To determine the effects of S. parasanguinis and nitrite on the P. aeruginosa denitrification transcriptome, RNA sequencing was performed on two different isolates of P. aeruginosa— a lab adapted acute wound isolate, PAO1, or a lab adapted chronic CF isolate, FRD1— in the presence or absence of either 0.5mM nitrite, S. parasanguinis, or the combination of nitrite and S. parasanguinis.Figure 1C shows the relative gene expression of the relevant reductase genes along with the anaerobic nitrate reduction regulator gene (anr) and the catalase gene (katA) that is responsive to H2O2. This evidence concerns the gene CAT and cystic fibrosis.