| Project/Area Number |
17380057
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied microbiology
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| Research Institution | Tohoku University (2006)
Akita Prefectural Agriculture, Forestry and Fisheries Research Center (2005) |
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Principal Investigator |
ITOH Yoshifumi Tohoku University, Graduate School of Agricultural Science, Professor, 大学院農学研究科, 教授 (70135127)
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| Co-Investigator(Kenkyū-buntansha) |
ABE Naoki Tohoku University, Graduate School of Agricultural Science, Research Associate, 大学院農学研究科, 助手 (90202671)
OGASAWARA Hironobu Akita Prefectural Agriculture, Forestry and Fisheries Research Center, Akita Research Center for Food and Brewing, Enzyme and Microbiology Group, Senior Researcher, 総合食品研究所・酵素・微生物班, 主任研究官 (50390901)
KIMURA Keitarou National Food Research Institute, Division of Applied Microbiology, Senior Researcher, 食品産業技術総合研究機構・食品総合研究所・微生物利用研究領域, 主任研究官 (20353980)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥11,800,000 (Direct Cost: ¥11,800,000)
Fiscal Year 2006: ¥5,700,000 (Direct Cost: ¥5,700,000)
Fiscal Year 2005: ¥6,100,000 (Direct Cost: ¥6,100,000)
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| Keywords | Microorgamism / Bacillus subtilis / Environmental adaptation / Gene regulation / Protein kinase / Transcriptional regulator / Polypeptide synthesis / プロテインカイネーズ / 納豆菌 / 粘質物 / ポリグルタミン酸 / 栄養応答 / 挿入配列 / 融合遺伝子 |
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| Research Abstract |
We investigated nutrient factors that affect the synthesis and degradation of extracellular polymer of glutamate, poly-γ-glutamate (PGA), in Bacillus subtilis NAFM5, a derivative of a starter strain for Natto (Japanese fermented soybean food). We also analyzed regulatory systems involved in the regulation of the PGA biosynthetic and degradative enzyme genes. Our major results include :
1. Regulation of the capBCAEPGA biosynthetic operon by nutrients.
L-Glutamate and glucose stimulated PGA production by 2.5-and 3-fold, but repressed expression of a capB::lacZ fusion to 1/2 and 1/6, respectively. Nutrient-rich GSP medium, which contained soybean protein hydroysates, greatly improved (11 fold of that in minimal medium), whereas LB medium almost prevent capB::lacZ expression and PGA production.
2. Regulation of the capBCAE PGA biosynthetic operon by the quorum-sensing system.
We found that degQ and degSU genes are essential for PGA synthesis and determined by gel-shift assays that DegU binds to-720 ro-660 region of the capB promoter.
3. Regulation of ywtD and ggt.]
We found that ggt is under the control of the ComQXPA quorum-sensing system. Genetic study showed that ywrD encodes an end-type of PGA hdrolase. This gene appeared not regulated by the quorum-sensing system.
4. Functional analysis of vvzD.
Using a knockout mutant of yvzD, we demonstrated that this gene encode a deanchoring enzyme detaching cell-wall associated PGA. Thus, at least three genes, yvzD, ywtD and ggt, are involved in PGA degradation. YvzD is also not controlled by the quorum-sensing system.
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