Herein, green approach was used to synthesize magnesium oxide nanoparticles (MgO-NPs) by harnessing metabolites of probiotic bacteria Lactobacillus gasseri. The bacterial-mediated green synthesis of MgO-NPs was characterized. Data showed that the color of the cell-free filtrate was changed from colorless to white after mixing with metal precursor and exhibited maximum surface plasmon resonance at ...