1990 Fiscal Year Final Research Report Summary
Regulation of Unsaturated Fatty Acid Synthesis by Low Temperature.
| Project/Area Number |
63480009
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
植物生理学
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| Research Institution | Hokkaido University |
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Principal Investigator |
SASAKI Shoji Science, Biology, Professor., 理学部, 教授 (10000811)
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| Co-Investigator(Kenkyū-buntansha) |
TAKADA Yasuhiro Science, Biology, Assistant., 理学部, 助手 (10163213)
OKUYAMA Hidetoshi Science, Biology, Ass. Professor., 理学部, 助教授 (90125295)
FUKUNAGA Noriyuki Science, Biology, Ass. Professor., 理学部, 助教授 (30113616)
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| Project Period (FY) |
1988 – 1990
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| Keywords | Desaturase / Unsaturation / Fatty Acid / Biosynthesis / Isomerization / Psychrophile / Psychrotroph / Low Temperature |
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| Research Abstract |
1. Mechanism of biosynthesis of unsaturated fatty acid in a psychrotrophic bacterium, Pseudomonas sp. strain E-3, was investigated.
(1) Fatty acid synthase from this bacterium was proven to have an ability to synthesize unsaturated fatty acid. This ability was inhibited by 3-decynoyl-N-acetylcysteamine, an inhibitor of anaerobic mechanism for unsaturated fatty acid synthesis.
(2) Oxygen-dependent fatty acid desaturate activity was demonstrated in the membrane fraction of this bacterium.
(3) It was shown that auxotrophic mutants for unsaturated fatty acid have extremely low activity of fatty acid desaturate.
(4) From the above results, it was concluded that the two mechanisms are coexisted in this bacterium, but the aerobic mechanism is indispensable for survival of this bacterium.
2. Isomerization of cis-to trans-from of unsaturated fatty acid was investigated in relation to thermal adaptation of a psychrophilic bacterium, Vibrio sp. strain ABE-1.
(1) The cellular phospholipid extracted from the cells grown at O^0 to 5^0 was found to contain exclusively cis-from palmitoleate as a main unsaturated fatty acid.
(2) Content of trans-from of palmitoleate was increased up to 12% with decreasing the content of cis-from when the cells were grown at 20^0 C.
(3) From the fact that melting point of fatty acid decreases in the order of saturated- > trans - > cis-unsaturated form, it was concluded that the isomerization contributes for homeoviscousity of this bacterial membrane.
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