Discovery of novel archaeal lineages and their ecophysiological functions in terrestrial subsurface environment

本文采用地球化学、微生物学和先进分子生态学等多相方法研究了未培养古细菌及其相关细菌在陆地地下环境中参与生物地球化学过程的系统发育和生态生理功能。特别是在冰川耕地、深层高温地下水、深层油气田等陆生地下环境中，发现了古细菌领域尚未确定的门或纲水平谱系。单细胞基因组分析提供了在陆地地下环境中发现的一些未培养的古细菌和细菌的基因组片段。此外，我们还成功地从陆地地下环境中获得了非培养古细菌的富集培养和纯培养，并对其系统发育和生态生理功能进行了表征。

This study investigated phylogeny and ecophysiplogical functions of uncultured archaea and their related bacteria likely contributing to biogeochemical processes in terrestrial subsurface environments by polyphasic approaches including geochemical, microbiological and the advanced molecular ecological approaches. In particular, the present study discovered unidentified phylum or class level lineages in the domain Archaea in terrestrial subsurface environments such as glacial till, deep high temperature groundwater, deep oil & natural gas fields, etc. Single cell genome analysis provided genome fragments of some of the uncultured archaea and bacteria found in the terrestrial subsurface environments. Furthermore, we have succeeded in obtaining enrichment culture and pure culture of uncultured archaea from terrestrial subsurface environments and characterized their phylogenetic and ecophysiological functions.