Brown Bag Lunch Series: Family Feud: Intraspecific Antagonism in Microbial Community Assembly

In this presentation, Lon Chubiz will explore the consequences of antagonistic interactions between microbes during assembly of microbial communities. Many experimental and theoretical studies on microbial communities focus on how interactions between microbes from diverse species shape their assembly. Often overlooked are interactions between members of the same species. These interactions are frequently highly competitive and negative, in contrast to many interactions between species. In work shared here, Chubiz and coworkers use a collection of genetically barcoded Pseudomonas aeruginosa environmental isolates to experimentally characterize patterns of assembly in communities of varied complexity (2 to 15 members). A simple pairwise fitness-based model predicts several lower-order community assemblages but fails to predict outcomes for higher-order communities. Comparative genomics and experiments reveal that phages present in some, but not all, P. aeruginosa isolates are drivers of divergence between modeling and experiments. This study provides insights into the effects strong, negative interactions have on community assembly outcomes.