新疆顿巴斯他乌盐湖沉积物免培养古菌多样性

Archaeal diversity in sediment of Dunbasitawu salt lake，Xinjiang，China，estimated by 16S rRNA gene sequence analyses

摘要:

摘要:【目的】了解新疆顿巴斯他乌盐湖沉积物免培养古菌组成及多样性。【方法】利用免培养法直接从顿巴斯他乌盐湖沉积物样品中提取环境总DNA，采用古菌通用引物对16S rRNA 基因进行扩增，构建基因克隆文库。对随机挑选的59个阳性克隆进行Hae Ⅲ限制性酶切分型并测序、BLAST比对及构建16S rRNA 基因系统发育树。【结果】文库覆盖率为89%，Shannon-Wiener 指数为2.69，共得到21个不同的可操作分类单元，分属于广古菌门(Euryarchaeota，92%)和泉古菌门(Crenarchaeota，8%)，其中多数为盐杆菌科 (Halobacteriaceae，88%)的盐杆菌属(Halobacterium，24%)、盐盒菌属(Haloarcula，18%)、盐碱红菌属(Natronorubrum，14%)、盐红菌属(Halorubrum，8%)等，与海盐环境( thalassohaline)获得的16S rRNA基因序列相似性最高(﹥95%);整个文库中约11%的克隆与可培养古菌多个属的相似性小于97%。【结论】顿巴斯他乌盐湖古菌多样性略低于同类高盐环境，组成较为一致，只是各类群所占百分比稍有不同，且可能存在一些潜在新物种或新类群。

Abstract:

Abstract:［Objective］We surveyed the composition and diversity of uncultured archaea in Xinjiang Dunbasitawu salt Lake sediment．［Methods］ Environmental total DNA was directly extracted from the sediment．We constructed clone library of 16S rRNA gene amplified with archaea-specific primers． A total of 59 positive clones were randomly selected from the library and identified by restriction length polymorphism (RFLP) with enzyme Hae Ⅲ． Clones with the unique RFLP pattern were sequenced，and then by phylogenetic analysis．［Results］ The clone coverage C value was 89%，and Shannon-Wiener index was 2. 69. In total，21 Operational Taxonomic Units (OTUs) were obtained and affiliated with Euryarchaeota (92%) and Crenarchaeota (8%)．The most of clones were affiliated to Halobacterium (24%)，Haloarcula (18%)，Natronorubrum (14%)，and Halorubrum (8%)，which belonged to family Halobacteriaceae (88%) with high similarity to that from thalassohaline environment．In addition，11% of clones had less than 97% similarity with archaea sequences deposited in GenBank database．［Conclusion］Compared with other similar Hypersaline environments，archaea diversity in Dunbasitawu salt lake was a little lower．The proportion of archara was different，but the composition is consistent． It was implied that some potential new species or lineages maybe exist in Dunbasitawu salt lake.