Phylogenetic and functional diversity of soil prokaryotic communities in temperate deciduous forests with different tree species

Supervisors: PD. Dr. Rolf Daniel (Main supervisor) and PD. Dr. Michael Hoppert

The soil environment is among the richest habitats for highly diverse microbial communities. Edaphic properties such as soil texture, soil pH, and nutrient supply from plant communities have a significant influence on the genetic and functional diversity of soil microorganisms. Soil is an important source of biotechnologically significant microorganisms and their gene products. However, the number of microorganisms obtained from it is limited when traditional culture-dependent methods are used. Metagenomics and metatranscriptomics are recent but rapidly growing fields that bypass the laboratory culturing phase to access a greater range of microorganisms in soil through the use directly isolated environmental DNA and RNA.
The aim of the project is to unravel the impact of tree species diversity on microbial community composition and function. Soil samples will be obtained from different forest stands of Hainich National Park (Thuringia, Germany). The project will look at bacterial and archaeal communities associated with the rhizosphere and the surrounding soil. On the basis of isolated metagenomic soil DNA, taxonomic composition of the entire prokaryotic community will be assessed by large-scale analysis of the 16S rRNA gene as the phylogenetic marker. To assess the active parts of the prokaryotic communities, 16S rRNA gene analysis will be based on isolated metagenomic RNA. In addition functional profiling of the soil microorganisms by large-scale sequencing of mRNA or functional genes will be performed. Data obtained from the DNA-based and RNA-based will be correlated to soil properties and data from analysis of soil carbon and nitrogen fluxes. In this way, phylogenetic and functional distribution profiles dependent on the tree species will be obtained and key players and functions will be identified.