Mycosynthesis of CuO Nanoparticles Using Aspergillus niger and Their Bioefficiency against Human Pathogens

In the present study, copper oxide (CuO) nanoparticles were biosynthesized from an Aspergillus niger cell-free extract (CFE), and several optimal operating parameters that affected the formation and dimensions of the CuO nanoparticles were determined, as follows: 15 mmol/L metal salt and 90 mL of CFE at room temperature for 24 h, to achieve an average size of 77 nm. Spectroscopic studies revealed an association between alcohol, alkene, and amine functional groups and the grain-shaped CuO nanoparticles. The elemental composition of the nanoparticles was confirmed by energy dispersive X-ray spectroscopy (EDX) data. Mycogenic CuO nanoparticles exhibited excellent antibacterial activity against Gram-positive bacterial species compared with Gram-negative bacterial species, i.e., Streptococcus pneumoniae MTCC 2672, Staphylococcus aureus MTCC 737, Micrococcus luteus MTCC 11948, Pseudomonas aeruginosa MTCC 424, and Escherichia coli MTCC 443, at 200 mg/mL, with inhibition zones of 9.2, 8.3 7.7, 7.2, and 6.1 mm, respectively. Finally, myogenic CuO nanoparticles exhibited good antifungal activity against Aspergillus fumigatus and Aspergillus versicolor.