Antifungal activity of cell-free supernatant
To evaluate the antifungal activity of cell-free supernatant,
the well diffusion method was used (Kalai-Grami et al.
2013). Disks of 4 mm diameter of 7 days old Botrytis
cinerea culture was cut and placed in the center of PDA
plates. Four wells of 4 mm diameter were punctured
around the fungus. One hundred ll of twofold serial dilutions
(1, 1/2, 1/4, 1/8) of cell-free supernatant or LB broth
(control) were deposited in each well. Plates were incubated
at 25 C for 7 days. The antifungal activity titer (AU
ml-1) was defined as the reciprocal of the highest dilution
that produced a detectable inhibition zone (Ben Slimene
et al. 2012