Structure of the rare archaeal biosphere and seasonal dynamics of active ecotypes in surface coastal waters

Marine Archaea are important players among microbial plankton and significantly contribute to biogeochemical cycles, but details regarding their community structure and long-term seasonal activity and dynamics remain largely unexplored. In this study, we monitored the inter-annual archaeal community composition of abundant and rare biospheres in northwestern Mediterranean Sea surface waters by pyrosequencing 16S rDNA and rRNA. A detailed analysis of the rare biosphere structure showed that the rare archaeal community was composed of three distinct fractions. One contained the rare Archaea that became abundant at different times within the same ecosystem; these cells were typically not dormant, and we hypothesize that they represent a local seed bank that is specific and essential for ecosystem functioning through cycling seasonal environmental conditions. The second fraction contained cells that were uncommon in public databases and not active, consisting of aliens to the studied ecosys...海洋古菌（Marine Archaea）是微生物浮游生物中的关键类群，可显著参与生物地球化学循环，但有关其群落结构、长期季节活性与动态变化的细节仍未得到充分探索。本研究通过焦磷酸测序16S rDNA与rRNA，对地中海西北部表层水体中丰度型与稀有型古菌群落的年际组成进行了监测。对稀有生物组（rare biosphere）结构的详细分析显示，稀有古菌群落由三个不同的组分构成。第一组分包含在同一生态系统内不同时期可转变为优势类群的稀有古菌；这类古菌通常并非处于休眠状态，我们推测其代表一类具有生态系统特异性的本地种子库，可通过响应季节性环境条件的循环变化，对生态系统功能的正常运转发挥不可或缺的作用。第二组分包含在公共数据库中罕见且未处于活跃状态的古菌，它们属于本次研究生态系统的外来类群……