This year’s iGEM Darmstadt team is working on project PHIRE BYRD – Phage mediated Immune Response by Recognizing Defensive Sleeper Cells. Multi drug resistant pathogens are becoming an increasing problem in multiple areas, especially when combined with resilient biofilms. Our main achievement is to add an additional safety layer to existing, non-pathogenic biofilms: We want to biotechnologically engineer our biofilm-forming host organism B. subtilis to automatically sense pathogens threatening the biofilm using quorum sensing (QS) signaling molecules. This genetic circuit triggers the production of lytic bacteriophages targeting the pathogenic bacteria. This way we want to create a modular system that is easily expandable to multiple pathogenic bacteria. Additionally, we are working on a QS based kill-switch to tackle the problem of unintentional release of GMOs into the environment. Finally, we are working on software solutions to greatly simplify the expansion of existing biotechnological biofilm applications with our additional safety layer.