Lactic acid bacteria (LAB) represent a bacterial group widely spread in niches of fermented food and gastrointestinal tracts of humans and many animals. They are especially known for their ability to produce a wide variety of bioactive metabolites. Thus, the current study aimed to isolate and characterize bacteriocin-producing LAB from fish samples. The selected isolate was identified based on morphological, biochemical and molecular [A1] as Lactobacillus sakei (GenBank, Accession No. MG654786). The bacteriocin was purified by salt precipitation, and molecular mass was determined by SDS-PAGE as 5 kDa. The potential of nanotechnology in enhancing the antimicrobial activity of Lactobacillus sakei bacteriocin was investigated. The characterization of silver nanoparticles was done by UV–Vis spectroscopy, scanning electron microscopy (SEM). The biosynthesized silver nanoparticles showed an extreme inhibitory action against tested bacterial pathogens. The present investigation would provide an eco-friendly approach to medicine, future drug development and may have applications in food biopreservative.