Biodegradation of zinc oxide nanoparticles by Rhizopus stoloniferas

This study investigated the ability of Rhizopus stolinifer to degrade zinc oxide nanoparticles (ZnO-NPs). The fungal isolated from agricultural soil cultivated with wheat crop (Triticum aestivum L.) in Abada village, Al-Nasiriyah, southern Iraq, using the dilution method. Soil samples were collected at a depth of (5–15) cm, and the study was conducted for a period of four months. The results showed the ability of Rhizopus stolinifer to grow in solid media (Potato Dextrose Agar) supplemented with Zinc oxide nanoparticles, at different concentrations (100, 200, 300 mg) and in the presence of different carbon and nitrogen sources (Glucose, maltose) (NaNO₃, NH₄Cl) at different incubation temperatures (15, 25, 35 °C) in the liquid mineral medium. The results showed a decrease in the pH value in varying ways: pH = (3.0 ,3.0,3.0) at a temperature of 15 °C, pH = (3.0, 3.0, 4.0) at a temperature of 25 °C, and pH = (3.0, 3.0, 3.0) and (3.0, 3.0, 4.0) in (Maltose + NaNO₃) at a temperature of 35 °C after 7 days incubation. The result confirmed the ability of Rhizopus stolonifer to biodegrade ZnO-NPs.