Using a medium suitable for continuous subculture of Pityrosporum ovale, the following observations have been made about this organism:
The organism grows well in the pH range 7.5-8.3 and gradually acidifies the medium.
Ammonium chloride and several amino acids stimulate growth but exogeneous vitamins seem relatively ineffective in promoting growth. Cysteine, as a sole source of amino nitrogen, does not support growth, possibly because of release of inhibitory sulfur-containing substances.
This organism is incapable of solubilizing wool keratin. It can, however, utilize amino nitrogen-containing substances released from hard keratin by hydrolysis.
Human serum temporarily inhibits the growth of P ovale. The inhibitory capacity is similar to that directed against Cryptococcus neoformans by human serum.
P ovale elaborates substances that substantially inhibit the growth of all dermatophyte organisms so far investigated.
Weary PE. Pityrosporum OvaleObservations on Some Aspects of Host-Parasite Interrelationship. Arch Dermatol. 1968;98(4):408-422. doi:10.1001/archderm.1968.01610160082018