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Study of methane metabolic cycle of microorganisms in marine sediment core using natural level radiocarbon analysis

利用自然水平放射性碳分析研究海洋沉积物岩心中微生物的甲烷代谢循环

基本信息

批准号：
16310002
负责人：
UTSUMI Motoo
金额：
$ 10.3万
依托单位：
University of Tsukuba
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 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16310002/
关键词：
methane methane hydrate Carbon isotope ratio biomarker microbial community RNA DNA 温暖化微生物 14C

项目摘要

This research was executed to develop various evaluation techniques for clarifying biomarker signals and their signal strength left for marine sediments concerning about methane hydrate, whether these signal had been newly generated by living microorganisms in the sediment or they were methane origin carbon on the site. At first, a graphitization technique for making precise and accurate radiocarbon measurements on small samples containing less than 100 μg of carbon was developed. The development of a microscale radiocarbon analysis technique is very important for advanced research in various fields of study, especially organic geochemistry. Using this method, the piston cores from the continental slope sediments in the Oyashio current region, which recently is found to bear immense amounts of methane hydrate, have been investigated about planktonic and benthic foraminiferal carbon isotope records during the past 34 kyr. Moreover, in order to investigate relation with foraminifera carbon isotopic signal and methane release from the seafloor, biomarker compositions and their carbon isotope have been analyzed in the light of the past activity of methanotrophic bacteria in the oxic-anoxic interface in the overlying water column and/or surface sediment. To analysis for microbial communities and microbial RNA in marine sediment core, we modified and developed DNA/RNA simultaneous extraction method using the Mutsu-bay sediments. We identified several partial sequences of 16S rDNA related to methanogens and methanotrophs in the sediment cores.

本研究旨在开发各种评价技术，以澄清有关甲烷水合物的生物标志物信号及其留在海洋沉积物中的信号强度，这些信号是否是由沉积物中的活微生物新产生的，或者它们是现场的甲烷源碳。首先，开发了一种石墨化技术，用于对碳含量低于100 μg的小样品进行精确和准确的放射性碳测量。微量放射性碳分析技术的发展对各个研究领域，特别是有机地球化学的深入研究具有重要意义。利用这种方法，从大陆坡沉积物中的Oyashio电流区，最近被发现含有大量的甲烷水合物的活塞芯，已经调查了过去34 kyr的浮游和底栖有孔虫的碳同位素记录。此外，为了研究有孔虫碳同位素信号与甲烷释放的关系，生物标志物组成和它们的碳同位素分析了过去的甲烷氧化细菌在上覆水体和/或表层沉积物中的缺氧-缺氧界面的活动。为分析海洋沉积物中微生物群落和微生物RNA，以陆津湾沉积物为研究对象，改进和发展了DNA/RNA同时提取方法。我们确定了一些16 S rDNA的部分序列相关的甲烷菌和甲烷氧化菌的沉积物柱样。