Keratinophilic fungi associated with birds: II. Physiological studies

Abstract

The growth of the keratinophilic fungi isolated from birds is inhibited by temperatures of 40°C; the fungi are restricted on the birds to the outer contour feathers. Spore germination of conidial Arthroderma uncinatum and Ctenomyces serratus does not occur below 90% r.h. and reaches a maximum at 100% r.h. Where associations have been shown between keratinophilic fungi and individual bird species, feather fats from these birds stimulate, or do not affect the growth of the fungi. A decrease in growth of a fungus in the presence of feather fats from birds was associated with the infrequent occurrence of that fungus on the birds. The feather fats thus play a large part in determining the occurrence of keratinophilic fungi on birds.