PT - JOURNAL ARTICLE AU - A. Dal Co AU - S. van Vliet AU - D. J. Kiviet AU - S. Schlegel AU - M. Ackermann TI - Short-range interactions govern the dynamics and functions of microbial communities AID - 10.1101/530584 DP - 2019 Jan 01 TA - bioRxiv PG - 530584 4099 - http://biorxiv.org/content/early/2019/10/21/530584.short 4100 - http://biorxiv.org/content/early/2019/10/21/530584.full AB - Communities of interacting microbes play important roles across all habitats on earth. These communities typically consist of a large number of species that perform different metabolic processes. The functions of microbial communities ultimately emerge from interactions between these different microbes. In order to understand the dynamics and functions of microbial communities, we thus need to know the nature and strength of these interactions. Here, we quantified the interaction strength between individual cells in microbial communities. We worked with synthetic communities of Escherichia coli bacteria that exchange metabolites in order to grow. We combined single-cell growth rate measurements with mathematical modeling to quantify metabolic interactions between individual cells and to map the spatial interaction network within these communities. We found that cells only interact with other cells in their immediate neighborhood. This short interaction range limits the coupling between different species and reduces their ability to perform metabolic processes collectively. Our experiments and models demonstrate that the spatial scale of biotic interaction plays a fundamental role in shaping the ecological dynamics of communities and the functioning of ecosystems.