正红菇菇位土壤可培养细菌多样性与网络结构分析

Diversity and Network Structure Analysis of Culturable Bacteria in Sporophore Site Soil of Russula griseocarnosa

【目的】通过对正红菇菇位土壤细菌的分离培养,探究其可培养细菌的多样性及其种间互作关系,为后续筛选促进正红菇菌丝体生长和子实体形成分化的菌根促生菌奠定基础。【方法】利用LB和ISP2两种培养基通过传统分离培养的方法对正红菇菇位土壤中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,使用R语言中的Bipartite包分析可培养细菌属间的相互作用。【结果】6份正红菇菇位土壤中共分离出128株细菌,隶属于3门16属34个OTUs,丰度最高的3个属分别是芽孢杆菌属、伯克霍尔德氏菌属和链霉菌属。属水平-采样品网络分析表明,可培养细菌分布具有随机的嵌套性。Bacillus属和Burkholderia属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】正红菇菇位土壤中具有丰富的细菌资源,细菌的群落组成和网络结构相结合分析可以更清晰阐明细菌间的相互作用关系。

【Objective】The diversity of culturable bacteria and their inter-species interactions were explored by isolating and culturing sporophore site soil bacteria of R.griseocarnosa.It provides insights into the mycorrhizal helper bacteria which may promote the growth of the mycelium and the formation and differentiation of sporophore of R.griseocarnosa.【Methods】The bacteria in the sporophore site soil of R.griseocarnosa were isolated and purified by traditional methods of separation and culture using LB and ISP2 media,and the species of the isolated strains was preliminarily identified by 16S rRNA gene sequence analysis.Interactions between culturable bacterial genera were analyzed using the Bipartite package in R.【Results】A total of 128 strains of bacteria were isolated from 6 sporophore site soils of R.griseocarnosa,which belonged to 34 OTUs(16 genera of 3 phyla).The three genera with the highest abundance were Bacillus,Burkholderia and Streptomyces.Genus-level-Sample network analysis showed that the distribution of culturable bacteria was randomly nested.Bacillus and Burkholderia are important groups in the community,which have more Effective Partners,Closeness and high Species Strength in the bacterial community.【Conclusion】There are abundant bacterial resources in the sporophore site soil of R.griseocarnosa.Combining the analysis of bacterial abundance and network structure can predict the interaction between bacteria more clearly.