Budget Amount *help |
¥19,370,000 (Direct Cost: ¥14,900,000、Indirect Cost: ¥4,470,000)
Fiscal Year 2012: ¥6,370,000 (Direct Cost: ¥4,900,000、Indirect Cost: ¥1,470,000)
Fiscal Year 2011: ¥6,370,000 (Direct Cost: ¥4,900,000、Indirect Cost: ¥1,470,000)
Fiscal Year 2010: ¥6,630,000 (Direct Cost: ¥5,100,000、Indirect Cost: ¥1,530,000)
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Research Abstract |
Phosphite dehydrogenase (PtxD), which catalyzes the nearly irreversible oxidation of phosphite to phosphate with the concomitant reduction of NAD+to NADH, has great potential for NADH regeneration in industrial biocatalysts. In order to obtain a heat-stable PtxD, we isolated a Ralstonia sp. strain 4506 that can grow at 45 oC on a minimal medium containing phosphite as the sole source of phosphorus. NADH regeneration system using PtxD of this strain (RsPtxD) was successfully applied to the production of L-tert-leucine, an important chiral building block used in the pharmaceutical industry. Then RsPtxD was modified by site-specific mutation to increase the substrate specificity for NADP. The resultant enzyme RsPtxD-DM was successfully used for shikimic acid production as a NADPH regeneration system.
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