| Project/Area Number |
61550699
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
化学工学
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| Research Institution | The University of Tokyo |
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Principal Investigator |
MIYAWAKI Osato Department of Agricultural Chemistry, The University of Tokyo, 農学部, 助手 (80012053)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1987: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1986: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | Coenzyme regeneration / Affinity / Bioreactor / NAD / Alanine dehydrogenase / Electrochemical regeneration / メディエーター / 補酵素 / アフィニティクロマトグラフィックリアクター / 脱水素酵素 / サイクリング反応 / 電気化学的補酵素酸化還元 |
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| Research Abstract |
1. Affinity chromatographic reactor was developed as a bioreactor with highly efficient usage of expensive coenzymes by making use of dynamic affinity between enzyme and coenzyme. Basic aspects of affinity chromatographic reactor was investigated theoretically to elucidate the necessary condition for the expression of the dynamic affinity. The results were well compared with experimental results for a system with single immobilized enzyme of alcohol dehydrogenase which catalyzed both reduction of propionaldehyde and oxidation of ethanol with NAD cycling.
2. Affinity chromatographic reactor was applied to the two enzyme system with alanine dehydrogenase and lactate dehydrogenase for the production of L-alanine from lactate. The dynamic affinity between enzymes and coenzyme was expressed essentially at the same condition as the single enzyme case described above. The dynamic affinity, however, was strongly dependent on the concentration of pyruvate, the intermediate product. At a steady state operation, fairly good results were obtained for the productivity of the reactor and NAD cycling number.
3. Electrochemical method with consumption of nonspecific electrical energy was investigated as an alternative way of coenzyme regeneration. From the measurement of hydrogen exchange reaction rate with NADH, phenazine methosulfate was selected as the best mediator for electrochemical oxidation of NADH. Reaction of glucose 6-phosphate dehydrogenase could be coupled with three methods of oxidative regeneration of NAD; (1) direct electrode oxidation, (2) mediated electrode oxidation and (3) mediated oxidation with oxygen as the final electron acceptor. As a method of coenzyme regeneration for bioreactors. electrochemical method should be improved in surface mass transfer rate.
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