Growth requirements and lipid metabolism of Pityrosporum orbiculare.

The yeast, Pityrosporum orbiculare, isolated from lesions from lesions of tinea versicolor, grows in vitro only if fatty acids from the C12 to C24 series are added to the culture medium. Except for elaidinic and nervonic acids, all saturated and unsaturated fatty acids tested support growth. P. orbiculare can synthesize various lipid fractions containing both saturated and unsaturated fatty acids from a single fatty acid. Glucose and asparagine stimulate growth but exogenous vitamins do not.