西藏米拉山土壤古菌16S rRNA及amoA基因多样性分析

Diversity of soil Archaea in Tibetan Mila Mountains

【目的】本研究旨在了解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。【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16SrRNA基因和氨氧化古菌amoA基因克隆文库。利用DOTUR软件将古菌和氨氧化古菌序列按照相似性97%的标准分成若干个可操作分类单元(OTUs)。【结果】通过构建系统发育树,表明古菌16SrRNA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。古菌16SrRNA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。

[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. The sequences of archaea and AOA were defined into operational taxonomic units （OTUs） according to the 97 % similarity threshold for OTU assignment was performed using the software program DOTUR. [ 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. 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.