Interactions and Community Dynamics in Multi-species Communities of Soil Bacteria

2015 - presentpresent

Given the great diversity of many natural communities, there is a fundamental interest in understanding the eco-evolutionary processes that lead to diversification. Multiple microcosm experiments have demonstrated that microbial diversifications can be fast and thus successfully studied in the lab. Most of this work has studied diversifications within single-species communities resulting from adaptations to available abiotic niches. However, in complex multi-species communities the eco-evolutionary dynamics may be driven by dynamic biotic factors and niches can emerge due to ecological interactions. Laboratory evolution studies in such contexts have been limited by the lack of suitable model systems and monitoring tools. To address this gap, a novel high-throughput approach is introduced that allows systematic investigation of changes in interactions as they spontaneously arise in multi-species laboratory communities. The proposal focuses on bacteria from the genus Streptomyces, which are prolific producers of interaction mediating secondary metabolites, and investigates the ecological and evolutionary dynamics in a large numbers of multi-species communities. A basic hypothesis that will be tested is that Streptomyces experiencing a novel and interaction-rich multi-species context are under strong selection to evolve and diversify their ecological interactions. The dependence of ecological diversity of beneficial mutants on species richness will be examined and the hypothesis that biotic selection pressures themselves evolve in the ecosystem will be investigated. Overall, the project will elucidate of the intimate relationship between ecological dynamics and evolutionary trajectories in interaction-rich communities.