Biosynthesis of antimicrobial silver nanoparticles by the endophytic fungus Aspergillus clavatus
Vijay C Verma1, Ravindra N Kharwar, Alan C Gange
1Mycopathology & Microbial Technology Laboratory, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi 221005, India.
Aim:
To induce the biosynthesis of silver nanoparticles (AgNPs) using Aspergillus clavatus and evaluate their antimicrobial potential.
Materials & Methods:
Aspergillus clavatus (AzS-275), an endophytic fungus isolated from sterilized stem tissues of Azadirachta indica A. Juss., was challenged with 1 mM AgNO(3) solution. The characterization of the AgNPs was carried out by x-ray diffraction spectrometry, transmission-electron microscopy and atomic force microscopy.
Results & Discussion:
The synthesized AgNPs were found to be extracellular, polydispersed spherical or hexagonal particles ranging from 10 to 25 nm in size. Antimicrobial activity was performed using a disc-diffusion method against Candida albicans, Pseudomonas fluorescens and Escherichia coli. The results showed an average minimum inhibitory concentration of 5.83 microg ml(-1) and minimum fungicidal concentration of 9.7 microg ml(-1) against C. albicans.
Conclusions:
AgNPs can be mycosynthesized extracellularly using A. clavatus as the fungal system, which is highly advantageous over chemical synthesis not only because it can be synthesized on a large scale, but because of the ease of downstream processing and its biomedical application in antimicrobial activity.
Related Concept Videos
Production of Antibiotics
Fungal Phylum Ascomycota
Microbial Leaching

