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为了解陕北土壤中芽胞杆菌的种类及其多样性,将采集于陕北5个地点的土壤样品利用温度筛选法、稀释平板计数法进行芽胞杆菌分离,用16SrDNA基因测序法进行种类鉴定。结果发现,从采集的土壤样品中共分离到31株芽胞杆菌,共19种芽胞杆菌,其中部分菌株为国内少见报道的菌株。通过16SrDNA基因序列的系统发育树分析发现,分离的菌株基本上和模式菌株亲缘关系较近,在种的系统发育上也存在一定的交叉,各菌株间序列差异较小。对土壤样品中芽胞杆菌多样性的研究中发现,不同土壤样品中的芽胞杆菌含量差异明显,表现为采自洛川毛主席故居土壤样品>采自黄陵黄帝陵墓土壤样品>采自宜川壶口瀑布土壤样品>采自富县石泓寺土壤样品>采自宝塔山宝塔下土壤样品,每个土壤样品中同种芽胞杆菌的含量差异也较明显,每个采集地点都含有特有的芽胞杆菌,说明陕北土壤中芽胞杆菌较丰富。
In order to understand the species and diversity of Bacillus in the soil in northern Shaanxi, the soil samples collected from 5 sites in northern Shaanxi were isolated by Bacillus using temperature screening method and dilution plate counting method, and 16S rDNA gene sequencing method was used to identify the species. A total of 31 Bacillus species were isolated from 19 soil samples collected from soil samples, some of which were rare in China. Phylogenetic tree analysis of the 16S rDNA gene sequence showed that the isolated strains were basically closely related to the model strains, and there was also some crosses in the phylogeny of the species, with little difference in sequence between the strains. In the study of Bacillus diversity in soil samples, the content of Bacillus in different soil samples was significantly different, which was characterized by the soil samples collected from the former residence of Chairman Luochuan Mao> soil samples collected from Huangling tomb in Huangling> Soil samples from mouth waterfalls> Soil samples taken from Shihong Temple, Fuxian County> Soil samples taken from the pagoda pagoda of Baita Mountain showed the same content of Bacillus subtilis in each soil sample. Each collection site contained Bacillus , Indicating that Bacillus in northern Shaanxi soil is rich.