Sorayya Asgari, Ebrahim Najd Gerami, Samad Zare, Ramin Manaffar,
Volume 3, Issue 1 (6-2016)
Abstract
Nowadays, nanoparticles (NPs) have the great potential application in different industries. Among all NPs, titanium dioxide NPs is the biggest ecotoxicological and ecophysiology concerns due to the increase of anthropogenic input into the aquatic ecosystems. In this study, the effects of titanium dioxide NPs enriched yeast on the growth, survival; digestive enzymes activity and lipid metabolism in Artemia urmiana (AU) and Artemia franciscana (AF) were investigated. The experiment was designed in two treatments (control and enriched yeast with titanium dioxide NPs) and each with four replicates for both Artemia species. At the end of experiment, the results indicated that titanium dioxide nanoparticles did not affect on the Artemia species growth but significantly increased AF survival. No significant difference was observed in AU survival. Also the results showed, NPs significantly decrease AU digestive enzymes activity and reverse pattern was observed for AF. The effect of NPs on the body lipid content was investigated in Artemia species and the results revealed that all the NPs decrease this parameter in AU but did not affect on AF lipid body content. The results obtained in this experiment, suggest that the eco-physiological effects of titanium dioxide NPs different in Artemia urmiana and Artemia franciscana.
Bahare Asgari, Dr Ali Mohammadi, Dr Bahare Attaran,
Volume 11, Issue 1 (6-2024)
Abstract
The aim of the present work was to produce a stable nanoemulsion containing clove (Syzygium aromaticum) essential oil (PCLO) and evaluate its antimicrobial activity. The effect of the preparation technique, the type of surfactant and the ratio of surfactant to oil was evaluated to optimize the preparation formula of oil-in-water nanoemulsion. The optimized formula prepared by low energy production method containing 4% w/w PCLO and 12% w/w mixed surfactant (SDS + Tween 80) produced a clear and stable nanoemulsion for 90 days with an average particle diameter below 150 nm. The antibacterial activity of pure PCLO and its nanoemulsions (NCLO) was investigated by disk diffusion, agar well, and broth methods in 3 indicator bacteria of gastrointestinal infections, Escherichia coli, Staphylococcus aureus, and Salmonella typhimurium. Minimum inhibitory concentration (MIC) and bacteriocidal concentration (MBC) as well as dynamic killing time were determined in the tested bacteria. Strong antibacterial activity of PCLO and NCLO was revealed in the concentration range of 1000-2000 ppm. The killing kinetics study showed that during the first 15 minutes of exposure to NCLO at the MIC concentration, there was a rapid and extensive reduction in the amount of viable microorganisms. The presented data, considering the optimal performance of antimicrobial substances in food, cosmetics and chemical industries, can help in the rational design of nanoemulsion-based essential oil delivery systems.
