Transcriptional profiling of Pseudomonas aeruginosa WT and Pho mutant colony biofilms in response to ethanol and Candida albicans

Pseudomonas aeruginosa is an opportunistic pathogen frequently isolated from co-infections with Candida albicans and other ethanol-producing organisms. We found that ethanol, including that produced by C. albicans, stimulates the PhoB regulon in P. aeruginosa. We identify a subset of PhoB-regulated genes as differentially expressed in response to ethanol which are slightly different than the set of genes with increased expression in a genetically induced low phosphate response via pstB mutation. Genome-wide transcriptional profiles of Pseduomonas aerguinosa after growth for 24 hours in colony biofilms on minimal media with or without 1 % ethanol or in co-culture with ethanol-producing (adh1∆/ADH1) or non-ethanol-producing (adh1∆/∆) Candida albicans.