Antimicrobial Activity of Some Essential Oils on Streptococcus Bovis (ES1) Isolated From Rumen Fluid

Abstract

Different substances are used to either eliminate or decrease thenumbers of rumen bacteria to alter their makeup. Essential oils (EO) are one ofthe substances used for this purpose. The present study was carried out todetermine the effects of EO extracted from orange peel (Citrus cinensis),cinnamon (Cinnamomumverum), Laurel (Laurusnobilis), oleaster(Eleagnusangustifolia), garlic (Allium sativum) and thyme (Tymusvulgare) onStreptococcus bovis (ES1). For this purpose, bacterial growth was measured byinoculating stock cultures grown in Hobson's M8 medium with a three-foldincreasing series of EO. Essential oil diluted in autoclaved water containing10% DMSO was added aseptically after the medium was autoclaved to give finalconcentrations ranging from 50 to 5,000 ppm (0.5 ml to each 6.5 ml of M8).Bacterial growth was measured by reading the optical density at 650 nm hourlyuntil the reading for bacterial growth decreased. Maximal bacterial growth ratewas calculated using the MicroFit v 1.0. The results show that the effects ofessential oils, doses and dose-oil interactions used in the study arestatistically significant. According to the results, garlic and cinnamonessential oil have strong antimicrobial activity on Streptococcus bovis (ES1).