AUTHOR=Gaba Swati , Rai Ashutosh Kumar , Varma Ajit , Prasad Ram , Goel Arti TITLE=Biocontrol potential of mycogenic copper oxide nanoparticles against Alternaria brassicae JOURNAL=Frontiers in Chemistry VOLUME=Volume 10 - 2022 YEAR=2022 URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2022.966396 DOI=10.3389/fchem.2022.966396 ISSN=2296-2646 ABSTRACT=The biological synthesis of nanoparticles using fungal cultures is a promising and novelty tool in nano-biotechnology. The potential culture of Trichoderma asperellum (T. asperellum) has been used to synthesize copper oxide nanoparticles (CuO NPs) in the current study. The necrotrophic infection in brassica species caused due to a foliar pathogen Alternaria brassicae (A. brassicae). Mycogenic copper oxide nanoparticles (M-CuO NPs) were characterized using spectroscopic and microscopic techniques such as UV-Visible spectrophotometer (UV-Vis), Transmission electron microscope (TEM), Scanning electron microscope (SEM), X-ray diffraction(XRD) and Fourier transform infrared spectroscopy (FTIR). The antifungal potential of CuO NPs was studied against A. brassicae. M-CuO NPs exhibited a surface plasmon resonance (SPR) at 303 nm and XRD confirmed the crystalline phase of NPs. FTIR spectra confirmed the stretching of amide bonds and carbonyl bond indicated the presence of enzymes in T. asperellum filtrate. SEM and TEM confirmed the spherical shape of M-CuO NPs with an average size of 22 nm. Significant antifungal potential of M-CuO NPs was recorded, as it inhibited the growth of A. brassicae upto 92.9% and 80.3% in supplemented media with C-CuO NPs at 200 ppm dose. Mancozeb and Propiconazole, inhibited the radial growth upto 38.7% and 44.2%. SEM confirmed the morphological changes in hyphae and affected the sporulation pattern. TEM revealed hardly recognizable organelles, abnormal cytoplasmic distribution and increased vacuolization and a light microscope confirmed the conidia with reduced diameter and fewer septa after treatment with both types of NPs. Thus, M-CuO NPs served as a promising alternative to fungicides.