極限微生物 地球生物圏フロンティア（深海・地底・南極）の微生物
スポンサーリンク
概要
- 論文の詳細を見る
The search for life on the edge of global biosphere is a frontier to bridge conventional bio⁄ecology and exo⁄astrobiology. This communication reviews the foci of microbiological studies on the inhabitants of the selected "edges", i.e., deep-sea, deep subsurface and Antarctic habitats. The deep-sea is characterized as the no-light (non-photosynthetic) habitat, and the primary production is mostly due to the chemosynthetic autotrophy at the hydrothermal vents and methane-rich seeps. Formation of the chemosynthesis-dependent animal communities in the deep leads to the idea that such communities may be found in "ocean" of the Jovian satellite, Europa. The oxygen minimal layer (OML) in mid-water provides another field of deep-sea research. Modern OML is a relatively thin layer, found between the water depth of 200 and 1000 m, but was much thicker during the periods of oceanic anoxia events (OAEs) in the past. The history of oceanic biosphere is regarded as the cycle of OAE and non-OAE periods, and the remnants of the past OAEs may be seen in the modern OML. Anoxic (no-O<SUB>2</SUB>) condition is also characteristic of deep subsurface biosphere. Microorganisms in deep subsurface biosphere exploit every available oxidant, or terminal electron acceptor (TEA), for anaerobic respiration. Sulfate, nitrate, iron (III) and CO<SUB>2</SUB> are the representative TEAs in the deep subsurface. Subsurface of hydrothermal vents, or sub-vent biosphere, may house brine (high salt) habitats and halophilic microorganisms. Some sub-vent halophiles were phylogenetically closely similar to the ones found in the Antarctic habitats which are extremely dry by the liophilizing climate. Below the 3000-4000 m-thick glacier on Antarctica, there have been >70 lakes with liquid water located. One of such sub-glacial lakes, Lake Vostok, has been a target of "life in extreme environments" and is about to be drill-penetrated for microbiological studies. These 'microbiological platforms' will provide new knowledge about the diversity and potential of the Earth's life and facilitate the capability of astrobiologial exploration.
- 日本宇宙生物科学会の論文
日本宇宙生物科学会 | 論文
- 須田立雄先生「ビタミンDと骨に関する研究」2001年度日本学士院章を受賞
- 放射線による突然変異と発癌の原因となる長寿命ラジカル
- TANPOPO : 有機物と微生物の宇宙空間曝露と微隕石及び微生物の捕集実験
- Radiation Doses for Human Exposed to Galactic Cosmic Rays and Their Secondary Products on the Lunar Surface
- 各種の筋活動抑制に対するラット足関節底屈筋の反応