Modeling the growth of Staphylococcus aureus as affected by black zira (Bunium persicum) essential oil, temperature, pH and inoculum levels
نویسندگان
1 Department of food hygiene and Aquaculture, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
2 Health Science Research Center, Department of Occupational Health Engineering, School of Health, Mashhad University of Medical Science, Mashhad, Iran
3 Department of Food Hygiene and Aquaculture, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
4 Department of Horticulture, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
5 Department of Clinical Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran.
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چکیده
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 0, 0.08, 0.16 and 0.24%), three incubation temperatures (15, 25 and 35˚C), three levels of pH (5, 6 and 7 adjusted by hydrochloric acid), and three inoculum size (102, 103 and 104 CFU mL-1) 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 30-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 < 0.05). The final model accurately predicted the growth initiation and inhibition of S. aureus.
