Iran has important potentialities in aromatic and medicinal plants because of the spontaneous flora; this is mainly connected to variety of its climate and nature of its grounds. The aromatic and medicinal plants are more and more used for several applications in pharmacy, medicine and food-processing therefore the necessity of their preservation. The genus Thymus (thyme) contains about 350 species of aromatic perennial herbaceous plants and sub shrubs 40 cm tall in the family Lamiaceae, native to temperate regions in Europe, North Africa and Asia. In this study, Thymus vulgaris were dried in shadow and appropriate condition. After extraction with water, antimicrobial effect of extract was determined by "Screening Antibacterial Activity" and "Disk Agar Diffusion Test" in 10, 20, 30 and 40 mg/ml of the extract against Staphylococcus aureus PTCC 2592. Statistical analysis was carried out by analysis of variance (ANOVA). The results showed that Thymus vulgaris extract in screening antibacterial activity method in 2000 μg/ml, inhibit Staphylococcus aureus growth. In "Disk Agar Diffusion Test, Thymus vulgaris watery extract, in 20, 30 and 40 mg/ml, the mentioned extract have shown inhibition of pathogen growth, but there was no inhibitry on 10 mg/ml. In conclusion The watery extract of Thymus vulgaris “in vitro” has a significant antimicrobial effect on gram-positive bacteria Staphylococcus aureus.

Keywords