Synthesis, characterization and anti-listeria monocytogenes effect of amino acid coated magnetite nanoparticles

Nanoparticles as antimicrobial agents are a novel field in nanomedicine and nanobiotechnology. Unlike many investigations about antimicrobial effects of silver nanoparticles, few experiments have been conducted about the impact of iron-oxide nanoparticles on microorganisms. In the current paper, we have synthesized and characterized amino acid (L-arginine and L-lysine)-coated magnetite nanoparticles and evaluated the effects of these particles on a pathogen strain of Listeria monocytogenes. Primary antibacterial tests were done by the microdilution method and for more investigation the effects of nanoparticles on the growth curve of L. monocytogenes were analyzed by a microbiological analyzer. We found that, in low concentrations (below 20 μg/ mL), L. monocytogenes can benefit from magnetite nanoparticles for more growth, probably as an iron source, but as concentration increases gradual bacteriostatic effects would appear and at 40 μg/mL magnetite nanoparticles have a significant bacteriostatic effect.