Biosynthesis of Trichoderma harzianum mediated silver nanoparticles (AgNPs), their characterization and in vitro antimicrobial potential against Fusarium oxysporum f. sp. lycopersici and Sclerotium rolfsii

Abstract

Silver nanoparticles (AgNPs) were efficiently produced using the extracellular culture filtrate of fungal biocontrol agent Trichoderma harzianum. UV-Visible spectroscopy analysis of T. harzianum-mediated AgNPs exhibited a sharp and well-defined absorption peak at 428.87 nm with a greatest absorbance of 2.143, indicating high NPs concentration. Transmission Electron Microscopy (TEM) analysis revealed that T. harzianum-derived AgNPs were predominantly spherical, well dispersed, and varied in dimensions from 13.28 to 15.12 nm. The antimicrobial capability of T. harzianum-mediated AgNPs was evaluated against test soil-borne fungal pathogens, namely F. oxysporum f. sp. lycopersici and Sclerotium rolfsii, using the poisoned food technique under in vitro conditions. Results revealed that in case of F. oxysporum f. sp. lycopersici, Trichoderma harzianum-derived AgNPs significantly restricted fungal growth, with inhibition increasing progressively from 28.61 % at 10 ppm to a maximum of 81.11 % at 100 ppm and an analogous trend of inhibition was noted against Sclerotium rolfsii, with growth inhibition increasing from 15.55 % at 10 ppm to 82.22 % at 100 ppm.