Evaluating the biological activities of biosynthesized ZnO nanoparticles using Escherichia coli

Abstract

About 50 isolates (83%) of Escherichia coli were identified from 60 stool sample, and 30 examined bacteria formed biofilm. ZnO NPs was synthesized by E. coli and a white cluster pellet appeared, followed by observing absorption peak of UV-Vis. spectroscopy at 268 nm. XRD pattern showed the lattice planes of 100, 002, 101, 102, 110, 103 and 112 compatible to the 2θ values of 32.45°, 34.73°, 36.56°, 47.70°, 55.86°, 62.12°and 63.10° respectively, and the diffraction peaks were assigned with the hexagonal phase, while SEM images exhibited that size of the particles ranged between 31.55-45.9 nm. ZnO NPs displayed antibacterial potentiality against pathogenic bacteria, and inhibition zones around ZnO NPs were as follows: 5, 4, 2, 2, and 2 mm for Pseudomonas aeruginosa, Staphylococcus aureus, Acinetobacter baumannii, Klebsiella pneumoniae, and E. coli respectively. In addition, ZnO NPs was able to decrease biofilm, revealing that after 48 h of incubation, inhibition percentage were 18.6, 27.7, 39.4, and 19.6 % against S. aureus, P. aeruginosa, A. baumannii, and K. pneumoniae, respectively. A549 cells viability was decreased by elevating the concentration of ZnO NPs, and the IC50 values of the A549 and WRL cells were 105.8 and 167.3 µg mL-1 respectively. In this study, the synthesized ZnO NPs using nonpathogenic E.coli showed antibacterial, antibiofilm and anticancer activities against the examined pathogenic bacteria. So, these nanoparticles can be further used in biomedical, pharmaceutical and other applications as an effective antimicrobial and anti-cancerous agent.

Keywords

• biosynthesized zno nps
• e.coli
• antibacterial
• antibiofilm
• anticancer