Transcriptome response to nitric oxide in Pseudomonas aeruginosa

DNA microarray analysis was employed to investigate the transcriptome response to nitric oxide in Pseudomonas aeruginosa. We focused on the role played by the nitric oxide-response regulators DNR and FhpR and an oxygen-response regulator ANR in the response. The transcriptome profiles of the P. aeruginosa strains before and after exposure to nitric oxide under the microaerobic conditions were analyzed. Wild type, its anr, dnr, and fhpR mutants, and the anr mutant that express dnr were used for the analyses. Pseudomonas aeruginosa wild type (PAO1ut), anr mutant (RManr), dnr mutant (RMdnr), anr mutant that constitutively expresses DNR (RManrEXdnr), and fhpR mutant (PDM2665) were cultivated microaerobically in LB in 1-liter jar fermenter. When optical density at 600 nm reached 0.3, nitric oxide-saturated water was added to the medium (final nitric oxide concentration was 20 micro-M). RNA was isolated from a 10 ml aliquot of the culture prior to the addition of nitric oxide and at 5 min after the addition. The experiment was performed in duplicate independent cultures.