Characteristics of Chlorophyll Formation in the Green Alga Golenkinia

Cells of the alga Golenkinia are bleached by growth in darkness in media containing sodium acetate. Re-greening of these cells is light dependent; neither glucose nor intermediates of chlorophyll synthesis can substitute. The amount of chlorophyll synthesized is proportional to the light intensity between darkness and 1,000 lux and to the duration of the exposure. Initially, only chlorophyll a is synthesized. After 9–12 hr illumination, formation of chlorophyll b and carotenoids begins. Chlorophyll production apparently occurs in two stages: (1) the first 12–16 hr of greening. This stage is sensitive to cyanide, azide or anaerobiosis and relatively resistant to DCMU. (2) the second 16–24 hr of greening. This stage is sensitive to DCMU and relatively resistant to inhibitors of respiration. Glucose stimulates greening in both stages. The metabolic requirements of chlorophyll synthesis are discussed.