Microbial Synthesis and Characterization of Silver Nanoparticles by Lactococcus lactis TNM-B1 and Its Antimicrobial Properties

M.B. Osho, A.O. Precious-Egere, A.O. Awotula
McPherson University,

Keywords: synthesis, silver nanoparticle, lactococcus lactis TNM-B1, characterization, antimicrobial properties


The use of bio-nanomaterial as a result of environmental remediation procedure, reliability and eco-friendliness has recorded an outstanding development in nanotechnology science. This work studied the biosynthesis of silver nanoparticles (AgNPs) by Lactococcus lactis TNM-B1from fermented Tigernut milk and its antibacterial properties against clinical isolates. AgNPs characterized by visual observation revealed the ability of the microbial system to form extracellularly silver nanoparticles at 35 °C, 160 rpm and 72 h; UV-Visible Spectroscopy showed peak at 400 nm which confirmed the presence of nanoparticles of cell-free extract and silver nitrate; Fourier Transform Infra-Red Spectroscopy ascertained the presence of protein functional group as a stabilizing agent; X-ray Diffraction spectra revealed several peaks over the spectrum of 2θ values of 32.1°, 46.2°, 57.6°, and 78.0° corresponding to the (111), (200), (220), and (311) planes as nanocrystals respectively and AgNPs structural elucidation from high-resolution scanning electron microscopy appeared as convex light core, mono-dispersed with average 15.26 mm width diameter. This study provided an insight into the potential use of nanoparticles as an alternative choice drug against antibiotic-resistant strains. It showed significant antimicrobial activity against Gram-negative (Klebsiella pneumonia, Salmonella typhi, Escherichia coli, Pseudomonas aeroginosa) except Proteus mirabilis compared with Ciprofloxacin having observable zones of inhibition.