FIG 2.

Inactivation of nlpD affects colony morphology and cell growth and viability. Representative stereomicroscope images show parental (A and C), ΔnlpD mutant (B and D), and complemented strain in the presence (E) or absence (F) of IPTG to regulate nlpD expression after 22 h of growth. Addition of IPTG recapitulates the parental colony morphology. (G) Growth curve of FA1090, ΔnlpD, and ΔnlpD::nlpD complemented strain with or without IPTG grown on a solid medium and measured as CFU per colony at the indicated times for six independent colonies of each strain. Error bars represent the standard error of the mean. Representative micrographs of NlpD+ (G) and NlpD− (H) subjected to BacLight live/dead stain. Red cells are dead, green cells are alive, and cells that appear yellow are likely two cells (one live, one dead) on top of one another in the visual field.