Biosynthesis of silver nanoparticles from Pseudomonas fluorescens and their antifungal activity against Aspergillus niger and Fusarium udum

Abstract In recent years, emerging plant diseases have posed a significant danger to global economies. Fungicide resistance and climate change are the two primary sources of pathogen outbreaks. The silver nanoparticles have been demonstrated to restrain pathogenic bacteria, fungi, and viruses with minimal risk of developing resistance and phytotoxicity. The synthesis of silver nanoparticles via chemical and physical methods raises concerns about environmental safety and production costs. The microbial bio-fabrication of silver nanoparticles is simple, cost-effective, and ready-to-use technology. In the current investigation, we used Pseudomonas fluorescens cell filtrates for the synthesis of silver nanoparticles. The silver nanoparticles were characterized using Dynamic Light Scattering (DLS), zeta potential (ζ), UV-Vis spectroscopy, SPR analysis, Transmission Electron Microscopy. Both silver nanoparticles and AgNO3 were tested for their ability to inhibit two phytopathogenic fungi, i.e., Fusarium udum and Aspergillus niger. Potent inhibition of mycelial growth was observed when silver nanoparticles were used at a concentration of 150 ppm. However, further research is needed to assess the toxicity of AgNPs before they are mass-produced and used in agricultural applications.