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

Emerging plant diseases have posed a significant danger to global economies in recent years. Fungicide resistance and climate change are the two primary sources of pathogen outbreaks. The silver nanoparticles (AgNPs) 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. We used Pseudomonas fluorescens cell filtrates to synthesise silver nanoparticles in the current investigation. The silver nanoparticles were characterised using Dynamic Light Scattering, zeta potential (zeta), UV-Vis spectroscopy, surface plasmon resonance analysis and transmission electron microscopy (TEM). Both silver nanoparticles and AgNO3 were tested for their ability to inhibit two phytopathogenic fungi, that is, 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.

Automated summary

Emerging plant diseases have become a significant threat to the global economy in recent years. The resistance of pathogens to fungicides and climate change are the main causes of outbreaks. Silver nanoparticles have shown the ability to effectively restrain pathogenic bacteria, fungi, and viruses, while minimizing the risk of resistance and phytotoxicity. However, more research is needed to assess their toxicity and address concerns about environmental safety and production costs before they can be widely used in agriculture.