Extracellular biosynthesis of bactericidal Ag/AgCl nanoparticles using the fungus Macrophomina phaseolina

SPAGNOLETTI, FEDERICO; GIACOMETTI, ROMINA; KRONBERG, M. FLORENCIA; SPEDALIERI, C

Buenos Aires

Congreso; Nanomercosur; 2017

Fundacion Argentina de Nanotecnologia

Green synthesis of metallic nanoparticles using biological sources has attracted much attention due to its economic aspects and potential applicability in a wide range of fields. The present study demonstrates an eco-friendly and low-cost method of biosynthesis of stable silver chloride nanoparticles (AgCl-NPs) using cell-free filtrate of phytopathogenic fungus Macrophomina phaseolina. UV-visible spectrum showed a peak at 420 nm corresponding to the surface plasmon resonance of nanoparticles. Scanning electron microscopy (SEM) revealed the presence of spherical silver particles of the size range 5 to 30 nm. The crystalline nature of the synthesized NPs was identified by X-ray diffraction (XRD) analysis. Spectrum of the nanoparticles exhibited 2θ values corresponding to silver chloride NPs. Antimicrobial activity against gram-positive and gram-negative bacteria was demonstrated. Although no effect in filamentous fungi or yeast was detected, a high inhibitory effect of biogenic nanoparticles was observed on growth kinetics of bacteria. Toxicity could be related to a loss in membrane integrity due to higher reactive oxygen species (ROS) generation.