Cytotoxic effects of Gamma Irradiation on Aspergillus occultus MN259598 strain to augment biological copper nanoparticle synthesis and to corroborate antibacterial properties on food- borne pathogens

The current scientific study focuses on the effects of gamma irradiation on fungal isolate Aspergillus occultus MN259598 strain to monitor the efficacy of extracellular Copper nanoparticle (CuNP) synthesis using C opper acetate as the starting material through a biological route. This study is a first report of Gamma irradiation being employed in order to document the possible role of irradiational stress in nanoparticles synthesis in Aspergillus occultus MN259598. Gamma irradiation doses of 0.66 Gy, 0.99 Gy, 1.33 Gy, 1.66 Gy and 1.99 Gy were used for the induction of physiological changes. Macromorphological alterations of the mycelia were observed when grown in broth medium. The lethalities and fungal architectural distortions observed as a part of the study profile of micromorphological characteristics of the irradiated organism were documented. The irradiated fungal cell free extracts (CFE) were used for the production of biogenic CuNPs through optimization studies. Simultaneously, the CFE of the wild type strain was also used for the NP synthesis. The particles were characterized employing UV-Visible (UV-Vis) spectrophotometry, Dynamic Light Scattering (DLS), Fourier Transform InfraRed spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and X- Ray Diffraction (XRD) analyses. Sizes of the NPs of treated (66.3 nm) and wild type strain (300 nm approx.) were found to differ enormously. The antimicrobial activity of CuNPs was determined using different food-borne pathogenic bacteria namely Escherichia coli , Bacillus cereus and Listeria monocytogenes .