Studies on past-environment by ice core analyses using microbial activities in the snow and ice

利用冰雪中微生物活动的冰芯分析研究过去环境

• 批准号: 16310004
• 负责人: KOHSHIMA Shiro
• 金额: $ 6.4万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16310004/
• 关键词: ice core; microorganism; glacier; past environment; algae; bacteria; gene analysis; snow and ice

We improved the method of biological ice-core analysis applying the following new techniques of DNA analysis, such as species identification by 16SrRNA gene analysis, RT-PCR and microbial community analysis by DGGE method. These improvements enabled identification and quantification of bacteria and cyanobacteria in the ice-cores and snow and ice samples which had been difficult with old techniques.We collected ice-core samples in Russian Altai, European Alps, Chilean Andes, Alaska and analyzed biotic contents in these cores, such as snow algae, bacteria, fungi and pollens. In all these analyses, we could show that we can use the snow algae and pollens in the ice core as a good markers for annual layers useful for accurate dating of mid-latitude ice cores. We also examined bacterial DNA in the Antarctic ice cores for potential use as new environmental markers for the study on the past environment. We found that the Antarctic ice core preserved many ancient airborne bacteria and that bac … More terial community contained in the ice core differed between the samples of glacial age and interglacial age. The results suggest that air borne bacteria in the Antarctic ice cores could be new environmental markers if we can identify the source of the bacteria. So, we also started preliminary sampling and analysis of airborne bacteria released from Amazonian tropical rain forest, one of the possible source of bacteria stored in the Antarctic ice cores.To make comparative studies among glacier ecosystems of various part of the world, we collected microbiologial samples at the glaciers of the following regions: Russian Altai, Alaska mountain-range, European Alps, Chilean Andes and Rwenzori mountains of Uganda. By analyzing these samples with new methods, we could obtain many results important to understand glacier ecosystems and improve biological ice-core analysis. For example, we could find more than 10 new bacterial species adapted to cold environment in the snow and ice. The results of these analyses also showed that bacterial community on the glacier changed depending on the altitude. The result implies that we can use bacteria in the ice core as new environmental markers as well as snow algae because their their biomass and species composition change with environmental condition.[ Less

我们应用以下DNA分析新技术改进了生物冰芯分析方法，例如通过16SrRNA基因分析进行物种鉴定、RT-PCR和通过DGGE方法进行微生物群落分析。这些改进使得能够对细菌和蓝藻进行鉴定和定量。我们在俄罗斯阿尔泰山、欧洲阿尔卑斯山、智利安第斯山脉、阿拉斯加采集了冰芯样本，并对这些冰芯中的生物含量进行了分析，例如雪藻、细菌、真菌和花粉 在所有这些分析中，我们可以证明我们可以使用冰芯中的雪藻和花粉作为年度层的良好标记，有助于准确测定中纬度冰芯的年代。检查了南极冰芯中的细菌 DNA，以寻找可能用作研究过去环境的新环境标记的可能性。我们发现，南极冰芯保存了许多古老的空气传播细菌，并且冰芯中含有细菌群落。冰期和间冰期样本之间的差异表明，如果我们能够确定细菌的来源，南极冰芯中的空气传播细菌可能是新的环境标记。因此，我们也开始对空气传播细菌进行初步采样和分析。亚马逊热带雨林释放的微生物是南极冰芯中储存的细菌的可能来源之一。为了对世界各地的冰川生态系统进行比较研究，我们在以下国家的冰川中采集了微生物样本：通过使用新方法分析这些样本，我们可以获得许多对于了解冰川生态系统和改进生物冰芯分析具有重要意义的结果。例如，我们可以在冰雪中发现10多种适应寒冷环境的新细菌物种。这些分析的结果还表明，冰川上的细菌群落会随着海拔高度的变化而变化。这一结果暗示着我们可以在冰雪中利用细菌。冰芯为新的环境标记以及雪藻，因为它们的生物量和物种组成随环境条件而变化。[ 更少