CAROTENOGENESIS IN DIPHENYLAMINE-TREATED EPICOCCUM NIGRUM LINK

1. 1. The effect of diphenylamine (1.0·10-5-1.0·10-3 M) has been studied on culture growth and carotenoid, ergosterol, fatty acid and protein synthesis in Epicoccum nigrum grown in submerged culture. 2. 2. Diphenylamine delayed total glucose uptake from about 80 h in normal cultures to about 160 h in 7.5 · 10-5 M diphenylamine-treated cultures. 3. 3. Carotenoid synthesis was stimulated by diphenylamine. Rhodoxanthin and torularhodin were completely absent in treated cultures, whereas the synthesis occurred of phytoene, lycopene, γ-carotene, β-carotene and of two carotenoids which were identified as 3,4-dehydro-β-carotene and 3,4,3′,4′-bis-dehydro-β-carotene. 4. 4. A hypothetical pathway for the biosynthesis of rhodoxanthin from β-carotene via β-cryptoxanthin, zeaxanthin, a double-bond rearrangement and eschscholtzxanthin has been proposed. 5. 5. Ergosterol synthesis diminished, up to 35% in 7.5 · 10-5 M diphenylaminetreated cultures. 6. 6. The fatty acid pattern changed qualitatively. Pentadecanoic and heptadecanoic acid were almost completely absent, whereas a C22:2 fatty acid was present in relatively large amounts in diphenylamine-treated cultures. 7. 7. The total protein content of mycelium and culture fluid was slightly affected by diphenylamine. © 1969.