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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Development of Electrostatic and Three-Dimensional Random Orientation Models for Enzyme-Electrode Interfaces in Direct Electron Transfer-Type Bioelectrocatalysis / 直接電子移動型酵素電極反応における酵素-電極界面の静電相互作用および三次元ランダム配向モデルの構築

Sugimoto, Yu 23 March 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第20426号 / 農博第2211号 / 新制||農||1048(附属図書館) / 学位論文||H29||N5047(農学部図書室) / 京都大学大学院農学研究科応用生命科学専攻 / (主査)教授 加納 健司, 教授 植田 充美, 教授 三上 文三 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
2

Improvement of the Performance of Direct Electron Transfer-Type Bioelectrocatalysis Based on the Understanding of the Interaction between Redox Enzymes and Electrodes / 酸化還元酵素と電極間の相互作用の理解に基づいた直接電子移動型酵素機能電極反応特性の向上

Hong-Qi, Xia 25 September 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第20715号 / 農博第2244号 / 新制||農||1053(附属図書館) / 学位論文||H29||N5081(農学部図書室) / 京都大学大学院農学研究科応用生命科学専攻 / (主査)教授 加納 健司, 教授 宮川 恒, 教授 三芳 秀人 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
3

Bioelectrochemical Characterization of Tungsten-Containing Formate Dehydrogenase and Development of Bioelectrocatalytic Interconversion System between Carbon Dioxide and Formate / タングステン含有ギ酸脱水素酵素の生物電気化学的特性評価と二酸化炭素/ギ酸イオン対の生物電気化学的相互変換系の構築

Sakai, Kento 26 March 2018 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21132号 / 農博第2258号 / 新制||農||1056(附属図書館) / 学位論文||H30||N5106(農学部図書室) / 京都大学大学院農学研究科応用生命科学専攻 / (主査)教授 加納 健司, 教授 小川 順, 教授 三芳 秀人 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
4

Enzymatic Biofuel Cells on Porous Nanostructures

Wen, Dan, Eychmüller, Alexander 22 November 2016 (has links) (PDF)
Biofuel cells (BFCs) that utilize enzymes as catalysts represent a new sustainable and renewable energy technology. Numerous efforts have been directed to improve the performance of the enzymatic BFCs (EBFCs) with respect to power output and operational stability for further applications in portable power sources, self-powered electrochemical sensing, implantable medical devices, etc. This concept article details the latest advances about the EBFCs based on porous nanoarchitectures over the past 5 years. Porous matrices from carbon, noble metal, and polymer promote the development of EBFCs through the electron transfer and mass transport benefits. We will also discuss some key issues on how these nanostructured porous media improve the performance of EBFCs in the end.
5

Fibras de carbono modificadas com a álcool desidrogenase para o estudo da bioeletroxidação do etanol utilizando espectrometria de massas diferencial eletroquímica (DEMS) / Modified Carbon Fibers with the Alcohol Dehydrogenase for the Study of Bioeletroxidation of the Ethanol Using Differential Electrochemical Mass Spectrometry (DEMS)

Souza, João Carlos Perbone de 21 November 2017 (has links)
Para a bioeletrocatálise de oxidação de etanol, a alteração da superfície eletródica e a otimização do processo de imobilização enzimática se fazem necessárias. Neste cenário, as fibras flexíveis de carbono (FFC) merecem destaque, pois além de sua superfície ser facilmente modificada devido à presença de carbono sp2, as mesmas possuem alta resistência mecânica e elasticidade, combinadas com a alta condutividade elétrica e térmica. Nesta tese de doutorado, apresenta-se como obter bioeletrodos de FFC modificadas com a enzima álcool desidrogenase (ADH) NAD-dependente, visando também aprimorar a oxidação da coenzima NADH (dinucleotídeo de nicotinamida e adenina). Os resultados mostram que quando as FCF são previamente submetidas a um tratamento oxidativo em meio ácido (KMnO4/H2SO4), obtém-se bioeletrodos estáveis, robustos e com alta área superficial. Além disso, observou-se que esses eletrodos possuem grupos funcionais contendo oxigênio que auxiliam na bioeletrocatálise de oxidação do etanol. Presume-se que presença de grupos quinonas seja responsável por facilitar a regeneração da coenzima, ou seja, estes grupos atuam decisivamente na oxidação do NADH. A alta qualidade dos bioeletrodos possibilitou manter a atividade catalítica da ADH por longo prazo, propriedade essa crucial para o estudo da oxidação do etanol acoplada à espectrometria de massas (DEMS). Devido a este estudo, foi possível observar concomitantemente a regeneração da coenzima (NADH -> NAD+) e a geração de acetaldeído como produto de bioeletroxidação do etanol, ambos em estado estacionário. Em suma, o estudo aqui apresentado introduz uma abordagem que combina não só o desenvolvimento de fibras de carbono tratadas quimicamente para aplicação em bioeletrocatálise, mas também um foco inédito no acoplamento entre a espectrometria de massas e a bioeletroquímica para a resolução de mecanismos enzimáticos. / Regarding the bioelectrocatalysis of the ethanol oxidation, the electrodic surface modification and the optimization of enzymatic immobilization are necessary. In this scenario, the flexible carbon fibers (FCF) are noteworthy, because besides their surface can be modified in an easy way due the presence of carbon sp2, they have high mechanical resistance and elasticity, combined with high electrical and thermal conductivity. In this doctoral thesis, it is presented how to obtain bioelectrodes of FFC modified with the enzyme alcohol dehydrogenase (ADH) NAD-dependent, as well as to improve the oxidation of the coenzyme NADH (nicotinamide adenine dinucleotide). The results show that when FCF is previously submitted to an oxidative treatment in acidic medium (KMnO4/H2SO4), stable, robust and high surface area bioelectrodes are obtained. In addition, it was observed that these electrodes have oxygen-containing functional groups that improve the bioelectrocatalysis of ethanol oxidation. There is proposed that the presence of quinone groups is responsible for facilitating the regeneration of the coenzyme, i. e., these groups act decisively in the oxidation of NADH. The high quality of the bioelectrodes allowed it to maintain the catalytic activity of the ADH for long term, property crucial for the study of the oxidation of ethanol coupled to mass spectrometry (DEMS). By using DEMS, there were possible to observe coenzyme regeneration and the generation of acetaldehyde as a bioelectrooxidation product of ethanol, both at steady state, which were simultaneously observed. In summary, the present study introduces an to an approach that combines not only the development of chemically treated carbon fibers for application in bioelectrocatalysis, but also an unprecedented focus on the coupling between mass spectrometry and bioelectrochemistry for the resolution of enzymatic mechanisms.
6

Elaboration de bioélectrodes à base de nanotubes de carbone pour la réalisation de biopiles enzymatiques Glucose/02 / Carbon nanotube-based bioelectrodes for Glucose/O2 biofuel cells

Reuillard, Bertrand 03 December 2014 (has links)
Ce mémoire est consacré à l'optimisation de la connexion enzymatique d'enzymes pour l'oxydation du glucose et la réduction de O2 sur matrices de nanotube de carbone (CNT) dans les biopiles à glucose.Premièrement, le transfert électronique indirect de la glucose oxydase (GOx) est optimisé dans une matrice nanostructurée de CNT contenant la 1,4-naphtoquinone comme médiateur rédox. Cette bioanode a ensuite été combinée avec des biocathodes similaires à bases d'enzymes à cuivre (laccase et tyrosinase). La biopile GOx-NQ/Lac a permis d'obtenir des puissances maximales de l'ordre de 1,5 mW.cm-2. Les utilisations de cette pile en décharge courte, longue et sa stabilité dans le temps ont également été étudiées. La seconde partie présente la préparation d'une autre anode basée sur la connexion indirecte d'une glucose déshydrogènase NAD+-dépendante (GDH-NAD+) comme alternative pour l'oxydation du glucose. La GDH-NAD+ a été combinée avec un catalyseur d'oxydation de NADH par différentes méthodes. Tout d'abord, elle a été encapsulée au sein du métallopolymère rédox, puis, la modification supramoléculaire a dans un second temps permis d'immobiliser le catalyseur moléculaire et l'enzyme à la surface des CNTs. Ces deux bioanodes ont permis respectivement l'obtention de courants catalytiques d'oxydation du glucose de 1,04 et 6 mA.cm-2. La seconde bioanode a été combinée avec une biocathode à base de BOD et a permis l'obtention de densités de courants maximales de l'ordre de 140 µW.cm-2 La dernière partie concerne l'élaboration d'une biocathode bienzymatique pour la réduction de O2. Le DET de la HRP sur CNTs a dans un premier temps été optimisé par modification de la surface par différents dérivés pyrène. Ensuite, la combinaison de la GOx et de la HRP sur la même électrode a permis de réduire efficacement O2 en 2 étapes. La biocathode est capable de délivrer une densité de courant maximale de l'ordre de 200 µA.cm-2. Cette dernière, combinée avec la bioanode GDH présentée précédemment a permis d'obtenir une biopile opérationnelle en conditions physiologiques et 10 mM de NAD+, en étant capable de débiter une densité de puissance maximale de l'ordre de 57 µW.cm-2. / This work focuses on the optimization of the electrical wiring of glucose oxidizing and dioxygen reducing enzymes on carbon nanotube (CNT) matrixes for glucose biofuel cells.In the first part, glucose oxidase (GOx) mediated electron transfer (MET) is optimized in nanostructured CNTs matrixes by mechanical compression of a CNTs/GOx composite containing 1,4-naphtoquinone as redox mediator. This bioanode was then combined with MCOs (laccase and tyrosinase) based biocathodes. The GOx-NQ/Lac biofuel cell was able to deliver a maximum power density of 1.5 mW.cm-2. The use of this biofuel cell in short/long time discharge and in storage has also been studied. The second part presents the preparation of another bioanode based on the indirect wiring of a NAD+-dependant glucose dehydrogenase (GDH-NAD+) as an alternative for glucose oxidation. The GDH-NAD+ has been combined with an NADH oxidation catalyst by two different techniques. The first one involves the encapsulation of the protein in the metallopolymer redox film, whereas the second one relies on the supramolecular modification of the CNTs by the molecular catalyst and the enzyme. Both bioanodes showed good catalytic properties toward glucose oxidation in presence of NAD+ with respectively 1.04 mA cm-2 and 6 mA cm-2. The latter has been combined with a BOD based biocathode to form a biofuel cell exhibiting maximum power densities of 140 µW cm-2. The last part of this work focuses on the design of a bienzymatic biocathode for O2 reduction. The DET of horseradish peroxidase (HRP) was first investigated and optimized by modification of the CNTs with pyrenes derivatives. The combination of the HRP with the GOx on the same electrode enables an efficient reduction of O2 in a 2-step process. The biocathode could exhibit maximum currents densities of 200 µA cm-2. This cathode along with the previous GDH bioanode formed a biofuel cell functional in physiological conditions and 10 mM NAD+ showing maximum power densities of 57 µW cm-2.
7

Fibras de carbono modificadas com a álcool desidrogenase para o estudo da bioeletroxidação do etanol utilizando espectrometria de massas diferencial eletroquímica (DEMS) / Modified Carbon Fibers with the Alcohol Dehydrogenase for the Study of Bioeletroxidation of the Ethanol Using Differential Electrochemical Mass Spectrometry (DEMS)

João Carlos Perbone de Souza 21 November 2017 (has links)
Para a bioeletrocatálise de oxidação de etanol, a alteração da superfície eletródica e a otimização do processo de imobilização enzimática se fazem necessárias. Neste cenário, as fibras flexíveis de carbono (FFC) merecem destaque, pois além de sua superfície ser facilmente modificada devido à presença de carbono sp2, as mesmas possuem alta resistência mecânica e elasticidade, combinadas com a alta condutividade elétrica e térmica. Nesta tese de doutorado, apresenta-se como obter bioeletrodos de FFC modificadas com a enzima álcool desidrogenase (ADH) NAD-dependente, visando também aprimorar a oxidação da coenzima NADH (dinucleotídeo de nicotinamida e adenina). Os resultados mostram que quando as FCF são previamente submetidas a um tratamento oxidativo em meio ácido (KMnO4/H2SO4), obtém-se bioeletrodos estáveis, robustos e com alta área superficial. Além disso, observou-se que esses eletrodos possuem grupos funcionais contendo oxigênio que auxiliam na bioeletrocatálise de oxidação do etanol. Presume-se que presença de grupos quinonas seja responsável por facilitar a regeneração da coenzima, ou seja, estes grupos atuam decisivamente na oxidação do NADH. A alta qualidade dos bioeletrodos possibilitou manter a atividade catalítica da ADH por longo prazo, propriedade essa crucial para o estudo da oxidação do etanol acoplada à espectrometria de massas (DEMS). Devido a este estudo, foi possível observar concomitantemente a regeneração da coenzima (NADH -> NAD+) e a geração de acetaldeído como produto de bioeletroxidação do etanol, ambos em estado estacionário. Em suma, o estudo aqui apresentado introduz uma abordagem que combina não só o desenvolvimento de fibras de carbono tratadas quimicamente para aplicação em bioeletrocatálise, mas também um foco inédito no acoplamento entre a espectrometria de massas e a bioeletroquímica para a resolução de mecanismos enzimáticos. / Regarding the bioelectrocatalysis of the ethanol oxidation, the electrodic surface modification and the optimization of enzymatic immobilization are necessary. In this scenario, the flexible carbon fibers (FCF) are noteworthy, because besides their surface can be modified in an easy way due the presence of carbon sp2, they have high mechanical resistance and elasticity, combined with high electrical and thermal conductivity. In this doctoral thesis, it is presented how to obtain bioelectrodes of FFC modified with the enzyme alcohol dehydrogenase (ADH) NAD-dependent, as well as to improve the oxidation of the coenzyme NADH (nicotinamide adenine dinucleotide). The results show that when FCF is previously submitted to an oxidative treatment in acidic medium (KMnO4/H2SO4), stable, robust and high surface area bioelectrodes are obtained. In addition, it was observed that these electrodes have oxygen-containing functional groups that improve the bioelectrocatalysis of ethanol oxidation. There is proposed that the presence of quinone groups is responsible for facilitating the regeneration of the coenzyme, i. e., these groups act decisively in the oxidation of NADH. The high quality of the bioelectrodes allowed it to maintain the catalytic activity of the ADH for long term, property crucial for the study of the oxidation of ethanol coupled to mass spectrometry (DEMS). By using DEMS, there were possible to observe coenzyme regeneration and the generation of acetaldehyde as a bioelectrooxidation product of ethanol, both at steady state, which were simultaneously observed. In summary, the present study introduces an to an approach that combines not only the development of chemically treated carbon fibers for application in bioelectrocatalysis, but also an unprecedented focus on the coupling between mass spectrometry and bioelectrochemistry for the resolution of enzymatic mechanisms.
8

Improvement of direct electron transfer-type bioelectrocatalytic property of D-fructose dehydrogenase by protein engineering approach / フルクトース脱水素酵素による直接電子移動型バイオエレクトロカタリシスのタンパク質工学的手法による特性改良

Hibino, Yuya 25 March 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21836号 / 農博第2349号 / 新制||農||1068(附属図書館) / 学位論文||H31||N5208(農学部図書室) / 京都大学大学院農学研究科応用生命科学専攻 / (主査)教授 加納 健司, 教授 三芳 秀人, 教授 三上 文三 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
9

Studies on Electron Transfer Pathway and Characterization of Direct Electron Transfer-Type Bioelectrocatalysis of Fructose Dehydrogenase / フルクトース脱水素酵素による直接電子移動型酵素電極反応の電子移動経路とその特性評価

Kawai, Shota 23 March 2015 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第19022号 / 農博第2100号 / 新制||農||1030(附属図書館) / 学位論文||H27||N4904(農学部図書室) / 31973 / 京都大学大学院農学研究科応用生命科学専攻 / (主査)教授 加納 健司, 教授 阪井 康能, 教授 小川 順 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
10

Development of Dual Gas Diffusion-Type Biofuel Cells on the Basis of Electrochemical Understanding of Enzyme-Modified Electrodes / 酵素機能電極の電気化学的理解に基づいた両極ガス拡散型バイオ燃料電池の開発

Song, Qingsheng 23 March 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第20425号 / 農博第2210号 / 新制||農||1047(附属図書館) / 学位論文||H29||N5046(農学部図書室) / 京都大学大学院農学研究科応用生命科学専攻 / (主査)教授 加納 健司, 教授 宮川 恒, 教授 三芳 秀人 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

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