Biosynthesis of Antibacterial Silver Nanoparticles by Endophytic Fungus <i>Nemania</i> sp. Isolated From <i>Taxus baccata </i>L. (Iranian Yew)

Abstract

Objectives: In this study, the mycosynthesis of silver nanoparticles was investigated using the endophytic fungi isolated from Taxus baccata L. (Iranian Yew). Methods: Endophytic fungi were isolated from Taxus baccata L. (Iranian Yew) and were subjected to mycosynthesis of silver nanoparticles (AgNPs), extracellularly. The characterization of produced AgNPs was done using UV-V spectroscopy, TEM, and FTIR. Further antimicrobial activity of synthesized AgNPs was tested against Bacillus subtillis, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus sp., and Salmonella typhi, using the agar well diffusion assay method. To identify the fungal isolate, the ITS region was amplified by polymerase chain reaction (PCR), using universal primers ITS1 and ITS4. For obtaining closely related phylogenetic sequences, sequence analysis of ITS- rDNA was run using the BLAST algorithm of the NCBI database. Results: The endophytic fungus, Nemania sp., was found to be a good producer of AgNPs. The surface plasmon resonance band in UV-Vis spectroscopy was at 460 nm, which confirmed the formation of AgNPs. The size range of the synthesized AgNPs was 5 to 70 nm, according to the TEM analysis. The FTIR study of AgNPs showed major peaks around 1035, 1392, 1514, 1644, 2922, and 3443 cm-1, which were responsible for different functional groups possibly involved in the synthesis and stabilization of AgNPs. Antibacterial activity showed maximum zone of inhibition of 17 mm against B. subtilis. Conclusions: Nemania sp. can be a fungal system for extracellular mycosynthesis of AgNPs, which is a simple and ecofriendly method for nanoparticle synthesis.