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Removal of technetium-99 by Euglena gracilis
https://repo.qst.go.jp/records/70922
https://repo.qst.go.jp/records/7092248fda4b1-b69a-449f-b023-feaba6fd2759
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2012-10-02 | |||||
| タイトル | ||||||
| タイトル | Removal of technetium-99 by Euglena gracilis | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
| 資源タイプ | conference object | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Ishii, Nobuyoshi
× Ishii, Nobuyoshi× Uchida, Shigeo× 石井 伸昌× 内田 滋夫 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | The long-lived B-emitter technetium-99 (Tc-99) is a man-made fission product of U-235 and Pu-239 with a relatively high fission yield of about 6%. In aerobic environments, Tc is normally present in a heptavalent form as pertechnetate (TcO4-). It has been thought that phytoplankton is unsuitable for remediation of Tc-99 contaminated waters. In this study, removal of Tc-99 by freshwater phytoplankton Euglena gracilis was described. E. gracilis was cultured in a solution containing Tc-99 for 63 days at 20C under 12 h light-dark cycles. Removal of Tc-99 from the solution was periodically determined using a Tri-Carb 2500TR liquid scintillation analyzer. Spirulina platensis (NIES-39), Chlamydomonas pulsatilla (NIES-122) and Chlorella vulgaris (NIES-227) were also tested for the removal of Tc-99. Among phytoplankton used, only E. gracilis removed significant amounts of Tc-99 from the solution as they grew. The removal continued for 50 days, at which time equilibrium was achieved. The maximum value of the removal was 70% of the total Tc-99 added. To clarify the intracellular uptake of Tc-99 by E. gracili, the removal of Tc-99 by killed cells was carried out. E. gracilis cells were killed by the addition of a protein synthesis inhibitor cycloheximid at a final concentration of 50 ug mL-1 or by heating cells at 60C for 1 hour. In both cultures, E. gracilis removed negligible amounts of Tc-99. In addition to the killed cells experiment, desorption of Tc-99 from cell surface were carried out. As the pH of the solution was increased from 3.5 to 7.5, a slight increase in desorption amounts of the Tc-99 was observed. The relative amount of desorption, however, was, at a maximum, 14% of the total Tc-99 removed. These results suggest that a slight amount of Tc-99 had been adsorbed onto the cell surface. Results of both the killed cell experiments and desorption experiments show that the removal of Tc-99 by E. gracilis was primarily the result of intracellular uptake. |
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| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | SETAC Asia Pacific 2012 Meeting | |||||
| 発表年月日 | ||||||
| 日付 | 2012-09-27 | |||||
| 日付タイプ | Issued | |||||
