Evaluation of toxicity of silver ions and nanoparticles using model bacteria with luminescent phenotype

It has been established using the model bacterial luminescence of the genetically modified bacteria Escherichia coli K12 TG1 that the damaging effect of silver nanoparticles (52 nm in size) developed more slowly and emerged at higher concentrations (approximately by 2 orders of magnitude) when compared with silver ions. A decline of bioluminescence and oxygen consumption is observed upon exposure to both nanoparticles and silver ions. Following the inhibition of biochemical processes, the silver bactericidal action (based on the ability to decrease the number of CFU) and morphological changes in the cells (according to the AFM data) are revealed. Similarly to the results of our previous studies on establishing the bactericidal effect of single-walled carbon nanotubes, the presented data allows us to suggest the use of bacterial luminescence changes for the primary assessment of the toxicity of silver nanoparticles.