The role of menthe piperita essential oil on rumen lactobacillus

Introduction: A research project was performed to examine the inhibitory effects of essential oil of Peppermint (Mentha piperita) on performance of ruminal Lactobacilli as the main bacteria engaged with acidosis in ruminants. In order to evaluate the effect of Mentha piperita essential oil on isolated Lactobacillus involve with rumen acidosis, rumen fluid sample was collected from the rumen of a caw equiped with fistula permanent. Some of plants produce a wide variety of organic compounds as secondary metabolites with antimicrobial characteristics.Methods: In this research, the effect of essential oil from the Mentha piperita extracted by the Clevenger apparatus, on isolated Lactobacilli from rumen of cows fed by a diet containing ۶۵% concentrate and ۳۵% forage studied. The rumen fluid was filtered by using the Hungate roll tube technique and double layer of muslin cloth. Bacterial isolation was done according to the standard methods. The lactobacillus identification at genus level were done using special culture media of MRS, and colonies selected and distinguished based on their size and morphology as well as catalase, oxidase and Gram staining tests. Complementary test experiments including biochemical, fermentation of carbohydrates, arginine hydrolysis, study of bacterial growth in different conditions with regards to environmental temperature and pH, sodium chloride concentration and CO۲ production from glucose were performed. The effect of M.piperita essential oils was done using the agar cup test. The antibacterial effects of essential oil were evaluated by using well diffusion agar method and measuring the inhibitory zone diameter in comparison with the control samples (distilled water).Results and Discussion: Thirty-six colonies of lactobacilluse genus were identified according these characteristics. It was confirmed that heterofermentative Lactobacillus with a proportion of ۵۸% were more than the homofermentative lactobacillus (۴۲%) following running purification and biochemical tests of arginine hydrolysis and fermentation of carbohydrates and co۲ production from glucose. Based on similarity biochemical and growth characteristics the ۳۶ isolated lactobacillus were classified into ۱۵ groups and ۳ stories. All the ۱۵ isolated groups of lactobacillus and Lactobacillus plantarum (standard strain) were sensitive to peppermint essential oil based on the characteristics of colonies.Conclusion: All the ۱۵ isolated groups of lactobacillus and Lactobacillus plantarum were sensitive to peppermint essential oil More in vivo experiments are required for reaching to the practical application of M.piperita essential oil utilization against the involved lactobacillus with rumen acidosis. However, due to the proven effectiveness of essential oils on pure culture of Lactobacilli in laboratory tests, it was concluded that these essential oils can be effective for acidosis reduction or control in ruminants, but more experiments with higher level of essential oils and larger size of animal groups are required in in vivo conditions.

کلیدواژه ها:

Menta Piperita ، Lactobacillus ، Essential Oil ، Rumen