FIG 3.

eDNA is released by bacterial lysis into the supernatant of growing C. perfringens biofilms. Strain CN3685 was inoculated in 24-well plates containing TGY, followed by incubation at 37°C for the indicated times, after which 1 ml of supernatant was removed. (A) eDNA was purified and quantified utilizing qPCR. In another set of experiments, 4- or 8-h biofilms (B) or planktonic cells (C) were stained using a Live/Dead BacLight kit, and fluorescence arbitrary units were obtained using a fluorometer. *, Statistical significance (P < 0.05), evaluated by the Mann-Whitney U test, compared to live bacteria. Biofilms (D) or 8-h planktonic cultures (E) were also photographed with an Evos inverted microscope using the light-cube green fluorescent protein 470/510 (live) or red fluorescent protein 531/593 (dead). The scale bar at the upper right applies to all panels.