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緑藻Dunaliella tertiolecta Butcherにおけるマンガンの吸収機構
http://hdl.handle.net/10232/13331
http://hdl.handle.net/10232/13331e2b89789-d0af-4107-9500-f3419a474583
| 名前 / ファイル | ライセンス | アクション |
|---|---|---|
AN00040498_v34-2_p183-244.pdf (7.7 MB)
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| Item type | 紀要論文 / Departmental Bulletin Paper(1) | |||||
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| 公開日 | 2012-05-07 | |||||
| タイトル | ||||||
| タイトル | Mechanism of Manganese Uptake by a Green Alga, Dunaliella tertiolecta Butcher | |||||
| タイトル言語 | en | |||||
| タイトル | ||||||
| タイトル | 緑藻Dunaliella tertiolecta Butcherにおけるマンガンの吸収機構 | |||||
| タイトル言語 | ja | |||||
| 著者 |
野呂, 忠秀
× 野呂, 忠秀 |
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| 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_6501 | |||||
| 資源タイプ | departmental bulletin paper | |||||
| アクセス権 | ||||||
| アクセス権 | open access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_abf2 | |||||
| 要約 | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | Although trace metals are present at low concentrations in seawater, algae are capable of accumulating such metals in high concentrations against a gradient. In order to clarify the uptake mechanism of trace metals, manganese (Mn) uptake from a culture medium by a euryhaline alga, Dunaliella tertiolecta BUTCHER was studied. D. tertiolecta was affected physiologically by Mn in the medium. Higher growth rates and evident elongation in cell length were observed from 0.1 to 1.0 ppm Mn in contrast to other concentrations tested. Crude protein and carbohydrate increased with increasing Mn concentrations with an optimum value at 0.05 to 0.1 ppm Mn. At 1.0 to 10 ppm Mn, protein and carbohydrate synthesis was inhibited. Chlorophyll-a content did not diminish in an Mn deficient medium, but apparently decreased when both Mn and Fe are deficient. Live D. tertiolecta cells accumulated Mn from the culture medium subject to environmental factors. Maximum uptake of Mn occured at pH 9.0, 10,000 lux and 20°C temperature. Dead cells are unable to take up Mn from the medium and, instead released accumulated Mn to the cell exterior. Mn uptake was activated during early exponential growth phase of the batch culture. It also synchronized with cell growth, with Mn content reduced at cell division and increased with cell growth. Mn levels inside the cell elevated sharply with increasing levels of exogenous Mn from 0.0 to 0.1 ppm. The absorption systems was apparently saturated at 0.1 ppm Mn since further increase up to 1.0 ppm external Mn resulted in virtually no further increase in the Mn content of D. tertiolecta. This saturation kinetics followed Michaelis Menten equation. Mn concentration factor in D. tertiolecta was 10-fold at 0.3 to 5.0 ppm and 100-fold at 0.1 ppm Mn in the medium. Mn uptake was inhibited by DCMU, TPAC, and KCN, and stimulated by respiratory substances, glucose. Zn and Cu ions in the medium also inhibited accumulation, while Na, K, Mg, Ca, P and Fe accelerated uptake of Mn. In D. tertiolecta, 72.8% of accumulated Mn was found in the tonoplast, 25.1% in protoplast as free ion or low molecular weight compound, and only 2.1% as firmly bounded to organelles or protoplast. The presence of Mn-stimulated ATPase was confirmed in whole cell homogenates. Mn-ATPase activity was one-tenth lower than that in Na, K-ATPase, and was strongly temperature dependent with an optimum at 25°C. Optimum pH for the activity was pH 8.0. With increasing Mn concentration, Mn-ATPase activity rose and reached a limiting value at 1.0 mM Mn (=55 ppm Mn). At higher concentrations, activity slowly diminished and eventually vanished at 8.0 mM Mn (=440 ppm Mn). Mn-ATPase was inhibited strongly by oligomycin and weakly by ouabine. The activity of Mn-ATPase was detected on cell plasma membranes. A highly significant correlation was noted between Mn-ATPase activity and Mn influx at concentrations of 0.0 to 5.0 ppm Mn (P<0.025;r=0.896). Form these results, Mn uptake mechanism of D. tertiolecta outlines an active transport process. Channels or pumps in the cell membrane are activated by energy from Mn-ATPase, which then takes up Mn from outside into the cell. Accumulated Mn are stored mostly in the form of ions or low molecular weight compounds near the cell membrane, while minimum amounts are transported to organelles i.e., chloroplast. Trace metal accumulation in other algae are likely to follow a similar mechanism found in D. tertiolecta. |
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| 内容記述言語 | en | |||||
| 収録雑誌名 |
ja : 鹿児島大学水産学部紀要 en : Memoirs of Faculty of Fisheries Kagoshima University 巻 34, 号 2, p. 183-244, 発行日 1985-12-25 |
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| 作成日 | ||||||
| 日付 | 1985-12-25 | |||||
| 日付タイプ | Issued | |||||
| ISSN | ||||||
| 収録物識別子タイプ | PISSN | |||||
| ISSN | 0453087X | |||||
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| 収録物識別子タイプ | NCID | |||||
| NC ID | AN00040498 | |||||
| 出版タイプ | ||||||
| 出版タイプ | VoR | |||||
| 出版タイプResource | http://purl.org/coar/version/c_970fb48d4fbd8a85 | |||||
| NDC | ||||||
| 主題Scheme | NDC | |||||
| 主題 | 660 | |||||
| 公開者・出版者 | ||||||
| 出版者 | 鹿児島大学 | |||||
| 出版者言語 | ja | |||||
| 公開者・出版者 | ||||||
| 出版者 | Kagoshima University | |||||
| 出版者言語 | en | |||||
