Effect of mucins on phage-host interactions in Bacillus subtilisJakin Lazar, Jaka (Avtor) Dragoš, Anna (Mentor) phage-host interactionsbacteriophagesmucinsBacillus subtilisThis thesis investigates the influence of mucins on phage and bacterial attachment, biofilm formation, and phage-bacteria interactions. The study focuses on Bacillus subtilis, a non-pathogenic bacterium commonly found in soil, plant rhizosphere and animal gut, and Vibrio anguillarum, a fish-pathogenic bacterium commonly found in marine environments. The experimental procedures encompassed a phage-attachment assay, confocal laser scanning microscopy, and flow cytometry, to determine phage and bacterial adherence to mucin-coated surfaces. Metabolic activity of attached bacterial cells was assessed through oxygen consumption rate measurements. The findings reveal that lytic Bacillus phages exhibited significantly greater attachment to mucin-coated surfaces in comparison to agar surfaces. Moreover, the attachment of B. subtilis and V. anguillarum cells increased on mucin-coated surfaces compared to non-coated surfaces. However, the attachment of V. anguillarum cells to mucin diminished in the presence of phages, in contrast to B. subtilis, where the positive effect of mucin on attachment persisted even when phages were present. Enhanced attachment to mucin was also supported by increased metabolic activity of surface-attached biomass, measured via oxygen consumption rates. Furthermore, B. subtilis biofilms formed on mucin-coated surfaces exhibited a more 3D complex structure compared to surfaces coated solely with phages, even in the presence of mucin. The work supports previous findings of Bacteriophage Adherence to Mucus (BAM) model, extending it new beneficial and pathogenic bacterial species. It also reveals that in different phage-host systems, mucins have different effects on phage-host interactions, which may have implications for phage therapies or probiotic treatments strategies.20232023-09-17 07:17:09Magistrsko delo/naloga150426VisID: 230038COBISS_ID: 164979715sl