Prokaryotic Diversity Changes and their Functional Interrelation to Land Use (ProFIL)

到目前为止，细菌多样性的功能相关性的研究主要限于几组参与N-循环和根际细菌的变形菌。前一个资助期的结果显示，酸杆菌占三个勘探站土壤中所有细菌的64%，酸杆菌的比生理活性出乎意料地高，特别是在Schwäbische Alb.使用三个勘探站的土地利用梯度作为主要变量，我们建议对组成进行详细研究，生理关键性状和酸菌多样性的功能意义。为了确定酸杆菌多样性和活性的决定因素，将对所有300个实验地块的样品进行核糖体RNA基因的深度测序和核糖体含量的定量，并通过多变量统计分析研究其与环境参数的相关性。将对选定地块的酸细菌群落结构的空间和短期时间变异性的影响进行研究。通过分析现有的宏基因组文库和表征代表性菌株，将获得关于优势土壤酸菌代谢特征的新信息。酸细菌在土壤碳和氮循环中的功能多样性和作用将使用稳定同位素探测和捕获探测结合的碳底物来解决。

So far, studies of the functional relevance of bacterial diversity have mostly been limited to a few groups of Proteobacteria involved in the N-cycle and to rhizosphere bacteria. Results of the preceding funding period revealed that Acidobacteria represent up to 64% of all bacteria in soils of the three exploratories and that the specific physiological activity of Acidobacteria is unexpectedly high particularly in soils from the Schwäbische Alb. Using a land use gradient across the three exploratories as the major variable, we propose to conduct a detailed study of the composition, physiological key traits and the functional implications of Acidobacteria diversity. In order to identify the determinants of Acidobacteria diversity and activity, deep sequencing of ribosomal RNA genes and quantification of the ribosome content will be conducted for samples from all 300 experimental plots and their correlation with environmental parameters will be investigated by multivariate statistical analyses. The effects of spatial and short-term temporal variability of the Acidobacteria community structure will be studied for a selected plot. Novel information on the metabolic traits of dominant soil Acidobacteria will be obtained by analyses of existing metagenomic libraries and by characterizing representative isolates. The functional diversity and role of Acidobacteria in the soil carbon and nitrogen cycles will be resolved using a combination of stable isotope probing and capture probing of incorporated carbon substrates.