Developing LPS-targeting bacteriocins as strain specific antibiotics.

Since interactions between microbes can determine assembly dynamics within microbiomes, outcomes of these interactions have the potential to directly shape functional outputs of microbial communities. A deeper understanding of the molecules that drive these interactions may therefore enable fine scale manipulation of microbiomes in both clinical and agricultural settings. The Baltrus lab has surveyed a variety of strains of the phytopathogen Pseudomonas syringae for antagonistic activity against each other, and in this process have uncovered and characterized highly specific antimicrobials including tailocins (which are antimicrobials derived from phage tails) as well as Lectin-like bacteriocins. Using multiple genetic and genomic assays, identify that the lipopolysaccharide layers is the likely the binding site for both and characterize correlated evolutionary patterns behind that drive switches in targeting and sensitivity to both types of antimicrobials. Lastly, we demonstrate the potential for these molecules to be developed into prophylactic antibiotics to protect crops from colonization by clinical and agricultural pathogens.