ANTIMICROBIAL ACTIVITIES OF ESSENTIAL OILS FROM DIFFERENT PLANT-SPECIES

The antimicrobial activity of different plant extracts from lavandula angustifolia and Allium cepia is being studied. Essential oils are obtained either by steam distillation or by ethanol extraction. Two successive extractions are generally made on each sample. Three antibacterial tests are used to determine the efficacy of plant extracts on different bacteria. We have also looked for fungicide activity of extracts on yeast as well as in filamentous fungi using the AFNOR NF X 41-514 standard. The different extracts inhibit the growth of Bacillus stearothermophilus. The Lavandula extracts are more active than the onion extracts. We have also tested the efficiency of extracts of 4, 7 and 25 days old in order to determine the stability of extracts time. Onion extracts show a good stability during time conservation at room temperature. On the contrary, the activity of Lavandula extracts decrease with time except for sample obtained after the second ethanolic extraction. Our experiments show that lavender extracts have a broader bactericide spectra than onion extracts. Moreover, two Lavandula extract have an activity against salmonella. The extract efficacity on Bacillus subtilis depends on the pH value. In general, extracts are more efficient at pH 7.2.