Green Synthesis of Silver Nanoparticles from Weissella cibaria UPMC 1451 and Evaluation of their Antibacterial Activity in vitro

This research aimed to generate silver nanoparticles (Aց NPs) using the Weissella cibaria (W. cibaria) UPMC 1451 supernatant and evaluate their effectiveness in inhibiting Klebsiella pneumoniae M1-RP-23–01. W. cibaria is a well-known starter culture that plays a very important role in the initial fermentation process of products such as kimchi and sourdough. It has been found that Weissella is beneficial as a novel probiotic due to its biotechnological capabilities. In the present study, Aց NPs were synthesised extracellularly using the W. cibaria UPMC 1451supernatant. The appearance of a dark brown colour in the solution indicates the presence of Aց NPs. Aց NPs were characterised using dynamic light scattering and Transmission Electron Microscopy. The hydrodynamic radius of Aց NPs was found to be 28.52 nm along with zeta potential (-30.0 mV) and polydispersity index (0.466). The TEM micrograph shows that the produced Aց NPs are spherical with an average diameter of 4.63 nm at a 10 nm scale. The antibacterial effectiveness of Aց NPs was tested against the bacterial strain K. pneumoniae by the agar well diffusion method. The diameters of the inhibition zone clearly showed that the Aց NPs have potent antibacterial properties against K. pneumoniae. In this study, the W. cibaria UPMC 1451 was used for the first time to generate Aց NPs. Henceforth, we conclude that Aց NPs biosynthesised are eco-friendly and exhibit antibacterial properties against K. pneumoniae, highlighting their potential as alternative antimicrobial agents and warranting further investigation for possible applications in agricultural and food-related environments.