JPH03147269A - Reserve type microorganism battery - Google Patents

Abstract

PURPOSE:To make use of the battery in the headline at desired time possible and to increase its portability by wrapping dried microorganisms, a mediator, water absorbing gel, and an anode with a water absorbing sheet. CONSTITUTION:Gelled agar-agar K is filled in a cathode chamber 131 in a cathode chamber frame 13 stacked on a back plate 11, and an ion exchange membrane 20 is stacked thereon. An electron generating substance X prepared by uniformly kneading of dried microorganism, a mediator, and water absorbing gell is bagged around an anode 30 with a water absorbing sheet 90, and an anode chamber frame 12 and a back plate 11 are stacked on the ion exchange membrane 20, so that the anode chamber 121 and the cathode chamber 131 are fastened in sealing state. By the use of dried and powdered microorganisms, a battery can be used by pouring water in the anode chamber 121 at a desired tine. Since water is unnecessary until the battery is used and no nitrogen gas is used, any attachment for generating nitrogen is unnecessary and a battery is made compact and lightweight and its portability is increased.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a water-filled microbial battery.

[Conventional technology]

As water injection type batteries, those using lead chloride or silver chloride for the anode and magnesium for the cathode are known.

However, since this battery uses hazardous materials such as lead and silver compounds, there are problems in its manufacture and waste disposal. Moreover, this battery is heavy and inconvenient to carry.

Therefore, as a battery that does not use lead or silver compounds, a microbial battery that uses electrons accumulated or generated within the body of a microorganism has been proposed [for example, Journal of Chemical Toxicity and Biotoxicity]. Journal of Chemistry
al Technology and Biotech
(1984) or British Patent Publication No. 2165087].

This microbial cell has an anode chamber and a cathode chamber separated by a cation exchange membrane, and the cathode chamber contains water, bacteria floating in the water, and a mediator that transfers electrons. This is done by bubbling nitrogen gas to extract electrons from the bacteria and use them as electrical energy.

[Problem to be solved by the invention]

However, since such microbial batteries use bacteria suspended in water, they start discharging as soon as they are assembled, making it impossible to use them at a desired time. Furthermore, since nitrogen gas is used, additional equipment is required, making the device larger and heavier, making it difficult to carry.

The present invention aims to provide a microbial battery that can be used at any desired time and is convenient to carry.The present invention also aims to provide a microbial battery that can be used at any desired time and is convenient to carry. It also aims to provide batteries.

[Means for Solving the Problems] The present invention provides a water-filled microbial cell in which dried microorganisms, Mediator-1 water-absorbing gel, and a cathode are wrapped in a water-absorbing sheet.

Furthermore, the present invention provides a water-injected microbial cell in which swollen water-absorbing gel, microorganisms, and mediators are uniformly held around the cathode by a water-absorbing sheet bag by water injection.

Further, the present invention provides a water-filled microbial cell in which the mediator is a biological redox substance and/or a derivative thereof.

Furthermore, the present invention provides a water injection type microbial cell in which the anode active material is a compound with a high redox potential.

Furthermore, the present invention provides a water injection type microbial cell in which the anode active material is fixed with a gelled water-absorbing material.

In the water injection type microbial battery of the present invention, dried and powdered microorganisms are used. This is an improved version of the conventional microbial battery that uses bacteria and blue-green algae suspended in water. By using dried microorganisms, it is possible to prevent discharge at the same time as the microbial cell is assembled, and it becomes possible to store the microorganism for use after a long period of time has passed since assembly.

Furthermore, since microorganisms can only be activated by water supply, it can be used at desired times.

The degree of drying of the microorganism is preferably such that free water outside the microorganism body is 0 to 2% by weight. For example, in the case of Escherichia coli, the amount of free water outside the bacterial cells is preferably 0 to 1% by weight.

The method for drying microorganisms is not particularly limited as long as the method does not kill the microorganisms, but freeze-drying is preferred. for example,
When drying E. coli, a bacterial culture solution with a moisture content of 75 to 80% is centrifuged at 10.00 rpm or higher to concentrate the bacterial cells, and a protective agent such as skim milk is mixed with the bacteria to -80 to 80%.
Dry E. coli containing approximately 0% free water can be obtained by suctioning at -20'C with a vacuum pump of 200 to 50 Torr for 1 to 2 days.

The microorganisms that can be used in the present invention are not particularly limited as long as they can grow in water, and aerobic bacteria, facultative anaerobes, or anaerobic bacteria can be used.

Among these, examples of this aerobic bacteria include Azotob
acter chroococcum Azoto
bactervineland ii, Pseudom
onas aeruginosa.

Pseudomonas putida, Bacillus
lus 5ubtilis (Bacillus subtilis) Yarrowia
1ipolytica (yeast), Hansenu
laanomala (yeast), especially Bacillus
Bacillus subtilis is preferred.

In addition, as a facultative anaerobe, Erwiniacaro
tovora, Lactobacillus del
brueckii (lactic acid bacteria), Lactobacillus
illus plar+tarum (lactic acid bacteria), Leu
conostoc mesenteroides
Escherichia coli, Pr
oteus vulgaris.

5treptococcus t, hermophila
usSSaccharomycescerevisia
e (baker's yeast), especially Escherichiacol
i (E. coli) is preferred.

Furthermore, as an anaerobic bacteria, Desulf○ν1bri
.

vulgaris (sulfate reducing bacteria), Clostri
diumbutylicum, especially De
sulf □ vibri.

vulgaris (sulfate-reducing bacteria) is preferred.

Moreover, two or more types of these microorganisms can also be used together.

Generally, in microbial batteries, a mediator is used that enters the body of the microorganism or steals electrons from the body surface and transfers them to an electrode. In the present invention, any material can be used as long as it has this function. Examples of this mediator include thionine, di-methylene blue, 2,6-cyclophenolindophenol, azure B, N, N, N', N
'-Tetramethyl-ρ-phenylenediamine Dihydrochloride, resorufin, safranin, sodium anthraquinone Pigments such as β-sulfonate, indigo carmine; Riboflavin (vitamin B) L-ascorbic acid, F A D (flavinadenine)
dinucleotide), F M N (fl
avinmononucleotide), l, -cystine, NADH (nicotinamide a
denine dinucleotide di
sodium salt),) Ltmi')Cmu, Yuhiki) 7 (Co-enzyme Q), hydroquinone (HQ), 2.6-cyclopenzoquinone, 2-methylbenzoquinone (p-torki7y), 2.5 -Dihydroxybenzoquinone, 2-hydroxy-1,4-naphthoquinone (HNQ) Biological redox substances such as glutathione, peroxidase, cytochrome C, ferredoxin, or derivatives thereof; Other Fe-EDTA, Mn-EDT
ASCo-EDTA, Zn-EDTA, methosulfate, 2,3,5.6-tetramethyl-p-phenylenediamine, N, N, N', N'-tetramethyl-p-phenylenediamine, N.

Mention may be made of N,N',N'-tetramethyl-p-phenylenediamine dihydrochloride.

The mediator is preferably a biological redox substance or a derivative thereof from the viewpoint of the lifespan of the microorganism, the lifespan of the microorganism battery, and safety for the human body. Among them, H.N.
Q, FMN, FAD, HQ or L-ascorbic acid are preferably used.

For example, when E. coli is used as the microorganism, HNQ, FMN, or FAD is preferable as the mediator.

Furthermore, two or more of these compounds may be used in combination as a mediator.

In the present invention, a small amount of water-absorbing gel is filled into the cathode chamber. The purpose of this is to allow the water-absorbing gel to quickly absorb water when water is poured, allowing the water to permeate the dried microorganisms and mediator uniformly, thereby allowing the current to be generated quickly.

Furthermore, microorganisms and mediators can be immobilized and held uniformly around the electrode, which eliminates the need for agitation with nitrogen gas, which was required in the conventional method, and the method can be made portable.

Examples of the water-absorbing gel include PVA-acrylate copolymer (Sumikagel, manufactured by Sumitomo Chemical), but it is not necessarily limited to this, and other general water-absorbing gels may also be used. can. In addition, in order to quickly absorb water and maintain uniformity inside the cathode chamber, it is preferable that the particle size of the water-absorbing gel is small (average diameter 10 to 200 μm).

In the water injection type microbial cell of the present invention, for example, a carbon fiber membrane can be used as the cathode, but it is not necessarily limited to this.
Any material that has high electrical conductivity and is harmless to microorganisms can be used.

In the water-injected microbial cell of the present invention, the dried microorganisms, mediator, and water-absorbing gel become electron-generating substances by injecting water, and these and the cathode are wrapped in a water-absorbing sheet.

Since the cathode is also wrapped, microorganisms and mediators can be retained around the cathode and current collection can be facilitated. In addition, since the bag is water-absorbing, water is quickly absorbed when water is poured, and current can be generated easily.

As the water-absorbing sheet, any water-absorbing material can be used, such as a non-woven fabric such as cotton or paper, or a woven fabric such as carbon cloth, but it is preferable to use a material that can be heat-sealed for convenience of processing.

The water absorbent sheet bag of the present invention may contain sugars such as glucose and lactose, and microbial nutrients such as skim milk. These nutrients can also be dried at the same time as the microorganisms.

The amount of dried microorganisms used in the water injection type microbial cell of the present invention is preferably 1 g or more per 15 cc of cathode chamber, for example. If the amount of dried microorganisms is less than 1 g, the electromotive force of the microorganism battery is insufficient.

In addition, the mediator is 0.1 to 2
5% by weight, especially 0. It is preferable to contain 4 to 5% by weight. If the amount of mediator is less than 0.1% by weight, the electromotive force will be insufficient, while if it exceeds 25% by weight, the electromotive force will decrease.

Further, it is preferable to use the water-absorbing gel in an amount of 2 to 20% by weight, particularly 5 to 10% by weight, based on the dry microorganism. If the water-absorbing gel is less than 2% by weight, current generation will not start up properly and microorganisms and mediators cannot be retained around the cathode, resulting in a decrease in electromotive force.On the other hand, if it exceeds 20% by weight, electromotive force will decrease. .

In the anode of the water injection type microbial cell of the present invention, the active material is a compound with a high redox potential, that is, the redox potential is 0.3 (E''/V, 25'C) or more, particularly 0.
5 (E'/V, 25'C) or more is preferable. This is because if a compound has a low redox potential, the difference in redox potential between the cathode and the anode is small and sufficient electromotive force cannot be obtained.

Further, it is preferable that this active material is fixed with a gelled water-absorbing material. Thereby, even if the active material has low solubility in water, the active material can be held uniformly in water.

As such an anode active material, for example, iridium ammonium hexachloride ((NH4)z (Ir (CI)b )
Potassium permanganate, iron(III) chloride (F e C
Is), potassium ferricyanide (K, (Fe
(CN) & )), among which iridium ammonium hexachloride is particularly preferred, but it is not necessarily limited to these.

For example, in the case of iridium ammonium hexachloride, the amount of the positive electrode active material used is preferably 0.2 mol or more.

Further, examples of the water-absorbing substance for fixing the anode active material include agar and the water-absorbing substance used in the cathode chamber described above, but the material is not necessarily limited thereto.

The anode of the water injection type microbial cell of the present invention is not particularly limited, and for example, the same carbon fiber membrane as the cathode can be used, but it is not necessarily limited to this.

Note that these cathodes and anodes are usually housed in a cathode chamber and an anode chamber of a cell with good airtightness, and the cathode chamber and anode chamber are separated, for example, by an ion exchange membrane to allow ion exchange. It is set in. As the water to be injected, pure water, tap water, pond water, industrial water, seawater, etc. can be used.

The present invention will be described below with reference to the drawings, but the present invention is not limited thereto.

As shown in FIG. 1, the water injection type microbial cell of the present invention mainly consists of a cell 10, an ion exchange membrane 20, a cathode 30, and an anode 40.
It is equipped with

The cell 10 is an outer container for a water injection type microbial cell, and here, as shown in FIG. It consists of a cathode chamber frame 12 and an anode chamber frame 13, but it is not necessarily limited to this. For example, a plurality of cathode chamber frames 12 such as two or three frames may be stacked. , at least a cathode chamber 121 and an anode chamber 13 inside.
1 can be formed into any shape. In addition, in this embodiment, these cathode chamber frame 12 and anode chamber frame 13 are aligned and fixed by fixing rods 14, 14, . . . installed at the four corners of both front plates 11, 11. However, it is not necessarily limited to this, and for example, these may be directly laminated. Further, these cathode chamber frames 12 are formed with one-way valves 122 and 122 made of, for example, stainless steel with adhesive silicone rubber, which serve as a water inlet into the cathode chamber 121 and have a back leak prevention function. However, such a one-way valve 122
．． There is no need to limit it to 122.

The material of this cell 10 can be, for example, acrylic resin, but it is not necessarily limited to this, and each of the back plates 11, 11, the frame 12 for the cathode chamber, and the frame 13 for the anode chamber are the same. It may be made of a different material or a different material.

Further, the ion exchange membrane 20 is interposed between the cathode chamber frame 12 and the anode chamber frame 13 to allow electron circulation between the cathode chamber 121 and the anode chamber 131 formed in the cell 10. It is a membrane that allows for partitioning. Note that as the material for this ion exchange membrane 20, those used for shipping can be used.

Further, in this embodiment, rubber packings 15 and 15 are interposed to improve airtightness at the joint between the cathode chamber frame 12 and the anode chamber frame 13, but these rubber packings 5 and I5 are not necessarily used. Although it is not necessary to do so, it is preferable to use it because a high airtightness can be obtained at this joint.

The cathode 30 and the anode 40 are housed in a cathode chamber 121 formed inside the cathode chamber frame 12 and an anode chamber 111 formed inside the anode chamber frame 13, respectively. The terminal of the lead wire 50 comes out from inside the room. It is also possible to use a plurality of cells by connecting the lead wires 50 in series or in parallel.

Further, around this cathode 30, as shown schematically in FIG. As shown in FIG. 1, the electron-generating substance X is further wrapped with a water-absorbing sheet 90 so that the electron-generating substance X does not leak to the outside.

Further, in the anode chamber 131 in which the anode 40 is housed, gelled agar containing the anode active material Y almost uniformly (
The water-absorbing material (K) is filled in, so that even if the anode active material Y has low solubility in water, the anode active material Y can be held uniformly in water.

In assembling the water-filled microbial cell of this embodiment, for example, as shown in FIG. 1, agar K is gelled in advance, and as shown in FIG. are uniformly kneaded to provide an electron generating substance X.

Thereafter, this gelled agar K is filled into the anode chamber 131 of the anode chamber frame 13, which has an opening on one side laminated on one back plate 11, as shown in FIG. Further, an ion exchange membrane 20 is laminated on the other opening of this anode chamber frame 13.

On the other hand, this electron generating substance
0, and then the cathode chamber frame 12 having the cathode 30 is laminated on the ion exchange membrane 20,
Next, the other back plate 11 is laminated on this cathode chamber frame I2, and these laminated bodies are fastened so that each cathode chamber 121 and anode chamber 131 are sealed.

Note that the assembly of this water injection type microbial battery is not necessarily limited to this, and any assembly order may be used.

Next, the operation of the water injection type microbial cell in this aspect of the present invention will be explained.

First, during storage, as shown in FIG. 1, storage stability is improved by storing the electron generating material X in the cathode chamber 121 in a dry state. Furthermore, since the storage property is good, this water injection type microbial battery can be used at any desired time.

Next, when water is injected into the cathode chamber 121 during use, the water injected into the cathode chamber 121 passes through the water absorbent sheet 90 and is quickly absorbed by the water absorbent gel 80. swells, and the water-absorbing sheet 1-90 swells over the entire area inside the cathode chamber 121, as shown in FIG. Also,
As the water-absorbing gel 80 absorbs water and swells, water quickly permeates into the dried microorganisms 60 and the mediator 70 shown in FIG. 3, so that a current can be generated easily. Furthermore, the dried microorganisms 60 and the mediator 70 can be fixed and held uniformly around the cathode 30, which eliminates the need for stirring using nitrogen gas (not shown), which was necessary in the conventional method, making the method portable. becomes possible.

On the other hand, the water absorbed by the water-absorbing gel 80 shown in FIG. 3 activates the dried microorganism 60, and then, as shown in FIG. , whereby it is itself reduced.

Next, the mediator 70 that stole this electron,
It goes to the cathode 30, emits electrons, and is oxidized. As a result,
A lead wire 5 with a resistor R interposed from the cathode 30 to the anode 40
0, electrons flow out and a current is generated. In addition,
The electrons that have gone to the anode 40 are accepted by the anode active material Y in the agar, and the anode active material Y that has accepted the electrons is reduced.

[Effect]

The water injection type microbial cell of the present invention has good storage stability by first storing it in a state in which no moisture is applied to the electron-generating substance in the cathode chamber. Furthermore, because of its good storage stability, this water-filled microbial battery can be used at any desired time.

Furthermore, since there is no need for water in the cathode chamber until use, and unlike conventional technology, no nitrogen gas is used, there is no need for incidental equipment to generate this nitrogen gas, making it smaller and lighter and portable. It becomes convenient.

Next, when water is injected into the cathode chamber during use, the water injected into the cathode chamber passes through the water-absorbing sheet and is quickly absorbed by the water-absorbing gel, thereby quickly discharging the water to the dried microorganisms and mediator. It penetrates, rises up, and can easily generate electric current. In addition, dried microorganisms and mediators can be fixed and held uniformly around the cathode, which eliminates the need for stirring using nitrogen gas (not shown), which was required in the conventional method, making it portable. Become.

On the other hand, the dried microorganism is regenerated by the absorption of water by this water-absorbing gel, and then the mediator enters the electron transport system of the dried microorganism and takes away electrons, thereby reducing itself. Next, the mediator that has stolen the electrons goes to the cathode, releases electrons, and is oxidized. As a result,
Electrons flow from the cathode to the anode, generating an electric current.

Note that the electrons that have gone to the anode are accepted by the anode active material in the anode chamber, and the anode active material that has accepted the electrons is reduced.

Furthermore, when a biological redox substance and/or its derivative is used as a mediator, the mediator is not toxic to microorganisms, so there is less risk of the microorganism being killed by the mediator during use. , thus increasing the lifespan of the microorganisms and thus the lifespan of the microbial battery.

Furthermore, when the anode active material is a compound with a high redox potential, a larger electromotive force can be obtained.

Furthermore, when the anode active material is fixed with a gelled water-absorbing material, the anode active material can be held uniformly in water even if the anode active material has low solubility in water.

〔Example〕

Examples of the present invention will be described in more detail below, but the present invention is not limited to these examples.

Note that this example uses the water injection type microbial cell shown in FIGS. 1 to 5 described above.

Example 1 In advance, 0.3 g of agar (water-absorbing substance) K and 20 g of water
m and is heated to 100°C to dissolve this agar K, and then this dissolved agar K is cooled to below 60'C,
Next, 1.74 g (0.2 mol) of iridium ammonium hexachloride, which is the anode active material Y, was added to the cooled agar K, stirred, and then cooled to room temperature to form a gel.

Next, agar K containing this anode active material Y was added to GF-
Anode chamber 131 (volume: 15 c
c) Pour it into the anode chamber and solidify it, and then use a Selemion membrane (manufactured by Asahi Glass), which is an ion exchange membrane 20, to seal the opening of the anode chamber frame 13 as shown in FIG. did.

On the other hand, 26.1 mg (10 mmol) of the mediator HNQ and 0.1 g of the water-absorbing gel Sumikagel N-100 (manufactured by Sumitomo Chemical) were placed in a mortar and rubbed. E. coli (lyophilized with monosodium glutamate)
3 g of Oriental yeast (0 grade) was added and further rubbed to produce an electron generating substance X. Next, this electron generating substance A bag is secured around the cathode 30 made of the same CF-20P 1, and then this cathode 30 is
The cathode chamber frame 12 (volume 15 cc) having the following structure is laminated on the ion exchange membrane 20, and then the other back plate 11 is laminated on this cathode chamber frame 12, and these laminations are performed. The body was tightened so that the cathode chamber 121 and the anode chamber 131 were sealed to produce a water injection type microbial battery.

Next, water is injected into the cathode chamber 121 of the cathode chamber frame 12 of the water-injected microbial battery manufactured in this manner from the water inlet 122, and the lead wire 5 with the resistor R interposed between the cathode and the anode of the battery.
0, and the voltage across this resistance was measured.

Note that 500Ω was used as the resistance R.

The results are shown in FIG.

As is clear from Figure 6, this water injection type microbial battery is
It functions as a battery and has a longer lifespan than conventional microbial batteries.

Example 2 189μ (10 mmol) of Fe as mediator
The voltage obtained was measured in the same manner as in Example 1 except that -EDTA was used.

The results are shown in Figure 7 (curve 1).

Comparative Example 1 In the same manner as in Example 2, a water-injected microbial cell using electron-generating material
, the voltage obtained for a water-filled microbial cell without Sumikagel and non-woven fabric (curve 4) was measured.

The results are also shown in FIG.

It is clear from FIG. 7 that this water-injected microbial cell using a water-absorbing gel and a water-absorbing nonwoven fabric started up well after water was injected and generated a current.

〔Effect of the invention〕

The water injection type microbial battery of the present invention is thus advantageous in that it can be used at any desired time and is convenient to carry.

Furthermore, when a biological redox substance and/or its derivative is used as a mediator, the mediator is not toxic to microorganisms, so there is less risk of the microorganism being killed by the mediator during use. Therefore, the effect of lengthening the lifespan of the microorganisms and, by extension, the lifespan of the microbial battery can also be obtained.

Furthermore, when the anode active material is a compound with a high redox potential, an effect is obtained in that a larger electromotive force can be obtained depending on the redox potential of the compound.

Furthermore, when the anode active material is fixed with a gelled water-absorbing material, an effect can be obtained in that the anode active material can be uniformly retained in water even if the anode active material has low solubility in water.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a water-injected microbial cell according to an embodiment of the present invention before water is injected into the cathode chamber, FIG. 2 is an exploded perspective view of a water-injected microbial battery according to an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention FIG. 4 is an enlarged view of a kneaded mixture of dried microorganisms, mediator, and water-absorbing gel used in a water-injected microbial battery according to one embodiment of the present invention after water is injected into the cathode chamber in a water-injected microbial battery according to one embodiment of the present invention. A schematic diagram, FIG. 5 is a schematic diagram showing the principle of electric current generation in a water injection type microbial cell according to one embodiment of the present invention, and FIGS. 6 and 7 are graphs showing the obtained voltage. Agar cell ion exchange membrane cathode anode dry microbial mediator water absorbent gel water absorbent nonwoven fabric

Claims (5)

[Claims] (1) A water-filled microbial battery in which dried microorganisms, a mediator, a water-absorbing gel, and a cathode are wrapped in a water-absorbing sheet. (2) The water-injected microbial cell according to claim 1, wherein the swollen water-absorbing gel, microorganisms, and mediator are uniformly held around the cathode by the water-absorbing sheet bag due to water injection. (3) The water-filled microbial battery according to claim 1 or 2, wherein the mediator is a biological redox substance or a derivative thereof. (4) The water injection type microbial cell according to any one of claims 1 to 3, wherein the anode active material is a compound with a high redox potential. (5) The water injection type microbial cell according to any one of claims 1 to 4, wherein the anode active material is fixed with a gelled water-absorbing substance.