Vibriobactin Mediated Biofilm Formation in Vibrio cholerae

Vibrio cholerae transitions between a free-swimming planktonic lifestyle and a multicellular community called a biofilm, which is used as protection from environmental stressors. The objective of this study was to analyze the role of vibriobactin in biofilm formation. These analyses utilized mutants defective in vibriobactin transport (viuA::tetR) or synthesis (?vibF) and were assayed in iron-replete (EZRDM) and -deplete (100 µg/ml EDDA) conditions. Our results show that biofilm cell density is significantly different between wild-type V. cholerae, viuA::tetR, and ?vibF over a period of 1-3 days in iron-replete and -deplete media. Confocal microscopy experiments using STYO-9 show that biofilm architecture and maturation is altered substantially in both viuA::tetR and ?vibF mutants compared to wild-type under iron-replete and -deplete conditions over a period of 1-3 days. Furthermore, competition indices show that viuA::tetR is outcompeted for space in biofilms by wild type and ?vibF is at a competitive advantage. Confocal microscopy experiments show that viuA::tetR and ?vibF have unique distributions in biofilms when mixed with wild type.