[Metabolism of carotenoids during dark and photooxidative degradation in Anabaena variabilis].

Changes of carotenoids were studied in the cells of the blue-green alga Anabaena variabilis incubated in dark for a long period of time in a phosphate buffer, and also upon photooxidative degradation of the "dark" culture, i. e. a culture that had been grown for 8 days and incubated in the darkness for a certain period of time. Incubation in the dark resulted in the formation and accumulation in the cells of two new pigments, xanthophyll-450 and beta,beta-carotene-4,4'-dione, whose content decreased only with lysis of the culture. The second pigment is presumed to be formed from less oxidized epiphase carotenoids. Dark and photooxidative degradation of the cells is accompanied with an increase in the level of epiphase xanthophylls (particularly, ketoxanthophylls) and a decrease in the level of carotenes and glycoside xanthophylls, whereas the total content of carotenoids decreases.