Fahime Yaghooti, Ali Mohamadi Sani
Department of Food Science and Technology, Quchan Branch, Islamic Azad University, Quchan, Iran
Key words: Cotoneaster nummularioides, Cynodon dactylon, Cardaria draba, methanolic extracts, Antibacterial activity.
The present study aimed at evaluating the in vitro antibacterial activity of methanolic extract of Cotoneaster nummularioides, Cynodon dactylon and Cardaria draba against different pathogenic microorganisms. The agar disk diffusion method was used to study the antibacterial activity of C. nummularioides, C. dactylon and C. draba methanolic extracts against 2 gram-positive and 2 gram-negative bacteria at concentration 300 and 400 mg/ml. The results revealed that the methanol extract of C. nummularioides presented the highest zone of inhibition against tested pathogens (7-12 mm inhibition zones). Other plants did not show significant zone inhibition. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were quantified by micro-dilution method. The leaf extract of C. nummularioides against Bacillus cereus (PTTC 1015) and Staphylococcus aureus (PTTC 1431) strains showed the best activities, with the lowest minimal inhibitory concentration (MIC) of 3.125 mg ml-1 and MBC was 102.08 and 108.33 mg ml-1 respectively for Staphylococcus aureus (PTTC 1431) and Bacillus cereus (PTTC 1015). The results showed that the methanol extract of the herb has antibacterial activity and therefore it could be used as a natural preservative ingredient in food and/or pharmaceutical industries.