基于高通量测序的辐射污染区细菌群落特征分析

Analysis of bacterial community in radiation polluted soils by high-throughput sequencing

【目的】为了更加全面地揭示辐射污染区细菌种群多样性,了解辐射污染对辐射区土壤中细菌群落结构的影响。【方法】运用高通量测序方法,分别进行了土样细菌16S r RNA基因的V3可变区测序,进而对无辐射污染对照和不同辐射污染程度的土样中细菌群落组成和多样性进行分析。【结果】研究共获得110 348条有效序列,17 604个OTUs,共涉及细菌域的19个门和6个潜在菌门和其它未分类菌群的726个属。多样性分析表明,辐射污染会引起土壤样品中微生物群落的分布显著差异化,显著提高细菌群落种群多样性和微生物丰度。微生物群落组成分析发现,在辐射污染胁迫下,辐射污染区样品中变形杆菌门分布比例显著下降;随着辐射污染程度的提高,放线菌门所占比例逐步提高,未分类菌门、厚壁菌门和酸杆菌门也有明显的提高。同时,研究发现辐射污染区中存在着大量未分类菌属。【结论】研究揭示了辐射污染区极为丰富的细菌多样性,大量微生物新物种资源有待发掘。

[Objective] To fully demonstrate the bacterial diversity in radiation polluted soils from the Northwestern China, and investigate effects of radiation pollution on the bacterial community. [Methods] Composition and structure of bacterial communities in soils from the control of no radiation pollution and the radiation contaminated in different levels was analyzed based on high-throughput sequencing of the V3 region of the 16 S r RNA gene. [Results] A total of 110 348 effective sequences and 17 604 OTUs were obtained, which were classified into 726 genera from 19 phyla and others including 6 candidate phyla and the unclassified in bacteria domain. The result of diversity analysis showed that the radiation pollution resulted in significant change in bacterial community in soils, and led to the improvement of bacterial diversity and richness. The analysis of bacterial composition indicated percent rates of bacteria from phylum Proteobacteria decreased significantly under the radiation stress, while the Actinobacteria increased gradually with the improvement in radiation levels. The proportion of the unclassified, Firmicutes and Acidobacteria rise obviously. Additionally, lots of unclassified genera exist in radiation pollution soils. [Conclusion] It proved extremely rich bacterial diversity in radiation contaminated area and a lot of novel microbial resources which need to further discover.