Green biosynthesis of silver nanoparticles using novel endophytic Rothia endophytica: Characterization and anticandidal activity

Nanotechnology has the ability to improve human health with novel tools for the treatment of diseases. In this study, Rothia endophytica is a novel endophytic bacterial strain isolated from healthy Maize roots for biosynthesis of silver nanoparticles (Ag-NPs). Rothia endophytica was found to be a good producer for Ag-NPswith a novel cubic shape. The surface plasmon excitation of biosynthesized Ag-NPs appeared at 410 nm according to UV?visible spectroscopy analysis. Transmission electron microscopy (TEM) showed well-dispersed cubic Ag-NPs with sizes ranged from 47 nm to 72 nm. The X-ray diffraction (XRD) pattern revealed face-centered cubic nano crystal structured Ag-NPs. FTIR spectral analysis demonstrated the existence of functional groups of strain-bio-molecules that could be responsible for fabrication, capping and stabilizing Ag-NPs. Our results showed a significant antifungal activity of biosynthesized Ag-NPsagainst Candida albicans (C. albicans) with MIC and MBC at 62.5 and 125 ?g/mL, respectively. AgNPs-treated C. albicans revealed elevation of membrane lipid peroxidation, reducing sugars and total proteins in a time-dependent manner, causing membrane leakage and eventually reducing cell viability. Ultrastructure changes observed in Ag-NPs-treated C. albicans demonstrated the permeabilization of the cell wall and subsequent disruption of the structural layers of the outer fungal cell wall in a time-dependent manner. In conclusion, our data suggest that novel biosynthesized Ag-NPs is a promising anticandidal agent to combat and reduce human pathogenic Candida.

Automated summary

This study utilized Rothia endophytica to biosynthesize silver nanoparticles and found it exhibited significant antifungal activity against Candida albicans, disrupting cell walls and reducing cell viability.