Modeling the growth of Staphylococcus aureus as affected by black zira (Bunium persicum) essential oil, temperature, pH and inoculum levels

Black zira (Bunium persicum) is a medicinal plant and spice, naturally grows in Iran. The aim of this study was to investigate the combined effects of different concentrations of Bunium persicum essential oil (EO; including ۰, ۰.۰۸, ۰.۱۶ and ۰.۲۴%), three incubation temperatures (۱۵, ۲۵ and ۳۵˚C), three levels of pH (۵, ۶ and ۷ adjusted by hydrochloric acid), and three inoculum size (۱۰۲, ۱۰۳ and ۱۰۴ CFU mL-۱) on the growth of Staphylococcus aureus in the brain heart infusion broth. Black zira EO was extracted and its component was identified using gas chromatography-mass spectrometry (GC-MS) analyses. The experiment was carried out in triplicate. Growth was monitored by visible turbidity during a ۳۰-day period. To evaluate effects of explanatory variable on time to detection (TTD) of bacterial growth, parametric survival models based on Log-normal distribution was used. All explanatory variables had significant association with time to detection (p < ۰.۰۵). The final model accurately predicted the growth initiation and inhibition of S. aureus.

کلیدواژه ها:

Black zira ، essential oil ، predictive modeling ، Staphylococcus growth