In the BOB project, the role of bacteriocins in shaping oral biofilms will be investigated by moving a Spanish researcher currently working in Ireland to the Norwegian University of Life Sciences. Bacteriocins are antimicrobial peptides produced by bacteria primarily known as killer peptides, and producing bacteria protect themselves expressing dedicated immunity proteins. The rise of whole-genome sequencing has revealed the presence of a large number of incomplete bacteriocin gene clusters in bacteria, and specifically, the presence of unpaired bacteriocin immunity genes. Little is known about the social role of bacteriocins and immunity genes. By using state-of-the-art bioinformatics, advanced genetic engineering techniques, biofilm assays and microscopy, BOB will interrogate how these components involve in microbe-microbe interactions during the formation of oral biofilms. First, an in silico analysis will give an overview of bacteriocin associated genes in oral streptococci. By construction of isogenic mutants and fluorescence labelling of strains, a set of biofilms will be studied to explore the role of these genes in biofilm formation. Initially, a biofilm model will be optimized using a known bacteriocin-producer and biofilm-forming Streptococcus mutans. Further the significance of unpaired immunity bacteriocin genes both in a mono and a mixed streptococcal biofilms will be examined. To gain a deeper understanding of how bacteriocin and immunity genes are regulated in oral biofilms, transcriptional reporters and RNA-seq will be performed. During the project, I will receive high-quality training through research that will significantly improve and complement my scientific knowledge and provide a strong platform for building an independent research career. The knowledge and competencies gained will help me achieve professional maturity and prepare me for a role as an independent researcher in the field of microbiology.