Transcriptome response to nitrosative stress in Rhodobacter sphaeroides 2.4.1. Cereibacter sphaeroides 2.4.1

DNA microarray analysis was employed to investigate the transcriptome response to nitrosative stress in a non-denitrifying facultative photosynthetic bacterium Rhodobacter sphaeroides 2.4.1. We focused on the role played by a nitric oxide-response transcriptional regulator NnrR in the response. The transcriptome profiles of R. sphaeroides 2.4.1 and its nnrR mutant before and after exposure to nitrosating agents S-nitrosoglutathione (GSNO) or sodium nitroprusside (SNP) under semiaerobic conditions were analyzed. Overall design: R. sphaeroides 2.4.1 and its nnrR mutant were cultivated in glass bottles under semiaerobic growth conditions. When the optical density at 600 nm reached approximately 0.15-0.2, 1 mM GSNO or SNP was added to the medium. RNA was isolated from a 50 ml aliquot of the culture prior to the addition of GSNO or SNP and at 15 min after the addition. The experiment was performed in duplicate independent cultures.