Screening of soil fungi in order to biosynthesize AgNPs and evaluation of antibacterial and antibiofilm activities

摘要

The biosynthesis of nanoparticles (NPs) has recently attracted a lot of research attention due to its being an eco-friendly and economical method. NPs are formed under normal temperatures and pressures. The shape and size ofNPs can be controlled by choosing a suitable pH and temperature. In this study, 24 strains of fungi isolated from desert soils were screened for AgNP synthesis. The MS17 isolated was chosen as the superior strain capable of rapidlysynthesizing monodisperse AgNPs. The optimum conditions for AgNP synthesis were investigated. AgNPs were characterized by UVa??visible spectrophotometry, dynamic light scattering, X-ray diffraction, transmission electron microscopyand Fourier-transform infrared. The NPs produced were found to be in the form of Ag/AgCl with a size range of 5a??15 nm. Then, the NPs were capped by proteins and carbohydrates, which play an important role in NP stability. The NPs werecapable of antimicrobial activities against the standard bacterial pathogens, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 1431 and the multidrugresistantP. aeruginosa B52 and P. aeruginosa 48.