Antimicrobial Activities of Coriandrum sativum, Anethum graveolens and Linum usitatissimum Essential Oil-Nanoemulsions For Use as Alternatives Food Preservative

Bacterial infectious diseases are still one of the main causes of death and severity of bacterial infections, which have markedly gone up mainly due to the emergence of multidrug resistant bacteria. The aim of this study was to prepare nano-emulsions using Coriander and Dill and Flaxseed essential oils and investigate their antibacterial activities. Three nano-emulsions (NEs) were produced by mixing essential oils, surfactants and water with droplet sizes of NEs formulations in the range of 25-62 nm. No toxicity was recorded for Coriander and Dill at 100 μl/ml while Flaxseed NE showed moderate toxicity. Standard local pure cultures of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae and Candida albicans were obtained. Dill NEs and Coriander NEs showed moderate activities against both S. aureus and E. coli with inhibition zone diameter rang ing from 12-14 mm and weak activities against K, pneumoniae and P. aeruginosa. The three tested Oil Nanoemulsions showed weak inhibition activity with an inhibition zone diameter of 10 mm against Candida albicans as a test yeast. The best minimum inhibitory concentrations (MICs) of nanoemulsions was for flaxseed NE against all the tested Gram negative bacteria but the results were higher than that obtained by the control antibiotic that showed excellent activity. In conclusion, the tested NEs showed inhibitory activity against the tested bacteria due to inhibition of vital microbial functions such as cellular transport and/or energy production.