adhere to an electrode.

【図４】 電極へメタン発酵菌以外の菌が付着した状態
を示す顕微鏡写真。FIG. 4 is a micrograph showing a state in which bacteria other than methane fermentation bacteria adhere to the electrode.

【符号の説明】[Explanation of symbols]

１…基板、２…第一の電極、３…第二の電極、４…第一
の突出部、５…第二の突出部、６…第一の電極、７…第
二の電極、８…メタン発酵菌、９…第一の電極、１０…
第二の電極、１１…メタン発酵菌以外の菌DESCRIPTION OF SYMBOLS 1 ... board | substrate, 2 ... 1st electrode, 3 ... 2nd electrode, 4 ... 1st protrusion, 5 ... 2nd protrusion, 6 ... 1st electrode, 7 ... 2nd electrode, 8 ... Methane fermentation bacteria, 9 ... first electrode, 10 ...
Second electrode, 11: bacteria other than methane fermentation bacteria

───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） //(Ｃ１２Ｎ 1/00 (Ｃ１２Ｎ 1/00 Ｂ Ｃ１２Ｒ 1:01） Ｃ１２Ｒ 1:01） Ｆターム(参考） 4B029 AA02 AA27 BB02 CC02 CC08 DF06 4B065 AA01X BB15 BC11 BC18 CA03 CA55 4D040 AA02 AA61 4D059 AA07 BA12 BK30 EB13 4D061 DA10 DB20 EA10 EB09 EB39 FA15 ──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. 7 Identification symbol FI Theme coat ゛ (Reference) // (C12N 1/00 (C12N 1/00 B C12R 1:01) C12R 1:01) F term (Reference 4B029 AA02 AA27 BB02 CC02 CC08 DF06 4B065 AA01X BB15 BC11 BC18 CA03 CA55 4D040 AA02 AA61 4D059 AA07 BA12 BK30 EB13 4D061 DA10 DB20 EA10 EB09 EB39 FA15

Claims (2)

【特許請求の範囲】[Claims] 【請求項１】 不均一電場を発生させることが可能な電
極を設けた基板を、メタン発酵菌を含むメタン発酵液中
に配置させるとともに、前記電極に交流電圧を印加して
前記発酵液中に不均一電場を発生させ、各菌細胞の誘電
泳動力の差によって、メタン発酵菌以外の菌を優先的に
電極に付着させ、前記発酵液中のメタン発酵菌の存在比
を高めることを特徴とするメタン発酵槽内の菌濃度制御
方法。1. A substrate provided with an electrode capable of generating a non-uniform electric field is disposed in a methane fermentation solution containing methane fermentation bacteria, and an AC voltage is applied to the electrode to allow the substrate to be disposed in the fermentation solution. By generating a non-uniform electric field, by the difference in dielectrophoretic force of each bacterial cell, bacteria other than methane fermentation bacteria are preferentially attached to the electrode, characterized by increasing the abundance ratio of methane fermentation bacteria in the fermentation solution. For controlling the concentration of bacteria in a methane fermenter. 【請求項２】 不均一電場を発生させることが可能な電
極を設けた基板を、メタン発酵菌を含むメタン発酵液中
に配置させるとともに、前記電極に交流電圧を印加して
前記発酵液中に不均一電場を発生させ、各菌細胞の誘電
泳動力の差によって、メタン発酵菌を優先的に電極に付
着させ、前記発酵液中のメタン発酵菌の存在比を低くす
ることを特徴とするメタン発酵槽内の菌濃度制御方法。2. A substrate provided with an electrode capable of generating a non-uniform electric field is placed in a methane fermentation solution containing methane fermentation bacteria, and an AC voltage is applied to the electrode to allow the substrate to be placed in the fermentation solution. A methane characterized by generating a heterogeneous electric field, preferentially attaching methane fermentation bacteria to the electrode by the difference in dielectrophoretic force of each bacterial cell, and reducing the abundance ratio of methane fermentation bacteria in the fermentation broth. A method for controlling the concentration of bacteria in a fermenter.
JP2000178767A 2000-06-14 2000-06-14 Control method for bacterium level in methane fermentation tank Withdrawn JP2001352970A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2000178767A JP2001352970A (en) 2000-06-14 2000-06-14 Control method for bacterium level in methane fermentation tank

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2000178767A JP2001352970A (en) 2000-06-14 2000-06-14 Control method for bacterium level in methane fermentation tank

Publications (1)

Publication Number Publication Date
JP2001352970A true JP2001352970A (en) 2001-12-25

Family

ID=18680146

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2000178767A Withdrawn JP2001352970A (en) 2000-06-14 2000-06-14 Control method for bacterium level in methane fermentation tank

Country Status (1)

Country Link
JP (1) JP2001352970A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008033049A1 (en) * 2008-07-14 2010-01-21 Harrendorf, Heinz, Dipl.-Ing. Treating substrates to produce biogas, comprises feeding suspension obtained by processing organic substances and fermentation substrate to cascaded biogas reactor and anaerobic and electrodynamic treatment of substances and microorganisms
CN108165471A (en) * 2018-03-01 2018-06-15 沈阳市农业机械化研究所 A kind of methane-generating pit

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008033049A1 (en) * 2008-07-14 2010-01-21 Harrendorf, Heinz, Dipl.-Ing. Treating substrates to produce biogas, comprises feeding suspension obtained by processing organic substances and fermentation substrate to cascaded biogas reactor and anaerobic and electrodynamic treatment of substances and microorganisms
DE102008033049B4 (en) * 2008-07-14 2011-07-07 Harrendorf, Heinz, Dipl.-Ing., 30539 Biogas plant for the anaerobic and electrodynamic treatment of substrates by means of a cascaded biogas reactor
CN108165471A (en) * 2018-03-01 2018-06-15 沈阳市农业机械化研究所 A kind of methane-generating pit

Similar Documents

Publication Publication Date Title
Umana et al. Protein-modified electrodes. The glucose oxidase/polypyrrole system
Xiao et al. A reagentless hydrogen peroxide sensor based on incorporation of horseradish peroxidase in poly (thionine) film on a monolayer modified electrode
KR101244056B1 (en) Immobilization support, process for producing the same, electrode, process for producing the same, electrode reaction utilizing apparatus and process for producing the same
Khan et al. Electrochemical behaviour of monolayer quinoprotein adsorbed on the electrode surface
US3839175A (en) Electrodeposition of enzymes
Matsunaga et al. Rapid determination of nicotinic acid by immobilized Lactobacillus arabinosus
Trnková et al. Catalytic signal of rabbit liver metallothionein on a mercury electrode: a combination of derivative chronopotentiometry with adsorptive transfer stripping
US3871961A (en) Method for accelerating the growth and increasing the yield of microorganisms
US20090178932A1 (en) Control of biocatalysis reactions
CN101140257B (en) Biologic sensor enzyme functional susceptivity film containing nickel and aluminum hydrotalcite nano piece and method of producing the same
GB2149423A (en) Electrically promoting the bioreaction of microorganisms
JPS6021453A (en) Method and device for discriminating cell secreting cellularcontent
Sahin et al. Polyvinylferrocenium based platinum electrodeposited amperometric biosensors for lysine detection
NL1035649C2 (en) Sensor, bioreactor, microbial fuel cell and method for measuring and utilizing the effects of vibrations and / or fields on a micro-organism for influencing a micro-organism.
Wang et al. Preserved enzymatic activity of glucose oxidase immobilized on an unmodified electrode
Beunink et al. Determination of oxygen gradients in single Ca-alginate beads by means of oxygen-microelectrodes
JP2001352970A (en) Control method for bacterium level in methane fermentation tank
Czajka et al. Scanning tunnelling microscopy study of polypyrrole films and of glucose oxidase as used in a third-generation biosensor
JP3494535B2 (en) Cell detaching device and detaching method
Yamada et al. Electron transfer at a planar bilayer lipid membrane incorporated with 7, 7, 8, 8-tetracyanoquinodimethane studied by ac impedance spectroscopy
Bianco et al. Electrochemistry of cytochrome c3 at a lipid-modified graphite electrode
EP0187681B1 (en) Process for producing amides by use of microorganisms
Kafi et al. Cell chip with nano-scale peptide layer to detect dopamine secretion from neuronal cells
Markx et al. Electro-orientation of Schizosaccharomyces pombe in high conductivity media
JP2001161359A (en) Method for producing microbial film and carrier for immobilization of microorganism

Legal Events

Date Code Title Description
A300 Application deemed to be withdrawn because no request for examination was validly filed

Free format text: JAPANESE INTERMEDIATE CODE: A300

Effective date: 20070904