Nitrate and nitrite inhibit biofilm formation in Burkholderia pseudomallei, but require a functional NarX-NarL sensing system

Pellicle biofilms were grown in technical triplicate aerobically for 24 hrs at 37C. Strains of B. pseudomallei used include the wild type, Bp1026b, as well as independent deletions of gene coding regions for narX and narL. Conditions tested were LB media, LB + 10 mM NaNO3, and LB + 10 mM NaNO2. RNA from the technical reps were pooled into one biological replicate. Samples were collected on 4 separate days, corresponding to A,B,C,D designations on the sample names, to minimize batch effect. RNA samples were purified and depleted of genomic DNA and as much ribosomal RNA as possible. RNA-seq libraries of cDNA were made using ScriptSeq Complete v2 RNA-seq kit using ScriptSeq Index PCR primers. Sequences were generated on a Illumina NextSeq using the NextSeq 500 hi-output v2 75-cycle kit.