FUNCTIONAL-ASPECTS OF SECONDARY CAROTENOIDS IN HAEMATOCOCCUS-LACUSTRIS (GIROD) ROSTAFINSKI (VOLVOCALES) .1. THE ACCUMULATION PERIOD AS AN ACTIVE METABOLIC PROCESS

Alterations of photosynthetic activity were investigated during accumu lation of secondary carotenoids in Haematococcus lacustris (Girod) Ros tafinski. Using several methods regarding (i) pigment pattern and pigm ent content (cytophotometry, computer-aided microscopic image analysis , in vivo absorption spectroscopy, high-performance liquid chromatrogr aphy) and (ii) photosynthesis (microfluorometry, modulated chlorophyll fluorescence and luminescence detection, 02 evolution and consumption measurement, 77 K fluorescence spectroscopy) we examined single cells and cell suspensions of the green alga. The results indicate decrease of both the photosystem II activity and the linear electron transport accompanying synthesis of secondary carotenoids. On the other hand, a ctivation of those processes leading to an increased transthylakoid pr oton gradient could be established during early accumulation period. T his is assumed to be an active adaptation of the photosynthetic appara tus to energetic requirements given by secondary carotenoid biosynthes is in H. lacustris.