Keratinophilic fungi and related dermatophytes in polluted soil and water habitats
Mohamed S. Ali-Shtayeh and Rana M.F. Jamous
Department of Biological Sciences, An-Najah Nat. University, Nablus, Palestinian Authority
The ability of 55 cycloheximide-resistant fungal species (117 isolates) to degrade human hair in vitro was investigated. The species were recovered from polluted (raw city wastewater-irrigation) and non-polluted (normal irrigation) field soils and raw city wastewater. The intensity of keratinolytic activity (IKA) was estimated on a scale of 0-100, based on morphological expression of keratinolysis. A high percentage of the species tested (48/55, 87%) demonstrated a varying degree of keratinolytic activity. Five species (Chrysosporium keratinophilum, Microsporum gypseum, Penicillium frequentans, Rhizopus stolonifer, and Trichophyton ajelloi) showed strong IKA, and were capable of producing invasive structures related to radial penetration and surface erosion contemporaneously. On the other hand, seven of all the tested species, including Acremonium species, Aspergillus carneus, Nectria inventa, Penicillium citrinum, Paecilomyces variotii, Plectosphaerella cucumerina, and Verticillium nubilum, showed no keratinolytic activity. The keratinolytic activity of the following species is recorded in this study for the first time: Acremonium strictum, Chrysosporium pannorum, Cladosporium herbarum, Fusarium tricinctum, Gliocladium viride, Humicola fuscoatra var. fuscoatra, Nectria ventricosa, Penicillium griseofulvum, P. islandicum, Verticillium catenulatum, and V. psalliotae. Isolates of the same species can vary in their IKAs. Thus, such a characteristic does not seem to be constant or species-specific.
In: Kushwaha RKS, Guarro J (Eds.). Biology
of Dermatophytes and other Keratinophilic Fungi.