FIG 6.

Subinhibitory concentrations of DAPG inhibit spore formation in B. subtilis. B. subtilis liquid shaking cultures were grown with or without 2.23 μM purified DAPG and sampled at 24, 30, and 42 h of growth. Samples were lightly sonicated, divided into heated (80°C for 30 min) and unheated portions, diluted, and plated to count viable spores (heated portion) and all viable cells (unheated portion). The percent spores in each biological replicate was calculated and normalized to the values of the untreated samples for that experiment. The average fold change (in percent spores) for three biological experiments was then calculated for each time point. The dashed line indicates the normalized methanol control value of 1 (indicating equivalent percent spores formed between treated and untreated samples). Error bars represent standard deviations. Significance was calculated using a Student's t test. **, P < 0.005.