Abstract: A method for designing a heat-resistant mutant enzyme, the method including the step of reducing a distance between the ?4 helix and the ?6 helix in a protein three-dimensional structure to become smaller than that of a wild type enzyme through deletion, replacement, addition, or insertion of one or several amino acids in the amino acid sequence of the wild type enzyme with respect to tyrosine-dependent short-chain dehydrogenase/reductase.

Abstract: A fuel cell with which in the case where an enzyme is immobilized to at least one of a cathode and an anode, sufficient buffer ability is able to be obtained even at the time of high output operation, ability inherent in the enzyme is able to be sufficiently demonstrated, and which has superior performance is provided. In a bio-fuel cell which has a structure in which a cathode and an anode are opposed to each other with an electrolyte layer containing a buffer substance in between, and in which an enzyme is immobilized to at least one of the cathode and the anode, a compound containing an imidazole ring is contained in the electrolyte layer as a buffer substance, and one or more acids selected from the group consisting of acetic acid, phosphoric acid, and sulfuric acid are further added.

Abstract: A fuel cell which can directly extract electric power from a polysaccharide, such as starch, is provided. A fuel electrode is formed by immobilizing with an immobilizer, on an electrode comprised of, e.g., carbon, an enzyme responsible for decomposing a polysaccharide into monosaccharides, an enzyme responsible for decomposing the monosaccharide formed, a coenzyme (e.g., NAD? or NADP+) which forms a reductant due to the oxidation reaction in the monosaccharide decomposition process, a coenzyme oxidase (e.g., diaphorase) for oxidizing the reductant of the coenzyme (e.g., NADH or NADPH), and an electron mediator (e.g., ACNQ or vitamin K3) for receiving electrons generated due to the oxidation of the coenzyme from the coenzyme oxidase and delivering the electrons to the electrode. The fuel cell comprises the fuel electrode and the air electrode that sandwich an electrolyte layer.

Abstract: A fuel cell is provided. The fuel cell includes at least one of a plant essential oil and a plant essential oil ingredient in an effective amount so as to function as a biological repellent.

Abstract: Disclosed herein is a system for inquiring about fitness of a beverage as battery fuel, including a search request receiving section configured to receive an input of beverage information regarding a beverage as a search request, a storage section having stored therein a reference database in which search requests and performance data of fuel cells are associated with each other, a search section configured to automatically search the reference database for performance data which coincides with the search request, and a search answer outputting section configured to output a search answer.

Abstract: There are provided a fuel cell and a production method therefor in which one or more types of enzymes or further coenzymes are enclosed in a micro space so that electrons can be efficiently extracted from a fuel such as glucose or the like by an enzyme reaction using the micro space as a reaction field, thereby producing electric energy, and in which the enzyme or further the coenzyme can be easily immobilized on an electrode. Enzymes 13 and 14 and a coenzyme 15 necessary for an enzyme reaction are enclosed in liposome 12, and the liposome 12 is immobilized on a surface of an electrode composed of porous carbon or the like to form an enzyme-immobilized electrode. An antibiotic 16 is bonded to a bimolecular lipid membrane constituting the liposome 12 to form one or more pores 17 permeable to glucose. The enzyme-immobilized electrode is used as, for example, a negative electrode of a biofuel cell.

Abstract: A fuel cell which can directly extract electric power from a polysaccharide, such as starch, is provided. A fuel electrode is formed by immobilizing with an immobilizer, on an electrode comprised of, e.g., carbon, an enzyme responsible for decomposing a polysaccharide into monosaccharides, an enzyme responsible for decomposing the monosaccharide formed, a coenzyme (e.g., NAD+ or NADP+) which forms a reductant due to the oxidation reaction in the monosaccharide decomposition process, a coenzyme oxidase (e.g., diaphorase) for oxidizing the reductant of the coenzyme (e.g., NADH or NADPH), and an electron mediator (e.g., ACNQ or vitamin K3) for receiving electrons generated due to the oxidation of the coenzyme from the coenzyme oxidase and delivering the electrons to the electrode. The fuel cell comprises the fuel electrode and the air electrode that sandwich an electrolyte layer.

Abstract: The present invention provides a fuel reformer which enables power generation to be actually performed even in the case of using very-safe familiar things such as food and drink and food scraps as a fuel of a biofuel cell. The fuel reformer is used for a fuel cell which generates power as an oxidation reduction reaction progresses using enzyme as a catalyst, and has: a primary fuel introduction unit for introducing a primary fuel; a fuel reforming unit communicating with the primary fuel introduction unit and reforming the primary fuel to a secondary fuel from which electrons can be emitted by an oxidation reduction reaction using enzyme as a catalyst; and a secondary fuel supplying unit communicating with the fuel reforming unit and supplying the secondary fuel to the fuel cell.

Abstract: A fuel cell and a method for manufacturing the same are provided, wherein at least one type of enzyme and coenzyme are confined in a minute space, an enzyme reaction is effected while this space serves as a reaction field. Thereby, electrons can be taken out of the fuel efficiently to generate electrical energy, and immobilization of these enzyme and coenzyme on an electrode can be performed easily. The enzyme and the coenzyme required for an enzyme reaction are encapsulated in a liposome, and the resulting liposome is immobilized on the surface of an electrode formed from porous carbon or the like so as to form an enzyme immobilization electrode. A transporter is incorporated in the liposome, as necessary. An electron mediator is also immobilized on the surface of the electrode. The resulting enzyme immobilization electrode is used as, for example, a negative electrode of a biofuel cell.

Abstract: A fuel cell having excellent properties is provided in which, when an enzyme is immobilized in at least one of a positive electrode and a negative electrode, a sufficient buffering capability can be provided even in a high power output operation and the inherent capability of the enzyme can be sufficiently exerted. In a biofuel cell including a structure in which a positive electrode 2 and a negative electrode 1 face each other with an electrolyte layer 3 therebetween, the electrolyte layer 3 containing a buffer material, and the biofuel cell including an enzyme immobilized in at least one of the positive electrode 2 and the negative electrode 1, the electrolyte layer 3 contains a compound including an imidazole ring as a buffer material and at least one acid selected from the group consisting of acetic acid, phosphoric acid, and sulfuric acid is further added to the electrolyte layer 3.

Abstract: There is provided a fuel cell whose current density and maintenance ratio can be improved when at least glucose dehydrogenase and diaphorase are immobilized on an anode using an immobilizing material composed of poly-L-lysine and glutaraldehyde. The fuel cell has a structure in which a cathode 2 and an anode 1 face each other with an electrolyte layer 3 therebetween, the anode 1 being obtained by immobilizing at least glucose dehydrogenase and diaphorase on an electrode using an immobilizing material composed of poly-L-lysine and glutaraldehyde, wherein the mass ratio of the poly-L-lysine to the glutaraldehyde in an immobilizing material is 5:1 to 80:1, the mass ratio of the glucose dehydrogenase to the diaphorase is 1:3 to 200:1, and the average molecular weight of the poly-L-lysine is 21500 or more.

Abstract: An electrode that can generate reduced coenzymes from a desired substrate in multiple stages is provided. An electrode includes a 2-hydroxycarboxylic acid synthase, a 2-oxo acid synthase, and a 2-oxo acid carboxylyase. The electrode includes a 2-oxo acid carboxylyase, which is a decarboxylase, in addition to a 2-hydroxycarboxylic acid synthase and a 2-oxo acid synthase, which are oxidoreductases; therefore, oxidation products having carboxyl groups, reactions of which do not proceed with oxidoreductases, can be decarboxylated and modified into substances with which oxidoreductases can act. Thus, oxidation reactions and decarboxylation reactions can repeatedly proceed with respect to desired substrates, and large quantities of reduced coenzymes can be generated thereby.

Abstract: To provide a fuel cell that can perform efficient power generation through a simple fuel supply. There is provided a fuel cell that generates electricity through progress of an oxidation-reduction reaction using an enzyme as a catalyst, the fuel cell including at least a fuel-vaporizing layer formed through vaporization of a fuel; an anode to which a vaporized fuel is supplied from the fuel-vaporizing layer; and a cathode connected to the anode in a state in which protons can be conducted. In the fuel cell, since a fuel is supplied to an electrode in a vaporized state, a vaporized fuel is supplied to an inner portion of the electrode and a reaction sufficiently proceeds at the inner surface of the electrode, which can achieve high output due to efficient power generation.

Abstract: A paste in which semiconductor fine grain such as titanium oxide fine grain or the like and a binder made of a polymer compound are mixed is coated onto a transparent conductive substrate and sintered, thereby forming a semiconductor layer made of the semiconductor fine grain, after that, ultraviolet rays are irradiated to the semiconductor layer and, by using a photocatalyst effect of the semiconductor fine grain, an organic substance remaining in the semiconductor layer is removed.

Abstract: A molecular device includes a gold electrode, cytochrome c552 or a derivative or variant thereof immobilized on the gold electrode, and an electron transfer protein coupled to the cytochrome c552 or the derivative or variant thereof. Electrons or holes, or both, are transferred through the electron transfer protein by transition of electrons between molecular orbitals of the electron transfer protein.

Abstract: A paste in which semiconductor fine grain such as titanium oxide fine grain or the like and a binder made of a polymer compound are mixed is coated onto a transparent conductive substrate and sintered, thereby forming a semiconductor layer made of the semiconductor fine grain, after that, ultraviolet rays are irradiated to the semiconductor layer and, by using a photocatalyst effect of the semiconductor fine grain, an organic substance remaining in the semiconductor layer is removed.

Abstract: A mutant protein having diaphorase activity is provided. A mutant protein includes an amino acid sequence obtained by deletion, replacement, addition, or insertion of at least one amino acid residue of a native-form amino acid sequence of SEQ. ID. No. 1, wherein the mutant protein has diaphorase activity with an enzyme activity of 245 or more.

Abstract: A heat-resistant bilirubin oxidase mutant is disclosed. The bilirubin oxidase mutant is obtained by deletion, replacement, addition or insertion of at least one amino acid residue of a wild type amino sequence of SEQ. ID. No. 1 of a bilirubin oxidase derived from an imperfect filamentous fungus, Myrothecium verrucaria. A biocathode including a thermo stable bilirubin oxidase mutant immobilized thereon, and its use in a biofuel cell is disclosed.

Abstract: An enzyme-immobilized electrode is provided and includes an electrode composed of porous carbon or the like, a phospholipid layer on the electrode (11), and enzymes immobilized onto the phospholipid layer. The enzymes are, for example, diaphorase and glucose dehydrogenase. An intermediate layer composed of a protein or the like may be provided between the electrode and the phospholipid layer. By using the enzyme-immobilized electrode as a negative electrode or a positive electrode in a fuel cell using an enzyme, one or a plurality of types of enzymes can be immobilized at optimal positions on the electrode, and thus, there are provided a highly efficient enzyme-immobilized electrode and a highly efficient fuel cell using the enzyme-immobilized electrode.

Abstract: Mutant diaphorase is capable of having, when forming a complex with a coenzyme, flavin mononucleotide, a conformation in which the distance between tryptophan at the 60th position from an N terminus and imino nitrogen at the 1-position of the coenzyme, flavin mononucleotide, is larger than that in a conformation of wild-type diaphorase of sequence ID No. 1.