Investigation on Antimicrobial Activity of Punica granatum Linn . Acetone Peel Extract

The present study evaluated the antibacterial activity of Punica granatum Linn. acetone peel extracts against human pathogenic bacterial strains and antifungal activity was evaluated against plant pathogenic fungus Pyricularia oryzae. Different concentrations (10, 20 and 30 mg/mL) of the acetone peel extracts were tested against pathogenic bacterial strains namely Bacillus cereus, B. subtilis, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. Antibacterial activity was measured using diffusion disc plates on agar. Inhibition diameters were measured after incubation for 24 to 48 h at 37°C. Blanks of solvent processed in the same way were also tested for antibacterial activity. The antifungal activity was carried out by using five different concentrations (50, 100, 150, 200 and 250 mg/mL) of P. granatum acetone peel extract against the test plant pathogenic fungus Pyricularia oryzae. Acetone peel extract of Punica granatum showed significant activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis and B. cereus in all the three concentrations tested. Maximum inhibitory zone was found against Bacillus cereus (35±0.40 mm) where as minimum inhibitory effect was recorded against B. subtilis (7±0.15 mm) at 10 mg/mL concentration. It was noted that acetone peel extract inhibited the growth of test fungi with increase in the concentration of the extract. Maximum zone of inhibition (mycelial dia of 11±0.20 mm) was found in 250 mg/mL concentration whereas, lowest inhibition (mycelial dia of 69±0.20 mm) was found in 50 mg/mL concentration. The present study showed interesting antimicrobial activity and further characterization may be carried out to test the acetone peel extracts for various therapeutic and pharmacological activities.