Deciphering biotic interactions and their role in soil microbial community assembly
Abstract
Soil microbial communities play key roles in ecosystem functioning. Yet, little is known about
the importance of microbe-microbe interactions in soil microbial community assembly and
functions. To address this knowledge gap, the objective of my thesis is to assess the role of
interactions between micro-organisms in soil microbial communities. For this purpose, we will
manipulate the interactions between microorganisms within complex soil microbial
communities by (i) removing different members of the soil community, (ii) adding microbial
taxa to the soil community and (iii) increasing the physical distance between members of the
soil community. How shifts in microbial interactions affect community assembly will be
determined after recolonization of sterile soil microcosms by the inoculated communities
during several weeks. The resulting communities will be analyzed by 16S rRNA and 18S rRNA
metabarcoding and bioinformatics tools such as network inference to identify the interacting
community members. The consequences on community functions will be assessed for C and N
cycles. This thesis project should allow unravelling soil microbial community assembly rules
and the assessment of community manipulation impact on soil functions, therefore paving the
way to steer soil microbial communities in agroecosystems.