Optimization of the Light Emission in Bacterial Bioluminescence Using Magnetic Nanoparticles

Vibrio fischeri bioluminescence inhibition assay (VFBIA) is known for bacterial contamination measurement in water and food. This system is a type of quorum sensing identification that is an intracellular cumulative active mechanism. This experiment aims to increase the light emission of bioluminescent bacteria (V. fischeri and Vibrio sp. Persian 1 strains) using magnetic nanoparticles (MNPs). To this end, different concentrations of magnetic nanoparticles were added to the artificial seawater medium (ASW). Standard strains (V. fischeri) and Iranian native strain (Vibrio sp. Persian 1) were cultured in magnetic nanoparticles containing media. In the following, nanoparticles’ features, including concentration, size, and surface modification, were optimized for sufficient bacterial growth. Mostly, nanoparticles with surface modifications using arginine and lysine (MNPs@Arg, MNPs@Lys) were selected accordingly, and the growth and light emission of bioluminescent bacteria in the presence of various factors of nanoparticles were analyzed. The results showed that ASW with 200 μg/L MNP@Lys and 150 μg/L MNP@Arg were suitable for increasing the growth rate and light emission of V. fischeri and Vibrio sp. Persian 1, respectively. V. fischeri and Vibrio sp. Persian 1 in the presence of a particular concentration of nanoparticles (MNP@Lys and MNP@Arg) in a medium grow faster and emit more rapid light than in the absence of nanoparticles. Finally, the results show that the iron nanoparticles do not have any bactericidal features. Also, they have a complex of ingredients that could improve the bacteria’s functions and growth.