Essences and extracts of herbs, possess a variety level of biological activities, in addition the antimicrobial activities of a large number of these have been proved. With regard to the biologically active compounds and traditional use of the Satureja bachtiarica, it seems that this plant has significant antimicrobial effects. Objectives: The aim of this study is to evaluate the antimicrobial effect of aqueous and ethanolic extracts of S. bachtiarica against Enterobacter aerogenes, Bacillus

more »

... tilis and Listeria innocua of the important food pathogen. Materials and Methods: In this experimental study, antimicrobial effect of extracts was evaluated by two methods, Collins method and disk agar diffusion method on Enterobacter aerogenes ATTC 13048, Listeria innocua ATTC 33090 and Bacillus subtilis PTCC 1720. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) determined using a dilution method. Statistical analysis was carried out by analysis of variance (ANOVA) technique. Results: All ethanolic extract concentrations had an inhibitory effect on the disk agar diffusion method. In Collins method ethanolic extract, prevented the growth of both strains on medium. The MBC of ethanolic extract of S. bachtiarica for B. subtilis and L. innocua was 16 and 32 mg/mL respectively, and for E. aerogenes was 64 mg/mL. But the MBC of aqueous extract of S. bachtiarica for B. subtilis and L. innocua was 32 and 64 mg/mL, respectively and for E. aerogenes was 128 mg/mL. Conclusions: The S. bachtiarica extract showed the more effective impact on the growth of B. subtilis PTCC 1720 and L. innocua ATTC 33090 than E. aerogenes ATTC 13048 (P < 0.05). The results indicated that ethanolic extract of S. bachtiarica had maximum effect on Gram positive bacteria B. subtilis PTCC 1720 and L. innocua ATTC 33090.