Effects of Starvation and Diphenylamine on Carotenoids in Phycomyces

Abstract

IN cultures of Phycomyces blakesleeanus treated with diphenylamine and methylheptenone, the synthesis of the more saturated polyenes is enhanced at the expense of β-carotene^1,2. Diphenylamine has a similar effect on cultures of Rhodospirillum rubrum at the expense of spirilloxanthin³. This effect of diphenylamine has been interpreted as blocking a series of dehydrogenation steps in the transformation of the more saturated to the less saturated carotenoids. Leucine, on the other hand, which stimulates production of β-carotene, contributes to intermediates in carotenoid synthesis.