Investigating The Role Of Putrescine Transport And Biosynthesis In Vibrio Cholerae Biofilm Formation.

Biofilms are structures formed by most bacteria, and in Vibrio cholerae they provide protection and passage through the gastric acid barrier. V. cholerae is the causative agent of the cholera disease. Formation of biofilms is regulated by a wide variety of signals, one being polyamines. In V. cholerae, norspermidine and spermidine have been shown to affect biofilm formation; however, putrescines role in regulating biofilm has not been studied. This research focused on the proposed putrescine transport system, PotE, and the two putrescine biosynthesis pathways. The objectives of this study were: characterize PotE and confirm that it is a putrescine/ornithine antiporter, determine the effect that putrescine has on biofilm formation in V. cholerae, and determine the effect that inhibiting the putrescine transport and biosynthesis pathways has on polyamine concentrations in V. cholerae. My results indicate that under most growth conditions tested putrescine does not appear to have an impact on biofilm formation in V. cholerae. There is one exception, wild type V. cholerae grown at a low pH with excess ornithine form less biofilms than wild type without ornithine or potE. Additionally, I was able to confirm that PotE is a putrescine/ornithine antiporter, the first confirmed putrescine transporter in V. cholerae.