Glucanoacetobacter kombuchae (RG3T), a novel bacteria for AgNPs biosynthesis: Characterization and comprehensive evaluation of bioactivity

Abstract

An innovative green route has been adapted in this study to biosynthesize Silver Nanoparticles (AgNPs) for the first time using the cell exudate of a novel bacteria Gluconacetobacter kombucha (RG3 T ). Bio-reduction of silver was carried out by adding AgNO 3 and glucose along with the bacterial cell exudate. The onset of dark brown colour indicated the synthesis of nanoparticles (NPs) and was further validated by absorption spectrum at 430 nm using UV–Vis Spectroscopy. X-ray diffraction (XRD) study clearly illustrated the crystalline phase of the formed NPs. Further, morphological studies was done by Transmission electron microscope (TEM) which showed an approximate size of 20 nm exhibiting the shape of a sphere. Along with this, results obtained from Scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), and Dynamic light scattering (DLS) particle size analyzer also confirmed the surface morphology and functional group of the NPs. Broad spectrum antibacterial activity with Gram positive and negative bacteria were evaluated along with the antioxidant activity which showed high potency of NPs. RG3 T -NPs were treated against cell lines like MCF-7, HEPG-2, and notedly against Triple negative human breast cancer (TNBC) cell line which showed it’s superior efficiency. Therefore, it can be concluded that RG3 T -NPs points itself to be a significant bio-material with antibacterial, cytotoxic, and antioxidant properties. • This is the first study to report biosynthesis of AgNPs using Glucanoacetobacter kombuchae (RG3 T ). • Green synthesis has been carried out using the cell exudate of RG3 T along with glucose and AgNO 3 . • Significant bioactivity was assessed by antibacterial, cytotoxic, and antioxidant activity.