Figure 3.
Expression of the motility genes is required for B. subtilis engulfment and killing of B. simplex biofilms. (a) upper—B. subtilis WT strain inoculated on MSgg biofilm-inducing medium at a distance of 0.8 cm from B. simplex. middle—B. subtilis ΔmotAB mutant inoculated at distance of 0.8 cm from B. simplex. lower—B. subtilis Δhag mutant inoculated at distance of 0.6 cm from B. simplex. Biofilms were grown for 3 days at 30 °C. Scale bars represent 2 mm. (b) Phag-gfp expression. B. subtilis Phag -gfp strain inoculated on biofilm-inducing medium at a distance of 0.8 cm from a B.simplex biofilm grown for 2 days at 30 °C. Scale bars represent 2 mm. (c) Colony forming units counts of B. simplex taken 3 days post inoculation next to B. subtilis WT (distance of 0.8 cm) or B. subtilis Δhag mutant (distance of 0.6 cm), as in a. The interacting colonies were collected, sonicated and plated to determine the number of replicative cells. n=3, error bars represent s.d.