Role of ecological interactions on diversification of coexisting species in microbial communities

This research project aims to experimentally determine the role of cross-feeding interactions in driving adaptive dynamics in microbial communities. Using two bacterial species, where Acinetobacter johnsonii cross-feeds resources to Pseudomonas putida, the specific goals are to (1) assess the conditions promoting phenotypic and genotypic divergence by evolving cross-feeding consortia under lab conditions over 800 generations; (2) characterize fitness tradeoffs and test frequency-dependence selection; and (3) assess co-evolution by tracking the fate of adaptive mutations in populations. To achieve this, the researchers employ a combination of experimental evolution, physiological assays, whole genomes and population sequencing, and reciprocal invasion experiments. This research provides an exceptionally comprehensive characterization of how species interactions shape evolutionary dynamics improving our ability to predict evolution in natural microbial communities.