| Project/Area Number |
61540473
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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 |
生態学
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| Research Institution | Nagoya University |
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Principal Investigator |
TERAI Hisayoshi Water Research Institute, Nagoya University Research Associate, 水圏科学研究所, 助手 (10023855)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1987: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1986: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | Denitrifying Bacteria / Denitrification Process / Fluorescent Antibody Stain / Aquatic Habitat / 群集動態 / 木崎湖 / 深見池 / 脱窒活性 / 溶存酸素・酸化環元電位制御培養系 |
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| Research Abstract |
This research project aimed (1) to clarify the development of denitrification process in freshwater lakes, (2) to elucidate the dominant denitrifying bacterial species in the natural aquatic habitat and to estimate each of their population by using fluorescent antibody staining method, and (3) to study on the regulatory mechanism of denitrifying activity by using automated dissolved oxygen controlling culture system.
As for the first aim, field experiments on the denitrifying activity measurement in water columns of Lake Kizaki and Lake Fukami-Ike in 1986 had clarified the denitrification process of both Lakes. Details of these results were reported in TERAI (1987) and TERAI (1988).
As for the second aim, 7 different denitrifying isolates from L. Fukami-ike were used as antigen and corresponding antisera were obtained from rabits. Byusing these antisera and FITC-conjugated anti-rabit globulin, denitrifying bacteria enriched in MPN counting medium were identified serologically. The results showed that 43 samples out of 586 MPN cultures (7.3%) were homologous with any one of the antigen bacteria. And 28 samples (4.8%) were homologous with only two antigen bacteria. These lower detection efficiencies (about half of those in L. Kizaki) means a diversity of the denitrifying bacterial species in L. Fukami-ike than in L. Kizaki. As for the direct estimation of denitrifying population by fluorescent antibody staining method, improvement of method such as elimination of background fluorescens or scannning counting method for all microscopic field in smear of l level is in progress.
As for the third aim, the effect of dissolved oxygen concentration on the synthesis of denitrifying enzymes such as nitrite reductase and nitrous oxide reductase was elucidated by using culturing system with automated dissolved oxygen oxygen concentration increased, nitrous oxide reductase was optimally synthesized between 1 and 2 ppm of D.O..
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