(A) Anaerobic kinetic growth curves of B. pseudomallei cultured in LB medium. B. pseudomallei wild-type K96243 (black circle), bpsl1039 Tn mutant (white circle), bpsl1039/pME1039 (square) strains were grown, and the numbers of viable bacteria were determined by plating on LB agar to obtain colony forming units (CFU). (B) B. pseudomallei K96243, bpsl1039 Tn mutant and bpsl1039/pME1039 strains were cultured in LB medium without (-NaNO3) or with (+NaNO3) sodium nitrate supplementation under aerobic (+O2) or anaerobic (-O2) conditions. A 96-well plate was incubated for three days. The degree of biofilm formation of B. pseudomallei K96243 wild-type (black bar), 6H4 (white bar) and 6H4/pME1039 (striped bar) strains were measured using crystal violet stain at OD630 nm. Three biological replicates were used, each with eight technical repeats. Results are presented as standard errors of the means for experiments done in triplicate, with five independent experiments. Asterisks indicate significant differences (P < 0.05, t-test).