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Thermal tolerance of prokaryote on surface of substrates

基材表面原核生物的耐热性

基本信息

批准号：
18340170
负责人：
URABE Tetsuro
金额：
$ 5.08万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18340170/
关键词：
deep bosphere extremophile geothemal FISH surface water sampling

项目摘要

One of the most crucial parameters that limits the habitable depth for extremophiles is temperature. The maximum temperature of growth for hyperthermophile is known to be 121 deg-C but some microbes live on a surface of substrates such as hydrothermal chimneys at temperatures more than 300 deg-C. Therefore, it is presumed that those attached to solid surface may be tolerable to extreme environment such as high temperature.We examined this hypothesis by in-situ sampling from geothermal reservoir using high-temperature, borehole fluid sampler which is tolerant to temperature as high as 300 deg-C. This borehole sampler enables us to get geothermal fluid in-situ to pressure-tight sample chamber (1250 ml) without drastic pressure change. Besides, all the parts can be sterilized either by autoclave or heating up to 200 deg-C.We applied the sampler to a geothermal well N18-OT-2 (1355m,>140 deg-C) that locates in Otari Village, Nagano Prefecture, central Japan. The fluid is rich in bicarbonate … More (2648 ppm), Na^+(1752 ppm) and Cl(1048 ppm). The oxygen isotopic content of the fluid (δ^<18>O<SMOW>=-8.3 permil) shows oxygen shift that is the sign of water rock interaction. The hydrogen isotopic content (^<18>D=-83 permil) is equivalent to local meteoric water. The dissolved organic carbon content (DOC) is as low as 4.55±0.53mg/L which is not high enough to assume intensive deep biosphere within the geothermal reservoir. Detailed geochemical and isotopic modeling indicate that the fluid was formed by 4:1 mixing between shallow, Ca-bearing hot spring water and CO_2 bearing deep geothermal fluid which may come form nearby Quaternary Kazafuki-dake volcano.It is worthy to note that a novel (phylum-level) thermophilic chemo-heterotrophic filamentous bacterium was obtained from the hot spring. Detailed information will be disclosed after publication. On the other hand, small number of cells that attached to the calcite scale of the well at the depth of 593 meters cannot be cultured or identified by CARD-FISH method due to their paucity. Less

限制极端微生物适宜居住深度的最关键参数之一是温度。已知超嗜热菌的最高生长温度为 121 摄氏度，但一些微生物生活在温度超过 300 摄氏度的基材表面，例如热液烟囱。因此，推测附着在固体表面的物质可能能够耐受高温等极端环境。我们通过使用耐高温钻孔流体采样器从地热储层进行原位采样来检验这一假设，该采样器可耐受高达 300 摄氏度的温度。该钻孔采样器使我们能够将地热流体原位采集到耐压样品室（1250 毫升），而无需剧烈的压力变化。此外，所有部件都可以通过高压灭菌器或加热至200℃进行消毒。我们将采样器应用于位于日本中部长野县小谷村的地热井N18-OT-2（1355m，>140℃）。该液体富含碳酸氢盐 (2648 ppm)、Na^+ (1752 ppm) 和 Cl (1048 ppm)。流体的氧同位素含量（δ^<18>O<SMOW>=-8.3 permil）显示出氧位移，这是水岩相互作用的标志。氢同位素含量(^ 18 D＝-83 permil)相当于当地大气水。溶解有机碳含量（DOC）低至4.55±0.53mg/L，不足以假设地热储层内有密集的深层生物圈。详细的地球化学和同位素模型表明，该流体是由浅层含Ca温泉水与可能来自第四纪风吹岳火山附近的含CO_2深层地热流体以4:1混合形成的。值得注意的是，从温泉中获得了一种新型（门级）嗜热化学异养丝状细菌。详细信息将在发布后披露。另一方面，593米深度井方解石垢上附着的少量细胞，由于数量稀少，无法用CARD-FISH法进行培养或鉴定。较少的