Production of silver Nano particle by mesophilic aerobic bacteria isolated from Persian Gulf

Nanoparticles are widely used in medical, pharmaceutical and health sciences. The aim of this project was to evaluate the mesophilic bacteria isolated from the Gulf coast in the production of silver nanoparticles and investigate the antimicrobial effect of these nanoparticles on some pathogenic bacteria.

This descriptive and cross-sectional study was performed over a period of 8-month from April to November 2017. The isolates were purified from water and sediments samples of the coasts of Hormozgan Province - Iran, after that the purified isolates were cultivated in Zobell Marine Broth medium. The obtained supernatant of the medium was added to the silver nitrate (AgNO3) solution (0/001 M) with (1:5) ratio at the light condition in order to the reduction of AgNO3 to metallic silver. The synthesis of silver nanoparticles (AgNPs) was investigated by UV-Vis spectrophotometer, Transmission electron microscope(TEM), and Fourier transform infrared (FTIR) spectroscopy analysis. The antimicrobial activity of AgNPs was evaluated against 6 microbes.

The results indicated that supernatants of all isolates are capable of producing silver nanoparticles. The surface plasmon resonance of AgNPs showed a maximum peak near 420 nm, which UV–vis spectra correspond to the absorbance of AgNPs. The results of TEM micrographs image of silver nanoparticles produced by dominant strain showed spherical shapes and size of 2/88 to 19 nm. The synthesized AgNPs showed the antimicrobial activity and inhibitory effects on the growth of tested microbes. 

The desired isolates have a potential ability to producing AgNPs, and to summarize, this is a low cost, ecofriendly, and quick method for the synthesis of AgNPs.