BIOSYNTHESIS OF BIOACTIVE SILVER NANOPARTICLES BY FUNGAL ISOLATE AND ITS APPLICATION AS ANTIBIOTICS AGAINST SELECTED BACTERIAL PATHOGENS

Abstract

Nanotechnology is an advanced discipline of science and technology for dealing with material sizes on the nanoscale. Nanoparticles, which have a dimension of less than 100 nm are among those materials. In this study, fungal isolates from dumpsite soil were screened on solid agar for antibiotic production and silver nanoparticle synthesis. Morphological and biochemical characteristics of the selected fungal isolate were investigated. The visual observation, UV spectrum analysis, and Fourier transform infrared spectroscopy (FT-IR) analysis were done. The antibacterial activity of the synthesized silver nanoparticle was investigated against five selected pathogenic bacteria. A total of sixteen (16) morphologically different fungi were isolated. Isolate MDS1 identified as Aspergillus sp. showed the highest antibiotic activity and was used for Silver nanoparticle synthesis. Colour change from yellow to brown, and 400 nm surface plasmon resonance (SPR) peak after 72 hours were obtained. FT-IR showed 15 peaks with ten functional groups contributing to the synthesis of Aspergillus sp. nanoparticle. The biosynthesized Aspergillus sp. MDS1 nanoparticle showed improved inhibitory effect compared to the Aspergillus sp. MDS1 extract, silver nitrate solution, and chloramphenicol antibiotics against Salmonella enterica (15 mm), Staphylococcus aureus (16 mm), and Enterococcus faecalis (15 mm) respectively. This study has shown that Aspergillus sp. MDS1, isolated from dumpsite soil is a potential nanoparticle producer which can be developed for the industrial production of biotechnologically important products such as antibiotics.