Biosynthesis of silver nanoparticles by fungi and their antibacterial activity

Nanotechnology is fast advancing and has currently become more effective than the conventional technologies used in water treatment for unconventional water supply sources. Fungi are more versatile in growth and metal tolerance in contrast to bacterial population. This work aims to achieve fourfold objectives: (1) demonstrate the extracellular synthesis of silver nanoparticle by using two filamentous fungi Penicillium citreonigrum Dierckx and Scopulariopsis brumptii Salvanet-Duval, isolated from east of Lake Burullus; (2) demonstrate the biosynthesized nano-silver particles by UV–visible absorption spectroscopy and transmission electron microscopy. The functional group of protein molecules surrounding silver nanoparticles was identified using Fourier transform infrared analysis; (3) check the antibacterial activity of biosynthesized silver nanoparticles at two concentrations (550.7 and 676.9 mg/l) and interact it with bacteria for different durations (15, 60 and 120 min); (4) use the polyurethane foam as silver carrier and nano-silver solution for the removal of pathogenic bacteria in polluted water. The synthesized silver nanoparticles showed an excellent antibacterial property on gram-positive and gram-negative bacterial strains.