Abstract

This study was carried out to evaluate the in vitro antibacterial activity of nanofluid based on Mentha pulegium essential oil and Zinc oxide (ZnO) nanoparticles (NPs) against different bacterial species. The essential oil was obtained by hydro-distillation using Clevenger and then ZnO NPs were added at the rates 0, 300, 500 and 1000 ppm to prepare nanofluids. The agar disk diffusion and micro-dilution methods were used to study the antibacterial activity. Minimum inhibitory concentration (MIC) against B.cereus, S.aureus, S.entrica and E.coli was determined respectively 7.8, 3.9, 15.6 and 62.5 ppm for ZnO NPs. Minimum bactericidal concentration (MBC) against the mentioned bacteria was respectively 15.6, 7.8, 31.2 and 125 ppm for ZnO NPs. S. aureus and E. coli were respectively the most and the least sensitive species. ZnO nanoparticles improved the antibacterial activity of M. pulegium essential oil which shows the potent application of the particles in different industries like food packaging, food and farmaceutical systems.

Key words: Nanofluid, Mentha pulegium, Antibacterial activity, Zinc oxide, Nanoparticles