Comparative Studies on Synthesis of Silver Nanoparticles by Fusarium oxysporum and Macrophomina phaseolina and It's Efficacy Against Bacteria and Malassezia furfur

We synthesized silver nanoparticles (Ag-NPs) by three fungi Fusarium oxysporum, F. oxysporum f sp. vasinfectum and Macrophomina phaseolina and the shape and size of the Ag-NPs synthesized were compared. These Ag-NPs were characterized by visual observation, UV-Visible Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Nanoparticle Tracking Analysis (NTA) and Transmission Electron Microscopy (TEM). Formation of Ag-NPs was primarily detected by change in color from yellowish to dark-brown after treatment with 1 mM AgNO₃. UV-Visible spectroscopy showed peak at 444 nm, 449 nm and 438 nm Fusarium oxysporum, F. oxysporum f sp.vasinfectum and Macrophomina phaseolina respectively. FTIR showed the presence of protein as capping agent, which increases the stability of Ag-NPs in the colloids. TEM demonstrated the presence of silver nanoparticles in the range of 3–30 nm. Among the fungi tested for antimicrobial activity of SNPs, M. phaseolina demonstrated the maximum activity against the test pathogens. The Minimum Inhibitory Concentration (MIC) of Ag-NPs synthesized from M. phaseolina was 0.03 mg/ml against Staphylococcus aureus (ATCC 25923) and 0.05 mg/ml against Salmonella typhi (ATCC 51812). M. phaseolina synthesized Ag-NPs showed maximum antifungal activity against M. furfur (MTCC-1374).M. furfur is a major agent for causing dandruff. Silver nanoparticles based antidandruff shampoo can be formulated. The results indicated that silver nanoparticles synthesized from biological system have remarkable potential as antifungal agents. This method is simple and economically viable, making it amenable to large-scale industrial production of Ag-NPs.