FIG. 4.

Biofilm formation by the aniA::kan mutant is enhanced in the presence of DETA/NO. (A) Biofilm mass of N. gonorrhoeae strain 1291 aniA::kan in the absence of nitrite (1) and in the presence of 20 μM DETA/NO (2) after 2 days of growth. Experiments were performed a minimum of three times, and a representative result is depicted in panel A. N. gonorrhoeae was visualized by GFP expression, and these images are three-dimensional reconstructions of stacked z series taken at a magnification of ×200 and rendered by Volocity. (B) Graphs showing COMSTAT analyses of biomass and average and maximum thickness. Statistical differences between biofilms with and without nitrite were determined via Student's t test (P < 0.001).