Effect of Zataria multiflora Boiss. essential oil on lag phase of growth of Staphylococcus aureus in a brain heart infusion broth

The excessive use of chemical preservatives, many of which are suspect because of their potential carcinogenic and teratogenic attributes or residual toxicity, has resulted in increasing pressure on food manufacturers to substitute of them by natural ones e.g. plant essential oils. The study of the effects of plant essential oils on different growth kinetics of food borne pathogens or food spoilage microorganisms in different model systems is requested to establish the usefulness of them as a natural antimicrobial preservatives. In this study, lag phase of growth (Lag) of Staphylococcus aureus in Brain Heart Infusion (BHI) broth as affected by different concentrations of Zataria multiflora Boiss. essential oil (0.0, 0.03 and 0.06%) during 43 days storage at three temperatures (35, 25 and 15ºC) was investigated. The Lag of S. aureus affected significantly (p< 0.05) by different concentrations of the essential oil. The Lag of S. aureus in BHI broth with 0% essential oil at 35, 25 and 15ºC were 7.25, 15.25 and 82 h respectively. While in BHI broth with 0.03 and 0.06% essential oils were 34.05, 94.8 h and 235.5 and 44.5, 110.5 and >1032 h respectively.