Abstract
In the current study, zinc oxide nanoparticles (ZnO-NP) were prepared using extracellular extracts of Aspergillus niger. Hence, the morphological structure, optical, and surface features of the synthesized nanoparticles were studied by X-ray diffraction, transmission electron microscopy, ultraviolet-visible and infrared absorption by Fourier transform. Use dynamic light scattering and zeta potential measurements to assess colloidal stability. The mean size of the synthetic particles is approximately 20 ± 5 nm and they have a hexagonal crystal structure. In addition, the prepared nanoparticles have strong light absorption in the ultraviolet region of λ = 265 and 370 nm. To achieve the goal of this study, the efficiency of ZnO-NP was determined as an antibacterial and antifungal against different bacterial and fungal strains. It was found that ZnO-NP showed significant antibacterial activity, where the inhibition zones were varied from 21 to 35mm in diameter against six bacterial species (i.e. K. pneumoniae, E. coli, A. baumannii, P. aeruginosa, S. aureus, and S. haemolyticus). In such a case, the minimal inhibitory concentration of zinc oxide nanoparticles against bacterial strains were 50, 12.5, 12.5, 50, 12.5, and 12.5μg/ml for K. pneumoniae, E. coli, A. baumannii, P. aeruginosa, S. aureus, and S. haemolyticus, respectively. Furthermore, ZnO-NP exhibits an antifungal behaviour against four fungal species (i.e., A. niger, P. marneffei, C. glabrata, and C. parapsilosis) with inhibition zone from 18 to 35mm in diameter. Whereas, the MICs for fungal isolates were 12.5μg/ml except A. niger was at 25μg/ml. Wi-38 cells were treated with ZnO-NPs exhibited different levels of cytotoxicity dependent upon the concentration of ZnO NPs using the MTT assay with IC50~800.42. Therefore, the present study introduces a facile and cost-effective extracellular green-synthesis of ZnO-NP to be used as antimicrobial and anticancer agents.
Highlights
In the presence of extracellular or intracellular extracts of microorganisms such as bacteria, fungi, and yeast strains, the biosynthesis of nanostructures has attracted attention due to its ease of preparation, photoelectric and physicochemical properties; in addition, it has excellent antimicrobial activity[1,2,3,4]
Wi-38 cells were treated with zinc oxide nanoparticles (ZnO-NP) exhibited different levels of cytotoxicity dependent upon the concentration of Zinc oxide (ZnO) NPs using the MTT assay with IC50~800.42
Other studies developed by ZnO Spherical nanoparticles by biosynthesis of ZnO-NPs via Catharanthus roseus were in the range of 2357 nm, and we revealed excellent antibacterial activity against S. aureus, B. thuringiensis, and E. coli Green injury[70]
Summary
In the presence of extracellular or intracellular extracts of microorganisms such as bacteria, fungi, and yeast strains, the biosynthesis of nanostructures has attracted attention due to its ease of preparation, photoelectric and physicochemical properties; in addition, it has excellent antimicrobial activity[1,2,3,4]. A large number of extracellular proteins and enzymes have the dual function of producing and coating mono-disperse nanoparticles[31]. Fungi are very tolerant of higher concentrations of metals and, due to the presence of a large number of extracellular proteins and redox enzymes; they have a large number of functional groups that can reduce metal ions to zero-valence metal nanoparticles[32]. When Nanoparticles interact with cells, cellular protection mechanisms are activated to minimize damage; if the production of highly active free radicals more exceeds the cell’s antioxidant defence capabilities, biomolecules will undergo oxidative damage, leading to cell death[33,34]
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