Endophytic Bacteria from Lannea coromandelica for Enhancing Silver Nanoparticle Biosynthesis

Biosynthesis offers a safe and eco-friendly approach for producing nanoparticles using microorganisms or plant-derived reducing agents. This study explores the novelty of using endophytic bacteria isolated from the roots and stems of Lannea coromandelica, a medicinal plant with untapped potential in green nanotechnology, for the biosynthesis of silver nanoparticles (AgNPs). Four bacterial isolates were used Enterococcus (AM 2), Azotobacter (AM 5), Micrococcus (BM 2), and Enterococcus (BM 4), in reaction with 2–3 mM silver nitrate (AgNO₃). Characterization was performed using Particle Size Analyzer (PSA), UV-Visible Spectrophotometry (UV-Vis), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM). The synthesized AgNPs had particle sizes ranging from 60 to 105.9 nm. Notably, AgNPs synthesized using Azotobacter (AM 5) and Micrococcus (BM 2) showed optimal size and stability, with PI (Polydispersity Index) values of 0.029673 and 0.01835, respectively, indicating uniform particle distribution. UV-Vis spectra confirmed stability for up to five days. FTIR revealed the presence of functional groups O-H, C-N, and Ag-O, validating biosynthesis. SEM analysis demonstrated spherical to semi-spherical morphologies, with AM 5 exhibiting the most homogeneous structure. These findings highlight the promising role of L. coromandelica-derived endophytes in the eco-friendly synthesis of AgNPs for potential nanomedicine and antimicrobial applications.