Intra-cellular biosynthesis of gold nanoparticles by fungus Penicillium chrysogenum

Abstract

Background: One of the nanobiotechnology concepts is application of bio systems for production of nanoparticles. Gold nanoparticles have shown many useful applications especially in medicine. Fungi are the best candidates for the synthesis of gold nanoparticles because of their ability to produce large amount of enzymes. The aim of this study was bioproduction of gold nanoparticles using Penicillium chrysogenum and its antibacterial impact on four common pathogenic bacteria was determined. Methods: Penicillium chrysogenum species isolated from effluent of Isfahan Foulad Mobarake factory. The biomasses of fungi were incubated with HAuCl4 solution in a shaker-incubator for 72 hr, and gold nanoparticles were produced. Production of gold nanoparticles was evaluated by UV-vis spectroscopy and X-ray diffraction. Also antibacterial effect of nanoparticles and fungi extract on 4 pathogenic bacteria including Bacillus subtilis, Staphylococcus areus, Pseudomonas aeroginosa, and Escherichia coli was studied. The minimum inhibitory concentration and minimum bactericidal concentration of the nanoparticles against mentioned bacteria were determined by microdilution method. Results: Synthesis of gold nanoparticles was confirmed by observing the characteristic peak at 532 nm using UV-vis spectroscopy. The XRD analysis also demonstrated that the nanoparticles are in the form of nanocrystaline. Also, it was shown that Penicillium chrysogenum produces intracellular gold nanoparticles in spherical and triangular shapes. Conclusion: Fungus Penicillium chrysogenumis able to produce intracellular gold nanoparticles in the size range of 50-200 nm.