Biosynthesis and antibacterial activity of MgO-NPs produced from Camellia-sinensis leaves extract

Magnesium oxides nanoparticles (MgO-NPs) were synthesized by a novel technique based on the leaf extract of Camellia sinensis (Green tea). The synthesized nanoparticles were evaluated for antibacterial activity (against both gram-positive and gram-negative pathogens) and therefore can be a suitable therapeutic alternative to the usage of antibiotics. The antibacterial activity of synthesized MgO-NPs is tested against clinical isolates of gram-negative ( Escherichia coli, Pseudomonas aeruginosa, Serratia mercescens, Klebsiella pneumoniae ) and gram-positive ( Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes ) pathogenic bacteria. Agar well diffusion assay data indicate that MgO-NPs exhibit antibacterial activity at all concentrations tested against both gram-negative and gram-positive pathogenic bacteria, producing zone of inhibition (ZOI) in the range of 9.6 ± 1.1 to 21.0 ± 1.5 mm diameters. The maximum response is observed at 25 μ g ml −1 concentration of MgO-NPs, producing a zone of inhibition ranging from 15 ± 1.2 mm ( E.coli ) mm to 21.0 ± 1.5 mm ( S. marcescens) .