Psl polysaccharide deficient mutant

Analysis of Pseudomonas aeruginosa PA01 (ATCC 15692) Psl polysaccharide deficient mutant. Psl polysaccharide deficient mutant is evaluated with microarray to understand the genes affected by this polysaccharide. Our results provide new vision on the roles played by Psl polysaccharide in P. aeruginosa. Exopolysaccharide Psl is a critical biofilm matrix component in Pseudomonas aeruginosa, which forms a fiber-like matrix to enmesh bacteria communities. Iron has been shown to serve as a signal in P. aeruginosa biofilm development, yet how iron controls biofilm formation is not clear. Here we perform a transcriptomic analysis to compare Psl negative strain versus its isogenic wild-type strain PAO1. The results indicate that the expression of genes involved in iron homeostasis and oxidative stress response increased drastically at transcriptional level in Psl negative strain, suggesting Psl deficiency induces iron limitation. Subsequent studies confirm that Psl can efficiently bind iron in vitro and Psl fibers functions as an iron storage channel in P. aeruginosa biofilms. We used two wild type (WT) replicates and two mutant (MT) replicates to compare the differential gene expression.