fa تحقيقي Original Paper <div><strong>ABSTRACT</strong><br> <strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Background and Objectives: </strong>Development of ecofriendly processes for the synthesis of metal nanoparticles is of great importance in the field of nanotechnology. Microorganisms such as bacteria could be suitable candidates for bioproduction of nanoparticles due to their simplicity and high compatibility with the environment. The aim of this study was to use bacteria isolates from the effluent of wastewater treatment plants to produce silver nanoparticles.<span dir="RTL"></span><br> <strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Methods:</strong> For identifying silver-resistant microorganisms, we used the agar diffusion method using PHG II medium containing 0.5 mM silver to determine minimum inhibitory concentration. Bacterial identification was done with biochemical testing and polymerase chain reaction (colony PCR). Finally, silver nanoparticles were produced in the desired bacteria, and the properties of these nanoparticles were studied.<br> <strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Results:</strong> We found five silver-resistant bacteria among which <em>Stenotrophomonas maltophilia</em> strain MS8 showed the highest resistance (MIC= 6 mM). The bacterium was able to synthesize silver nanoparticles in spherical shapes. The results obtained from visual observations using UV-VIS, TEM and XRD showed that the bacterium was able to reduce silver ions into silver nanoparticles with maximum size of 20 nm. <span dir="RTL"></span><br> <strong>Conclusion:</strong> Based on our findings, this bacterium could be useful for biosynthesis of silver nanoparticles.<span dir="RTL"></span><br> <strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; KEYWORDS:</strong> Bacteria, Biosynthesis, Minimum Inhibitory Concentration.&nbsp;<span dir="RTL"></span></div> Bacteria, Biosynthesis, Minimum Inhibitory Concentration. 42 47 http://mlj.goums.ac.ir/browse.php?a_code=A-10-1-490&slc_lang=fa&sid=1 Shima Kazemi 100319475328460014379 100319475328460014379 Yes Department of Microbiology, Falavarjan Branch, Islamic Azad University, Falavarjan, Isfahan, Iran Monir Doudi 100319475328460014380 100319475328460014380 No Department of Microbiology, Falavarjan Branch, Islamic Azad University, Isfahan, Iran Gholm Reza Amiri 100319475328460014381 100319475328460014381 No Department of Biology, Falavarjan Branch, Islamic Azad University, Isfahan, Iran