Fig. 1.

Conditioned medium from B. subtilis pellicles is selectively toxic towards potential competitors. A) Monitoring pellicle formation and growth of the indicated strains when grown in MSgg medium and MSgg medium supplemented with conditioned medium (CM) from WT B. subtilis in increasing concentrations (10%, 25% and 50% v/v). Cells were grown at 30 °C and images were obtained at 72 h post inoculation and are representative of data presented in B. B) The number of CFU obtained when indicated strains were either grown in MSgg medium or MSgg medium supplemented with conditioned medium (CM) from WT B. subtilis in increasing concentrations (10%, 25% and 50% v/v). Cells were grown at 30 °C, and were harvested at 72 h post inoculation. Graphs represent mean ± SD from three independent experiments (n = 9). Statistical analysis was performed using Brown-Forsthye and Welch’s ANOVA, with Dunnett’s T3 multiple comparisons test. P < 0.05 was considered statistically significant. Scale bar = 5 mm.