Influence of Iron, Biosurfactant and Quorum Sensing on Surface Motility and Biofilm Formation in Pseudomonas Aeruginosa
R. Glick, S. Satanower, O. Avidan, E. Banin
Mina and Everard Goodman Faculty of Life sciences, Bar-Ilan University, Ramt-Gan, Israel

Iron is an essential element for life but also serves as an environmental signal for biofilm development in the opportunistic human pathogen Pseudomonas aeruginosa. Under iron limited conditions P. aeruginosa displays enhanced twiching motility and forms flat unstructured biofilms. In this study we present evidence suggesting that quorum sensing-dependent iron-regulated production of the biosurfactant rhamnolipid is important to facilitate the flat unstructured biofilm phenotype. We show that under iron limitation, the quorum sensing system controlling rhamnolipid production is induced and the timing of rhamnolipid expression is shifted to the initial stages of biofilm formation (vs. later in biofilm developmen under iron-repleted conditions) and results in increase surface motility. In support, a mutant defective in biosurfactant production showed lower surface motility under iron restricted conditions and developed structured biofilms similar to those developed by the wild type under iron-replete conditions. These results highlight the importance of biosurfactant production in determining the mature structure of P. aeruginosa biofilms under ironlimiting conditions.

מיכל - 20.1.13
מאיה - 9.11.14
נטע - 2.4.20