FIG 7.

Inhibitory effect of PVD compounds on B. megaterium on standard SM plates (top) and the deferrated SM plates (bottom). Here, 50% methanol was used as the control. B. megaterium was precultured in liquid standard SM or the deferrated SM at 28°C for 24 h to the desired cell density of 2 × 10⁸ CFU/ml and then evenly sprayed onto the surface of standard SM plates and deferrated SM plates for 1 s. Subsequently, 10, 25, 50, and 100 μl of PVD compounds were injected into the central hole of deferrated SM plates, respectively. The diameters of the inhibitory zones were measured when B. megaterium covered the entire control plates.