Graduate Students Mini Symposium I - 2026

13:15 h Nitin Bohra - AG Erb
Bottom-up assembly of self-regulated metabolic and genetic linked in vitro network

Cellular resource allocation and efficient utilization are paramount for the survival and functionality of living organisms. Central to this process is the regulation of gene expression in response to key metabolites, a fundamental strategy employed by the living cells. In this study we build an in vitro self-regulated metabolic and genetic linked network (MGLN) able to perform “decision-making” i.e., it autonomously activates its genetic layer upon producing a target metabolite. We achieved this goal by integrating the metabolism of the crotonylCoA/ethyl-malonyl-CoA/hydroxy butyryl-CoA (CETCH) cycle producing glycolate, with cell-free protein synthesis using recombinant elements (PURE). We demonstrate this concept by regulating gene expression with glycolate produced from CO2, and glycolate-inducible transcription factor GlcR from Paracoccus denitrificans. We are currently further optimizing such MGLN by using a machine-learning based algorithm (METIS), recently developed in our lab, for bottom-up assembling cell-free systems able to autonomously self-repair.

13:45 h Annabell Wagner - AG Junker

Functional trait differentiation dominates over taxonomic divergence in light-structured phyllosphere bacterial communities

The phyllosphere is one of the most important habitats for bacteria on the Earth’s surface. We investigated how bacterial communities associated with the leaf surface of Quercus robur respond to environmental conditions on a spatial and temporal scale using a trait-based approach. We collected samples from light-exposed and shaded leaves in a forest in Germany. We combined 16S amplicon sequencing with phenotypic trait information. Our results show that functional traits explain significantly more variation in bacterial communities than taxonomic composition. Overall, our results demonstrate that ecological strategies are the main driver of composition of phyllospheric bacterial communities rather than taxonomic identity.