| Project/Area Number |
62560187
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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 |
General fisheries
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| Research Institution | the University of Tokyo |
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Principal Investigator |
HINO Akinori The University of Tokyo, 農学部, 助教授 (90012012)
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| Co-Investigator(Kenkyū-buntansha) |
IIDA Takaji The University of Tokyo, 農学部, 助手 (70159557)
OGAWA Kazuo The University of Tokyo, 農学部, 助手 (20092174)
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| Project Period (FY) |
1987 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1988: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1987: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | Brachionus plicatilis / Bacterial Flock / Protozoa / Energy Flow / Vitamine B12 / 食物連鎖 / 細菌 / ビタミンB12 |
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| Research Abstract |
This is the fundamental study for making clear the function of micro organisms which are co-existing in the culture of the rotifer Brachionus plicatilis,as a part of researches for dissolving the massmortality of long-term retardation of growth which still occur in mass culture of the animal. Results obtained are shown under.
1. As a result of evaluating the changes of size frequency distribution of suspending solids in the rotifr mass culture,the animal did not start to ingest bacterial flocks till swept clear Nannochloropsis,the food manually provided. After then,the clearance rate for bacterial flocks was near twice as much as for Nannochloropsis.
2. Vitamin B 12 ,which had been proved to be essential for the growth of the rotifer,is contained little either in Nannochloropsis or baker's yeast which are commonly used as food for rotifer culture. The main source of B 12 in mass culture was thought to be a metabolite of bacteria from the following results. 20 % of bacterial strain isolated form rotifer mass culture had B12 productivity,and produced 1-5 ng/ml・day of B12 in log phase of their growth stages,which is fairly high compared by B12 demand of the rotifer,and showed remarkable growth promotion in the axenic culture of the animal when put in as 10^7 - 10^<10> CFU/ml.
3. The nutritive lucking of baker's yeast was thought to extend over a wide range from the results that the growth promotion of B12-producing bacteria was more remarkable in the rotifer culture provided with Nannochloropsis than in that with baker's yeast as a basic food source.
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