Bacteriophages are still a relatively unknown component of the human microbiome. However, they can play a powerful role in the life cycles of bacteria. Biochemist Thomas Böttcher from the University of Vienna and PhD student Magdalena Jancheva were able to show for the first time how Pseudomonas bacteria use a self-produced signal molecule to selectively manipulate phages in a competing bacterial strain to defeat their enemy. This targeted control of phages provides entirely new biotechnological and therapeutic approaches, e.g. for phage therapies. The results produced in the context of an ERC grant have been published in the “Journal of the American Chemical Society”.