Bacteria in semi-arid gypsum soils

We examined the distribution of bacterial taxa and traits in semi-arid Mediterranean gypsum soils to infer processes underlying the community assembly of soil bacteria. Particularly, we pyrosequenced a phylogenetic marker (16S rRNA gene) to identify bacterial taxa in plant patches (n = 15) and adjacent open spaces (n = 13). A total 24,486 sequencing reads were grouped into 3290 operational taxonomic units (OTUs) defined at 97 % sequence identity. The presence or absence of ten functional traits potentially relevant for the survival in either landscape component (plant patch vs. gap) were coded for each OTU based on a literature search. Soil samples were characterised using 11 physical and chemical variables.

本研究针对地中海半干旱石膏质土壤中的细菌类群与功能性状分布特征展开调查，旨在推断驱动土壤细菌群落构建的潜在过程。具体而言，我们通过焦磷酸测序（pyrosequencing）技术对系统发育标记基因16S rRNA基因进行扩增测序，以鉴定植物斑块（n = 15）与邻近开阔空地（n = 13）中的细菌类群。共计获得24,486条测序读段，按照97%的序列相似性阈值聚类为3290个操作分类单元（operational taxonomic units, OTUs）。本研究基于文献调研，为每个OTU编码了10种可能与两类生境（植物斑块与空隙生境）下的生存适配相关的功能性状的有无信息。同时通过11项物理与化学指标对土壤样品进行了理化性质表征。