[Effect of vitamin A on the biosynthesis of carotene by Blakeslea trispora]

Retinol stimulates carotene synthesis in the microscopic fungus Blakeslea trispora; the stimulating effect of vitamin A is not manifested in the presence of cycloheximide. Vitamin A and beta-ionone are presumed to affect carotene synthesis in Blakeslea trispora by imitating the action of natural compounds stimulating isoprenoid synthesis--trisporic acids.