Prevalence and distribution of airborne and waterborne fungi and actinomycetes in the Nile river

The objective of this research was to investigate the prevalence and distribution of airborne and waterborne fungi and actinomycetes along the main stream of the Nile river during April to July, 2005. Air and water samples were collected at eight sites within a ~50 km stretch of the river. The distribution and prevalence of air and water microorganisms varied with location. The highest counts of airborne fungi (516 CFU/p/h) and actinomycetes (222 CFU/p/h) were detected at suburban sites near cultivated areas. However, the highest counts of waterborne fungi (56.4 CFU/ml) and actinomycetes (15.4 CFU/ml) were detected at Al-Galaa (city centre) and Kafr-El-elwe (south Cairo), respectively. A total of 1,816 fungal colonies (943 isolates from air and 873 from water samples) belonging to 27 genera were identified. Aspergillus, Alternaria, Cladosporium, and yeasts were the predominant fungal types in both air and water environments. Dreschlera, Emericella, Nigrospora, Spicaria, Stachybotrys, and Verticillium were only detected in the air, and Epicoccum, Philaphora, Phoma and Ulocladium were only detected in the water. Mycotoxin-producing fungi represented by Aspergillus flavus, Aspergillus parasiticus, Penicillium, Fusarium, and Trichoderma were found in the air and water environments. Significant differences (P ≤ 0.05) were found between fungal populations in air and water at different sampling sites. No significant differences (P ≥ 0.05) were found between waterborne actinomycetes. Sampling location, human activity, and pollution load are the main factors affecting the variability and biodiversity of microorganisms in different microenvironments.