Figure 3.

Effect of different amounts of AHL extract on PM production (A) and initial growth rate (B) of R. rubrum. Cell-free supernatants from the stationary phase of a microaerobic Fed-Batch cultivation, in which PM production is completely inhibited, were extracted with dichloromethane, evaporated to dryness and resuspended in acetonitrile (ACN). Different volumes of AHL extract (black bar) or ACN (gray bars) were added to the culture at the point of PM induction (A) or prior to inoculation (B). Initial growth rates of cells were calculated from data obtained from the first 20 hours of the experiment. Growth conditions are comparable to those used for Figure 2. The shown data represent the average of two biological replicates (two shake-flask cultivations of each extract amount were cultivated at the same time. The extract used in this experiment was obtained from the harvest of one Fed-batch cultivation). Error bars were calculated by error propagation of the deviations of three equivalent experiments (for each experiment extracts from one Fed-Batch cultivation were supplemented to shake-flask cultures).