Antifungal Effect of Silver Nanoparticles on Selected Fungi Isolated from Raw and Waste Water

In the present study, fungi from waste water of different sources in Madinah, KSA, was isolated in order to determine the effective dose and shape of silver nanoparticles necessary for treating them. Waste water was collected from two sources, homes and hospitals (Ohud Hospital). Additionally, bottled drinking water (Taibah) and autoclaved distilled water was used as control. Uncoated silver nanoparticles were used. The particles were with two shapes (rod, cube) and four concentrations (0, 1, 10 and 100 mu g/ml) were selected and distilled water was used as a solvent. Fungi were isolated and purified on potato dextrose agar media. A total of eight genera and nine fungal species were identified: Aspergillus flavus, A. niger, A. terreus, Fusarium oxysporium, F. solani, Geotrichum candidum, Mucor hiemalis, Penicillium chrysogenum, Rhizopus oryzae, Trichoderma harizianum and Trichophyton sp., Aspergillus sp. was the highest in its number collectively, thus was considered for further experiment. Silver nanoparticles were tested on two Aspergillus sp. i.e. A. niger and A. terreus. The gradual growth reduction was clear in both Aspergillus species as the concentration of the silver nanoparticles increased. A. terreus had higher reduction compared to A. niger. No significant differences were found among the 1, 10, and 100 mu g/ml concentrations. The rod shaped nanoparticles showed less growth for the fungi studied compared to the cube shaped. It is possible to use silver nanoparticles as antifungal substances; however, more considerations should be taken.