Innovative biosynthesis of silver nanoparticles using yeast glucan nanopolymer and their potentiality as antibacterial composite

Abstract

Nanometals (NM) frequently possess potent antimicrobial potentials to combat various pathogens, but their elevated biotoxicity limits their direct applications. The biosynthesis of NM and their capping/conjugation with natural biopolymers can effectually enhance NM stability and diminish such toxicity. Yeast β-glucan (βG), from Saccharomyces cerevisiae, was extracted and transformed to nanoparticles (NPs) using alkali/acid facile protocol. The βG NPs were innovatively employed for direct biosynthesis of silver nanoparticles (Ag NPs) without extra chemical processes. The physicochemical assessments (Fourier-transform infrared, X-ray diffraction, and transmission electron microscopy) validated NPs formation, interaction, and interior capping of Ag NPs in βG NPs. The synthesized βG NPs, Ag NPs, and βG–Ag NPs composite were negatively charged and had minute particle sizes with mean diameters of 58.65, 6.72, and 63.88 nm, respectively. The NPs (plain Ag NPs and composited βG–Ag NPs) exhibited potent comparable bactericidal actions, opposing Gram+ (Staphylococcus aureus) and Gram‒ (Escherichia coli, Salmonella Typhimurium, and Pseudomonas aeruginosa). Scanning micrographs, of treated S. aureus and S. Typhimurium with βG–Ag NPs, elucidated the powerful bactericidal actions of nanocomposite for destructing pathogens' cells. The inventive Ag NPs biosynthesis with βG NPs and the combined βG–Ag NPs nanocomposites could be impressively recommended as powerful antibacterial candidates with minor potential toxicity.