Biosynthesis, Characterization and Biological Application of Gold Nanoparticles Synthesized by Lactobacillus plantarum LZ95

Abstract

Nanotechnology is a rapidly progressing and multidisciplinary field of science that deals with matter at atomic and molecular level. Nanoparticles among all other nanomaterials, attain a significant status due to their remarkable impact on fields such as electronics, cosmetics, therapeutics, materials, and medicine. Synthesis of nanoparticles can be achieved by biological, chemical and physical methods. Despite of the promising results and size of nanoparticles, chemical and physical methods are costly, toxic and not eco-friendly. Hence, green synthesis of nanoparticles is preferable as they offer ease of handling, synthesis and minimum level of toxicity. In this study, biogenic production of gold nanoparticles is accomplished by Lactobacillus plantarum LZ95. In the green synthesis of nanoparticles bioactive oxidoreductase enzymes are provided by bacteria that act as catalyst in bio-reduction reaction and reduce gold ions in solution to gold nanoparticles. Characterization of these nanoparticles was performed by UV/Vis spectroscopy that displayed peak at 540nm. EDS analysis helped in evaluating their elemental composition, which showed presence of gold element in sample mixture. Crystalline structure of nanoparticles was examined by XRD pattern, whereas FTIR results presented the presence of bands shown at 3341.71, 1649, 1232.92, 1071.49 cm-1 which confirms the presence of hydroxyl (O H), alkene (C=C), amine (C N), and alcohol (C O) groups, respectively. Morphology, diameter and uniformity of these AuNPs were analyzed by SEM which displayed the presence of spherical nanoparticles having a size range from 40 nm to 70 nm. Antimicrobial activity of gold nanoparticles was performed against two strains of Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Pseudomonas nitroreducin and Salmonella enterica.