北极苔原土壤中可培养细菌的分离及其抗菌活性测定

【目的】北极地区具有高纬度、低温、高辐射等独特的环境条件。北冰洋及周围大面积的陆地区域鲜有人类踪迹,其中微生物数量不可低估。本研究旨在了解北极土壤中的可培养微生物的多样性及其抗菌活性。【方法】对来源于北极黄河站附近的7份不同植物根下苔原土壤进行直接涂布和富集培养后涂布。【结果】共获得细菌菌株721株,对其中608株进行细菌16S rRNA基因序列测定,归属于86个属,229个种,主要分布于变形菌门(Proteobacteria,54.3%)、放线菌门(Actinobacteria,21.2%)、拟杆菌门(Bacteroidetes,12.8%)、厚壁菌门(Firmicutes,10.0%)和奇异球菌门(Deinococcus-Thermus,1.6%)。其中从16S rRNA基因序列同源性推测有22株细菌菌株为潜在新种/属。从分离菌株中筛选出16株可抑制金黄色葡萄球菌(Staphylococcusaureus)或鲍氏不动杆菌(Acinetobacterbaumannii)生长的拮抗菌。【结论】获得了北极土壤地区特有的微生物菌株资源,为进一步筛选拮抗菌的活性物质提供了菌株基础。

Isolation of antibacterial and culturable bacteria from Arctic tundra soils

Objective] The Arctic region has unique environmental characteristics such as high latitude, low temperature and high radiation. There are few human traces in the Arctic Ocean and the surrounding land area, but the number of microorganisms hidden in Arctic region is underestimated. We explored the culturable bacterial diversity and antibacterial activity in Arctic tundra soil. Methods] We isolated bacteria from 7 soil samples collected from different plant roots near the Yellow River Station in Ny-Ålesund (Svalbard) Arctic. Results] A total of 721 strains were isolated from samples, 608 strains of which belong to 86 genera and 229 species after 16S rRNA gene sequencing. These 16S rRNA gene sequences mainly grouped into the following 5 phyla:Proteobacteria (54.3%), Actinobacteria (21.2%), Bacteroidetes (12.8%), Firmicutes (10.0%) and Deinococcus-Thermus (1.6%). It was suggested 22 strains could be potential novel species for their low sequence similarity. Furthermore, 16 antibacterial strains which could inhibit the growth of Staphylococcus aureus or Acinetobacter baumannii were screened. Conclusion] The research obtained special bacteria resource of arctic soil, and solidified the foundation of studying bioactive substances.