Green synthesis of silver nanoparticles using a bioflocculant produced by a kombucha tea yeast isolate for antimicrobial and biosafety testing

Abstract The eco-friendly synthesis of nanoparticles has attained magnificent recognition in the present century due to its emphasis on reducing the environmental impact of chemical processes. The study investigated the utilization of a bioflocculant for the synthesis of silver nanoparticles to test their antimicrobial effect against two pathogenic microorganisms. Characterization techniques including UV–vis spectroscopy, Fourier-transform infrared, scanning electron microscopy, and dispersive X-ray spectroscopy were utilized in the present study to learn about the different properties of the synthesized nanoparticles. UV-visible spectroscopy viewed absorption bands at 250 nm and 435 nm for the bioflocculant and silver nanoparticles, respectively. Functional groups including alcohols, carboxylic, amine, aromatic compounds, sulfates, and halo compounds were observed for the bioflocculant FT-IR. Silver IR spectra showed absorption peaks indicating alcohols, alkenes, sulfonyl chloride, and halo compounds. SEM spectrum of the bioflocculant and silver nanoparticles presented spherical and flak-like morphologies, respectively. The SEM-EDX analysis of the silver nanoparticles showed elemental silver with 59.64 wt% previously not present from the bioflocculant before synthesis. The bioflocculant was not effective against the tested strains and AgNPs were effective against Escherichia coli in a concentration-dependent manner. These results show that a bioflocculant can be used to synthesize AgNPs with antibacterial potential.