Study the antimicrobial effects of ethanolic extract of Thymus vulgaris on foodborne bacteria in vitro

Subject Areas : Industrial Food Microbiology

Meysam Alimoradi ¹ , Mehrdad Ataie Kachoie ² , Fariborz Moattar ³

1 - Department of Medicinal Plants, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran.
2 - Department of Medicinal Plants, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran.
3 - Department of Pharmacology, School of Pharmacy, Isfahan University of Medical Sciences, Isfahan, Iran.

Received: 2021-02-13 Accepted : 2021-05-03 Published : 2022-06-22

Keywords: Foodborne bacteria, ethanolic extract, Thymus vulgaris, Antimicrobial Effects,

Abstract :

Thymus vulgaris is a plant of family Lamiaceae that has high antimicrobial properties. The present study was performed to evaluate the antimicrobial effects of the ethanolic extract of Thymus vulgaris on food-borne bacteria. Aerial part of Thymus vulgaris was used to prepare methanolic extract. The diameter of the growth inhibition zone of bacteria was assessed using disk diffusion. Minimum inhibitory concentration (MIC) and Minimum Bacterial Concentration (MBC) of ethanolic extract of Thymus vulgaris were evaluated on the target bacteria using ELISA plate. The diameter of the growth inhibition zone of bacteria against the ethanolic extract of Thymus vulgaris ranged from 7.87±0.61 to 16.99±0.37 mm. Application of 50 mg/ml concentration of ethanolic extract of Thymus vulgaris caused the highest diameter of the growth inhibition zone of Pseudomonas aeruginosa (11.38±0.43 mm), Escherichia coli (12.00±0.35 mm), Staphylococcus aureus (16.33±0.69 mm) and Listeria monocytogenes (16.99±0.37 mm). The antimicrobial effects of ethanolic extract of Thymus vulgaris were dose-dependent (P <0.05). The diameter of growth inhibition zone of 50 mg/ml of ethanolic extract of Thymus vulgaris on Pseudomonas aeruginosa, Staphylococcus aureus and Listeria monocytogenes was higher than all antibiotics (P <0.05). The lowest MIC and MBC values were obtained for Staphylococcus aureus (4 and 6 mg/ml, respectively) and Listeria monocytogenes (4 and 6 mg/ml, respectively). Thymus vulgaris ethanolic extract can be used as a combination with antimicrobial properties in food.