| Project/Area Number |
04660119
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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 |
応用微生物学・発酵学
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| Research Institution | Tottori University |
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Principal Investigator |
IZUMI Yoshikazu Tottori University TITLE OF POSITION Professor, 工学部, 教授 (40026555)
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| Co-Investigator(Kenkyū-buntansha) |
OHSHIRO Takashi Tottori University TITLE OF POSITION Research Associate, 工学部, 助手 (00233106)
SHIMAO Masayuki Tottori University TITLE OF POSITION Associated Professor, 工学部, 助教授 (00032285)
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1993: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1992: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | methylotroph / L-serine / enzymatic synthesis / serine pathway / セリンヒドロキシメチルトランスフェラーゼ / Hyphomicrobium属細菌 |
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| Research Abstract |
The production process of L-serine from methanol and glycine has been developed using a methylotroph with serine pathway. We screened a high producer, Hypgomicrobium methyovorum, which is an obligate methylotroph. A glycine-resistant mutant GM2 showed improved serine production (34 mg/ml). Furthermore other methylotrophic bacteria were examined for their ability to produce L-serine from methanol and glycine in a resting cell reacton. Among strains exhibiting L-serine productivity, the strain MN43 WAS found to exhibit the highest productiveity. Under optimized conditions usng this bacterium 71 mg/ml L-serine was produced. The high L-serine degrading activity of this bacterium was entirely suppressed by adding 1 mM CdCl_2, resulting in an enhanced converison ratio of glycine to L-serine (ca. 100% molar conversion). The GM2 strain was found to have elevated activities of methanol dehvdrogenase and serine hydroxymethyltransferase (SHMT). Since thers has so for been little information on the systematic characterization of enzymes of serine pathway in methylotroph, not only the adove two enzymes but also other three enzymes, serineglyoxylate aminotransferase, hydroxypyruvate reductase, glycerate kinase, were purified to hmogeneity. The gene of SHMT was cloned and its deduced amino acid sequence had homology to those of Escherichia coli (55%) and rabbit liver (44%), whereas the enzyme of the bacterinum was immunochemically distinguishadble from those of microorganisms other than Hyphomicrobium strains and mammalian livers.
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