西藏米拉山土壤古菌16S rRNA及amoA基因多样性?分析

摘要：【目的】硝化作用在全球土壤氮循环中具有重要的作用，虽然细菌一度被认为单独负责催化这个过程的限速步骤，但是最近一些研究结果表明泉古菌具有氨氧化的能力。本文通过构建古菌16S rRNA 基因克隆文库和氨氧化古菌amoA基因文库，分析西藏米拉山高寒草甸土壤中古菌及氨氧化古菌群落结构组成情况，为揭示青藏高原高寒草甸土壤古菌的多样性提供理论基础。【方法】采用未培养技术直接从土壤中提取微生物总DNA，分别利用通用引物构建古菌16S rRNA 基因和氨氧化古菌amoA基因克隆文库。【结果】通过构建系统发育树，表明古菌16S rRNA 基因克隆文库包括泉古菌门和未分类的古菌两大类，并且所有泉古菌均属于热变形菌纲。氨氧化古菌amoA基因克隆文库中序列均为泉古菌。通过DOTUR软件分析，古菌16S rRNA基因和古菌amoA基因克隆文库分别包括64个OTUs和 75个OTUs。【结论】西藏米拉山高寒草甸土壤中古菌多样性比较丰富，表明古菌在高寒草甸土壤的氮循环中可能具有重要的作用。所获得的一些序列与已知环境中土壤、淡水及海洋沉积物中获得的一些序列具有很高的相似性，其古菌及氨氧化古菌来自不同环境的可能性比较大，可能与青藏高原的地质历史变迁过程有关。米拉山古菌及氨氧化古菌与陆地设施土壤中相似性最高，说明与西藏米拉山高寒草甸土壤的退化有关。

Diversity of soil Archaea in Tibetan Mila Mountains

Abstract: Objective] In order to study the diversity of archaea and ammonia-oxidizing archaea (AOA) of the alp prairie soil in Mila Mountain of Tibet. Methods] Total microbial DNA was directly extracted from the alp prairie of Mila Mountain. The clone library of 16S rRNA genes and amoA genes were amplified by PCR with universal primer sets. Through 16S rRNA gene and amoA gene cloning library technology to analysis the composition of Archaea and AOA community structure in the alp prairie soil of Mila Mountain. Results] Phylogenetic analysis revealed archaea in the soil of Mila Mountain including the Crenarchaeota (71.7%) and unclassified_Archaea (28.3%) phyla. All the Crenarchaeota belong to the Thermoprotei. Phylogenetic analysis revealed AOA in the alp prairie soil of Mila Mountain belonged to the kingdom Crenarchaeota. Through DOTUR software analysis, Archaea and AOA species composition from Mila Mountain included 64 OTUs and 75 OTUs. Conclusion] These findings show prolific archaeal diversity in the alp prairie soil of Mila Mountain, where they may be actively involved in nitrification. In addition, there have some unclassified Archaea in the clone library, it means that they may represent some novel archaeal groups.and what? Meaningless!