Aims: This study was aimed to screen and isolate soil and endophytic fungi with the ability to biosynthesize stable silver nanoparticles (SNPs) with antimicrobial and antiproliferative activities. Methodology and results: A total of 60 fungal isolates isolated from soil and plant samples were screened for their ability to biosynthesize SNPs. Among which, 21 isolates have supported the biosynthesis of SNPs. Furthermore, the endophytic isolate PRR2.1 synthesized highly thermostable SNPs with long shelf life. The PRR2.1 isolate was identified as Albifimbria verrucaria by morphological and molecular means. The synthesis of SNPs was initially monitored by UV-Vis spectroscopy. Further characterization by transmission electron microscopy, X-ray diffraction and dynamic light scattering revealed well-dispersed spherical crystalline in nature SNPs with a mean size of 14 nm and zeta potential of –24.47 mV. Fourier transform infrared spectroscopy showed the presence of biomolecules adsorbed on the surface of biosynthesized SNPs responsible for their synthesis and stability. The mycosynthesized SNPs exhibited stronger antifungal activity against pathogenic strains of Aspergillus niger, A. flavus, A. fumigatus and Candida albicans with respect to its antibacterial activity against Escherichia coli, Staphylococcus aureus, Bacillus cereus and Klebsiella pneumoniae compared to standard antifungal itraconazole and antibiotic cefadroxil with mostly consistent minimum inhibitory concentration of 5.31 μg/mL. The biosynthesized SNPs demonstrated dose-dependent in vitro antiproliferative activity against cancerous HeLa cell line with IC50 value of 2.52 μg/mL and less cytotoxic activity against WI-38 (normal human lung fibroblasts) cell line with CC50 value of 10.2 μg/mL. Conclusion, significance and impact of study These results show the potential of endophytic fungi biosynthesized SNPs as possible biofriendly, safe and efficient antimicrobial agents with promising antiproliferative activity and low cytotoxicity, which can be furtherly implemented in various biomedical and biotechnological applications.
Silver ; Nanoparticles ; Soil Microbiology ; Endophytes ; Anti-Infective Agents ;