SYNTHESIS AND CHARACTERISATION OF SILVER NANOPARTICLES USING CELL-FREE ENZYMES OF Enterococcus faecalis AND ITS APPLICATION AS ANTIMICROBIAL AGENT

ABSTRACT

Nanoparticles are products of nanotechnology which are used in a wide range of applications from medical, industrial, agricultural and environmental. This study was carried out to assess the effectiveness of cell-free enzymes of Enterococcus faecalis in the synthesis and characterisation of silver (Ag) nanoparticles and their application as antimicrobial agents. Standard methods were employed in the culturing and extraction of cell-free enzymes from Enterococcus faecalis. The synthesised nanoparticles were characterised using UV-VIS, FTIR, XRD, SEM and EDX. The results obtained from UV-VIS revealed that Ag nanoparticles were formed at 400nm with a maximum absorbance of 0.8 a.u. FTIR showed peaks at 2937cm^-1 and 3375cm^-1. These peaks coincide with the CH stretch, amine (NH₂) stretch or the alcohol (-OH) stretch. The analysis from XRD showed that Ag nanoparticles were detected at nine peaks with percentage composition by weight ranging from 1.39 - 35.01wt%. The SEM image revealed that the nanoparticles were found to be tubular in shape with particle sizes of 34.52 nm, height of 1.95 mm and bulk density of 0.43 g/cm³. The EDX result showed that synthesised nanoparticles were composed of Ag, carbon, oxygen and trace amounts of phosphorus, chloride and calcium. The antibiogram of the Ag nanoparticles showed that at 1000mg/L, they were effective in the inhibition of Staphylococcus aureus (MRSA) at the intermediate level. The inhibition zones of the other microbes fell in the resistant range. The cell-free enzymes of Enterococcus faecalis are effective in the synthesis of Ag nanoparticles that possess antibiotic properties. Further studies are suggested to determine a low concentration of Ag nanoparticles which will be effective against other clinical isolates.