Silver nanotoxicity using a light-emitting biosensor Pseudomonas putida isolated from a wastewater treatment plant

Development of High-Throughput Methods for Nano- and Bulk Silver Toxicity Assays Using Bioluminescent Recombinant <i>Pseudomonas</i> Wastewater Isolates

“…The reports are contradictory regarding the modes of toxicity and whether elevated toxicity of nanoparticles compared to bulk particles is truly a nano-effect or simply due to higher rate of ion release. [10] reported that nano-silver is more toxic than bulk silver due to the higher rate of ion release of nano-silver which conflicts the report from [5,11] who reported that the higher toxic effect is due to the nano-scale size of silver nanoparticle. Also, some of these reports have shown that nano-and bulk silver reduced bioluminescence at certain concentrations; this has created basis for further research in this study.…”

“…This was also the same for bulk silver but to a lower extent. These settling properties that do not allow for even dispersion of particles in solution were issues in a study of silver particles toxicity by [10] where he used bovine serum albumin (BSA) solution to disperse and dissolute silver particles prior to toxicity testing. He reported that a higher toxicity was observed upon using BSA as stabilizer.…”

“…Though, BSA was also used in this study with little or no effect on the dispersal of the particles in solution (particles still remained undispersed). [10] observed that solubility strongly affects the toxicity level and without stabilizer for solubility, toxicity was reduced; this may Toxicity Assays Using Bioluminescent Recombinant Pseudomonas Wastewater Isolates probably indicate that compounds that were not soluble were not available to the bacterial cells (no interaction). In addition, [16] showed that nanoparticles like titanium oxide with low solubility showed no toxicity to mammalian cells while nanoparticles such as Zinc oxide with higher solubility showed a higher toxicity.…”

“…are able to metabolize a wide variety of nutrients and are ecologically relevant and well adapted to WWTPs, which potentially makes them good indicator organisms for wastewater systems. Also, they are not growth-medium dependent [10]. [5,10,11] successfully developed bespoke biosensors from WWTPs which consist biosensor based on growth inhibition of Pseudomonas spp.…”

“…Also, they are not growth-medium dependent [10]. [5,10,11] successfully developed bespoke biosensors from WWTPs which consist biosensor based on growth inhibition of Pseudomonas spp. that has lux-operon transferred from E. coli S17λ pir by transconjugation for assessing toxicity of wastewater pollutants.…”