The disk diffusion test was performed using the procedure as described
by Jorgensen et al., 1999. The inoculum suspension of each
microbial strain was swabbed on the entire surface of Mueller-Hinton
agar (MHA, Difco) for bacteria and SDA for yeasts. Sterile 6 mm
filter paper discs were aseptically placed on MHA and SDA surfaces.
Crude methanolic extracts (15 µl) were immediately added to
discs. A 15 µl aliquot of 10% DMSO was also added to a sterile paper
disc as a negative control. Penicillin G (10 unit/ml) and amphotericin
B (10 mg/ml) were used as positive controls. The plates were
left at ambient temperature for 15 min to allow excess prediffusion
of extracts prior to incubation at 37°C for 24 h for bacteria and at
30°C for 72 h for yeasts. Diameters of inhibition zones were measured.
The experiment was done in triplicate.