| Project/Area Number |
03452275
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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 |
農業気象・生物環境制御学
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| Research Institution | The University of Tokyo |
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Principal Investigator |
KURATA Kenji Univ.of Tokyo, Fac.of Agric., Ass.Prof., 農学部, 助教授 (90161736)
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| Co-Investigator(Kenkyū-buntansha) |
KOZAI Toyoki Chiba Univ., Dept.of Hort., Prof., 園芸学部, 教授 (90081570)
IBATAKI Yasuomi Univ.of Tokyo, Fac.of Agric., Instructor, 農学部, 助手 (50242160)
GOTO Eiji Univ.of Tokyo, Fac.of Agric., Instructor, 農学部, 助手 (00186884)
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| Project Period (FY) |
1991 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥6,900,000 (Direct Cost: ¥6,900,000)
Fiscal Year 1993: ¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1992: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1991: ¥3,500,000 (Direct Cost: ¥3,500,000)
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| Keywords | Flow Visualization / Liquid Culture / Plant Cell Culture / Shake Culture / Shear Stress / 細胞培養 / バイオリアクター / ストロボスコープ / 粘性率 |
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| Research Abstract |
The objectives of the study were to analyze the physical stress imposed on cells or cell aggregates in liquid culture caused by agitaion or aeration for supplying oxygen to cells or for mixing the medium. The adopted methods of analysis were to visualize the medium movement and to analyze it. The selected culture vessels for analysis were flasks for shake culture and bioreactors.
The tracer method was adopted for visualization method, in which we utilized nylon particles for tracers. By photographing the trajectories of the nylon particles during a short period, the liquid movement was visualized. When data on streamline direction were also needed, light was emitted by a stroboscope to mark the beginning and end of the streamlines. The obtained images of streamlines were analyzed by a computer and distribution of streamlines, rotation and shear stress in the flow field were calculated. These flow characteristics were selected as ones relevant to hydrostatic stresses to the cells.
In the case of the flask shake culture, a laser light sheet (laser light spread in thin plane) was used to visualize the liquid movement in a horizontal plane at the middle of the liquid. The results showed a flow pattern which consisted of high velocity region, moderate velocity region, and low velocity region. The pattern itself rotated in accordance with the flask rotation. The patterns were dependent on the rotation speed. With the increase of the rotation speed, the averages of the absolute values of rotation and shear stress increased. Unlike the case of shake culture, liquid movement in a bioreactor was fully three-dimensional, and we need two images taken simultaneously from two angles, In this case, identifying the same particle in the two images were requested. We are making efforts to overcome this difficulty.
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