Preparation of Bacterial Cellulose Fungicide Nanocomposite Incorporated with MgO Nanoparticles

In recent years, increased consumption of broad-spectrum antimicrobial compounds has enhanced the resistance of various pathogens, including fungi, to existing drugs. Therefore, finding effective and novel compounds that have high antifungal activity are essential. The present research was aimed to exploring the optimum conditions for synthesis of novel nanocomposites containing MgO nanoparticles (NPs) in the cellulose biopolymer matrix with highest antifungal activity. For this purpose, nine experiments were designed using Taguchi method and employing different ratios of cellulose biopolymer and MgO NPs at different stirring times. The synthesized nanocomposite and its components were evaluated by ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, X-ray powder diffraction, high-resolution field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and transmission electron microscopy. The results of the structural analysis, including phase identification, crystal structure, chemical properties, appearance, and particle size, confirmed the formation of cellulose-MgO nanocomposite and improvement of its characterization. The bionanocomposite produced with 4 mg/ml MgO, 1 mg/ml cellulose and 90 min stirring time showed the highest antifungal activity and prevented the growth of fungus Aspergillus niger by 85.03%. The results of colony forming unit and disc diffusion showed improvement of antifungal activity of cellulose-MgO nanocomposite compared to its components. Based on the results of the present study, the formation of cellulose-MgO nanocomposite by preventing agglomeration of MgO NPs and enhancing their contact surfaces, improves the antifungal activity of these NPs.