PHOTOCHEMICAL STUDIES OF CAROTENOID BIOSYNTHETIC PATHWAY IN NEUROSPORA CRASSA

Procedures are described for obtaining phytoene and each of the carotenoid pigments of Neurospora crassa spectroscopically and radiochemically pure when 2-14C-mevalonate is used as a labeled precursor. Using these techniques, 14C-label was shown to be incorporated into phytoene, zeta-carotene, neurosporene, beta-zeacarotene, gamma-carotene, lycopene, and 3,4-dehydrolycopene. The carotenoid beta-zeacarotene, which had not previously been reported to be synthesized by Neurospora crassa, was shown to accumulate under certain culture conditions. Labeling and time-course data are presented which support the proposal that the carotenoids are all synthesized from phytoene by a series of sequential reactions. © 1969.