Synthesis of Selenium Nanoparticles Using Probiotic Bacteria Lactobacillus acidophilus and Their Enhanced Antimicrobial Activity Against Resistant Bacteria

In the present study, nontoxic selenium nanoparticles were synthesized extracellularly using probiotic bacteria Lactobacillus acidophilus. The synthesized Lactobacillus acidophilus mediated selenium nanoparticles (LA-SeNPs) show the surface plasmon resonance (SPR) at 385 nm. The hydrodynamic radius of LA-SeNPs was found to be 34.13 nm along with polydispersity index (0.28) and zeta potential (+ 37.86 mV). TEM shows that the average diameter of LA-SeNPs is 2-15 nm. FTIR suggest that extracellular proteins present in bacterial culture were responsible for reduction and stabilization of Se ions to LA-SeNPs. The antibacterial activity of synthesized nanoparticles was studied against five different sensitive and resistant bacterial strains. The MIC90 for bacterial strains were in the range +/- 1 to +/- 10 mu g/ml. The inhibition and degradation of bacterial biofilm were studied against all the tested strains. The synthesized nanoparticles were cyto-compatible against human HEK-293 normal cell lines shown by MTT assay.