织金洞钟乳石沉积物表面可培养细菌多样性和网络分析

【背景】洞穴环境中蕴含丰富而独特的细菌资源,对洞穴环境中细菌的分离培养有助于了解洞穴细菌多样性及细菌资源的挖掘和利用。【目的】利用不同培养基分离细菌,探究钟乳石表面可培养细菌的多样性及其种间互作关系。【方法】通过11种培养基对织金洞内钟乳石沉积物表面的细菌进行分离纯化,并利用16S rRNA基因序列分析初步确定分离菌株的分类地位。在R软件下,通过Bipartite包分析可培养细菌属间的相互作用。【结果】从钟乳石沉积物表面共分离出206株细菌,它们隶属于4门25属45种,香农(Shannon)指数为4.78,辛普森(Simpson)指数为0.95。变形菌门(Proteobacteria)和芽孢杆菌属(Bacillus)分别为样品中可培养细菌的优势门(47.09%)和优势属(29.61%)。无机寡营养培养基有助于洞穴钟乳石沉积物细菌的分离。属水平-采样点网络分析表明,可培养细菌分布具有非随机、显著的嵌套性。芽孢杆菌属(Bacillus)、德沃斯氏菌属(Devosia)、产碱杆菌属(Alcaligenes)、节杆菌属(Arthrobacter)和短杆菌属(Brevibacterium)在细菌群落中存在较多的有效合作值(Effective Partners)和亲密度(Closeness),被其他细菌所依赖程度(Species Strength)较高,是该群落中的重要组成类群。【结论】织金洞内钟乳石沉积物表面存在丰富的细菌资源,分析细菌类群在群落中的作用应结合细菌相对丰度和网络分析。

Diversity and network analysis of culturable bacteria on stalactite sediment in Zhijin cave

[Background] There are abundant bacterial resources in the cave environment. The isolation and cultivation of bacteria in the cave helps for the understanding bacterial diversity, as well as the exploration and utilization of bacterial resources. [Objective] To isolate the bacteria by using different media, and to explore the diversity and interactions of cultivable bacteria on the stalactite surface in cave. [Methods] Totally, 11 kinds of media were used to isolate and purify the bacteria, then the taxonomic position of the isolates was preliminarily determined by analysis of their 16S rRNA gene sequence. Additionally, bipartite packet was used to analyze the interaction among the culturable bacteria under R environment. [Results] A total of 206 strains of bacteria were isolated from the samples. These bacteria belonged to 45 species of 4 genera and 25 genera in community with the Shannon index of 4.78 and the Simpson index of 0.95. Proteobacteria and Bacillus are the dominant phylum (47.09%) and genus (29.61%), respectively. The inorganic oligotrophic media were helpful for the isolation of bacteria from stalactite sediments in the cave. Based on genus level-sampling site network analysis shows that the distribution of culturable bacteria has a non-random and significant nestedness community. Bacillus, Devosia, Alcaligenes, Arthrobacter, and Brevibacterium with more effective cooperation and closeness in community are highly dependent on other bacteria, and are the key groups in the community. [Conclusion] There are abundant bacterial resources on the surface of stalactite sediments in Zhijin cave. The relative abundance and network analysis of different groups should be combined to determine the role of bacteria in communities.