Biosynthesis of Silver Nanoparticles Using Culture Filtrates of Lactic Acid Bacteria and Analysis of Antifungal Activity

The biosynthesis of silver nanoparticles (AgNPs) is a recent approach in nanotechnology with promising application in food industry, pharmacy and medicine. In the present study, the biosynthesis of silver nanoparticles from aqueous solution of AgNO3 was performed using the cell free supernatant of Lactobacillus plantarum strain LAB 58. The silver nanoparticles biosynthesis was identified by the change of colour of culture filtrate from yellow to brown due to the excitation of surface Plasmon vibrations by absorbance at 420 nm. Transmission electron microscopy (TEM) analysis revealed that the silver nanoparticles were spherical or polyhedral, with size range from 2 to 45 nm. AgNPs presented antifungal activity against spoilage fungi from genera Fusarium, Penicillium and Aspergillus. Optic microscopy analysis revealed hyphal alteration of Fusarium structures under the influence of treatment with AgNPs. The biosynthesized silver nanoparticles may have application as antifungal agents in food control and medicine.