CONICET | Buscador de Institutos y Recursos Humanos

The worldwide escalation of microbial resistance to conventional antibiotics represents a challenge for the scientific community to develop new bioactive compounds and novel approaches for coping with this problem. Particularly, the silver-based nanomaterials attract enormous attention for potential prevention of microbial infections due to their documented antimicrobial and disinfectant properties, being the use of microorganisms for the eco-friendly synthesis of these materials in the limelight of current nanotechnology. The objectives of this study were production of silver nanoparticles using Pseudomonas aeruginosa extract and optimization of the biosynthesis process. The effects of quantity of extract, AgNO3 concentration, temperature and influence of the synthesis medium on the formation of silver nanoparticles were studied. The biosynthesized nanoparticles were characterized using techniques such as UV-vis spectroscopy, Dynamic Ligth Scattering (DLS), and Transmission Electron Microscopy (TEM). The formation of silver nanoparticles at the end of the reaction was confirmed with the obtained UV-vis spectroscopy results. The more efficient synthesis was obtained from a silver nitrate concentration of 10 mM with a percentage of bacterial supernatant from 30% v/v and a temperature of 37 °C for 18 hours. The use of tryptic soy broth or Luria Bertani broth favored the biosynthesis process. The analysis of the TEM images and the results of the DLS technique confirmed that silver nanoparticles were spheroidal and posses a relatively uniform size distribution. We reported a simple and green chemistry approach for the biological synthesis of silver nanoparticles using the culture supernatant of a P. aeruginosa reference strain at 37 °C and without any harmful reducing agents.