Biogenic Synthesis of Silver Nanoparticles Using Pimpinella anisum L Seed Aqueous Extract and Its Inhibitory Action against Some Phytopathogens

Biogenic synthesis of silver nanoparticles (AgNPs) using plant extracts has become a promising substitute for the conventional chemical synthesis method. The present study aims to develop a simple, cost-effective, environmentally friendly method for silver nanoparticles (AgNPs) synthesis using seed aqueous extract of (Pimpinella anisum L.) as a reducing agent at room temperature. Characterization of AgNPs was done by UV−visible spectroscopy, high-resolution transmission electron microscopy (HR-TEM), Fourier transform infrared (FTIR) spectroscopy, and selected area electron diffraction (SAED). Phytochemical analysis was performed to determine the phytochemicals responsible for the reduction and capping of the biosynthesized AgNPs. The antibacterial activity of AgNPs was checked against some important phytopathogenic bacteria (Agrobacterium tumefaciens, Erwinia amylovora, Pectobacterium carotovorm subsp. carotovorum, Pseudomonas lachrymans, Ralstonia solanacearum) and Pseudomonas tolaasii, Gram-negative bacteria causing bacterial blotch on cultivated mushrooms (Agaricus bisporus). The UV-Vis spectrum of the synthesized silver colloidal solution showed a strong absorption band at 441 nm, HR-TEM analysis revealed that AgNPs were spherical with an average size of 15 - 37 nm, Moreover, the synthesized silver nanoparticles have shown strong antibacterial activity against all tested pathogenic bacteria, by measuring the inhibition zone using the agar well diffusion method. The obtained results revealed that biosynthesis of AgNPs using plant extract is a promising method in agricultural applications.