Bacterial interactions and secondary metabolites in plant and soil environment

Phylum Actinobacteriota represents one of the major phyla in plant and soil environments. Known for the ability to produce numerous secondary metabolites, Actinobacteriota may affect other bacteria and plants in various ways. The thesis aimed at assessing the connection between the production of secondary metabolites and interactions of actinobacteria in plant and soil environments. In the first part, we assessed how rare actinobacteria from acid soil affect cultivable soil bacteria. We isolated a collection of actinobacteria from acid soil dominated by previously uncultivable lineage and isolated a representative described as a new family Treboniaceae and multiple other potentially novel species of known genera. The genome and metabolome analysis of Trebonia kvetii, sp.nov. gen.nov., demonstrated its ability to produce unusual and potentially novel bioactive metabolites. We designed an experiment where a single strain was co-cultivated with the total soil bacterial community of the same soil in a set up, where a free exchange of diffusible metabolites was allowed between them. Three actinobacteria strains coming from distinct lineages were selected for this interaction. Each strain significantly and specifically affected cultivable bacteria as well as the metabolite pool, part of which was induced..