Lactic acid bacteria (LAB) are widely regarded as safe for use and have long been consumed in various fermentedfoods. Selenium offers substantial potential benefits, including immune system support, fertility enhancement, andantimicrobial and anticancer activity. This study investigated the inhibitory potential of biogenic seleniumnanoparticles (SeNPs) prepared by using Lactobacillus casei supernatant. Selenium nanoparticles were biosynthesizedusing L. casei and subsequently characterized through visual observation, UV–visible spectrophotometry, FourierTransform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy(TEM), Energy Dispersive X-ray (EDX) analysis, and X-ray Diffraction (XRD). The antimicrobial potential of theLactobacillus casei-mediated selenium nanoparticles (LC-SeNPs) was evaluated using the agar well diffusiontechnique. A noticeable colour transition from light yellow to ruby red was observed, indicating nanoparticleformation. The absorption spectrum of LC-SeNPs extended between 250 and 450 nm, with a prominent surfaceplasmon resonance peak recorded at 350 nm. The FTIR absorption peaks were from 3626.00 cm-1 to 460.73 cm-1indicating hydroxyl, ester aldehyde, amine, phenol, and ether groups, were responsible for effective bio-reduction andstabilization of the nanoparticles. The SeNPs were observed to be spherical in shape and occurred in aggregated forms,with particle sizes ranging from 20 to 100 nm. XRD confirmed their crystallographic nature. E. coli (25 mm) and S.pneumoniae (17 mm) showed susceptibility, demonstrating LC-SeNPs' effective antimicrobial activity. These L.casei-synthesized SeNPs are eco-friendly, non-toxic and has significant medical application.
Ogunleye et al. (2026) studied this question.