| Project/Area Number |
62560058
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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 |
土壌・肥料
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| Research Institution | Tohoku University |
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Principal Investigator |
SATO Kyo Institute of Genetic Ecology, Tohoku University, 遺伝生態研究センター, 助教授 (80006006)
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| Project Period (FY) |
1987 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1989: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1988: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1987: ¥800,000 (Direct Cost: ¥800,000)
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| Keywords | Soil Microorganism / Enrichment Culture / Soil Bacterial Flora / Cellulose-Decomposing-Microorganisms / Cellulose-Decomposition / Monosaccharide / Gram-negative Bacteria / N率 / 集積培養 / セルロース分解能 / セルロース分解微生物 / 硝酸化成菌 / 土壌細菌群 / 最確値法 / 希釈寒天平板法 / 土壌微生物 |
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| Research Abstract |
Population dynamics of cellulose-decomposing microorganisms in soil were studied under several conditions in connection with those of other groups of microorganisms. The cellulose-decomposing microorganisms were isolated from soil based on the dynamics obtained. Microbiological characteristics and some factors influencing the cellulose-decomposing activity of the isolates were investigated. The main results obtained were as follows:
1. Microbiological processes in soil suspensions adopted as the simplest enrichment culture method by applying powdered cellulose were followed: (1) Populations of cellulose-decomposing microorgaisms increased soon after incubating the soil suspensions depending on the amount of cellulose applied. They decreased temporarily and abruptly in the suspension with a large amount of cellulose. (2) Populations of other groups of microorganisms, especially Gram-negative bacteria changed similarly to those of the cellulose-decomposing microorganisms. (3) pH value of
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the suspension decreased depending on the amount of cellulose and an abrupt decrease in the pH of the suspension with a large amount of cellulose corresponded to the decrease in the microbial population. (4) Addition of CaCO_3 relieved the abrupt drop of pH as well as the populations.
2. The enrichment was also conducted by using field soil condition at 60% WHC: (1) The populations of several microbial groups investigated here changed similarly to those in the soil suspension. (2) However, the change as well as that of pH was not so dramatic as those in the soil suspension and they were similar to those in the suspension supplied with CaCO_3. (3) Production of monosaccharide was followed by its disappearance suggesting that there might be some nutritional interrelationships between the cellulose-decomposing microorganisms and other groups of microorganisms. (4) These microbiological processes were modified by the kinds of nitrogen compounds as well as simple sugars supplemented to cellulose.
3. About 50 strains of Cellulose-decomposing microorganisms were isolated from the soil through the enrichment culture. (1) All the isolates fell into bacteria, and they seemed to be comprised of few kinds of species or genera of bacteria. (2) Cellulose-decomposing activity of the isolates was affected by several nutritional conditions such like nitrogen sources and coexistence of simple sugars. Less
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